US20070248116A1

US20070248116A1 - Communication control apparatus and method of controlling same

Info

Publication number: US20070248116A1
Application number: US11/733,820
Authority: US
Inventors: Masashi Hamada
Original assignee: Individual
Current assignee: Canon Inc
Priority date: 2006-04-21
Filing date: 2007-04-11
Publication date: 2007-10-25
Also published as: US20100194649A1; JP2011501560A; WO2009051584A1; US9484618B2; CN101828303B; CN101828303A; KR101491875B1; JP5479348B2; EP2203954B1; EP2203954A1; KR20100080910A; BRPI0722109A2

Abstract

If a request for communication-band allocation control that is based upon narrowband QoS control is issued during execution of communication-band allocation control by an access point based upon broadband QoS control, a response is issued to instruct that the request be issued again following elapse of a stipulated time. If communication-band allocation control that is in progress ends and a request for communication-band allocation control is issued again following elapse of the stipulated time, then this communication-band allocation control is executed.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to control for allocating a communication band on a network.
2. Description of the Related Art
When a node is added to a service request network, addition of the node is accompanied by execution of processing for changing the provided service. In a technique proposed in the prior art, a service request message that prevailed prior to the addition of the node is also accepted when this processing is executed, thereby preventing loss of the service request message. For example, see Patent Document 1: U.S. Pat. No. 6,823,399 (Japanese Patent Laid-Open No. 2001-230793).
In another technique proposed in the prior art, session identification information is shared between nodes, whereby differential information is sent to a node on the service provider side so that service information is updated to the latest service information with the appropriate amount of data when service is resumed. For example, see Patent Document 2: US2005-198397 (Japanese Patent Laid-Open No. 2005-216313)
However, in cases where a band for a certain specific communication is reserved on a network and a plurality of services that provide “QoS” to assure a constant communication speed are utilized on the same network, there are instances where network resource information is shared by each of the services. Further, in a case where services are activated in parallel, a problem which arises is that when network-resource allocation requests occur simultaneously, an appropriate residual resource determination cannot be made. Furthermore, in a case where a currently active service controls the starting and stopping of provision of another service, all devices that are to enjoy the service must be notified of information. This increases the communication load on the network.

SUMMARY OF THE INVENTION

The present invention realizes to delay, until the completion of communication-band allocation control that has been initiated first, the start of succeeding communication-band allocation control.
According to one aspect of the present invention, there is provided a method of controlling a communication control apparatus, comprising the steps of: executing communication-band allocation control in accordance with a request from a communication apparatus; and controlling in such a manner that until communication-band allocation control based upon a request from a first communication apparatus ends, the start of communication-band allocation control based upon a request from a second communication apparatus is delayed.
According to another aspect of the present invention, there is provided a communication control apparatus comprising: execution device adapted to execute communication-band allocation control in accordance with a request from a communication apparatus; and control device adapted to for control in such a manner that until communication-band allocation control based upon a request from a first communication device ends, the start of communication-band allocation control based upon a request from a second communication device is delayed.
Further features of the present invention will become apparent from the following description of exemplary embodiments (with reference to the attached drawings).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating an example of the configuration of a wireless network system according to a first embodiment of the present invention;

FIG. 2 is a diagram illustrating an example of a wireless access point as well as function layers in a personal computer;

FIG. 3 is a diagram illustrating a message sequence on the network according to the first embodiment;

FIG. 4 is a diagram illustrating a message sequence on the network according to the first embodiment;

FIG. 5 is a diagram illustrating a message sequence on the network according to the first embodiment;

FIG. 6 is a flowchart illustrating processing at a wireless access point;

FIG. 7 is a flowchart illustrating processing at a wireless access point; and

FIG. 8 is a diagram illustrating a message sequence on the network according to a second embodiment.

DESCRIPTION OF THE EMBODIMENTS

Preferred embodiments of the present invention will now be described in detail with reference to the drawings.

First Embodiment

In a first embodiment, the present invention will be described taking as an example a wireless network system in which a QoS wireless LAN compliant with the IEEE 802.11e standard is used as a communication medium on a communication path and is supported together with QoS middleware compliant with the UPnP QoS standard. With a QoS wireless LAN, QoS control that is based upon resource management of a narrowband [in wireless-cell (BSS) units] is carried out. In the case of QoS middleware, QoS control that is based upon resource management of a broadband (subnet units) is performed.
In a case where a communication-path reservation request based upon narrowband QoS control occurs during the course of communication-path reservation processing between devices based upon broadband QoS control, the communication-path reservation requested based upon the narrowband QoS control is inhibited until one processing unit of broadband QoS control has been completed. The processing for accomplishing this will be described.
FIG. 1 is a diagram illustrating one example of the configuration of a wireless network system in the first embodiment. A wireless access point 101 supports QoS control that is based upon narrowband (BBS units) resource management and QoS control that is based upon broadband (subnet units) resource management. A server apparatus 102 has a function for performing QoS control that is based upon broadband (subnet units) resource management. In this example, a personal computer is described as an example of the server apparatus 102. A client apparatus 103 supports broadband QoS control and narrowband QoS control and functions as a wireless station that performs wireless communication with the wireless access point 101. In this example, a display unit is described as an example of the client apparatus 103, although it may be another apparatus such as a notebook personal computer. A client apparatus 104 supports broadband and narrowband QoS control in a manner similar to that of the client apparatus 103. In this example, the client apparatus 104 is a content providing apparatus for supplying content information such as moving pictures. A client apparatus 105 supports only narrowband QoS control and functions as a wireless station for performing wireless communication with the wireless access point 101. In this example, a display unit is described as an example of the client apparatus 105, although it may be another apparatus such as a notebook personal computer. A client apparatus 106 supports only narrowband QoS control in a manner similar to that of the client apparatus 105. In this example, the client apparatus 106 is a content providing apparatus for supplying content information such as moving pictures.
Within a wireless cell controlled by the wireless access point 101 in the configuration shown in FIG. 1, setup of traffic stream (TS) in accordance with QoS middleware control is performed between the display unit 103 and content providing apparatus 104. Further, TS setup in accordance with QoS LAN control is performed between the display unit 105 and client apparatus 106.
FIG. 2 is a diagram illustrating an example of a wireless access point as well as function layers in a personal computer. As illustrated in FIG. 2, the system broadly comprises a network application function unit 200, a transport control function unit 210, an 802.11e QoS control function unit 220 and a communication media control function unit 230.
The network application function unit 200 includes an AV stream application 201, a UPnP AV 202 and a UPnP QoS control unit 203. The transport control function unit 210 includes a UDP TCP/IP 211 and a bridge 212.
The 802.11e QoS control function unit 220 includes an admission control unit 221, a resource management unit 222 and a policy management unit 223. The communication media control function unit 230 includes a wireless LAN (MAC) 231, a wireless LAN (PHY) 232, a wired LAN (MAC) 233 and a wired LAN (PHY) 234. Here MAC is the abbreviation of Medium Access Control, and PHY is the abbreviation of Physical Layer.
Described next will be a case where TS setup in accordance with QoS wireless LAN control is performed between the display unit 105 and content providing apparatus 106 during setup of a TS in accordance with QoS middleware control between the display unit 103 and content providing apparatus 104. Specifically, this is processing in which if a communication-band allocation request based upon narrowband QoS control occurs after the wireless access point 101 has started communication-band allocation processing that is based upon broadband QoS control, then the issued communication-band allocation request is made to wait until the communication-band allocation processing ends.
FIGS. 3 to 5 are diagrams illustrating a message sequence on the network according to the first embodiment, and FIGS. 6 and 7 are flowcharts illustrating processing at the wireless access point 101.
First, audio-video content of the content providing apparatus 104 is decided by the display unit 103 using a remote controller, and the display unit 103 transmits a message for acquiring traffic specs (TSPEC) that is necessary for transmitting the audio-video content. Accordingly, a TSPEC acquisition (Getting TSPEC) message (300, 400, 500) is sent to the content providing apparatus 104 via the wireless access point 101. The TSPEC that has been stored in the content providing apparatus 104 is then transmitted to the display unit 103. Using TSPEC, the display unit 103 transmits a TS reservation request (Request Traffic QoS) message (301, 401, 501) for content transmission. The TS reservation request message (301, 401, 501) is sent to a CDS (Content Delivery Service) of the personal computer 102.
Next, the CDS transmits a status acquisition (Get QoS State) message (302, 402, 503) to each device that supports QoS middleware control. In this example, the message is transmitted to the wireless access point 101, display unit 103 and content providing apparatus 104, and the media-resource availability status of each device is received as status of the response to the TS reservation request message.
Upon receiving the status acquisition message, the wireless access point 101 starts the processing of the flowchart shown in FIG. 6 in addition to the QoS middleware control processing. First, the wireless access point 101 determines whether TS setup processing based upon wireless QoS control is in progress. Here the wireless access point 101 determines whether an ADDTS request (ADDTS Req.) message is being received (S601). If this message is being received, then the wireless access point 101 determines whether the current state is one in which an ADDTS response (ADDTS Res.) message has not been transmitted (S602). If the message is not being transmitted, then the wireless access point 101 waits for completion of transmission of the ADDTS response message.
Further, in a case where setup processing is not in progress, the wireless access point 101 sets a status for instructing that a request be issued again following elapse of a stipulated time (306, 406) when the ADDTS request message is received from the display unit 105 (S603). As a result, in a case where the ADDTS request message has been received from the display unit 105, the wireless access point 101 transmits the ADDTS response message that includes a TS Delay value to the display unit 105 and instructs the display unit 105 not to issue the request again during the stipulated time. The wireless access point 101 starts a timer for measuring a delay time (303, 403) during which acceptance of the ADDTS request message is delayed (S604).
Next, the wireless access point 101 waits for receipt of a TS setup (Setup Traffic QoS) message (307, 505), which specifies TS acquisition for transmission of content, from the personal computer 102 (S605). Here the wireless access point 101 waits until the timer times out (S606) and receives the message before the timer times out (FIG. 3). Alternatively, the wireless access point 101 clears the timer (S607) when the timer times out (FIG. 4). The wireless access point 101 then clears the status that instructs the display unit 105 to wait the stipulated period of time before it again requests the ADDTS request message (S608), and ends this one unit of processing.
It should be noted that the above-mentioned delay time is a period of time necessary for the personal computer 102 to acquire the media-resource availability status of each device and for the completion of transmission of a message that specifies TS acquisition for content transmission using the media-resource availability status as a criterion. Further, the stipulated time stipulates a period of time longer than the delay time.
The calculation equations cited below are used as one example. However, if the time is sufficiently longer than the time necessary for completion of transmission of Setup Traffic QoS message, then it is possible to apply another calculation equation with regard to the delay time.
The calculation equations are as follows:
(delay time)=(number of devices in the same network)×(time needed for TS setup message exchange of UPnP QoS standard per device)+(maximum time required for QoS management control processing of UPnP QoS standard of server) (stipulated time)=(delay time)+(protect time)
Next, upon receiving an ADDTS request message (304, 404, 502) from the display unit 105, the wireless access point 101 starts executing the processing of the flowchart shown in FIG. 7 in addition to the normal wireless QoS control processing.
First, the wireless access point 101 determines whether the timer that measures delay time is operating (S701). If the timer is operating, then the wireless access point 101 sends back an ADDTS response message (305, 405) in which the above-mentioned stipulated time has been set to the TS Delay value (S706). If the timer is not operating, then the wireless access point 101 determines whether the ADDTS request message (304, 404) was received during the delay time. If the message was not received, then the wireless access point 101 sends back an ADDTS response message (504) that is in accordance with the normal TS allocation processing (S705) and terminates one unit of processing.
It should be noted that processing for a case where an ADDTS request message has been received during operation of the timer and an ADDTS request message has been received after time-out of the timer (processing following “YES” at S702) will be described in detail in a second embodiment below.
On the other hand, if the display unit 105 receives the ADDTS response message (305, 405) inclusive of the TS Delay value from the wireless access point 101, re-transmission of the ADDTS request message is delayed for the period of time indicated by the TS Delay value. When the time indicated by the TS Delay value ends, an ADDTS request message (309, 409) is again transmitted to the wireless access point 101.
As a result, the wireless access point 101 starts executing the processing of FIG. 7 again. In a case where reservation of TS is possible with the remaining wireless network resources, the wireless access point 101 adds on a parameter indicative of acceptance. If reservation of TS is not possible, then the wireless access point 101 adds on a parameter indicating that acceptance is not possible and sends back an ADDTS response message that is in accordance with the normal TS allocation processing.
On the other hand, if the display unit 105 has received from the wireless access point 101 a message (310, 410, 504) to which the parameter indicating acceptance of the TS setup request has been appended, then the fact that TS setup has succeeded is recognized.
By virtue of the above-described processing, the wireless access point 101 that supports multiple-system QoS control processing delays, until the end of one unit of system QoS control processing started first, the start of system QoS control processing that is started subsequently. As a result, multiple system QoS control in which amount of remaining resources of the same communication path is used as a criterion is implemented exclusively, thereby making it possible to implement system QoS control that is based upon accurate resource management of the communication path.

Second Embodiment

A second embodiment of the present invention will now be described in detail with reference to the drawings. Described in the second embodiment is processing executed at the wireless access point in a case where requests to start processing for reserving a TS communication path have been issued successively from the display unit 105 and content providing apparatus 106.
The configuration of the wireless network system of the second embodiment is similar to that of the first embodiment shown in FIG. 1 and need not be described again.
FIG. 8 is a diagram illustrating a message sequence on the network according to the second embodiment. First, in a manner similar to that of the first embodiment, audio-video content is decided by the display unit 103. When the personal computer 102 receives a TS reservation request message (801) from the display unit 103, it transmits a Get QoS State message to each device. Upon receiving the Get QoS State message, the wireless access point 101 starts the processing of the flowchart of FIG. 6 in a manner similar to the first embodiment.
Upon receiving an ADDTS request message from the display unit 105 (804), the wireless access point 101 starts executing the processing of the flowchart shown in FIG. 7. First, the wireless access point 101 determines whether the timer for measuring the delay time is operating (S701). Since the timer is operating, the wireless access point 101 sends back an ADDTS response message (805) in which the above-mentioned stipulated time has been set to the TS Delay value (S705) and terminates one unit of processing.
Further, if the wireless access point 101 receives an ADDTS request message (808) from the content providing apparatus 106 after the timer times out (807), then the wireless access point 101 starts executing the processing of the flowchart shown in FIG. 7. First, since the timer is not operating, a “NO” decision is rendered at S701 and the wireless access point 101 determines whether the ADDTS request message was received during the operation of the timer (S702). Since the message was received from the display unit 105, the wireless access point 101 determines whether the stipulated time of which it has been notified by the ADDTS response message (805) has already elapsed (S703).
Since the stipulated time has not yet elapsed in this case, the wireless access point 101 determines whether the device that was the source of transmission of the present ADDTS request message (808) and the device that was the source of transmission of the already received ADDTS request message 804 are identical (S704). Here, since the apparatus is the content providing apparatus 106, the wireless access point 101 sends back an ADDTS response message in which the stipulated time has been set to the TS Delay value (S706) and terminates one unit of processing.
Further, in a case where it is determined at S703 that a period of time greater than the stipulated time has elapsed or in a case where it is determined at S704 that the devices are the same, the wireless access point 101 sends back an ADDTS response message (813) that is in accordance with the normal TS allocation processing (S705) and terminates one unit of processing.
As a result, by processing for reserving a TS communication path performed upon expiration of the stipulated time, it is possible to furnish a TS communication path in succession from the device that issued the request for communication-path reservation processing first, inclusive of delay time.

Other Embodiments

It goes without saying that the object of the invention is attained also by supplying a recording medium storing the program codes of the software for performing the functions of the foregoing embodiments to a system or an apparatus, reading the program codes with a computer (e.g., a CPU or MPU) of the system or apparatus from the recording medium, and then executing the program codes.
In this case, the program codes read from the recording medium implement the novel functions of the embodiments and the recording medium storing the program codes constitutes the invention.
Examples of recording media that can be used for supplying the program codes are a flexible disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD-R, magnetic tape, non-volatile type memory card or ROM, etc.
Furthermore, besides the case where the aforesaid functions according to the embodiment are implemented by executing the program codes read by a computer, it goes without saying that the present invention also covers a case where an operating system or the like running on the computer performs a part of or the entire process based upon the designation of program codes and implements the functions according to the embodiments.
The present invention further covers a case where, after the program codes read from the recording medium are written to a memory provided on a function expansion board inserted into the computer or provided in a function expansion unit connected to the computer, a CPU or the like provided on the function expansion board or in the function expansion unit performs a part of or the entire process in accordance with the designation of program codes and implements the function of the above embodiments.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2006-118441, filed Apr. 21, 2006, which is hereby incorporated by reference herein in its entirety.

Claims

1. A method of controlling a communication control apparatus, comprising the steps of:

executing communication-band allocation control in accordance with a request from a communication apparatus; and

controlling in such a manner that until communication-band allocation control based upon a request from a first communication apparatus ends, the start of communication-band allocation control based upon a request from a second communication apparatus is delayed.

2. The method according to claim 1, wherein communication-band allocation control based upon a request from the first communication apparatus is communication-band allocation control for performing communication-band allocation based upon network resource management of a first range, and communication-band allocation control based upon a request from the second communication apparatus is communication-band allocation control for performing communication-band allocation based upon network resource management of a second range different from the first range.

3. The method according to claim 2, wherein communication-band allocation control based upon a request from the first communication apparatus is performed based upon control of a management apparatus that controls the network resources of the first range.

4. The method according to claim 1, wherein end of the communication-band allocation control based upon a request from the first communication apparatus is at least completion of allocation of the communication band or time-out of a timer that measures delay time.

5. The method according to claim 3, wherein end of the communication-band allocation control based upon a request from the first communication apparatus is recognized by a command for setting up the communication band from the management apparatus.

6. The method according to claim 1, wherein at said control step, a response to a request from the second communication apparatus is transmitted, said response instructing that a request is to be issued again following elapse of a stipulated time.

7. The method according to claim 6, wherein the stipulated time is a time obtained by adding a protect time to a time required for completion of the communication-band allocation.

8. The method according to claim 6, wherein at said control step, in a case where a communication-band allocation request has been issued by a third communication apparatus, a command is issued so as to issue the request again upon elapse of the stipulated time if the stipulated time has not elapsed.

9. A communication control apparatus comprising:

execution device adapted to execute communication-band allocation control in accordance with a request from a communication apparatus; and

control device adapted to for control in such a manner that until communication-band allocation control based upon a request from a first communication device ends, the start of communication-band allocation control based upon a request from a second communication device is delayed.

10. The apparatus according to claim 9, wherein communication-band allocation control based upon a request from the first communication apparatus is communication-band allocation control for performing communication-band allocation based upon network resource management of a first range, and communication-band allocation control based upon a request from the second communication apparatus is communication-band allocation control for performing communication-band allocation based upon network resource management of a second range different from the first range.

11. The apparatus according to claim 10, wherein communication-band allocation control based upon a request from the first communication apparatus is performed based upon control of a management apparatus that controls the network resources of the first range.

12. The apparatus according to claim 9, wherein end of the communication-band allocation control based upon a request from the first communication apparatus is at least completion of allocation of the communication band or time-out of a timer that measures delay time.

13. The apparatus according to claim 11, wherein end of the communication-band allocation control based upon a request from the first communication apparatus is recognized by a command for setting up the communication band from the management apparatus.

14. The apparatus according to claim 9, wherein said control device transmits a response to a request from the second communication apparatus is transmitted, said response instructing that a request is to be issued again following elapse of a stipulated time.

15. The apparatus according to claim 14, wherein the stipulated time is a time obtained by adding a protect time to a time required for completion of the communication-band allocation.

16. The apparatus according to claim 14, wherein in a case where a communication-band allocation request has been issued by a third communication apparatus, said control device issues a command such that the request will be issued again upon elapse of the stipulated time if the stipulated time has not elapsed.

17. A program for causing a computer to execute the method of controlling a communication control apparatus set forth in claim 1, said program being recorded on a computer-readable recording medium.

18. A computer-readable recording medium on which has been recorded a program for causing a computer to execute the method of controlling a communication control apparatus set forth in claim 1.