JP2007142752A - Communication repeater and its communication control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication repeater capable of conducting priority control even for a packet without a priority information and maintaining proper sound quality, and to provide its communication control method. <P>SOLUTION: An access point 10 performs operation comprising the steps of discriminating whether a packet received at a packet acquiring portion 40 is based on a priority control method or not; outputting a priority existence information indicative of existence of a priority information; discriminating a direction for output based on a through-route of the packet received at a route discriminator 42; outputting a route identification information based on the discrimination; discriminating, at a priority processing portion 44, a type of the packet according to a priority existence information without a priority information; determining priority of the packet for the discriminated type of the packet; and appending and sending out a set value indicative of priority for the packet as a priority information. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a communication relay device and a communication control method thereof. The communication relay apparatus according to the present invention particularly relates to a wireless LAN access point that preferentially controls packets to be communicated. The communication control method according to the present invention relates to a packet priority control method in a wireless LAN access point.

Generally, a wireless LAN (Local Area Network) has an infrastructure mode using an access point. IP (Internet
Some protocol telephone systems communicate via this infrastructure mode wireless LAN. In this access point, two priority control methods are generally used. The first priority control method is a method in which priority information is described in a TOS (Type of Service) field of a packet for control. The second priority control method is a method of controlling by writing priority information in a COS (Class of Service) field of a VLAN (Virtual LAN) tag and is called IEEE (Institute of Electrical and Electronics Engineers) 802.1p.

  Further, Patent Literature 1 proposes a communication relay method and apparatus based on priority control different from that described above. Patent Document 1 includes several requests for stream communication by VoIP (Voice over IP) used for IP telephones, and stable wireless communication is ensured by priority control in wireless terminal communication so as to satisfy these requests. A method and apparatus for realizing the above is disclosed. In addition, there is also described a method of giving priority to a specific communication by intentionally shortening a waiting time until the end of another communication when communicating in a DCF (Distributed Coordination Function) mode. This method is effective because a system configuration with compatibility is possible, but if the number of wireless terminals operating in this manner increases, there is a risk that the collision probability increases and the communication quality decreases. It also describes that priority control is performed according to the type of data to be communicated.

If it describes concretely about patent document 1, the stream server which manages the radio | wireless communication of a radio | wireless terminal apparatus and a radio relay station will be newly added to a radio | wireless communications system. The wireless relay station stores a priority table in which identifiers of communications to be relayed preferentially are stored, and relays the communication specified by the registered identifiers with priority. The stream server requests registration of the communication identifier in the priority table in response to a communication start request from the wireless terminal device. The wireless relay station registers each communication identifier in the priority table within a predetermined range in which the sum of the consumed bandwidth of communication specified by the communication identifier does not exceed the proportion of the available bandwidth of the wireless network.
JP 2005-80157 A

  For priority control in the above-described wireless LAN system, for example, a TOS value or a COS value is used as priority information. However, in this system, priority control is not performed for packets for which priority information is not set. As a result, when priority control is not performed, voice data of the other party arrives with a delay when talking on an IP phone via a wireless LAN. This delay deteriorates the sound because it causes the sound to be played back with delay or to generate a noise of sound interruption.

  It is an object of the present invention to provide a communication relay apparatus and a communication control method therefor that can eliminate such drawbacks of the prior art and can preferentially control a packet without priority information to maintain voice quality.

  In order to solve the above-described problems, the present invention provides a communication relay device that is arranged between a plurality of wireless terminal devices and a communication network and relays communication between them. The communication relay device prioritizes received packets. First control means for determining whether or not it is based on a specific control method, outputting priority presence / absence information indicating the presence / absence of priority information, and determining the direction of output based on the passage route of the received packet A second discriminating means for outputting the route identification information based on the packet, the type of the packet is discriminated according to the priority presence / absence information not including the priority information, and the priority order of the packet is determined for the discriminated packet type. And priority processing means for adding a setting value indicating the priority order to the packet as priority information.

  Further, in order to solve the above-described problem, the present invention provides a communication relay device that relays communication between a plurality of wireless terminal devices and a communication network, and controls communication in the communication relay device. In the control method, this method includes a first step of determining whether or not the received packet is based on a preferential control method, and outputting priority presence / absence information indicating the presence / absence of priority information, and passing of the received packet The second step of determining the output direction based on the route, outputting the route identification information based on the determination, and determining the packet type according to the priority presence / absence information not including the priority information, And a third step of determining a priority of the packet with respect to the type and adding a set value indicating the priority to the packet as priority information.

  The communication relay apparatus of the present invention determines whether or not the packet received by the first determination unit is based on a priority control method, outputs priority presence / absence information indicating the presence / absence of priority information, and second determination unit The direction of output is determined based on the passage route of the packet received in step 1, the route identification information based on the determination is output, and the priority processing means determines the type of packet according to priority presence / absence information that does not include priority information. The priority of the packet is determined for the determined packet type, and a setting value indicating the priority is added to the packet as priority information and transmitted, so that the packet can be preferentially handled. Communication can be performed while maintaining voice quality independent of the wireless terminal device.

  Further, the communication control method of the present invention determines whether or not a received packet is based on a preferential control method, outputs priority presence / absence information indicating the presence / absence of priority information, and based on the passage route of the received packet. Determines the direction to be output, outputs route identification information based on the determination, determines the packet type according to priority information that does not include priority information, and determines the packet priority for the determined packet type By adding a setting value indicating the priority order to this packet as priority information, it becomes possible to preferentially handle the packet, and communication can be performed while maintaining voice quality independent of the wireless terminal device. .

  Next, an embodiment of a communication relay device according to the present invention will be described in detail with reference to the accompanying drawings. Referring to FIG. 1, the embodiment of the communication relay device according to the present invention determines whether or not a packet received by the packet acquisition unit 40 is based on a preferential control method, and gives priority presence / absence information indicating the presence / absence of priority information. The route identification unit 42 determines the output direction based on the passage route of the packet received by the route discrimination unit 42, outputs the route identification information based on the discrimination, and the priority processing unit 44 converts the priority presence information that does not include the priority information. The packet type is determined accordingly, the priority of the packet is determined for the determined packet type, and the setting value indicating the priority is added to the packet as priority information and transmitted, so that the packet is prioritized. Therefore, communication can be performed while maintaining voice quality independent of the wireless terminal device.

  In this embodiment, the communication relay device of the present invention is applied to the access points 10, 12 and 14. The illustration and description of parts not directly related to the present invention are omitted. In the following description, the signal is indicated by the reference number of the connecting line in which it appears.

  As shown in FIG. 2, the wireless communication system 16 includes access points 10, 12 and 14, and wireless terminal devices 18, 20 and 22. In the wireless communication system 16, the access points 10, 12 and 14 are connected to the communication network 24 via wires 26, 28 and 30, respectively. Further, the access points 10, 12 and 14 are respectively wireless terminals 32, 34 and 36 when the wireless terminals 18, 20 and 22 are within the allowable range of wireless communication at the access points 10, 12 and 14. Wirelessly communicates with 18, 20, and 22. The communication network 24 is configured by an IP (Internet Protocol) network or the like as an example.

  Note that the access points 10, 12 and 14 can also access the wireless LAN via radio, not shown.

  Each of the access points 10, 12 and 14 uses exactly the same configuration. Therefore, of the three access points in this embodiment, the access point 10 is given as a configuration example and the configuration is shown in FIG.

  As shown in FIG. 1, the access point 10 includes a reception unit 38, a packet acquisition unit 40, a route determination unit 42, a priority processing unit 44, and a transmission unit 46. The reception unit 38 basically has a function of receiving a packet supplied to the access point 10, and includes a wired reception unit 48 and a wireless reception unit 50. The wired receiving unit 48 has an interface function for receiving a stream (data string) from the communication network 24 via the wired line 26. In addition, the radio reception unit 50 has an interface function of receiving the radio wave 32 from the radio terminal device 18 into the antenna and receiving it as the signal 32, and downconverting the signal 32 to the baseband. The wired reception unit 48 outputs the waveform-shaped data 52 to the packet acquisition unit 40. The radio reception unit 50 outputs the baseband data 54 to the packet acquisition unit 40.

  The packet acquisition unit 40 has a function of confirming whether or not the acquired packets 52 and 54 include a TOS value that defines a priority control method. The packet acquisition unit 40 outputs priority presence / absence information indicating the presence / absence of priority information and the acquired packets 52 and 54 to the route determination unit 42 as packets 56. The priority presence / absence information is set to “1” indicating the presence of priority information when priority information is included, for example, and is set to “0” when there is no priority information.

  Note that the packet acquisition unit 40 may be configured to check not only the TOS value but also the COS value in the COS field of the VLAN tag.

  The route determination unit 42 has a function of determining from which application the packet 56 is sent. The path determination unit 42 identifies whether or not the acquired packet 56 is a wired-to-wireless downstream path or a wireless-to-wired upstream path. The route identification information is also indicated by “1” / “0” in accordance with, for example, downlink / uplink. The route determination unit 42 outputs priority presence / absence information, route identification information, and the acquired packet 58 to the priority processing unit 44.

  The priority processing unit 44 has a function of performing priority processing on the packet 58 according to priority information, priority presence / absence information, and path identification information. In order to realize this function, the priority processing unit 44 includes a priority control unit 60, an information addition / separation unit 62, and a packet determination unit 64.

  The priority control unit 60 controls the output of packets supplied to the priority order to the communication partner, and the information addition / separation unit 62 and the packet discrimination unit 64 according to the priority information, priority presence / absence information, and path identification information. It has a function to control the operation. The priority control unit 60 outputs the packet 58 subjected to this control as a packet 66 to the information addition / separation unit 62 and the packet determination unit 64. The priority control unit 60 outputs the packet 66 processed by the information addition / separation unit 62 and the packet discrimination unit 64 to the transmission unit 46 as a packet 68. The packet 66 will be described later.

  The information addition / separation unit 62 has a function of adding information to or separating information from the packet 66 supplied under the control of the priority control unit 60. The information here means priority information. A packet 66 is supplied to the information adding / separating unit 62. The priority control unit 62 also supplies priority information for the communication partner when the route identification information is “0”, and outputs this priority information and control signal to the information adding / separating unit 62. The information adding / separating unit 62 is controlled to add priority information to a predetermined position in the packet 66. Further, the priority control unit 60 supplies the priority information included in the packet 66 even when the path identification information is “1”, and outputs the priority information and the control signal to the information adding / separating unit 62. The information adding / separating unit 62 is controlled to add priority information from a predetermined position in the packet 66. The information addition / separation unit 62 outputs the packet 66 processed by the control to the priority control unit 60.

  Further, the information adding / separating unit 62 is configured to transmit the packet 56 from the wired to wireless route, that is, when the route information is “1”, and the connection destination of this route is a communication relay such as an access point. When the connection destination is not a device but a wireless terminal device and the acquired packet 56 includes a VLAN tag (CoS field), the VLAN tag is not necessary in the packet transmitted from the communication relay device to the wireless terminal device. The VLAN tag including the CoS field of the packet 56 may be separated. Separation is to delete the VLAN tag of the acquired packet 56, for example. The information adding / separating unit 62 outputs the processed packet 66 to the priority control unit 60.

  The priority control unit 60 supplies the supplied packet 66 to the packet determination unit 64 when the priority information is “0”. The packet discrimination unit 64 has a function of discriminating the type of packet. In order to realize this function, the packet determination unit 64 includes a Session Initiation Protocol (SIP) packet determination unit 70 and a Real-time Transport Protocol (RTP) packet determination unit 72. The SIP packet discrimination unit 70 analyzes the supplied packet 66 because it is an application layer signal protocol used for call start, change and end. For example, when a SIP address is detected by packet analysis, the SIP packet determination unit 70 determines that the packet 66 is a SIP packet. The SIP packet determination unit 70 outputs packet identification information indicating that the packet 66 is SIP to the priority control unit 60.

  The SIP packet discriminating unit 70 is not only a SIP address, but also includes a transport layer port number, UDP (User Datagram Protocol), TCP (Transmission Control Protocol), VoIP (Voice over Internet Protocol), and MAC (Medium Access Control). The determination may be made by applying an address or the like.

  In addition, the RTP packet determination unit 72 has a function of determining whether or not, for example, the characteristics of the RTP header are included by packet analysis. When the RTP header is detected, the RTP packet determining unit 72 determines that the packet 66 is an RTP packet. The RTP packet determination unit 72 outputs packet identification information indicating that the packet 66 is RTP to the priority control unit 60.

  The priority control unit 60 outputs the packet 68 to the transmission unit 46 in the order of priority from the upstream / downstream supplied packet, that is, the packet holding the priority information, the SIP packet, the RTP packet, and other packets. To do. The priority control unit 60 adds priority information to the uplink / downlink packet and outputs the packet to the transmission unit 46.

  Note that the access point 10 may also transmit packets according to the above-described priority even when relaying packets supplied from wired to wired.

  The transmission unit 46 includes a wired transmission unit 74 and a wireless transmission unit 76. The transmission unit 46 basically has a function of transmitting the packet 68 supplied as the access point 10 in accordance with uplink / downlink. The wired transmission unit 74 has a function of transmitting the supplied upstream packet 68 and transmits the packet 68 as a packet 26 to the communication partner via the communication network 24. The wireless transmission unit 76 has an interface function for up-converting the supplied baseband downlink packet 68. Radio transmitting section 76 outputs upconverted packet 68 as signal 32 to radio terminal apparatus 18 from an antenna (not shown). The access point 10 sends out voice packets and call control packets with priority.

  2 has a function of performing wireless communication with the access point 10. The wireless terminal device 18 is, for example, an IP telephone with a wireless LAN function. As shown in FIG. 3, the wireless terminal device 18 includes a wireless transmission / reception unit 78 and a mutual conversion unit 80. Although not shown, the wireless terminal device 18 has a microphone and a speaker, and inputs and outputs audio. The radio transmission / reception unit 78 has a function of transmitting and receiving calls and voices. The mutual conversion unit 80 has a mutual conversion function in call processing.

  Next, priority control at the access point 10 will be briefly described. As shown in FIG. 4, when the wired receiver 48 receives the signal 26 and outputs the signal 26 to the packet acquisition unit 40 as a packet 52, the packet acquisition unit 40 extracts the priority information from the packet 52, The presence or absence is confirmed (step S10). Further, when the radio reception unit 50 receives the signal 32 and outputs the signal 32 to the packet acquisition unit 40 as a packet 54, the packet acquisition unit 40 extracts priority information from the packet 54 and confirms the presence or absence of the priority information. The presence / absence of the confirmed priority information is output to the route discrimination unit 42 together with the packet 56.

  Next, the route discriminating unit 42 identifies whether or not the packets 52 and 54 are a downlink route indicating wired to wireless or an uplink route indicating wireless to wired (step S12). The route determination unit 42 supplies the packet 58 and the identification information of the determined route to the priority control unit 60 of the priority processing unit 44.

  Next, the priority order of the packet 58 received by the priority control unit 60 in the priority processing unit 44 is identified, and is output to the transmission unit 46 as a packet 68 according to the priority order (subroutine SUB). If priority information does not exist in the packet 58, the SIP packet determining unit 70 and the RTP packet determining unit 72 determine whether the packet is a SIP or RTP packet that is a priority packet in voice communication, and then determine the priority. Specifically, if priority information is not added to the packet in the downstream path, the information addition / separation unit 62 adds priority information based on the priority in voice communication, and outputs it to the wireless transmission unit 76. On the upstream path, if priority information is not added to the packet, the information addition / separation unit 62 adds priority information based on the priority in voice communication, and outputs the priority information to the wired transmission unit 74.

  Next, the transmission unit 46 transmits the packet 68 to the communication partner (step S14). Specifically, the packet 68 to be output to the upstream path is transmitted from the wired transmission unit 74 as the signal 26. In addition, the packet 68 to be output to the downstream path is transmitted from the wireless transmission unit 76 as the signal 32. By controlling the operation in this way, voice packets and call control packets are preferentially transmitted. After transmission, the access point 10 returns to the priority information confirmation process for the next supplied packet again (to step S10), and repeats the above process.

  Next, the priority setting procedure for the received packet 58 will be described (subroutine SUB). First, it is determined whether or not priority information exists in the received packet 58 (sub-step SS10). Judgment is based on information already obtained in the confirmation. When priority information exists (YES), the process proceeds to priority setting (to sub-step SS12). Further, when the priority information does not exist (NO), the process proceeds to the determination of the type of the received packet 58 (to substep SS14).

  The priority is set by setting a priority information value to be given the highest priority and adding this information to the packet 58 (substep SS12).

  Next, the packet 58 is discriminated (substep SS14). Under the control of the priority control unit 60, the packet discrimination unit 64 discriminates and recognizes the packet type. After this determination, the process proceeds to a process for determining the type of the packet 58 (to sub-step SS16). It is determined whether or not the packet 58 is SIP (substep SS16). When the packet 58 is SIP (YES), the process proceeds to the setting of the second priority (to sub-step SS18). If the packet 58 is not SIP (NO), the process proceeds to determination of the type of the next packet (go to sub-step SS20).

  The priority order is set by setting the second priority information value and the SIP setting value, and adding the SIP setting value to the packet 58 as the priority information in which this order is set (sub step SS18).

  Next, it is determined whether or not the packet 58 is RTP (substep SS20). When the packet 58 is RTP (YES), the process proceeds to the setting of the third priority (to sub-step SS22). If the packet 58 is not RTP (NO), the process proceeds to the setting of the fourth priority information (go to sub-step SS24).

  Next, the priority order is set by setting the third priority information value and the RTP setting value, and adding the RTP setting value to the packet 58 as the priority information in which the order is set (sub-step SS22). The fourth priority information is set as another predetermined information value, and the other information value is added as the priority information in which this order is set.

  In this embodiment, priority information values, SIP setting values, RTP setting values, and other setting values are set and added. This set value may be set in the order of the above-described priority. Thus, the voice packet and the call control packet are operated so as to be transmitted with priority.

  After each priority information setting (substeps SS12, SS18, SS22, and SS24), the process proceeds to RETURN and the priority setting in the priority control is completed.

  In this way, the wireless LAN access point identifies packets that are prioritized in voice communication, such as RTP packets and SIP packets, adds priority information to the packets, and operates and processes each packet with priority. Enables voice quality calls independent of wireless terminal devices in an IP telephone environment using a wireless LAN. Further, a protocol that can be recognized by the wireless LAN access point, such as ICMP (Internet Control Message Protocol), can also be a target of priority control.

It is a block diagram which shows the schematic structure of the access point to which the communication relay apparatus based on this invention is applied. It is a schematic block diagram which shows the structural example of the radio | wireless communications system to which the access point of FIG. 1 is applied. FIG. 3 is a block diagram illustrating a schematic configuration of a wireless terminal device used in the wireless communication system of FIG. 2. It is a flowchart explaining the operation | movement procedure in the access point of FIG. 5 is a flowchart illustrating a priority setting procedure in the priority control of FIG. 4.

Explanation of symbols

10 Access point
38 Receiver
40 Packet acquisition unit
42 Route discriminator
44 Priority processing section
46 Transmitter
60 Priority control section
62 Information addition / separation section
64 packet discriminator
70 SIP packet discriminator
72 RTP packet discriminator

Claims (7)

In a communication relay device that is disposed between a plurality of wireless terminal devices and a communication network and relays communication between them, the communication relay device includes:
First determination means for determining whether or not the received packet is based on a priority control method, and outputting priority presence / absence information indicating presence / absence of priority information;
A second discriminating means for discriminating a direction of output based on a passage route of the received packet, and outputting route identification information based on the discrimination;
The type of the packet is determined according to priority presence / absence information not including the priority information, the priority of the packet is determined for the determined packet type, and the setting value indicating the priority is given priority to the packet And a priority processing means for adding information. The communication relay device according to claim 1, wherein the priority processing means includes information adding means for adding the set value as priority information to the packet;
Third discriminating means for discriminating the type of the packet not including the priority information and outputting the discriminated identification information as priority information;
And priority control means for processing and sending out the packets supplied by the information adding means and the third determining means with reference to the priority information, the priority presence / absence information and the route identification information. Communication relay device to do.   3. The communication relay device according to claim 1, wherein the priority processing unit transmits the packet to the wireless terminal device within a communication range in accordance with the priority order. 4.   4. The communication relay device according to claim 2, wherein the priority is set in the order of priority information included in the packet, SIP (Session Initiation Protocol) setting value, and RTP (Real-time Transport Protocol) setting value. A communication relay device, wherein priority information is added to the packet. In a communication control method of arranging a communication relay device that relays communication between a plurality of wireless terminal devices and a communication network and controlling communication in the communication relay device, the method includes:
A first step of determining whether or not the received packet is based on a priority control method and outputting priority presence / absence information indicating the presence / absence of priority information;
A second step of determining a direction of output based on a passage route of the received packet and outputting route identification information based on the determination;
The type of the packet is determined according to priority presence / absence information not including the priority information, the priority of the packet is determined for the determined packet type, and the setting value indicating the priority is given priority to the packet Including a third step of adding as information The method according to claim 5, wherein the third step is a fourth step of determining a type of the packet for the packet not including the priority information, and outputting the determined identification information;
A fifth step of associating a priority with a setting value corresponding to the identification information and using the priority information;
And a sixth step of adding the priority information to the supplied packet.   7. The method according to claim 5, wherein the priority is in the order of priority information included in the packet, SIP (Session Initiation Protocol) setting value and RTP (Real-time Transport Protocol) setting value. Is added to the packet.

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