JP2008219358A - Wireless communication system, wireless communication apparatus, wireless communication method, and computer program - Google Patents

Abstract

In a CE device using IEEE 802.11, it is difficult for an end user to input parameters necessary for connection and to set a channel. In addition, it is difficult to scan a wireless device in the Power Save mode without missing packets.
Before connection, arbitrary information can be exchanged between wireless devices, parameters for connection are automatically exchanged and set, and channel arrangement is automatically performed to improve channel use efficiency of the entire network. Even in the Power Save mode, scanning is performed reliably by operating the state from the scanning side.
[Selection] Figure 1

Description

  The present invention relates to a wireless communication system, a wireless communication apparatus, a wireless communication method, and a computer program that communicate with each other between a plurality of communication stations such as a wireless LAN (Local Area Network) or PAN (Personal Area Network). In particular, a wireless communication system, a wireless communication apparatus, and a wireless communication method, in which wireless devices before connection search for an appropriate connection partner in advance and form a network by commonly specifying information necessary for connection in a simple procedure, And a computer program.

  More specifically, the present invention determines the channel arrangement of each network in consideration of the channel efficiency of the entire coexisting networks in a communication environment where a plurality of radio frequency bands usable for communication are allocated as channels. The present invention relates to a wireless communication system, a wireless communication apparatus, a wireless communication method, and a computer program, and more particularly, an accurate scanning operation in a communication environment in which each wireless apparatus operates autonomously while enabling power management operation. The present invention relates to a wireless communication system, a wireless communication apparatus and a wireless communication method, and a computer program that optimize the channel arrangement.

  A wireless network is attracting attention as a system free from wiring in the conventional wired communication system. For example, a wireless LAN standard such as IEEE (The Institute of Electrical and Engineering Engineers) 802.11a, IEEE 802.11b, or IEEE 802.1g is typical. According to the wireless LAN, flexible Internet connection is possible. In addition to replacing the existing wired LAN, Internet connection means can be provided in public places such as hotels, airport lounges, stations, and cafes. Wireless LANs are already widely used, and it is common to install wireless LAN functions not only on information devices such as personal computers (PCs) but also on CE (Consumer Electronics) devices such as digital cameras and music players. It is becoming.

  In order to configure a LAN using wireless technology, a device serving as a control station called an “access point (AP)” or “coordinator” is provided in the area, and the network is under the overall control of this control station. The method of forming is generally used. The control station arbitrates access timings of a plurality of terminal stations in the network and performs synchronous wireless communication in which the terminal stations are synchronized with each other.

  As another method of configuring a wireless network, all terminal stations operate on peer-to-peer in an autonomous and distributed manner, and the terminal station itself determines access timing “ad hoc ( "Ad-hoc) communication" has been devised. Especially for small-scale wireless networks composed of a relatively small number of clients located in the vicinity, ad hoc communication that allows asynchronous communication directly between arbitrary terminals without using a specific control station is appropriate. It is thought that it is.

  For example, networking in IEEE 802.11 is based on the concept of BSS (Basic Service Set). The BSS is defined as an “infrastructure mode” in which a control station exists, and an IBSS (Independent BSS) defined in an ad hoc mode including only a plurality of MTs (Mobile Terminals: mobile stations or terminal stations). ).

  Under the infrastructure mode, the control station collects the range where radio waves reach in the vicinity of its own station as BSS, and configures a so-called “cell” in the so-called cellular system. A terminal station existing in the vicinity of the control station is accommodated in the control station and enters the network as a member of the BSS. That is, the control station transmits a control signal called a beacon at an appropriate time interval, and the terminal station that can receive this beacon recognizes that the control station exists in the vicinity, and further establishes a connection with the control station. To do.

  Under infrastructure mode, the terminal station needs to establish an association with a specific control station. The process in which the terminal station searches for the first control station to connect to is called “scanning”. The scan operation is roughly divided into a passive scan and an active scan. In the passive scan, the terminal station moves between channels and collects information necessary for establishing an association included in a beacon periodically transmitted from the control station. On the other hand, in the active scan, the terminal station transmits a Probe Request frame and receives a Probe Response frame from the control station. The Probe Response frame includes information necessary for establishing the association, and the terminal station collects this information while moving the channel. After performing these scannings, the terminal station selects a BSS to join and establishes an association with that BSS.

  FIG. 22 shows an example of IEEE 802.11 operation in the infrastructure mode. In the illustrated example, the communication station STA0 operates as a control station, and the other communication stations STA1 and STA2 operate as terminal stations. The communication station STA0 as the control station transmits a beacon at a constant time interval as shown in the chart on the right side of the figure. The next beacon transmission time is managed in the control station as a parameter called target beacon transmission time (TBTT). When the time arrives at the TBTT, the control station operates the beacon transmission procedure.

  The terminal stations STA1 and STA2 around the control station can receive the beacon notified by the control station and recognize the next beacon transmission time TBTT from the internal Beacon Interval field and the reception time of the beacon. The BSS shifts to the Power Save mode as necessary, and each terminal station can perform a receiving operation only intermittently, thereby reducing power consumption. Specifically, the terminal station enters a sleep state (Doze) in which the power of the receiver is turned off until the next time or a plurality of beacon reception times TBTT ahead. The timing at which each terminal station in the Power Save mode wakes up is centrally managed by the control station.

  On the other hand, in IBSS in ad hoc mode, each terminal station autonomously defines IBSS after negotiating with other terminal stations. These terminal station groups define TBTT at regular intervals. When each terminal station recognizes that the TBTT has arrived by referring to its own clock, if it recognizes that no one has transmitted a beacon after a random backoff delay, Send.

  FIG. 23 shows an example of IEEE 802.11 operation in the ad hoc mode. In the example shown in the figure, two terminal stations (MTs) form a IBSS. In this case, any one MT belonging to the IBSS transmits a beacon every time TBTT arrives. There is also a case where beacons transmitted from each terminal station collide.

  In IEEE 802.11, the Power Save mode is also defined in IBSS, and the terminal station can enter a Doze state in which the power of the receiver is turned off as necessary. A predetermined time zone from the beacon transmission time TBTT is defined as an ATIM (Announcement Traffic Indication Message) Window. Until the end of the ATIM Window period, all terminal stations belonging to the IBSS are in the Active State. In this time zone, basically, terminals operating in the sleep mode can also receive signals. Is possible. The terminal station enters Doze State from the end of ATIM Window until the next beacon transmission time TBTT. If each terminal station has information addressed to someone, the terminal station holds transmission information by transmitting an ATIM packet to the above-mentioned communication partner in the time zone of this ATIM Window. Notify the receiver that you are doing. The terminal station that has received the ATIM packet does not shift to the Doze state until the reception from the station that has transmitted the ATIM packet is completed, and operates the receiver.

  In any of the infrastructure and ad hoc communication modes described above, in order to use a wireless network, it is necessary to specify an SSID (Service Set Identifier) common to all wireless devices participating in the BSS. Unlike wired communication, wireless communication is exposed to the risk of information leakage due to interception. Therefore, it is necessary to encrypt the communication path as a countermeasure. For this reason, encryption keys such as WEP (Wired Equivalent Privacy) key and PSK (Pre Shared Key) need to be designated in common for all wireless devices in the BSS.

  However, it is difficult for the end user operating the CE device to understand the meaning of these setting values and to set them correctly. In addition, unlike a PC, performing this type of setting on a user interface installed in a CE device tends to be complicated. For example, in ETSI (European Telecommunications Standards Institute) HIPERLAN Type 2, a method for automatically transmitting and setting a network identifier and an encryption key between wireless devices is specified as an Authentication Key Management (ETSI TS). 101 761-4 V1.1.1 (2000-06)). On the other hand, in IEEE 802.11, since there is no specification regarding such a setting method, it is difficult for wireless devices before connection to specify information such as SSID, WEP key, and PSK in common.

  Here, since portable devices such as digital cameras and music players have limited functions unlike PCs, there is a specific and clear purpose of use when a user intends to configure a wireless network. For example, the purpose of using the network such as exchanging photos between digital still cameras, exchanging music between music players, exchanging playlists, and the like can be mentioned. In other words, there is no point in connecting a digital still camera that wants to exchange photos and a music player that uses playlist exchange, so it is desirable to know the type of device of the connection partner when searching for the connection partner.

  In recent years, it has become common for one portable device to have a plurality of functions such as a digital still camera and a music player. In such a case, in order to find a preferable connection partner, not only the type of device but also the type of application currently running on this device, that is, whether it is a photo exchange application or a music exchange application It is desirable to know each other by. In addition, when exchanging playlists of photographs and songs taken by individuals, it is important to know who wants the content, so it is desirable to know who the user of each wireless device is. Furthermore, since some applications that operate on the wireless device always accept new connections and others want to accept connections only when the application is in a special state, it is desirable to know information about the current state of the application.

  However, there is no specification regarding such a setting method in IEEE 802.11. In addition, in the communication system defined by IEEE 802.11, information that can be arbitrarily set by the user and exchanged before connection is limited to 32 bytes of the network identifier. For this reason, since arbitrary attribute information such as the type of application, device user, and application status cannot be exchanged prior to connection, it is difficult to find a connection partner according to the type and status of the application.

  For example, a method has been proposed in which a communication mode for authentication different from a mode for performing normal communication is prepared, and a network identifier and an encryption key are encrypted and transmitted in that mode (for example, Patent Document 1). checking). However, in this method, since the network identifier and the encryption key are encrypted and transmitted after the connection partner is determined, the information for determining the connection partner is only the identification number for identifying the wireless device. In other words, information that can be exchanged prior to communication is limited, and there is no problem if there is only one device that is a connection destination candidate, but there are multiple devices that are connection destination candidates in the vicinity. It is difficult to decide which of these devices should be connected.

  In addition, there are a plurality of radio wave frequencies that can be used for IEEE802.11 communication, which are allocated as channels. According to the IEEE 802.11 specification, several different networks (BSS) can exist on a single channel, but to improve throughput and packet delay, different spatially overlapping networks are allocated to different channels. Is required. However, it is difficult for an end user who operates a wireless device to optimally set channel settings for a plurality of wireless networks. IEEE802.11 stipulates a scanning operation for a communication station to enter a network or acquire information necessary for network formation. Which channel is selected, which control station BSS is entered Is implementation dependent.

  Various methods for automatically setting a channel have been proposed. For example, a method of assigning channels based on the number of communications and traffic (see, for example, Patent Document 2), or a method of assigning channels based on the signal level of control information and the number of receptions (see, for example, Patent Document 3) A method of checking whether a channel is free by the presence or absence of radio waves by carrier sense and setting a communication channel (see, for example, Patent Document 4), a method of selecting a channel based on the number of interference resources (See, for example, Patent Document 5), a method for switching channels based on the number of error packets or the number of successful packets per unit time (see, for example, Patent Document 6), distance, A method of assigning channels based on the results of measuring propagation loss and interference level (see, for example, Patent Document 7) Such as has been proposed. Also, a method has been proposed in which, when there is no free channel, a channel is set based on a random level, a received signal level, and a predetermined value (see, for example, Patent Document 8).

  Conventionally proposed channel automatic setting methods can be broadly classified into methods used when there is no free channel or when there is at least one free channel.

  In the case where there is no free channel of the former, parameters such as the number of communication of each channel, traffic, carrier sense, number of interference resources, number of error packets, propagation loss, interference level, signal level, number of control signals, etc. Based on the measured value, the channel with the least other influence will be selected. Here, since it is not realistic for the wireless device to scan over all channels and measure these parameters at all times, it is unavoidable to use the result of a short time measurement for each channel. However, the radio wave environment at the time of measurement does not always represent the average or characteristic state of the channel. The parameter may be measured when a burst transfer occurs on the channel, or when no communication is performed at all. In spite of a channel that has almost no communication, it may happen that the measurement is performed during communication. That is, the measurement result of the parameter performed by the wireless device for each channel is not sufficiently reliable, and unlike the original intention, there is a possibility of selecting a crowded channel on average.

  On the other hand, under the latter situation where at least one free channel exists, a channel from which no control signal is received is found as a free channel based on the above method. Intuitively, it seems that efficient network operation can be realized by selecting an empty channel, but this selection does not necessarily improve the efficiency of the entire system. This is due to the following circumstances.

  The inventors believe that communication packets should have priorities according to their original purpose. For example, a communication such as voice communication that requires a real-time property that does not allow a delay while having a low bit rate should be separated from other communication. In addition, communications that allow a slight delay due to the buffer, such as video streaming, but do not allow a long-term rate drop should be separated from bursty and best-effort communications such as file transfer. .

  Consider an example in which three networks A, B, and C that perform voice communication and one network D that performs file transfer are arranged in a channel in a communication environment where three channels 1, 2, and 3 can be used. Try. However, it is assumed that the necessary bandwidth for voice communication is sufficiently smaller than the bandwidth allowed for one channel.

  Under this condition, when the above-described method of locating a new network in search of an empty channel is applied, assuming that the network is configured in the order of A, B, C, and D, A is 1 channel and B is 2 Channels C are arranged in 3 channels. If this happens, D must share some channel, and the shared voice communication will be disturbed. That is, when configuring a new network, it is not always necessary to improve the channel efficiency of a plurality of networks as a result of successively configuring the network with empty channels.

  The voice communication requires real-time property, but is sufficiently smaller than the band allowed for one channel, and a plurality of networks performing voice communication can sufficiently coexist on the same channel. Therefore, in the above example, it is most efficient to place A, B, and C in channel 1, D in channel 2, and leave channel 3 free for additional communications. It is considered good.

  The problem of such channel arrangement is not only when using an empty channel, but also when deciding which channel to share in a situation where there is no free channel and a shared channel must be used. is there. Regarding the prioritization of wireless communication, for example, in IEEE 802.11e, standardization work is progressing for the purpose of improving the communication quality (QoS: Quality of Service) in the wireless section, and communication quality such as audio and video has been improved. Although a mechanism for improving best effort communication has been established, the standard is not yet widespread. Even if QoS is used, optimizing the channel allocation leads to improved system performance. Considering that the number of wireless devices will increase in the future, optimizing channel allocation will remain an important issue in the future.

  In the IEEE 802.11 standard, power management specifications for power saving are also defined and actually implemented (described above). However, the standard specifies the operation when power management is enabled, but the timing and conditions under which power management is enabled are out of the scope of the specification. It is.

  The basis of the power management operation of the wireless device in IEEE 802.11 is to stop the reception operation. However, since communication cannot be performed while the communication is stopped, the communication station on the receiving side needs to move the receiver intermittently. That is, it is necessary to switch between stopping and operating the receiver according to a predetermined rule between communication stations on the transmission side and the reception side. In the case of IEEE 802.11, the transmission side and the reception side synchronize between the transmission side and the reception side using the beacon transmission timing and the contents of the beacon frame. On the other hand, since a terminal not participating in the network is not synchronized with the beacon of any network, the power saving mode cannot be used before connection to the network.

  For example, as a condition for using power management, a method has been proposed in which the power saving mode is not used when scanning is performed (see, for example, Patent Document 9). Under infrastructure mode, the control station can always receive radio waves without going to sleep, so the terminal station can communicate only if it is released when it is scanning. There will be no obstacles. On the other hand, in the ad-hoc mode, even if the terminal station on the scanning side cancels the sleep state, if the existing terminal station to be scanned is in the sleep state, depending on the timing, the scan packet I cannot receive it. As a result, it becomes difficult to realize an accurate scanning operation. In other words, if there is no communication at all and a channel scan is performed, unlike the original intention, there is a possibility of selecting a channel that is congested on average, so the channel arrangement is optimal. It becomes difficult to make it.

Japanese Patent No. 3628250 Japanese Patent No. 2629640 Japanese Patent No. 2750207 Japanese Patent No. 3043958 Japanese Patent No. 3457667 Japanese Patent No. 3744365 JP 2001-204075 A Japanese Patent No. 3019149 JP 2004-234667 A

  An object of the present invention is to enable a wireless network before connection to search for an appropriate connection partner in advance and to specify information necessary for connection in a simple procedure in common, and to form a network suitably. A wireless communication system, a wireless communication apparatus, a wireless communication method, and a computer program are provided.

  A further object of the present invention is to suitably arrange the channel arrangement of each network in consideration of the channel efficiency of the entire plurality of coexisting networks in a communication environment in which a plurality of radio frequency bands usable for communication are allocated as channels. An object is to provide an excellent wireless communication system, wireless communication apparatus, wireless communication method, and computer program that can be determined.

  A further object of the present invention is to realize an accurate scanning operation and optimize a channel arrangement in a communication environment in which each wireless device operates autonomously while enabling power management operation. Another object of the present invention is to provide a wireless communication system, a wireless communication apparatus, a wireless communication method, and a computer program.

  The present invention has been made in consideration of the above problems, and a first aspect thereof is a wireless communication system including a plurality of wireless devices that perform packet communication on a channel that can be used for communication. User data exchange means for exchanging user data between wireless devices before forming a network, and when the wireless device forms a network or joins an existing network, it scans the channel and Searching for a wireless device, collecting user data including arbitrary information for confirming a connection partner from the found wireless device, determining a wireless device to be a connection partner based on the user data, User data including connection parameters necessary for wireless connection is exchanged with the wireless device as the connection partner, and wireless communication is performed using the exchanged connection parameters. It is a wireless communication system and performing connection 置間.

  However, “system” here refers to a logical collection of a plurality of devices (or functional modules that realize specific functions), and each device or functional module is in a single housing. It does not matter whether or not (hereinafter the same).

  According to wireless communication technology, a flexible connection environment can be provided, and various wireless LAN products are rapidly spreading at present. For example, in a wireless LAN standard represented by IEEE 802.11, a network can be operated in an infrastructure mode and an ad hoc mode. In addition, a Power Save mode in which the receiver is shifted to the Doze state as required is defined, and power saving of the wireless device can be achieved in both the infrastructure mode and the ad hoc mode.

  Here, unlike wired communication, wireless communication is exposed to the risk of information leakage due to eavesdropping. Therefore, it is necessary to encrypt the communication path as a countermeasure, and wireless devices before connection between SSID and Information such as WEP key and PSK must be specified in common. However, it is difficult for an end user who operates a CE device (equipped with a wireless LAN function) to understand the meaning of these setting values and to set them correctly.

  In addition, since many CE devices have limited functions and have a clear purpose of use, when searching for a connection partner, you should make a wireless connection according to the type of the partner device and the type of application running on the device. It is desirable to determine whether or not However, in the communication method defined by IEEE 802.11, the information that can be set by the user arbitrarily and that can be exchanged before connection is limited to 32 bytes of the network identifier. Arbitrary attribute information such as status cannot be exchanged prior to connection, and it is difficult to find a connection partner according to the type and status of the application.

  On the other hand, in the wireless communication system according to the present invention, when a new wireless device forms a network or joins an existing network, it scans the channel and searches for surrounding wireless devices and searches for them. Collect user data including arbitrary information for confirming the connection partner from the received wireless device, determine a wireless device as a connection partner based on the user data, and connect with the wireless device as the connection partner User data including connection parameters necessary for wireless connection is exchanged between the wireless devices, and wireless devices are connected using the exchanged connection parameters.

  The wireless communication system according to the present invention is configured so that arbitrary information of 32 bytes or more can be exchanged between wireless devices. For example, when each network is operated in accordance with the IEEE 802.11 standard, the user data exchanging means may exchange user data using a Vendor Specific IE in an IEEE 802.11 Management frame. it can. The wireless device should include the device type, the type of application currently running, the name of the user, the status of the current application, etc. in the user data. It is possible to determine a wireless device or a wireless network to which the wireless device should participate. A plurality of Vendor Specific IEs may be included in one frame, and user data may be divided and transmitted.

  Next, the wireless device enters, as user data, a network identifier and an encryption key for encrypting a communication path between the wireless devices, and exchanges them with a partner to be connected. The encryption key mentioned here corresponds to a WEP key or PSK. The wireless device can perform encrypted communication by joining the normal IEEE 802.11 wireless network using the exchanged network identifier and encryption key, or configuring a new wireless network.

  In addition, the scan frame and the response frame to the scan frame include information related to an application running on the wireless device or information related to a user of the wireless device. Therefore, the wireless device on the scanning side evaluates the contents of the response frame to determine the connection partner, or the wireless device on the scanning side evaluates the contents of the scanning frame to determine the connection partner. Judgment can be made.

  The scanning-side wireless device can transmit a scan frame using a Probe Request frame, and the scanned-side wireless device can reply using a response frame using a Probe Response frame.

  Also, when a wireless device forms a network or joins an existing network, the identity of the connection partner is confirmed through a challenge / response procedure from among the wireless devices that have been scanned and confirmed, and this result is used. You can also limit the connection partners.

  Further, when the wireless device to be connected is determined, one of the wireless devices generates connection parameters such as a network identifier and an encryption key. The wireless communication system according to the present invention further includes a determination unit that determines which one of a set of wireless devices that are connected to each other generates or transmits a connection parameter.

  One criterion is based on the current state. When a new wireless device participates in a situation where a network has already been formed, the new participant must use the network identifier and encryption key of the existing network, so the wireless device already participating in the network Transmits the network identifier and encryption key to the newly joining wireless device. Further, under the infrastructure mode, the wireless device that is the control station can be seen as always participating in the network from the time of activation, so that it is always on the side of generating and transmitting connection parameters.

  On the other hand, under the ad hoc mode, either wireless device may determine the network identifier, but it must be uniquely determined. Therefore, one of the wireless devices is determined as the connection parameter transmission source based on the information that there is no possibility of having the same value such as the MAC address of each wireless device or the random value generated for each wireless device. It may be.

  In addition, when transmitting and receiving connection parameters such as a network identifier and an encryption key between wireless devices as connection partners, it is necessary to pay sufficient attention to eavesdropping. Therefore, the wireless communication system according to the present invention further includes public key exchanging means for exchanging each other's public key as user data between wireless devices to be connected. Each wireless device can generate a session key based on its private key and the public key of the connection partner. Then, the wireless device that is the connection parameter transmission source encrypts and transmits the connection parameter using the session key, and the wireless device that is the destination of the one connection parameter decrypts the received connection parameter with the session key. It is possible to obtain a ground for preventing eavesdropping.

  Further, the wireless device can omit the scanning operation by further including a channel and a basic network identifier (BSSID) in the connection parameters necessary for the wireless connection.

  As described above, according to the wireless communication device of the present invention, even when there are a plurality of wireless devices in the vicinity, the wireless device is connected to which device it should be connected to, which network it should participate in, Thus, it is possible to accurately determine whether a new network should be created, and to configure a wireless network with minimal user effort.

  In the case of a multi-channel communication system, when a wireless device forms a new network or enters an existing network, it is necessary to determine the network channel arrangement. There are a plurality of radio wave frequencies that can be used for IEEE802.11 communication, and they are allocated as channels. Here, several different networks can exist in a single channel. However, in order to improve throughput and packet delay, it is required to allocate different networks that are spatially overlapped to different channels. However, the method for determining the channel arrangement is implementation-dependent, and it is difficult for the end user operating the wireless device to optimally set the channel settings of a plurality of wireless networks.

  The wireless device needs to measure the communication status of each channel at the time of channel selection, but it is not realistic to scan all channels and measure these parameters at all times, and it is for each channel. The result of a short time measurement must be used. In such a case, the parameter may be measured when a burst transfer happens to occur on the channel, or when there is no communication at all, and an inappropriate channel may be selected. There is sex.

  Also, when configuring a new network, if the network is configured with empty channels one after another, the channel efficiency of the plurality of networks as a whole is not necessarily improved. This is because, when there are no free channels and a plurality of networks must coexist on a single channel, depending on the combination of networks, a situation may occur in which communication fails. For data communication, communication that requires real-time performance with low bit rate, such as voice communication, and video streaming, even if some delay is allowed by the buffer, video rate streaming does not allow long-term rate reduction Such communication is roughly classified into bursty and best effort communication such as file transfer. The present inventors consider that when placing a network in a channel, there is a priority according to the original purpose of each communication.

  Therefore, in the wireless communication system according to the present invention, the user data exchanged between wireless devices at the time of scanning includes information on the currently used application or information on the band used for the application to be operated in the future. May determine a channel to be set on the basis of an application in which the user operates and information identifying an application currently operating in each wireless device detected by scanning.

  That is, when attempting to newly configure a wireless network, the wireless device can obtain information on an application that is using the existing network and a wireless band that is used by the application. And, using these information, for example, while considering the conditions such as assigning the best effort type application that uses the maximum bandwidth in bursts to the application that requires the real-time property that packet delay is not allowed, to different channels, Perform channel assignment for new wireless devices.

  Specifically, a wireless device that operates a best effort type application forms its own network on a channel where an existing best effort type network exists. In addition, when a necessary bandwidth can be secured in a channel where an existing streaming network exists, a wireless device operating a streaming application forms its own network on the channel.

  According to such a channel arrangement method, even when a plurality of wireless networks are spatially overlapped, it is possible to configure a wireless network with the least channel waste and few communication failures. Even if there is a channel in which no wireless communication is performed, the wireless device may daringly select a channel that has already been used. This selection is performed in order to optimize the utilization efficiency of the entire band including all channels.

  The IEEE802.11 standard defines the operation when power management is enabled for power saving, but enables power management at any timing and under any conditions. Is outside the scope of the specification, that is, implementation-dependent.

  The basic power management operation is to stop the reception operation, but the radio device on the reception side needs to move the receiver intermittently. That is, between the wireless devices on the transmission side and the reception side, it is necessary to switch between stopping and operating the receiver according to a predetermined rule. Normally, the transmission side and the reception side are synchronized using the beacon transmission timing and the contents of the beacon frame. On the other hand, since a terminal not participating in the network is not synchronized with the beacon of any network, the power saving mode cannot be used before connection to the network.

  As a condition for using power management, it is preferable not to use the power saving mode when scanning is performed. The scanning operation under the infrastructure mode is that the terminal station searches for the control station. Since the control station does not enter the sleep state and can always receive radio waves, the terminal station does not fail in communication if the sleep state is canceled only when it is in a scanning state. On the other hand, in the ad-hoc mode, even if the terminal station on the scanning side cancels the sleep state, if the existing terminal station to be scanned is in the sleep state, depending on the timing, the scan packet I cannot receive it. As a result, it becomes difficult to realize an accurate scanning operation.

  Therefore, in the wireless communication system according to the present invention, at least some of the wireless devices have a function of temporarily stopping the operation of the receiver to save power, but the wireless device on the scanning side is Prior to scanning, a continuous reception mode request packet is transmitted according to a transmission rule in a predetermined power saving mode on a channel usable for the communication. On the other hand, in the surrounding wireless devices that have received the continuous reception mode request packet, by temporarily canceling the Power Save mode or prohibiting the transition to the Doze state under the Power Save mode, To operate. Then, the wireless device on the scanning side uses a period in which the surrounding wireless devices continuously operate the receiver, and broadcast addresses that do not particularly specify a destination on the channel that can be used for the communication. A scan frame is transmitted. The surrounding wireless devices can receive the scan frame because the receiver is not in the sleep state. As a result, the wireless device on the scanning side can successfully perform scanning even though the power save mode cannot be used before configuring the IEEE 802.11 network.

  If the wireless device to be scanned is released from the power saving state, it continues to consume power, so it must return to the original normal Power Save mode.

  Therefore, the wireless device on the scanning side exchanges user data including connection parameters necessary for wireless connection with the wireless device that is the connection partner, and then cancels the continuous operation of the receiver. May be.

  Alternatively, if the wireless device to be scanned does not finish the exchange of user data for the connection after a considerable amount of time has passed for the exchange of user data for the connection, The operation may be canceled.

According to a second aspect of the present invention, there is provided a computer program written in a computer-readable format so that processing for performing packet communication on a channel usable for communication is executed on a computer. Whereas
Application that performs packet communication or user data packet that converts user data including arbitrary information that a user instructing execution of the application wants to exchange with another wireless communication device to a predetermined user data packet format Creation procedure and
A packet transmission procedure for wirelessly transmitting a user data packet created by executing the user data packet creation procedure as a management packet;
A packet reception procedure for receiving a management packet wirelessly transmitted from another wireless communication device;
A user data extraction procedure for extracting user data from a data packet portion included in a management packet received by executing the packet reception procedure;
A connection control procedure for joining an existing wireless network or configuring a new wireless network based on a network identifier and an encryption key, and controlling connection with other wireless communication devices;
The user data is exchanged with other wireless communication devices that are connection candidates, the other party to be connected is determined using the exchanged user data, and the same network identifier and encryption key as the determined other party to be connected are determined. A data processing procedure to be set in the connection control procedure;
Is a computer program characterized in that

In addition, the third aspect of the present invention realizes a power saving function for temporarily stopping the operation of the receiver and executes processing for performing packet communication on a channel usable for communication on a computer. A computer program written in a computer readable format, said computer program
Prior to the scanning operation, a procedure for transmitting a continuous reception mode request packet for requesting a continuous reception operation to another wireless communication device;
A procedure for transmitting a continuous reception mode request packet according to a predetermined transmission rule in the power saving mode;
In response to receiving the continuous reception mode request packet, a procedure for performing a continuous reception operation;
A procedure for starting an intermittent reception operation when a predetermined condition is satisfied or a predetermined time has elapsed when performing a continuous reception operation;
Is a computer program characterized in that

  The computer program according to each of the second to third aspects of the present invention defines a computer program written in a computer-readable format so as to realize predetermined processing on the computer. In other words, by installing the computer program according to each of the second to third aspects of the present invention in the computer, a cooperative action is exhibited on the computer, and the wireless communication system according to the first aspect of the present invention. , A wireless device that operates as a control station or a terminal station in the infrastructure mode or a terminal station in the ad hoc mode can be configured. By activating a plurality of such wireless communication devices to construct a wireless network, it is possible to obtain the same effects as the wireless communication system according to the first aspect of the present invention.

  According to the present invention, wireless devices before connection search for an appropriate connection partner in advance, and information necessary for connection can be specified in common by a simple procedure, and a network can be suitably formed. A wireless communication system, a wireless communication apparatus, a wireless communication method, and a computer program can be provided.

  Further, according to the present invention, in a communication environment in which a plurality of radio frequency bands that can be used for communication are assigned as channels, the channel arrangement of each network is preferably considered in consideration of the channel efficiency of the entire plurality of coexisting networks. An excellent wireless communication system, wireless communication apparatus and wireless communication method, and computer program can be provided.

  Further, according to the present invention, it is possible to optimize the channel arrangement by realizing an accurate scanning operation in a communication environment in which each wireless device operates autonomously while enabling the power management operation. An excellent wireless communication system, wireless communication apparatus, wireless communication method, and computer program can be provided.

  According to the present invention, by allowing arbitrary information to be exchanged before connection of IEEE802.11, it is possible to connect with power management and channel setting with high usage efficiency with a simple user operation. Become.

  Other objects, features, and advantages of the present invention will become apparent from more detailed description based on embodiments of the present invention described later and the accompanying drawings.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

A. System Configuration FIG. 1 schematically shows a hardware configuration of a wireless device capable of performing a communication operation in a wireless network according to the present invention. The wireless device is an information device equipped with a wireless LAN card such as a personal computer, or a CE device such as a digital camera or a music player.

  In the illustrated wireless device, a CPU (Central Processing Unit) 101 includes a memory device such as a ROM (Read Only Memory) 102 and a RAM (Random Access Memory) 103, a peripheral device 104, and an external storage device such as a HDD (Hard Disk Drive). 105 and a peripheral device such as the wireless LAN interface 106 are interconnected via a bus. Two or more buses are connected via a bridge device.

  The CPU 101 loads the control code stored in the ROM 102 or the program code installed in the external storage device 105 onto the RAM 103 and executes it to execute device operations using the peripheral device 104 (for example, in a digital camera). The overall operation of the apparatus, such as shooting and image playback operations, playlist display and music playback operations in a music player, and communication operations using the wireless LAN interface 106, is comprehensively controlled.

  In the example shown in FIG. 1, the wireless LAN interface 106 passes a frame of an IEEE802.11 MAC (Media Access Control) layer to the RAM 103 via a bus, and the CPU 101 performs processing of the MAC layer. However, the gist of the present invention is not limited to the configuration of the radio apparatus as shown in FIG. 1, and another configuration as shown in FIG. 2 is also conceivable. In FIG. 2, the wireless LAN interface unit 110 is connected to the bus via the I / O interface 107. The I / O interface 107 that connects the wireless LAN interface unit 110 and the bus is generally MSIO (Memory Stick IO), SDIO (Secure Digital IO), USB (Universal Serial Bus), or the like.

  FIG. 3 shows an internal configuration of the wireless LAN interface unit 110. The CPU 111 and the RAM 113 in the wireless interface unit 110 are used to perform IEEE 802.11 MAC (Media Access Control) layer processing, and a frame equivalent to IEEE 802.3 is sent to the host CPU 101 through the I / O interface 118 and the I / O interface 107. It is like that.

  FIG. 4 illustrates a configuration example of a wireless system configured by using a plurality of wireless devices illustrated in FIG. 1 or FIG. In the figure, a wireless device 11 functions as a so-called access point (AP), and the other wireless devices 21 to 24 function as terminal stations (STAs), and as a whole, a wireless network, that is, a BSS (Basic). Service Set). Such a wireless network is suitable, for example, for an application in which the wireless device 11 functions as a server that stores photos and music content, and the wireless devices 21 to 24 browse content stored in the wireless device 11. It is a configuration.

  FIG. 5 illustrates another configuration example of a wireless system configured by using a plurality of wireless devices illustrated in FIG. 1 or FIG. In the figure, wireless devices 31 to 35 are all equal terminal stations (STAs), and form a BSS in a so-called ad hoc mode. An application is considered in which the wireless devices 31 to 35 function as a server and a client, respectively, and exchange photo data, music data, a playlist, a message, and the like with each other.

  FIG. 6 shows a state in which pictures are exchanged using a wireless network when the wireless device is a digital camera. In the figure, the cameras 41 and 51 are equipped with exchange buttons 42 and 52, respectively, and when the user presses the exchange buttons 42 and 52 at the same time, a wireless connection is established so that pictures can be exchanged.

  FIG. 7 shows a state in which music exchange or playlist exchange is performed using a wireless network when the wireless device is a music player. When three users put the music players 61, 71, 81 into the music exchange mode or the playlist exchange mode, a list of surrounding wireless devices is displayed on the display devices 62, 72, 82. The user selects a partner to be exchanged from a list of surrounding wireless devices by using the selection buttons 63 and 73 and designates it with the decision buttons 64 and 74, and performs wireless connection, and music or play between the music players 61 and 71. List exchange is performed.

  In the example shown in FIG. 7, the music players 61 and 71 are connected because they have selected and determined each other. On the other hand, the music player 81 is not connected yet because the information of the surrounding music players is displayed on the display device 82 but no button operation is performed.

  Both the example of the camera and the music player shown in FIG. 6 and FIG. 7 require an application or middleware to search and select the content actually held by the other party after the wireless connection is made. is necessary. However, since this point is not directly related to the gist of the present invention, the description is omitted here.

  According to the present invention, the wireless device exchanges arbitrary information of 32 bytes or more between the wireless devices before making a connection for performing normal IEEE802.11 data communication (that is, before forming the BSS). be able to. FIG. 8 shows a functional configuration of the wireless device in this case.

  The illustrated radio apparatus includes a user data packet creation unit 2, a packet transmission unit 3, a packet reception unit 5, a user data extraction unit 4, a data processing unit 1, and a connection control unit 6. .

  The user data packet creation means 2 converts user data into a predetermined user data packet format. The user data referred to here is data including an application operating on the wireless device or arbitrary information that a user operating the wireless device wants to exchange with another wireless device.

  The packet transmission means 3 wirelessly transmits the user data packet created by the user data packet creation means 2 as a management packet. On the other hand, the packet receiving unit 5 receives a packet transmitted from another wireless device, and passes the data packet part included in the management packet to the user data extracting unit 4. Then, if the user data exists in the received packet that has been passed, the user data extraction unit 4 extracts the user data and passes it to the data processing unit 1.

  The data processing means 1 exchanges the user data with other wireless devices as connection candidates through the user data packet creation means 2 and the user data extraction means 4, and connects using the exchanged user data. The other party to be connected is determined, and the same network identifier and encryption key as the determined other party to be connected are set in the connection control means 6.

  The connection control means 6 joins an existing wireless network or configures a new wireless network based on the set network identifier and encryption key.

  In this way, the wireless device separates the wireless network by the network identifier, encrypts data based on the encryption key, and performs packet communication. In the case of IEEE 802.11, a network identifier corresponds to an SSID, an encryption key corresponds to a WEP key or PSK, a data packet corresponds to a data frame, a management packet corresponds to a management frame, and the like. The wireless device can transmit and receive a management packet for managing communication different from the data packet used for packet communication.

  The wireless device should include the device type, the type of application currently running, the name of the user, the status of the current application, etc. in the user data. A wireless device or a wireless network to which the wireless device should participate is determined. Next, the network identifier and the encryption key are entered as user data, and exchanged with the other party to be connected. The exchanged network identifier and encryption key are used to join a normal IEEE 802.11 wireless network or to configure a new wireless network.

  According to the functional configuration shown in FIG. 8, even when there are a plurality of wireless devices in the vicinity, the wireless device can determine which device it should connect to, which network it should join, and its own new network. It is possible to accurately determine whether to create a wireless network, and to configure a wireless network with minimal user effort.

  FIG. 9 shows a modification of the configuration shown in FIG. The illustrated radio apparatus further includes channel setting means 7.

  The wireless device includes, as user data, information related to a currently used application or a band used by an application to be operated in the future. The information regarding the used band here includes any one of information for identifying the application, an average band used by the application, a maximum band used by the application, and a time during which the application continuously uses the maximum band.

  The data processing means 1 determines a channel to be set based on information for identifying an application that is currently operating, and instructs the channel setting means 7 about the channel. Then, the channel setting unit 7 matches the channel of the wireless device with the channel designated by the data processing unit 1.

  When trying to newly configure a wireless network, the wireless device illustrated in FIG. 9 can obtain information on an application that is using an existing network and a wireless band that is used by the application. And, using these information, for example, while considering the conditions such as assigning the best effort type application that uses the maximum bandwidth in bursts to the application that requires the real-time property that packet delay is not allowed, to different channels, Perform channel assignment for new wireless devices. According to such a channel arrangement method, even when a plurality of wireless networks are spatially overlapped, it is possible to configure a wireless network with the least channel waste and few communication failures.

  FIG. 10 shows still another modification of the configuration shown in FIG. The illustrated wireless device is configured to save power by temporarily stopping the operation of the receiver.

  The packet transmission unit 3 transmits a continuous reception mode request packet according to a transmission rule in a predetermined power saving mode in response to an instruction from the data processing unit. The continuous reception mode request packet here is transmitted as user data, for example.

  On the other hand, the packet receiving unit 5 passes the received continuous reception mode request packet to the data processing unit 1.

  Prior to the scanning operation, the data processing unit 1 instructs the packet transmission unit 3 to transmit the continuous reception mode request packet. Further, when the continuous reception mode request packet is received, an instruction to continuously operate the receiver is issued to the packet receiving means 5, and after that, when a certain condition or a certain fixed time has passed, the receiver of the packet receiving means 5 is received. Instructs to operate intermittently.

  When receiving an instruction to continuously operate the receiver from the data processing unit 1, the packet receiving unit 5 operates the receiver continuously. Further, when an instruction to intermittently operate the receiver is received, the receiver is intermittently operated according to a predetermined rule.

  The wireless device illustrated in FIG. 10 transmits a continuous reception mode request packet that triggers a surrounding wireless device to enter a continuous reception state prior to scanning. On the other hand, when a wireless device already configuring the network receives the continuous reception mode request packet, it changes its state to the constant reception mode and temporarily cancels the Power Save mode (or enters the Doze state under the Power Save mode). Prohibit transition). Since the receiver is not in the sleep state in this way, a continuous reception mode request packet for scanning transmitted by a wireless device that cannot use the PowerSave mode before configuring the IEEE 802.11 network, or the above-described Packets for exchanging user data can no longer be received.

  Here, in the hardware configuration shown in FIG. 1, the user data packet creation means 2, the user data extraction means 4, the connection control means 6, and the data processing means 1 in FIGS. The software program stored in 105 is developed on the RAM 103 and executed by the CPU 101. The packet transmission unit 3, the packet reception unit 5, and the channel setting unit 7 are realized by the wireless LAN interface 106.

  Alternatively, in the hardware configuration shown in FIG. 2, the user data packet creation means 2, the user data extraction means 4, the connection control means 6, and the data processing means 1 in FIGS. The CPU 101 and the CPU 111 inside the wireless LAN interface unit 110 are shared and executed.

B. System Operation Next, the operation of the wireless device in a communication environment in which a network is operated according to IEEE 802.11 will be described.

B-1. Overall Flow to Realize IEEE802.11 Connection First, the processing operation in which wireless devices exchange user data to realize the connection shown in FIG. 6 or FIG. 7 will be described. FIG. 11 shows, in the form of a flowchart, the processing procedure of the wireless apparatus for performing IEEE 802.11 wireless connection. However, the wireless device is assumed to have the functional configuration shown in FIG. 8 or FIG.

  The wireless device scans or receives a scan to obtain information on surrounding wireless devices (step S1).

  Next, as necessary, the wireless device exchanges data for confirming the identity of a specific partner that cannot be obtained only by scanning (step S2).

  Next, the wireless device analyzes the information obtained in step S1 and step S2, and determines a partner to be connected (step S3). If the connection partner cannot be automatically determined, the user can be determined. Then, connection parameters for IEEE 802.11 wireless connection, that is, an SSID and an encryption key are automatically generated as necessary.

  Next, the wireless device that has generated the connection parameter sends the connection parameter to the partner (step S4). A wireless device that does not generate connection parameters receives connection parameters from the other party.

  Next, the wireless device performs IEEE 802.11 wireless connection using the transmitted connection parameter (step S5). As a result, a BSS that connects wireless devices is formed on an appropriate channel. The channel arrangement method will be described later.

  The above-described user data is used for exchanging all information in the step before performing the wireless connection of IEEE802.11. Also, the following transmission frame is defined as user data to be used in the scanning process in step S1.

Existence frame: A frame indicating the presence of the user, which is transmitted when scanning is performed. An response frame which is transmitted when receiving an Existence frame.

  FIG. 12 shows a sequence diagram for exchanging user data between the wireless device A and the wireless device B for wireless connection. However, in the same figure, it is assumed that the wireless device A is the scanning side and the wireless device B is scanned.

  First, in order to realize the processing corresponding to step S1 in the flowchart shown in FIG. In the Existence frame, the channel where the local station is currently located, the nickname of the local station to be used when the other party displays the user, and information for determining which one generates the SSID in the subsequent process (level information) Information on the type of device, the application running on the device, and the status of the application. Here, an Existence frame is transmitted to a broadcast address that does not specify a receiving party.

  When the wireless device B receives the existence frame, the wireless device B transmits an presence response frame to the wireless device A. In the same way as the Existence frame, the Existence response frame is also used to determine which channel the current station is currently on, the nickname of the own station that the other party uses when displaying the user, and which determines the SSID in the subsequent process. Information (level information described later), the type of device, the application running on the device, and the status of the application.

  In the sequence example shown in FIG. 12, only the wireless device A performs scanning, but the wireless device A and the wireless device B perform scanning simultaneously (that is, each of the wireless devices A and B as the side on which scanning is performed). A frame may be transmitted).

  Although omitted in the figure, this sequence is inserted between the extension response and the public key exchange when the partner in step S2 in the flowchart shown in FIG. 11 is confirmed.

B-2. Scanning Operation and Connection Partner Determination Next, information analysis processing corresponding to step S3 in the flowchart shown in FIG. 11 will be described first.

  As a result of performing a scanning operation for exchanging an Existence frame and a response frame thereto, the wireless device A on the scanning side determines a connection partner from one or more of the found wireless devices. There are various ways to determine the connection partner. The main difference between the example of the camera shown in FIG. 6 and the example of the music player shown in FIG. 7 is in how to determine the connection partner. Hereinafter, how to determine a connection partner in each example will be described.

  As an example of a method of determining a connection partner with a camera, a connection is made when the connection buttons of two cameras are pressed simultaneously. Therefore, the information to be communicated to other wireless devices is information that the user is a camera, the photo exchange application is currently running, and that the button is pressed by the user and the connection is accepted. is there. The wireless device exchanges these pieces of information with the other party to be connected by including them in an Existence frame and an Existence response frame which are user data. As a result, the side performing scanning can determine the connection partner by evaluating the contents of the returned response frame. Further, the side receiving the scan can determine the connection partner by evaluating the contents of the Existence frame sent from the side to be scanned.

  Furthermore, it is necessary to consider the operation when three or more wireless devices press buttons simultaneously. When three connection buttons are pressed, a method of simultaneously connecting all three devices is conceivable, but it is desirable not to connect them in terms of security. This is because when two users are trying to connect, the third may be a wireless device that is trying to gain unauthorized access beyond the wall. In the present embodiment, information indicating the state of the device in the presence response frame is confirmed, and if the device is pressing the button, 1 is added to the reception count. If no other wireless device is found within 3 seconds, a connection error is assumed. Also, when two or more devices are found, it is handled as a connection error. Then, only when only one device is found, the process proceeds to the next public key step on the sequence shown in FIG.

  FIG. 13 is a flowchart showing a processing procedure performed by a wireless device that newly joins a network or a wireless device that first configures the network, in order to determine a wireless device that simultaneously presses buttons as a connection partner as described above. It is shown in the form of

  First, the wireless device transmits an existence frame (step S11), and tries to receive an extension response frame from surrounding wireless devices (step S12).

  When an response frame is received from one of the wireless devices (Yes in step S13), the received frame is analyzed, and the replying wireless device is a camera and a photo exchange application is started. Whether the button is pressed on the replying wireless device (step S15). If any check result is affirmative, the reception count is incremented by 1 (step S16).

  Further, when the response frame cannot be received (No in step S13), the reply source wireless device does not start the camera photo exchange application (No in step S14), or the button is pressed on the reply source wireless device. When not pressed (No in step S15), the process up to step S16 is skipped and the reception count is not changed.

  The wireless device repeatedly performs the above-described operation of receiving the response frame in steps S12 to S16 until 0.3 seconds elapse after the transmission of the extension frame in step S11 (step S17).

  When 0.3 second elapses, the wireless device changes the channel (step S18). The channel is arranged to change cyclically, and after changing the channel, it is determined whether or not the channel has returned to the first channel (step S19). Here, you may scan over all the channels which can be used by IEEE802.11. However, in the case of IEEE802.11b and 802.11g, the adjacent and next adjacent channels have a large interference. Therefore, the channels used by the application are determined in advance as, for example, 1, 6, 11 channels, and only this channel is scanned. It may be.

  If the channel changed in step S18 is a new channel that has not yet been scanned (No in step S19), the procedure from steps S11 to S17 is repeated again for this channel.

  Further, when the channel is changed in step S18 to return to the first channel, that is, when the scanning of all the channels to be used is completed (Yes in step S19), an attempt is made to receive an existence response frame (step S20).

  Here, when an existence frame can be received from any of the wireless devices (Yes in step S21), an response frame corresponding to the received existence frame is returned (step S22). Then, the received Existence frame is analyzed, whether the transmission source wireless device is a camera and the photo exchange application is activated (step S23), or whether the button is pressed on the transmission source wireless device (step S23). S24) are sequentially checked. If any check result is affirmative, the reception count is incremented by 1 (step S25).

  In addition, when the Existence frame cannot be received (No in step S21), the transmission source wireless device has not started the camera photo exchange application (No in step S23), or the button is pressed on the transmission source wireless device. If not (No in step S24), the process up to step S25 is skipped and the reception count is not changed.

  The wireless device repeatedly executes the operation of receiving the Existence frame in Steps S20 to S25 described above until 3 seconds elapse after the transmission of the Existence frame in Step S11 (Step S26).

  When the reception operation of the existence frame ends (Yes in step S26), the value of the reception count is checked. If the reception count is 0, that is, if no other wireless device is found within 3 seconds, this processing routine is terminated as a connection error (Yes in step S27). If the reception count is 1, that is, only one device is found (Yes in step S28), the process proceeds to the public key step. If two or more devices are found (No in step S28), the processing routine is terminated as a connection error.

  On the other hand, as an example of a method of determining the connection partner in the music player, the user is made to select the connection partner. In this case, information indicating that the user is the music player and the music exchange application is operating is inserted into the Existence frame or the Extension response frame, which is user data, and transmitted to the other party. Further, the nickname is also transmitted so that the user can easily identify the listed wireless devices. The wireless device that has received the Existence frame or the Existence response frame displays a nickname when the other party is a music player and a music exchange application is operating. When I join the network, I scan every 3 seconds until a connection partner is determined. When received from a new partner, the number of display lines is increased one by one and displayed sequentially. In the user interface shown in FIG. 7, the user wants to connect himself / herself from the lists displayed on the display devices 62, 72, and 82 of the music players 61, 71, and 81 using the selection buttons 63 and 73, respectively. The partner is selected and determined with the decision buttons 64 and 74. When the connection partner is selected by the user in this way, the process proceeds to the next public key step in the sequence shown in FIG.

  FIG. 14 shows, in the form of a flowchart, a processing procedure performed by a wireless device that newly joins the network or a wireless device that first configures the network for allowing the user to select a connection partner as described above.

  The wireless device first transmits an existence frame (step S31), and tries to receive an extension response frame from surrounding wireless devices (step S32).

  Here, when the presence response frame can be received from any of the wireless devices (Yes in step S33), the received frame is analyzed for information, the wireless device that is the return source is a music player, and the music exchange application is It is checked whether or not it is activated (step S34). When a music player in which the music exchange application is activated is found (Yes in step S34), the reception result is recorded (step S35).

  The wireless device repeatedly executes the above-described operation of receiving the response frame in steps S32 to S35 until 0.3 seconds elapse after the transmission of the extension frame in step S31 (step S36).

  When 0.3 second elapses, the channel is changed (step S37). Arrange the channels to change cyclically. Then, after changing the channel, it is determined whether or not the channel has returned to the first channel (step S38). In the case of a new channel that has not been scanned yet (No in step S38), the procedure from steps S31 to S35 is repeated again for this channel.

  In addition, when the channel is changed and returned to the first channel in step S37, that is, when the scanning of all the channels to be used is completed (Yes in step S38), the presence response frame recorded in step S35. As a result of reception, a list of detected music players is displayed (step S39).

  The user can specify a desired connection partner from the list display via the user interface of the wireless device (step S40).

  If there is no designation from the user (No in Step S41) and 3 seconds have not passed since the transmission of the first Existence frame (Step S31) (No in Step S42), the wireless device is not sent from another wireless device. Wait for an existence frame (step S43).

  Here, when an Existence frame can be received from any of the wireless devices (Yes in Step S44), an Ex response response frame is returned to the Existence (Step S45), and the received Existence frame is analyzed. At this time, it is checked whether or not the transmission source wireless device is a music player and the music exchange application is activated (step S46). Then, a list of detected music players is displayed as a result of receiving the Existence frame (step S39).

  The wireless device scans at intervals of 3 seconds until a connection partner is determined (No in step S41). That is, until 3 seconds elapse after the transmission of the Existence frame (No in Step S42), the process returns to Step S43 and attempts to receive the Extension response frame. Whenever 3 seconds elapse (Yes in step S42), the process returns to step S31, and an Existence frame is transmitted again.

  When the connection partner is selected by the user (Yes in step S41), the process proceeds to the next public key exchange step.

  Note that the flowcharts shown in FIG. 13 and FIG. 14 show a processing procedure assuming a wireless device that newly enters the network or newly configures the network. For this reason, after the start of the processing, the existence is always performed. A frame is transmitted to scan. When a new wireless device participates in a wireless device already connected by IEEE 802.11, the already connected wireless device operates as a scanned side and transmits an Existence frame. Without waiting for reception.

B-3. Exchange of Connection Parameters with Connection Partner Here, a description will be given of public key exchange processing performed following the scanning operation. Although not used in the present embodiment, as a method for determining the connection partner in more detail before exchanging the public key, a process of strict confirmation of the connection partner using confirmation of secret data by challenge / response is performed. You can also put it in. For this purpose, the following user data is defined: The identity of the connection partner can be confirmed through a challenge / response procedure, and the connection partner can be limited using this result.

Challenge frame ... Frame for sending challenge data Challenge response frame ... Frame for sending back hash values of challenge data and secret data

  FIG. 15 shows a challenge-response communication sequence. When confirming the other party, this sequence is inserted between the Existence response and the Public key Exchange in the communication sequence shown in FIG. In this sequence, it is assumed that both the wireless device A and the wireless device B have in advance common secret data transferred by a method other than the wireless method used for this communication. The challenge-response process is a process for securely and reliably determining that the secret data match each other.

  The secret data is data of about several tens to several hundreds of bits. As secret data, characters exchanged with the other party by the user may be input from the user interface, may be transmitted using a method such as infrared or non-contact proximity communication, or may be transmitted through a wired connection. . In a camera or the like, one may display a character or a pattern of light and darkness or a color, and the other may recognize it by photographing it with a camera. Data on dynamic pattern changes of light and dark and color can also be created. In addition, a music player can send data using voice if a microphone is attached. Alternatively, secret data can be used without special communication means after the second connection by exchanging secret data with the other party at the first connection.

  On the assumption that secret data is shared, the wireless device A sends a random number to the Challenge frame and sends it to the wireless device B.

  The wireless device B generates a data string in which secret data is added to the sent random number and applies this to the hash function. Here, the hash function is a function or procedure for summarizing a sequence of character strings such as documents and numbers into data of a fixed length, and MD5, SHA1, or HMAC using these may be used. it can.

  The wireless device B puts the generated hash value in a Challenge response frame and returns it to the wireless device A. On the other hand, the wireless device A obtains a hash value by the same method as the wireless device B from the transmitted random number and secret data. Then, the hash value sent from the wireless device B is compared with the hash value calculated by itself. If they match, it is verified that they have a common secret data with a very high probability. Even if the hash value is intercepted, it is very difficult to guess the secret data, and therefore it is very unlikely that the secret data will be known to a third party. In FIG. 15, the wireless device A confirms the secret data of the wireless device B. Although not shown here, since the two-way confirmation is performed in this embodiment, the procedure of the wireless device B confirming the secret data of the wireless device A by switching the roles of the wireless device A and the wireless device B thereafter. Also running.

  In the example of the camera whose processing procedure is shown in FIG. 13, when three or more connection partner candidates are found, a connection error is issued. On the other hand, when a challenge / response procedure as shown in FIG. 15 is used, if three or more connection partner candidates are found, only wireless devices whose opponents are confirmed by the challenge / response are counted. By doing so, an appropriate connection partner can be narrowed down.

  Further, in the example of the music player whose processing procedure is shown in FIG. 14, the found wireless devices are displayed in a list, and the connection is made only in response to an instruction from the user. On the other hand, when the challenge / response procedure as shown in FIG. 15 is used, the wireless device whose partner is confirmed by the challenge / response is automatically connected to the security level. The user operation can be simplified without lowering.

  The challenge response is a technique well known in the art as a method of authenticating without sending the password itself by using a one-way function, and detailed description thereof is omitted in this specification.

  When the connection partner is determined by the above-described procedure, the process proceeds to the process of exchanging connection parameters with the connection partner, that is, the SSID and the encryption key. At this point, it is necessary to determine which wireless device generates and transmits the SSID and encryption key. Specifically, the determination is made based on the following two criteria.

  One criterion is based on the current state. When a new wireless device participates in a situation where a BSS has already been formed, the new participant needs to use the SSID and encryption key of the existing BSS, so that the wireless device already participating in the BSS The SSID and the encryption key are transmitted to the newly participating wireless device. Also, under the infrastructure mode, the wireless device that is the control station (AP) can be seen as always participating in the BSS from the time of activation, so that it is always on the side of generating and transmitting connection parameters.

  On the other hand, when both are in the same state, that is, in the case of ad hoc mode, neither of them has yet formed a BSS, and when the first BSS is formed by these two parties, either may determine the SSID, but it is unique. Therefore, the second criterion is necessary. As an example, there is a method using the size of the MAC address. The other party's MAC address can be acquired through exchange of an Existence frame and an Existence response frame. For example, if it is determined that the larger MAC address is the transmitting side and the smaller one is the receiving side, it is uniquely determined which side sends the SSID and the encryption key without adding a special exchange. Alternatively, a very large random value of about 128 bits may be generated and compared. In this case, the possibility of being the same value is not zero, but the probability is very low, so that it becomes practical enough.

  Basically, as shown above, assuming three types: a control station, an ad hoc terminal already participating in the BSS, and a terminal not yet participating in the BSS, an SSID and an encryption key are generated and transmitted. The wireless device on the side can be determined. Furthermore, a determination method that introduces a level value is also conceivable so that the convenience of the application can be considered.

  FIG. 16 shows a processing procedure for setting the level value of the wireless device in the form of a flowchart.

  First, the wireless device checks whether or not it is operating as an access point (step S51), and if it is an access point, sets 100 as its level value (step S52).

  If the wireless device is not an access point (No in step S51), the wireless device then checks whether it has already entered the BSS (step S53).

  If the wireless device has already entered the BSS (Yes in step S53), the level value is set to 50 (step S54). When it is desired to retain the participating BSS (Yes in step S55), N is further added to the level value (step S56).

  On the other hand, when the wireless device has not yet entered any BSS, the level value is set to 0 (step S57). Here, when it is desired to determine the connection parameter itself (step S58), M is appropriately added to this level value (step S59).

  According to the processing procedure shown in FIG. 16, the level value is set as follows according to the operation status of the wireless device. The level value is an index value indicating the degree of wanting to become the connection parameter transmission side or the degree of wanting to keep the BSS. Then, the wireless device includes the level value in the Existence frame or the Existence response frame transmitted by itself during the scanning operation, and notifies the connection partner.

  Further, FIG. 17 shows a procedure of connection parameter transmission / reception determination processing in which a level value is introduced in the form of a flowchart.

  First, the wireless device extracts a level value from the Existence frame or the Existence response frame received from the connection partner (step S61), and compares it with the level value it has (step S62).

  Here, when the level value of the connection partner is larger (Yes in step S63), the connection parameter is received from the connection partner (step S70).

  On the other hand, when the level value of the connection partner is not larger (No in step S63), it is next checked whether or not the level value of the connection partner is smaller than itself (step S64).

  When the level value of the connection partner is smaller than that of the user (Yes in step S64), the user becomes the connection parameter transmission source. In this case, when the wireless device has already participated in the BSS (Yes in Step S67), the wireless device transmits the connection parameter set in the BSS to the connection partner (Step S71). When the wireless device has not yet participated in the BSS (No in step S67), it generates a connection parameter itself (step S48) and transmits it to the connection partner (step S71).

  When the level value matches that of the connection partner (No in step S64), the MAC addresses are subsequently compared (step S65), and the larger MAC address is determined as the connection parameter transmission source.

  That is, when the MAC address of the connection partner is larger, the connection parameter is received from the connection partner (step S70). Further, when the own MAC address is larger, if the user has already participated in the BSS (Yes in Step S67), the connection parameter set in the BSS is transmitted to the connection partner (Step S71). When the wireless device has not yet participated in the BSS (No in step S67), it generates a connection parameter itself (step S68) and transmits it to the connection partner (step S71).

  If the processing procedure shown in FIG. 17 is followed, the exchanged level value is compared and a larger one generates a connection parameter (generated using a random number) and transmits it to the wireless device of the connection partner. If the level value is the same, the connection parameter is generated and transmitted with the larger MAC address.

  In the above-described example, the level values of ad hoc terminals already participating in the BSS and terminals not participating in the BSS have a range, but if this is done, for example, the level value is usually set to the lowest value. It is possible to use it by setting the value to a higher level when it is desirable for the station to set the connection parameters for the convenience of the application. In the flowchart shown in FIG. 16, in step S39, the wireless device adds M to the level value for the convenience of the application.

  In this specification, the case where two ad hoc BSSs already configured are merged is not particularly described, but the present invention can be applied to such a specification. Specifically, by changing the level value of the ad hoc terminals already participating in the BSS (corresponding to step S36 in the flowchart shown in FIG. 16), one ad hoc BSS is given priority over the other ad hoc BSS. It can survive.

  When the wireless device transmits / receives connection parameters such as SSID and encryption key to / from the connection partner, it is necessary to pay sufficient attention to wiretapping. There is no problem when handling data that can be disclosed to anyone, but if the BSS is encrypted and used as a base for preventing eavesdropping, the connection parameter will be meaningless if it is eavesdropped. Therefore, in this embodiment, in order to prevent eavesdropping, the following user data is defined.

Public key exchange frame ... Frame that sends the public key to the partner to be connected Parameters Frame ... Frame that sends the SSID and encryption key encrypted with the session key

  The wireless device performs a DH (Diffie-Hellman) key exchange with a connection partner using a public key exchange frame, and generates a session key in a manner that is not easily known to an eavesdropper.

  FIG. 18 shows a connection parameter transmission / reception procedure using DH key exchange and common key encryption. In the figure, first, wireless device A and wireless device B send each other's public key to a connection partner using a public key exchange frame. Next, a session key is generated from the public key received from the other party and the private key that the user has.

  Next, the wireless device A encrypts a connection parameter using the session key by an AES (Advanced Encryption Standard) method that is a common key encryption, and sends it to the wireless device B that is a connection partner using a Parameters frame.

  On the other hand, when the wireless device B receives the connection parameter, the wireless device B returns a Parameters reply frame to confirm the reception and notify the error when the notified encryption method is not supported. Although omitted in FIG. 18, the wireless device A on the connection parameter transmission side retransmits the Parameters frame according to the contents of the Parameters reply frame, or retransmits after changing the encryption method.

  In this way, after the exchange of connection parameters common to the wireless devices A and B, that is, the SSID and the encryption key, is completed, the IEEE 802.11 connection is made using the exchanged connection parameters (FIG. 12). checking).

  In normal IEEE 802.11 connection operation, when a wireless device newly forms a BSS, the SSID is scanned in all channels, set to the found channel, and a 6-byte identifier uniquely assigned to each BSS. A procedure for setting a certain BSSID (Basic Service Set Identification) in the hardware is taken. That is, a procedure for obtaining a channel and BSSID necessary for connection using the SSID as a key is performed.

  In many wireless LAN interface firmware and drivers, when configuring an ad hoc BSS, only the SSID and the encryption key are specified. However, the above-mentioned IEEE 802.11 scan is also specified by specifying the channel and BSSID. Some of the actions can be omitted. Therefore, by including the channel and BSSID in addition to the SSID and encryption key in the Parameters frame, the scan operation of IEEE 802.11 can be omitted when the corresponding wireless LAN interface is used, so that the connection can be made in a shorter time. I have to.

B-4. Transmission of User Data When wireless connection is performed according to the procedure shown in FIG. 12, user data exchanged between wireless devices to be connected to each other can be transmitted on an IEEE 802.11 frame. The IEEE 802.11 frame is classified into a control frame, a data frame, and a management frame. Of course, other special types of frames can be defined and user data can be exchanged using these frames. However, in the following, user data will be exchanged using the existing Management frame. explain.

  The Management frame includes a frame for notifying BSS information, a frame for connection, and authentication, but in this embodiment, user data is put in a Probe Request and Probe Response frame for notifying BSS information. ing.

  The Existence frame is a frame that is transmitted to a broadcast address by the scanning wireless device without designating a reception partner (in other words, toward a plurality of wireless devices at the same time). One Existence response frame is a frame that is returned when the wireless device receives the Existence frame. The scanning-side wireless device can transmit an Existence frame using the Probe Request frame, and the scanned-side wireless device can reply using the Probe Response frame using the Existence response frame. In general, the Probe Request frame is used for the terminal station to collect information necessary for active scanning, that is, participation from the access point to the BSS under the infrastructure mode (described above).

  FIG. 19 shows the frame formats of the probe request and the probe response frame, respectively. However, FIG. 19A shows a normal Management frame configuration, and FIG. 19B shows a Management frame including user data.

  As shown in the figure, the Probe Request is composed of elements of a MAC header, an SSID, and a supported rate. On the other hand, the Probe Response includes elements such as a MAC header, a Timestamp, a Beacon interval, a capability information, an SSID, a supported rate, and a DS Parameter Set. Among these, each element of SSID, Supported rate, and DS Parameter Set has a format called IE (Information Element). The IE format includes 1-byte ElementID, 1-byte Length, and variable-length Information.

  In addition to the above-mentioned elements, the probe response frame element may include various IEs such as an extended rate and a WPA IE.

  The purpose of the IE is identified by ElementID. An IE whose Element ID is 221 (0xDD) can be used as a Vendor Specific IE, so that the user data to be exchanged between wireless devices to be connected can be described in this field in this embodiment. ing. However, since the length indicating the length of the IE is only 1 byte, the length of the information is limited to a maximum of 255 bytes. Since user data exchanged between wireless devices to be connected includes information of various types and various lengths, 255 bytes is not sufficient. Therefore, a plurality of Vendor Specific IEs are included in one frame, and user data is divided and transmitted. Therefore, the user data packet creation means 2 in FIG. 8 includes a fragment part (not shown) for dividing user data, and the user data extraction means 4 reconstructs the divided user data. It is assumed that a defragmenter (not shown) is provided. Packet fragmentation and defragmentation are defined in, for example, the Internet Protocol (IP). Fragment is a function that originally transfers a packet by dividing it into an MTU (Maximum Transfer Unit) size or less.

  In the wireless LAN interface, hardware that has a function of sending a frame describing a freely created Vendor Specific IE on a Probe Request or Probe response, and notifying the driver of the Vendor Specific IE from the received frame; There are firmware and driver products. Therefore, in this embodiment, such a product may be used. Even in the case of a product without such a function, if user data is exchanged using IE, there is no need to define a new IEEE802.11 frame. Less changes are required.

B-5. Following determination of the channel arrangement, explain in detail how to determine the channel used in the wireless apparatus shown in FIG. As described above, the wireless device shown in FIG. 9 requires real-time capability that does not allow packet delay based on information about the application being used by the wireless device that is a candidate for the connection partner and the wireless bandwidth used by the application. New wireless device channels so that there is no waste of channels and communication failures are reduced while considering such conditions, by dividing them into streaming communications and best-effort communications that use the maximum bandwidth in bursts. Perform placement.

  Here, the communication of the camera and the communication of the music player can be cited as applications of the wireless device. In the following description, it is assumed that the camera has a best-effort photo exchange application and the music player has a best-effort playlist exchange application and a music stream application.

  In the present embodiment, an application running on an existing wireless device can be known by exchanging an Existence frame and an Existence response frame at the time of the first scan of the wireless device. Therefore, it is possible to know the type of communication performed in the existing BSS from this information. Of course, information that explicitly indicates the type of communication may be included. Further, in the above assumed environment, since the streaming application is only the music stream of the music player, it is uniquely determined how many pairs of communication are possible for one channel. However, in another example, a completely different device may stream the video. In this case, since it is necessary to know the band used by each device, it is necessary to include information including specific numbers of used bands in the user data.

  FIG. 20 shows, in the form of a flowchart, the processing procedure for the wireless device to determine the channel arrangement using the information of the application used by the surrounding wireless devices.

  First, the wireless device sequentially transmits an Existence frame to a broadcast address that does not designate a receiving party in each channel, and receives an Response frame returned from a peripheral wireless device, thereby performing a scanning operation. This is performed (step S81).

  If the BSS does not exist yet (No in step S82), it is decided to use the channel currently set by the wireless device (step S91), and this processing routine ends.

  If the BSS already exists (Yes in step S82), it is further checked whether or not the wireless device itself uses the best effort application (step S83).

  Here, when the wireless device itself uses the best effort application (Yes in step S83), the content of each received response is analyzed, and the same best effort as that of itself is detected in the detected existing BSS. It is checked whether there is any BSS (step S84).

  If the same best effort BSS as that of the user already exists (Yes in step S84), it is decided to use the same channel as that of the existing best effort BSS (step S85). finish.

  On the other hand, if the same best effort BSS as that does not exist yet (No in step S84), it is checked whether there is an empty channel (step S86). If there is an empty channel, the wireless device determines to use the channel (step S92), and if there is no empty channel, determines to use the currently set channel (step S91).

  The “vacant channel” here does not mean that there is no wireless device using the channel, but means that there is no wireless device implementing the protocol according to the present embodiment. Even in a situation where a normal control station (AP) or an ad hoc BSS exists, it is considered as an “empty channel”.

  In addition, although it has been confirmed that the BSS already exists (Yes in Step S82), when the wireless device itself does not use the best effort application (when the streaming application is used) (Step S83). No), it is checked whether there is any existing BSS performing streaming communication (step S87).

  When there is already a BSS for streaming communication (Yes in step S87), it is checked whether or not the necessary bandwidth is sufficient on the channel used by this existing BSS (step S88). Is determined to be used (step S89), and this processing routine is terminated.

  Here, whether or not “the necessary bandwidth is sufficient” is determined by subtracting the bandwidth used by the radio apparatus that has already formed the BSS from the maximum bandwidth that can be used in one radio channel. Judgment is made based on whether or not there is a remaining bandwidth that you are trying to use.

  In addition, when the wireless device itself performs streaming communication but no existing BSS performs streaming communication (No in step S87), the BSS that performs streaming communication uses the BSS. When the necessary bandwidth of the wireless device cannot be secured on the channel (No in step S88), it is checked whether there is a free channel (step S90). The empty channel check performed here is the same as the process performed in step S86.

  If there is an empty channel (Yes in step S90), the wireless device determines to use the channel (step S92), but if there is no empty channel (No in step S90), the error is in use of the channel. Handle (step S93).

  According to the processing procedure shown in FIG. 20, even if there is a channel for which no wireless communication is performed, the wireless device may daringly select a channel that has already been used. It should be appreciated that such a selection is made to optimize the utilization efficiency of the entire band including all channels.

B-6. Realization of Power Management IEEE 802.11 defines a Power Save mode in which a wireless device operates a receiver intermittently, and power management can be realized in both infrastructure mode and ad hoc mode (described above). ).

  Under infrastructure mode, the control station can always receive radio waves without going to sleep, so the terminal station can communicate only if it is released when it is scanning. There will be no obstacles. On the other hand, in the ad-hoc mode, even if the terminal station on the scanning side cancels the sleep state, if the existing terminal station to be scanned is in the sleep state, depending on the timing, the scan packet There is a problem of not being able to receive.

  Therefore, in the present embodiment, the wireless device on the scanning side introduces a procedure for invalidating the operation in which the surrounding wireless devices transition to the Doze state prior to scanning, and the wireless device on the scanning side is for scanning. And packets for exchanging user data as described above can be reliably received.

  Hereinafter, a scan operation performed by the wireless apparatus having the functional configuration illustrated in FIG. 10 in the Power Save mode will be described.

  It is assumed that each scanning device and each wireless device to be scanned are mounted with ad hoc PM (Ad-hoc Power management) defined in IEEE 802.11. A wireless device in which power management is implemented can select two operations of a CA (Continuous Active) mode and a PS (Power Save) mode. FIG. 24 shows a state transition diagram of the wireless device related to power management. The mode selection is normally specified by the user using the wireless device.

  The CA mode is a mode in which the receiver is always moved. In PS (Power Save) mode, the radio is dynamically set to two states, an active state and a doze state. In the active state, the wireless device is energized, and can receive packets but consumes power. On the other hand, in the Doze state, the radio power is kept to a minimum, and packets cannot be received.

  When the wireless device is in the Power Save mode, if there is no communication, the wireless device is in the Active state from the beacon transmission time TBTT to the end of the ATIM Window period, and the next beacon transmission from the end of the ATIM Window. The state is in the Doze state until the time TBTT (described above). Therefore, in a state where there is no communication, the wireless device under the Power Save mode can receive a packet only during the ATIM Window period. For example, when the beacon interval is set to 100 milliseconds and the ATIM Window is set to 10 milliseconds, 90% of packets randomly transmitted from the wireless device on the scanning side cannot be received.

  Therefore, in this embodiment, the wireless device on the scanning side does not use the ATIM Window provided after the TBTT, but performs a procedure for invalidating the operation in which the surrounding wireless devices transition to the Doze state prior to scanning. The wireless device to be scanned can reliably receive a packet for scanning and a packet for exchanging user data as described above.

  Specifically, the wireless device on the scanning side transmits a continuous reception mode request packet that serves as a trigger for the surrounding wireless devices to enter a continuous reception state prior to scanning. On the other hand, when a wireless device already configuring the network receives the continuous reception mode request packet, it changes its state to the constant reception mode and temporarily cancels the Power Save mode (or enters the Doze state under the Power Save mode). Prohibit transition). Since the receiver is not in the Doze state in this way, a packet for exchanging user data as described above transmitted by a wireless device that cannot use the Power Save mode before configuring the IEEE 802.11 network is as follows. It will not be impossible to receive.

  FIG. 21 shows an example of a communication sequence for the scanning wireless device to invalidate the Doze state of the surrounding wireless devices.

  In the figure, the wireless device A is about to scan. On the other hand, the wireless device B has already formed an ad hoc PM BSS with another wireless device (not shown), is currently in the Power Save mode, and appropriately switches between the Doze state and the Active state.

  First, the wireless device A enables the “continuous reception mode request packet transmission function”. This function is implemented by some wireless LAN interface firmware and drivers, monitors the size of the ATIM Window included in the beacon, and enters the Power Save mode if the ATIM Window size is set. The continuous reception mode request packet is transmitted during the period of the ATIM Window. This continuous reception mode request packet is transmitted as user data using a Probe Request (described above).

  When the data processing means of the wireless device B receives the continuous reception mode request, it sends a continuous operation instruction to the packet transmission means 3 and the packet reception means 4, invalidates the Doze state, and is always in the Active state even in the Power Save mode. To enable packet reception.

  When the wireless device A finds a plurality of BSSs, the wireless device A transmits a continuous reception mode request packet in accordance with these beacons, so that the wireless devices belonging to the BSSs of all the ad hoc PMs finally enter the active state. be able to.

  In this way, after all the peripheral wireless devices are kept in the Active state, connection processing such as user data exchange is executed according to the procedure shown in FIG. 12, so that scan packets are not missed. .

  In the procedure shown in FIG. 21, while the user data such as the confirmation of the connection partner and the connection parameters are exchanged, the wireless device to be scanned always maintains the active state even in the power save mode. This prevents the user data from being missed from the wireless device on the scanning side.

  In the above description, the channel changing operation is omitted for the sake of simplification. However, when scanning is performed, the same operation as described above is performed in all the channels used. When scanning, the “continuous reception mode request packet transmission function” is first enabled for each channel in order to set the receiving side of all channels to the active state, and then again on each channel. A scan may be performed by transmitting a frame.

  Although not shown in FIG. 21, the wireless device B that is to be scanned continues to consume the same amount of power as in the CA mode, so it must return to the original normal PS mode. For example, the following two triggers are conceivable for the wireless device B to return to the PS mode.

  The first trigger is after exchanging connection parameters with the wireless device A. Thereafter, since the wireless device A performs a normal IEEE 802.11 ad hoc PS connection in synchronization with the BSS beacon including the wireless device B, packets can be exchanged according to the ad hoc PS procedure. For this reason, the wireless device B does not always need to be in the active state after exchanging connection parameters with the wireless device A.

  A second trigger for returning the wireless device B to the PS mode can be a timeout. Wireless device B is brought into the Active state by wireless device A, but eventually wireless device A may not participate in the BSS of wireless device B. In this case, the wireless device B needs to promptly cancel the invalidation of the Doze state and return to the normal PS mode. Therefore, if the exchange of user data for connection does not end even after a considerable amount of time has passed, the wireless device B returns to the PS mode.

  For example, when the wireless device is a camera, if the connection timeout is 3 seconds based on the judgment condition when 3 units are simultaneously pressed, 6 seconds will be considered when the exchange button is pressed at the timing of just 3 seconds, and then Considering the packet exchange time for connection, the timeout value is 8 seconds. In the case of a music player, since it is impossible to predict the time until the user selects a peripheral wireless device found in the first scan, the timeout value is set to 3 seconds and the power save mode is immediately returned (or The invalidation of the Doze state may be canceled).

  Although not shown in FIG. 18, after the user designates the connection partner and before transmitting the public key exchange frame, the “continuous reception mode request packet transmission function” is enabled again, and the wireless device B is activated. The state is set so that subsequent exchanges are not missed.

  In addition to the above-described two triggers, if the wireless device that performed the scan does not participate in the discovered BSS, it sends user data indicating cancellation, and enters this into the normal PowerSave mode using this as a trigger ( Alternatively, the prohibition of the Doze state may be canceled).

  The present invention has been described in detail above with reference to specific embodiments. However, it is obvious that those skilled in the art can make modifications and substitutions of the embodiment without departing from the gist of the present invention.

  In the present specification, the embodiment applied to a wireless network defined in IEEE 802.11 has been mainly described, but the gist of the present invention is not limited to this. By applying the present invention to various wireless communication systems in which a plurality of radio frequency bands that can be used for communication are allocated as channels and each wireless device operates autonomously while enabling power management operation, a network can be obtained. The channel arrangement is determined so that the whole is efficient, and wireless devices before connection can search for an appropriate connection partner in advance, and information necessary for connection can be designated in common by a simple procedure.

  In short, the present invention has been disclosed in the form of exemplification, and the description of the present specification should not be interpreted in a limited manner. In order to determine the gist of the present invention, the claims should be taken into consideration.

FIG. 1 is a diagram schematically illustrating a hardware configuration of a wireless device capable of performing a communication operation in a wireless network according to the present invention. FIG. 2 is a diagram schematically illustrating another hardware configuration example of a wireless device capable of performing a communication operation in the wireless network according to the present invention. FIG. 3 is a diagram showing an internal configuration of the wireless LAN interface unit 110. FIG. 4 is a diagram showing a configuration example of a radio system in which an infrastructure mode BSS is configured by using a plurality of radio apparatuses shown in FIG. 1 or FIG. FIG. 5 is a diagram illustrating a configuration example of a wireless system in which an ad hoc mode BSS configured by using a plurality of wireless devices illustrated in FIG. 1 or FIG. 2 is formed. FIG. 6 is a diagram illustrating a state in which photo exchange is performed using a wireless network when the wireless device is a digital camera. FIG. 7 is a diagram illustrating a state in which music exchange or playlist exchange is performed using a wireless network when the wireless device is a music player. FIG. 8 is a block diagram illustrating a functional configuration example of the wireless device. FIG. 9 is a diagram illustrating a modification of the wireless device illustrated in FIG. 8. FIG. 10 is a diagram showing still another modification of the configuration shown in FIG. FIG. 11 is a flowchart illustrating a processing procedure of the wireless device for performing wireless connection. FIG. 12 is a sequence diagram for exchanging user data between the wireless device A and the wireless device B for wireless connection. FIG. 13 is a flowchart showing a processing procedure performed by a wireless device that newly joins a network or a wireless device that first configures the network, in order to determine a wireless device that simultaneously presses buttons as a connection partner. FIG. 14 is a flowchart illustrating a processing procedure performed by a wireless device that newly joins a network or a wireless device that first configures the network, for allowing the user to select a connection partner. FIG. 15 is a diagram illustrating a challenge-response communication sequence. FIG. 16 is a flowchart illustrating a processing procedure for setting the level value of the wireless device. FIG. 17 is a flowchart showing a procedure of connection parameter transmission / reception determination processing in which a level value is introduced. FIG. 18 is a sequence diagram showing a connection parameter transmission / reception procedure using DH key exchange and common key encryption. FIG. 19A is a diagram showing the frame format of the Probe Request and Probe Response frames (however, a normal Management frame configuration). FIG. 19B is a diagram showing the frame format of the probe request and probe response frames (however, the management frame structure including user data). FIG. 20 is a flowchart illustrating a processing procedure for a wireless device to determine a channel arrangement using information on applications used by peripheral wireless devices. FIG. 21 is a diagram illustrating a communication sequence example for the scanning side wireless device to invalidate the Doze state of the surrounding wireless devices. FIG. 22 is a diagram illustrating an operation example of IEEE 802.11 in the infrastructure mode. FIG. 23 is a diagram illustrating an operation example of IEEE 802.11 in the ad hoc mode. FIG. 24 is a state transition diagram of a wireless device related to power management.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Data processing means 2 ... User data packet preparation means 3 ... Packet transmission means 4 ... User data extraction means 5 ... Packet reception means 6 ... Connection control means 7 ... Channel setting means 11, 21, 24, 31-35 ... Wireless devices 41, 51 ... Cameras 42, 52 ... Exchange buttons 61, 71, 81 ... Music players 62, 72, 82 ... Display devices 63, 73 ... Selection buttons 64, 74 ... Decision buttons 101 ... CPU
102 ... ROM
103 ... RAM
104 ... Peripheral device 105 ... External storage device 106 ... Wireless LAN interface 107 ... I / O interface 110 ... Wireless LAN interface 111 ... CPU
112 ... ROM
113 ... RAM
118 ... I / O interface 119 ... Wireless transceiver

Claims (32)

A wireless communication system including a plurality of wireless devices that perform packet communication on a channel that can be used for communication,
User data exchange means for exchanging user data between wireless devices before forming a network,
When a wireless device forms a network or joins an existing network, it scans the channel and searches for surrounding wireless devices, and arbitrary information for confirming a connection partner from the found wireless device User data including data, determining a wireless device to be connected based on the user data, and including user parameters including connection parameters necessary for wireless connection with the wireless device to be connected And connecting between wireless devices using the exchanged connection parameters,
A wireless communication system. The user data for confirming the connection partner includes an application operating on the wireless device or a data communication method used in the application, or information on a user of the wireless device.
The wireless communication system according to claim 1. The connection parameters required for the wireless connection include identification information of a network connecting the wireless devices and an encryption key for encrypting a communication path between the wireless devices.
The wireless communication system according to claim 1. There are several radio wave frequencies that can be used for communication, and they are allocated as channels.
The user data exchanged between the wireless devices at the time of the scan includes information on a currently used application or a use band of an application to be operated from now on,
The wireless device determines a channel to be set based on an application in which the wireless device operates and information identifying an application currently operating in each wireless device detected by scanning.
The wireless communication system according to claim 1. At least some wireless devices have a function to temporarily stop the operation of the receiver to save power,
The radio device to be scanned transmits a continuous reception mode request packet as user data according to a transmission rule in a predetermined power saving mode on a channel usable for the communication,
The surrounding wireless devices that have received the continuous reception mode request packet operate the receiver continuously,
The wireless device on the scanning side performs scanning using a period in which surrounding wireless devices continuously operate the receiver.
The wireless communication system according to claim 1. The wireless device on the scanning side transmits a scan frame as user data to a broadcast address that does not particularly specify a destination on the channel that can be used for communication, and the scan from surrounding wireless devices. Scanning by receiving user data as a response frame for the use frame,
The wireless communication system according to claim 1. The user data constituting the scan frame and the response frame to the scan frame includes information about an application running on the wireless device, or information about a user of the wireless device,
The wireless device on the scanning side evaluates the content of the response frame to determine the connection partner, or the wireless device on the scanning side evaluates the content of the scan frame to determine the connection partner ,
The wireless communication system according to claim 6. When a wireless device forms a network or joins an existing network, the connection partner is limited through a challenge-response procedure from among wireless devices that have been scanned and confirmed.
The wireless communication system according to claim 1. A determination means for determining which one of a set of wireless devices as connection partners generates or transmits a connection parameter;
The wireless communication system according to claim 1. When a wireless device newly joins in a situation where a network has already been formed, the determination unit determines that the wireless device already participating in the network is a connection parameter transmission source.
The wireless communication system according to claim 9. Under the infrastructure mode, the determination means determines that the wireless device serving as the control station is a connection parameter transmission source.
The wireless communication system according to claim 9. Under the ad hoc mode, the determining means is based on the MAC address of each wireless device, a random value generated for each wireless device, or other information that has no or very low possibility of being the same value. Determine the wireless device as the connection parameter source,
The wireless communication system according to claim 9. A public key exchange means for exchanging each other's public key as user data between wireless devices to be connected;
Each wireless device generates a session key based on its private key and the public key of the connection partner,
The wireless device that is the connection parameter transmission source encrypts and transmits the connection parameter using the session key, and the wireless device that is the connection parameter reception destination decrypts the received connection parameter with the session key.
The wireless communication system according to claim 1. There are several radio wave frequencies that can be used for communication, and they are allocated as channels.
The connection parameters required for the wireless connection include a channel and a basic network identifier,
The wireless device skips the scanning operation,
The wireless communication system according to claim 1. Each network is operated in accordance with the IEEE 802.11 standard,
The user data exchanging means exchanges user data using a Vendor Specific IE field of an IEEE 802.11 Management frame.
The wireless communication system according to claim 1. The scanning wireless device transmits a scan frame using a Probe Request frame, and the scanned wireless device returns a response frame using a Probe Response frame.
The wireless communication system according to claim 15. A wireless device that is a source of user data includes a plurality of Vendor Specific IEs in one frame, and fragments and transmits user data. A wireless device that is a recipient of user data Use the data defragmented,
The wireless communication system according to claim 15. The wireless device allocates another channel with a best-effort application that uses the maximum bandwidth in bursts and an application that requires real-time processing in which packet delay is not allowed.
The wireless communication system according to claim 4. Wireless devices running best-effort applications should form their networks on channels where existing best-effort networks exist,
The wireless communication system according to claim 4. When a wireless device that operates a streaming-type application can secure a necessary bandwidth in a channel where an existing streaming-type network exists, the wireless device forms a network on the channel.
The wireless communication system according to claim 4. The wireless device that has received the continuous reception mode request packet cancels the continuous operation of the receiver after exchanging user data including connection parameters necessary for wireless connection with the wireless device that is the connection partner. ,
The wireless communication system according to claim 5. If the wireless device that has received the continuous reception mode request packet does not finish exchanging user data for connection even after a considerable amount of time has passed for exchanging user data for connection, Cancel the continuous operation of
The wireless communication system according to claim 5. A wireless communication device that performs packet communication on a channel that can be used for communication,
Application data running on the wireless communication device or user data including arbitrary information that the user operating the wireless communication device wants to exchange with another wireless communication device is in the form of a predetermined user data packet User data packet creation means for conversion;
Packet transmitting means for wirelessly transmitting the user data packet created by the user data packet creating means as a management packet;
A packet receiving means for receiving a management packet wirelessly transmitted from another wireless communication device;
User data extracting means for extracting user data from a data packet portion included in the management packet received by the packet receiving means;
A connection control unit that joins an existing wireless network based on a network identifier and an encryption key or configures a new wireless network, and controls connection between the packet transmitting unit and the packet receiving unit with another wireless communication device;
Exchanging the user data with another wireless communication device as a connection candidate through the user data packet creating means and the user data extracting means, and determining a partner to be connected using the exchanged user data, Data processing means for setting the same network identifier and encryption key as the determined counterpart to be connected to the connection control means;
A wireless communication apparatus comprising: There are several radio wave frequencies that can be used for communication, and they are allocated as channels.
Channel setting means for setting a channel for wirelessly transmitting and receiving packets by the packet transmitting means and the packet receiving means;
The data processing means determines a channel to be set based on information on a currently used application or a use band of an application to be operated in the future, and instructs the channel setting means to set the channel;
24. The wireless communication apparatus according to claim 23. The user data packet creation means converts user data including information on a bandwidth currently used by an application currently operating or an application to be operated into a packet format,
The user data extraction unit extracts user data including information on a currently used application or a band used by an application to be operated from the packet received by the packet reception unit.
25. The wireless communication apparatus according to claim 24. A wireless communication device having a power saving function for temporarily stopping the operation of a receiver and performing packet communication on a channel usable for communication,
Data transmission means for wirelessly transmitting data;
Data receiving means for receiving data wirelessly transmitted from another wireless communication device;
Data processing means for controlling transmission / reception data processing by the data transmission means and the data reception means, and operations of the data transmission means and the data reception means based on the processing results,
The data processing means includes
Prior to the scanning operation, the data transmission means is instructed to transmit a continuous reception mode request packet for requesting a continuous reception operation to another wireless communication device,
In response to receiving the continuous reception mode request packet in the data reception means, the data reception means is instructed to perform a continuous reception operation, and then a predetermined condition is satisfied or a predetermined time has elapsed. Sometimes instructing the receiving means to perform an intermittent receiving operation,
The data transmission means transmits a continuous reception mode request packet according to a predetermined transmission rule in a power saving mode in response to an instruction to transmit a continuous reception mode request packet from the data processing means,
The data receiving means performs a continuous receiving operation in response to an instruction of continuous receiving operation from the data processing means, and intermittently in response to an instruction of intermittent receiving operation from the data processing means. Receive operation,
A wireless communication apparatus. The data transmission means includes user data packet creation means for converting user data including arbitrary information that the user wants to exchange with another wireless communication device into a predetermined user data packet format, and the user data A packet transmission means for wirelessly transmitting the user data packet created by the packet creation means as a management packet;
The data receiving means is a packet receiving means for receiving a management packet wirelessly transmitted from another wireless communication device, and user data from a data packet part included in the management packet received by the packet receiving means. Comprising user data extraction means for retrieving;
27. The wireless communication apparatus according to claim 26. Perform wireless communication operation in accordance with the IEEE 802.11 standard,
Each of the packet transmission means and the packet reception means exchanges user data using a Vendor Specific IE field of an IEEE 802.11 Management frame.
The wireless communication apparatus according to claim 23 or 27, wherein A wireless communication method for performing packet communication on a channel usable for communication,
Application that performs packet communication or user data packet that converts user data including arbitrary information that a user instructing execution of the application wants to exchange with another wireless communication device to a predetermined user data packet format Creation steps,
A packet transmission step of wirelessly transmitting the user data packet created in the user data packet creation step as a management packet;
A packet receiving step of receiving a management packet wirelessly transmitted from another wireless communication device;
A user data extracting step of extracting user data from a data packet portion included in the management packet received in the packet receiving step;
A connection control step of joining an existing wireless network based on the network identifier and the encryption key or configuring a new wireless network to control connection with other wireless communication devices;
The user data is exchanged with other wireless communication devices that are connection candidates, the other party to be connected is determined using the exchanged user data, and the same network identifier and encryption key as the determined other party to be connected are determined. A data processing step to be set in the connection control step;
A wireless communication method comprising: A wireless communication method for realizing a power saving function for temporarily stopping the operation of a receiver and performing packet communication on a channel usable for communication,
Prior to the scan operation, transmitting a continuous reception mode request packet for requesting a continuous reception operation to another wireless communication device;
Transmitting a continuous reception mode request packet according to a predetermined transmission rule in the power saving mode;
Performing a continuous reception operation in response to receiving a continuous reception mode request packet;
A step of starting an intermittent reception operation when a predetermined condition is satisfied or a predetermined time has elapsed when performing a continuous reception operation;
A wireless communication method comprising: A computer program written in a computer-readable format to execute processing for performing packet communication on a channel usable for communication on a computer,
Application that performs packet communication or user data packet that converts user data including arbitrary information that a user instructing execution of the application wants to exchange with another wireless communication device to a predetermined user data packet format Creation procedure and
A packet transmission procedure for wirelessly transmitting a user data packet created by executing the user data packet creation procedure as a management packet;
A packet reception procedure for receiving a management packet wirelessly transmitted from another wireless communication device;
A user data extraction procedure for extracting user data from a data packet portion included in a management packet received by executing the packet reception procedure;
A connection control procedure for joining an existing wireless network or configuring a new wireless network based on a network identifier and an encryption key, and controlling connection with other wireless communication devices;
The user data is exchanged with other wireless communication devices that are connection candidates, the other party to be connected is determined using the exchanged user data, and the same network identifier and encryption key as the determined other party to be connected are determined. A data processing procedure to be set in the connection control procedure;
A computer program for executing A computer described in a computer-readable format so as to execute a process for performing packet communication on a channel that can be used for communication while realizing a power saving function for temporarily stopping the operation of the receiver. A program for the computer
Prior to the scanning operation, a procedure for transmitting a continuous reception mode request packet for requesting a continuous reception operation to another wireless communication device;
A procedure for transmitting a continuous reception mode request packet according to a predetermined transmission rule in the power saving mode;
In response to receiving the continuous reception mode request packet, a procedure for performing a continuous reception operation;
A procedure for starting an intermittent reception operation when a predetermined condition is satisfied or a predetermined time has elapsed when performing a continuous reception operation;
A computer program for executing