WO2017002996A1 - Airtime control method in wireless lan network - Google Patents

Abstract

The present invention relates to a technique for a wireless LAN AP controlling uplink/downlink airtime, preferably for each SSID, in a wireless LAN network having the wireless LAN AP and one or more stations connected thereto. More specifically, the present invention relates to a technique for setting a critical time for each preset airtime management cycle (e.g.: 100 msec bitframe), comparing uplink/downlink airtime monitored in real-time with each critical time, and if the monitored airtime exceeds the critical time, accordingly controlling the traffic of a wireless LAN network so that the uplink/downlink airtime is adjusted. According to the present invention, a merit is that uplink/downlink airtime is selectively controlled for each SSID, and thus communication quality (QoS) that is equivalent to or better than a certain degree may be guaranteed to a user who is part of a specific service group (e.g.: a specific SSID).

Description

Air time control method in WLAN network

The present invention relates to a technology in which a WLAN AP controls uplink / downlink air time by SSID in a WLAN network in which one or more stations are connected.

More specifically, the present invention sets a threshold time for each preset air time management period (e.g., 100 msec bit frame), compares each threshold time with real-time monitored uplink / downlink air time, and monitors the monitored air. The present invention relates to a technique for controlling uplink / downlink airtime by controlling traffic of a WLAN network when the time exceeds a threshold time.

It is very difficult to properly manage wireless traffic in a WLAN network in which a WLAN AP and multiple stations are connected. When some stations generate excessive traffic, other stations connected to the same WLAN AP may experience a significant performance degradation. You will feel it. If a plurality of users are connected to one WLAN AP, such as a cafe, this often occurs.

Stations connected to one WLAN AP share a network resource such as an air medium and a WLAN AP. Thus, when some stations excessively occupy network resources, problems occur in other stations.

Such a relationship also occurs between the uplink and the downlink. If excessive traffic occurs on either the uplink or the downlink, the WLAN communication cannot be properly processed on the other side. In particular, if uplink traffic is excessively used, IP set-top boxes that mainly utilize downlink traffic may not provide reliable services.

In order to solve some of these problems, conventionally, a method of differentially allocating throughput (throughput, amount of data transmitted per unit time) for each SSID has been attempted. The purpose of this is to differentially allocate throughput by SSID to suppress traffic of SSID with low throughput and to ensure stable communication service for SSID with high throughput.

However, when the traffic is transmitted at a low bit rate due to device performance problem on the side where the low throughput is allocated, the network resource is consumed in spite of the small amount of data transmitted per unit time. As a result, the other SSID side has a problem that the data can not be properly transmitted and received even though the throughput is allocated high.

Accordingly, there is a demand for a technology capable of stably guaranteeing wireless communication performance of other stations even when some of a plurality of stations connected to one WLAN AP attempt to generate excessive traffic. The present invention attempts to solve this problem in terms of airtime rather than dealing with throughput in the prior art. However, controlling the airtime in a WLAN network is very difficult and requires sophisticated technology.

On the other hand, the prior art literature found by the applicant in relation to the present invention is as follows.

1. Republic of Korea Patent Application No. 10-2007-7024178 "Medium time allocation and scheduling using super-zone structure of super-zone structure to provide QOS in wireless LAN network"

2. Korean Patent Application No. 10-2004-0060165 "Mobile IP system and method using diameter based dynamic IP allocation in broadband wireless access communication system such as WiBro"

3. Republic of Korea Patent Application No. 10-2011-0047920 "Channel selection and communication method considering the interference of Wi-Fi in multi-channel wireless sensor network"

4. Korean Patent Application No. 10-2008-0137787 "Network sharing method and system of mobile communication terminal with Wi-Fi function"

5. Republic of Korea Patent Application No. 10-2010-0105168 "Method and apparatus for transmitting WLAN network sharing data in Wi-Fi P2P group"

6. Korean Patent Application No. 10-2009-0000466 "Differentiation method and apparatus for network connection path"

An object of the present invention is to provide a technique for controlling the uplink / downlink airtime by the SSID, preferably by the WLAN AP in the WLAN network to which the WLAN AP and one or more stations are connected.

In particular, an object of the present invention is to set the threshold time for each preset air time management period (e.g., 100msec bit frame) and compare each threshold time with the uplink / downlink air time monitored in real time, and the monitored air time is When the threshold time is exceeded, the technology to control the uplink / downlink air time by controlling the traffic of the WLAN network accordingly.

In order to achieve the above object, a first embodiment of the present invention is a method of controlling an uplink air time by a WLAN AP in a WLAN network in which a WLAN AP and one or more stations are connected. Setting an uplink threshold time for a management cycle; (b) monitoring uplink airtime in real time for each airtime management period in the WLAN network; (c) comparing the uplink airtime and uplink threshold time monitored in real time; (d) identifying an uplink overheat event in which real-time monitored uplink airtime exceeds an uplink threshold time; and (e) changing and broadcasting an environment parameter of the WLAN network in response to an uplink overheating event.

In this case, preferably, in step (a), a threshold time for each uplink SSID is individually set within a range of uplink threshold time for each of the plurality of SSIDs, and in step (b), an uplink is performed for each of the plurality of SSIDs. Individual real-time monitoring of airtime, comparing the uplink airtime monitored by SSID and the threshold time by uplink SSID in step (c), and the uplink airtime monitored by SSID in step (d) Identify an overheating event for each uplink SSID that exceeds a threshold time for each uplink SSID corresponding to the SSID, and change and broadcast an environment parameter of the WLAN network in response to the overheating event for each uplink SSID in step (e). .

Preferably, in step (e), the environmental parameter comprises one or more of the ECW parameter value and the AIFSN parameter value, and increases or decreases one or more of the ECW parameter value and the AIFSN parameter value in response to an uplink overheat event. Cast.

A second embodiment of the present invention is a method of controlling a downlink air time by a WLAN AP in a WLAN network to which a WLAN AP and one or more stations are connected, and (a) a downlink threshold for a preset airtime management period. Setting a time; (b) monitoring the downlink airtime in real time for each airtime management period in the WLAN network; (c) comparing the downlink airtime and downlink threshold time monitored in real time; (d) identifying a downlink overheat event in which real-time monitored downlink airtime exceeds a downlink threshold time; (e) stopping the downlink data transmission in the corresponding airtime management period in response to the downlink overheating event.

In this case, preferably, in step (a), each downlink SSID threshold time is individually set within the range of downlink threshold time for each of the plurality of SSIDs, and in step (b), downlink air is set for each of the plurality of SSIDs. Real-time monitoring of the time individually, comparing the downlink air time monitored by the SSID in real time by the SSID and the threshold time for each downlink SSID in step (c), and the downlink air time monitored by the SSID in step (d) by the corresponding SSID Identify overheating events for each downlink SSID that exceed a threshold time for each downlink SSID corresponding to and transmit downlink data in a corresponding airtime management cycle of the corresponding SSID in response to the overheating events for each downlink SSID in step (e). Abort.

In addition, after step (e), (f) resuming downlink data transmission interrupted in the next airtime management cycle; preferably further comprises a.

On the other hand, the computer-readable recording medium according to the present invention records a program for executing the airtime control method in the WLAN network as described above.

According to the present invention, there is an advantage of controlling uplink / downlink airtime in a WLAN network.

In addition, according to the present invention, by selectively controlling the uplink / downlink air time for each SSID, there is an advantage of ensuring a communication quality (Qos) of a certain level or more to a user belonging to a specific service group (for example, a specific SSID).

1 is an exemplary diagram of an overall configuration for airtime control in a WLAN network according to the present invention;

2 is an exemplary diagram illustrating a menu for setting a threshold of uplink / downlink airtime and a menu for setting a threshold of uplink / downlink airtime for each SSID in a WLAN AP according to the present invention;

3 is an exemplary view illustrating a process of measuring uplink airtime in real time according to the WLAN data reception according to the present invention;

4 is an exemplary view illustrating a process of measuring downlink airtime in real time according to wireless LAN data transmission in the present invention;

5 is an exemplary diagram illustrating a WLAN environment parameter for changing a setting to control an uplink airtime according to the present invention;

6 is an exemplary diagram illustrating a concept of managing downlink airtime for each SSID according to an airtime management cycle according to the present invention;

7 is a flowchart illustrating a process of controlling uplink airtime in a WLAN network according to the present invention;

8 is a flowchart illustrating a process of controlling downlink airtime in a WLAN network according to the present invention.

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

1 is an exemplary diagram of an overall configuration for airtime control in a WLAN network according to the present invention. Referring to FIG. 1, a WLAN AP according to the present invention performs uplink and downlink while wirelessly communicating with a plurality of stations STA_1 to STA_9 within WLAN coverage.

A plurality of stations STA_1 to STA_9 connected to one WLAN AP share and share common network resources, that is, a transmission medium and a processor of the WLAN AP. Accordingly, a larger uplink air time results in less air time available for the downlink and conversely, a larger down link air time results in less air time available for the uplink. Similarly, if some stations take up a lot of airtime, the airtime available to other stations is reduced.

Accordingly, in the present invention, the WLAN AP sets and controls the ratio or threshold of air time that the uplink or downlink may occupy, thereby preventing the other from being greatly disturbed by either of the uplink and the downlink. Preferably, such airtime control may be performed for each SSID. Through this, a plurality of stations connected to one WLAN AP can perform WLAN communication in harmony without being excessively disturbed by each other.

Here, the physical layer of the WLAN AP may provide an application program interface (API) that calculates airtime of individual traffic and provides a result value to hardware or software.

2 is an exemplary diagram illustrating a menu for setting a threshold of uplink / downlink airtime and a menu for setting a threshold of uplink / downlink airtime for each SSID in a WLAN AP according to the present invention.

Referring to (a) of FIG. 2, the WLAN AP separately sets thresholds (uplink threshold time and downlink threshold time) of uplink air time and downlink air time, for example, 70% and 30, respectively, through the operation of an administrator. Can be set to%.

In addition, referring to FIG. 2B, when the WLAN AP provides a plurality of SSIDs, a threshold time ratio for the uplink for each of the plurality of SSIDs (eg, SSID_A = 60% and SSID_B) for each airtime management period. = 30%, SSID_C = 10%) can be set for each SSID, and the threshold time rate for the downlink (eg, SSID_A = 50%, SSID_B = 30%, SSID_C = 20%) can also be set for each SSID.

For example, if the airtime management period is '100 msec' corresponding to one beacon frame, when the threshold time ratio for the uplink is 60% for SSID_A, 30% for SSID_B, and 10% for SSID_C, the uplink The threshold time for means that SSID_A is assigned as 60 msec, SSID_B is 30 msec, and SSID_C is 10 msec.

In the present invention, a period for managing whether the air time of the uplink or the downlink exceeds a preset threshold, that is, the 'airtime management period' is set to an integer multiple of the WLAN beacon frame. For example, a beacon frame of 100 msec may be set as an airtime management period, as described above. In addition, three beacon frames may be set as an airtime management cycle. In this case, the airtime management period is '300 msec'. If the critical time rate for the uplink is SSID_A 60%, SSID_B is 30%, and SSID_C is 10%, the threshold time for the uplink is 180 msec. This means that SSID_B is allocated as 90 msec and SSID_C as 30 msec.

FIG. 3 is an exemplary view illustrating a process of measuring uplink airtime in real time according to WLAN data reception according to the present invention.

Referring to FIG. 3, when the WLAN AP detects a packet reception from a station (CCA detect), it marks a time point (rx_start_time) of an individual uplink air time and then completes data reception on a packet basis (CCA End). If this is detected, the end point (rx_end_time) of the individual uplink airtime is marked.

The uplink air time required to receive one packet or data can be calculated by subtracting the uplink air time start point (rx_start_time) from the end point of the uplink air time (rx_end_time).

Individual uplink airtimes are summed over the airtime management cycle (eg one beacon frame) to check whether the uplink airtime exceeds the preset threshold (uplink threshold time) in that airtime management cycle. .

In this case, the WLAN AP may classify and manage uplink airtimes by SSID (for example, SSID_A, SSID_B, and SSID_C). As a result, as described above with reference to FIG. 2B, it is possible to check whether the uplink air time exceeds the uplink threshold time set for each SSID.

4 is an exemplary view illustrating a process of measuring downlink airtime in real time according to the wireless LAN data transmission in the present invention.

Referring to FIG. 4, when the WLAN AP detects a packet transmission request to a station (Tx Start), it starts the packet transmission accordingly and marks the time point (tx_start_time) of the individual downlink airtime, and then in a packet unit. When data transmission is completed (Tx End (OK)) or transmission failure is identified (RetryLimit), it is detected and marks the end point (tx_end_time) of the individual downlink airtime.

Then, by subtracting the start time (tx_start_time) of the downlink air time from the end point (tx_end_time) of the downlink air time, the downlink air time required to transmit one packet or data can be calculated.

The individual downlink airtimes are summed over the airtime management period (eg one beacon frame) to check whether the downlink airtime exceeds the preset threshold (downlink threshold time) in that airtime management period. .

In this case, the WLAN AP may manage downlink airtimes by SSID (for example, SSID_A, SSID_B, and SSID_C). As a result, as described above with reference to FIG. 2B, it is possible to check whether the downlink air time exceeds the uplink threshold time set for each SSID.

5 is an exemplary diagram showing a WLAN environment parameter for changing the configuration to control the uplink air time according to the present invention. Referring to FIG. 5, the WLAN AP monitors the uplink airtime in real time, and if the actual uplink airtime identifies an uplink overheating event exceeding a preset uplink threshold time, the wireless AP may be mitigated. Broadcast by changing and setting environment parameters ('WLAN environment parameters') of LAN network.

Here, the WLAN environment parameter set by the WLAN AP includes one or more of an ECW parameter value and an AIFSN parameter value. By setting and changing these parameter values, uplink airtime can be controlled by adjusting the density at which multiple stations transmit data to the WLAN AP.

For example, setting and changing ECW parameter values increase or decrease the time delay in packet retransmission due to collision in the time range of 2 ^ECWmn to 2 ^{ECW max} . That is, if the value of 'ECWmin' or 'ECWmax' is increased, a random retransmission delay time is increased when a physical layer collision occurs while an individual station transmits a packet to a WLAN AP. The result is a reduction in the actual uplink airtime incurred.

On the contrary, if the value of 'ECWmin' or 'ECWmax' is reduced, a random retransmission delay time is reduced when a physical layer collision occurs while an individual station transmits a packet to a WLAN AP. The result is an increase in the actual uplink airtime incurred.

In addition, changing the setting of the AIFSN parameter value increases or decreases the time interval between frames when the station transmits data to the WLAN AP, thereby decreasing or increasing the actual uplink airtime caused by the station. Is derived.

6 is an exemplary diagram illustrating a concept of managing downlink airtime for each SSID according to an airtime management cycle according to the present invention.

Referring to FIG. 6, when the WLAN AP monitors downlink airtime in real time and identifies a downlink overheating event whose actual downlink airtime exceeds a preset downlink threshold time, the corresponding airtime management cycle ( Example: downlink data transmission at 100 msec) is stopped.

In this case, the WLAN AP may monitor downlink airtime for each SSID (eg, SSID_A, SSID_B, SSID_C), and set downlink threshold times (eg, 50 msec, 30 msec, and 20 msec) for each SSID. have.

As a result, downlink overheating events can be identified by individual SSIDs, and downlink overheating events can be identified by individual SSIDs. As shown in FIG. 6, downlink data transmission is stopped within one airtime management cycle (cycle 1). Then, the suspended downlink data transmission is resumed in the next airtime management cycle (cycle 2).

For example, if the WLAN AP recognizes that the downlink threshold time (50 msec) has already been exhausted for the SSID_A during the first airtime management period while transmitting the data_A, the WLAN AP stops transmitting the data_A. Then, when the corresponding airtime management cycle elapses and the next airtime management cycle starts, the transfer of the interrupted data_A is resumed.

7 is a flowchart illustrating a process of controlling uplink airtime in a WLAN network according to the present invention.

Step S110: A first embodiment of the present invention is a method of controlling an uplink air time by a WLAN AP in a WLAN network in which a WLAN AP and at least one station are connected. Set the uplink threshold time (Th-uplink) for -airtime.

Meanwhile, when the WLAN AP has a plurality of SSIDs, threshold time (Th-uplink, SSID) for each uplink SSID may be individually set within a range of uplink threshold time for each of the plurality of SSIDs.

Steps S120 and S130: Monitor uplink airtime T-ul (t) in real time for each airtime management cycle in the WLAN network. Then, the uplink airtime and the uplink threshold time monitored in real time are compared.

In this case, when the WLAN AP has a plurality of SSIDs, the uplink air time may be individually monitored in real time for each of the plurality of SSIDs, and accordingly, the uplink air time and the uplink SSIDs for each SSID are monitored in real time. And to compare the threshold time.

Steps S140 and S150: If the uplink airtime monitored in real time identifies an uplink overheating event exceeding the uplink threshold time, the WLAN environment parameter is changed and broadcasted to mitigate the uplink overheating event.

In this case, when the WLAN AP includes a plurality of SSIDs, the uplink air time monitored for each SSID in real time may be configured to identify an overheat event for each uplink SSID that exceeds a threshold time for each uplink SSID corresponding to the corresponding SSID. Accordingly, in response to an uplink overheating event (hereinafter, referred to as 'uplink SSID overheating event') identified for each SSID, the WLAN environment parameter is changed and broadcasted.

Here, the WLAN environment parameter preferably includes one or more of an ECW parameter value and an AIFSN parameter value. When the uplink overheating event is identified in the WLAN network, one or more of the ECW parameter value and the AIFSN parameter value are broadcasted to mitigate this. The results of the WLAN network when the WLAN environment parameters are changed and set are as described above with reference to FIG. 5. When it is determined that the uplink overheating event is sufficiently resolved according to a preset criterion, it is preferable to restore the WLAN environment parameter back to the original value.

8 is a flowchart illustrating a process of controlling downlink airtime in a WLAN network according to the present invention.

Step S210: A second embodiment of the present invention is a method in which a WLAN AP controls downlink air time (T-dl (t)) in a WLAN network in which a WLAN AP and one or more stations are connected. The downlink threshold time (Th-downlink) is set for the preset airtime management period.

Meanwhile, when the WLAN AP includes a plurality of SSIDs, threshold time (Th-downlink, SSID) for each downlink SSID may be individually set within the range of the downlink threshold time for each of the plurality of SSIDs.

Steps S220 and S230: The downlink airtime is monitored in real time for each airtime management cycle in the WLAN network, and then the downlink airtime and the downlink threshold time monitored in real time are compared.

In this case, when the WLAN AP includes a plurality of SSIDs, the downlink airtimes are individually monitored in real time for each of the plurality of SSIDs. Accordingly, the downlink air time and the threshold time for each downlink SSID are monitored in real time for each SSID. It is configured to compare.

Steps S240 and S250: If the downlink airtime monitored in real time identifies a downlink overheating event exceeding the downlink threshold time, downlink data transmission in the corresponding airtime management cycle is stopped.

In this case, when the WLAN AP has a plurality of SSIDs, the downlink air time monitored in real time for each SSID is configured to identify an overheat event for each downlink SSID that exceeds a threshold time for each downlink SSID corresponding to the corresponding SSID. Accordingly, in response to an overheating event for each downlink SSID, the downlink data transmission in the corresponding airtime management period of the corresponding SSID is stopped.

Step S260: After stopping the downlink data transmission within one airtime management period, it may be configured to resume the interrupted downlink data transmission in the next airtime management period.

Here, when the WLAN AP has a plurality of SSIDs, the downlink data transmission is stopped in the corresponding airtime management cycle of the corresponding SSID in response to an overheating event for each downlink SSID, and then the SSAP is stopped for each SSID in the next airtime management cycle. Configured to resume one downlink data transmission.

The invention can also be embodied in the form of computer readable codes on a computer readable recording medium. At this time, the computer-readable recording medium includes all kinds of recording devices in which data that can be read by a computer system is stored.

Examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage, and the like, which may be implemented in the form of a carrier wave (eg, transmission over the Internet). . The computer readable recording medium can also store and execute computer readable code in a distributed manner over networked computer systems. And functional programs, codes, and code segments for implementing the present invention can be easily inferred by programmers in the technical field to which the present invention belongs.

Claims (8)

A method of controlling an airtime by a WLAN AP in a WLAN network to which a WLAN AP and at least one station are connected, (a) setting an uplink threshold time for a preset airtime management period; (b) monitoring uplink airtime in real time for each airtime management period in the WLAN network; (c) comparing the real-time monitored uplink airtime with the uplink threshold time; (d) identifying an uplink overheat event in which the real-time monitored uplink airtime exceeds the uplink threshold time; (e) changing and broadcasting an environment parameter of a WLAN network in response to the uplink overheating event; Air time control method in a WLAN network comprising a. The method according to claim 1, In step (a), the threshold time for each uplink SSID is individually set within the range of the uplink threshold time for each of the plurality of SSIDs. In step (b), the uplink airtime is individually monitored in real time for each of the plurality of SSIDs, In step (c), the uplink air time monitored for each SSID is compared with the threshold time for each uplink SSID. In step (d), the uplink airtime monitored for each SSID in real time identifies an overheat event for each uplink SSID that exceeds a threshold time for each uplink SSID corresponding to the corresponding SSID. And in step (e), broadcast by changing and setting an environment parameter of a WLAN network in response to an overheating event for each uplink SSID. The method according to claim 2, In the step (e), the environmental parameter is configured to include one or more of the ECW parameter value and the AIFSN parameter value. The method according to claim 3, And in step (e), increasing and decreasing one or more of the ECW parameter value and the AIFSN parameter value in response to the uplink overheating event to broadcast. A method of controlling an airtime by a WLAN AP in a WLAN network to which a WLAN AP and at least one station are connected, (a) setting a downlink threshold time for a preset airtime management period; (b) monitoring downlink airtime in real time for each airtime management period in the WLAN network; (c) comparing the real-time monitored downlink airtime with the downlink threshold time; (d) identifying a downlink overheat event in which the real-time monitored downlink airtime exceeds the downlink threshold time; (e) stopping transmission of downlink data in a corresponding airtime management period in response to the downlink overheating event; Air time control method in a WLAN network comprising a. The method according to claim 5, In step (a), a threshold time for each downlink SSID is individually set within the range of the downlink threshold time for each of the plurality of SSIDs. In step (b), the downlink airtime is individually monitored in real time for each of the plurality of SSIDs, In step (c), the downlink air time monitored for each SSID is compared with a threshold time for each downlink SSID. In step (d), the downlink air time monitored for each SSID in real time identifies an overheat event for each downlink SSID that exceeds a threshold time for each downlink SSID corresponding to the corresponding SSID. And stopping downlink data transmission in a corresponding airtime management period of the corresponding SSID in response to an overheating event for each downlink SSID in the step (e). The method according to claim 5, After step (e), (f) resuming the interrupted downlink data transmission in a next airtime management period; Air time control method of the WLAN network further comprises. A computer-readable recording medium having a computer recorded thereon a program for executing an airtime control method in a wireless LAN network according to any one of claims 1 to 7.

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