JP5033603B2 - Wireless communication terminal, wireless base station, and packet communication method - Google Patents

Description

  The present invention relates to a wireless communication terminal, a wireless base station, and a packet communication method that transmit and receive multiple types of packets.

  In wireless communication systems, it is becoming common to transmit packets that are required to suppress transmission delay, such as packets that include encoded audio data. On the other hand, packets with low necessity for suppressing transmission delay, such as control packets including control data used for establishing and maintaining communication, are also transmitted.

  For this reason, a technique for setting a first communication session and a second communication session between a wireless communication terminal and a communication destination device of the wireless communication terminal is known ((X.S0011-004-D “cdma2000 (See Wireless IP Network Standard: Quality of Service and Header Reduction "(3GPP2).) The first communication session is used to transmit a specific type of packet, specifically, a packet that is required to suppress transmission delay. The second communication session is a logical communication path used for transmission of a packet of a type different from the specific type of packet.

  In such a technique, QoS control that gives priority to a packet transmitted using the first communication session over a packet transmitted using the second communication session is possible, and transmission of the packet transmitted by the first communication session is possible. Delay can be suppressed.

Further, a method has been proposed in which a session identifier for identifying a communication session is added to the header of each packet transmitted using each of the first communication session and the second communication session (see Patent Document 1).
Japanese Patent Laying-Open No. 2007-300266 (paragraphs [0002] and [0022])

  By the way, in the wireless communication between the wireless communication terminal and the wireless base station, in order to distinguish the packet transmitted using the first communication session from the packet transmitted using the second communication session, the following (a ) Or (b) may be used.

  (A) A method described in Patent Document 1, that is, a method of adding a session identifier to the header of each packet transmitted using each of the first communication session and the second communication session.

  (B) A method in which addition of a session identifier to a packet transmitted using the first communication session is omitted. Specifically, by setting a dedicated wireless communication channel for the first communication session, a packet transmitted using the first communication session is distinguished from a packet transmitted using the second communication session.

  In the method (a), the first communication session and the second communication session can be set on the same wireless communication channel. Therefore, when the transmission rate per wireless communication channel is high, the transmission rate is maximized. Can be used.

  In the method (b), since the ratio of the header in the packet transmitted using the first communication session (that is, the ratio of overhead) can be reduced, the transmission rate per radio communication channel is low. It is valid.

  Usually, in a wireless communication system, the transmission rate per wireless communication channel changes due to changes in wireless communication quality. However, in the method described in Patent Document 1, since the method (a) is always used, there is a problem that a packet transmission method corresponding to the wireless communication quality cannot be selected.

  Accordingly, the present invention has been made to solve the above-described problem, and a wireless communication terminal capable of selecting a packet transmission method according to wireless communication quality when a plurality of communication sessions are set. An object of the present invention is to provide a radio base station and a packet communication method.

  The first feature of the present invention is that a plurality of types of packets including a specific type of packet (for example, RTP packet) are transmitted to a communication destination device (for example, PDSN 300, SIP telephone 500) via the radio base station (radio base station 200). , Or a wireless communication terminal that transmits and receives to / from the SIP server 600), and is different from the first communication session (auxiliary service instance ASI) that is a logical communication path used for transmission of the specific type packet and the specific type packet. A communication session setting unit (control unit 110) for setting a second communication session (main service instance MSI), which is a logical communication path used for transmission of a type of packet, with the communication destination device; A radio quality information acquisition unit (for example, a modulation class) that indicates radio quality between stations. A session identifier (service instance flow ID) for identifying transmission using the first communication session according to the wireless quality information acquired by the line quality information acquiring unit 163) and the wireless quality information acquiring unit ) Is added to the packet of the specific type (channel sharing method), or the second packet transmission method (channel occupancy method) of omitting the addition of the session identifier to the packet of the specific type A packet transmission method selection unit (method selection unit 164) for selecting the session identifier addition for adding the session identifier to the specific type of packet when the first packet transmission method is selected by the packet transmission method selection unit Unit (control unit 110), the session identifier adding unit, If the by serial packet transmission scheme selection section second packet transmission method is selected, and the gist of omitting the addition of the session identifier for the particular type of packet.

  According to such a feature, it is possible to provide a wireless communication terminal capable of selecting a packet transmission method according to wireless communication quality when a plurality of communication sessions are set.

  A second feature of the present invention relates to the first feature of the present invention, wherein the packet transmission method selection unit determines whether or not the wireless quality is improved based on the wireless quality information, and The gist is to select the first packet transmission method when it is determined that the wireless quality is improved.

  A third feature of the present invention relates to the first feature of the present invention, wherein the packet transmission method selection unit determines whether or not the wireless quality has deteriorated based on the wireless quality information, and The gist is to select the second packet transmission method when it is determined that the quality has deteriorated.

  A fourth feature of the present invention relates to the first feature of the present invention, wherein a wireless communication channel (wireless communication channel CH) configured using at least one physical channel defined by a physical resource is defined as the wireless base station. A wireless communication channel setting unit (wireless communication unit 102) set between the communication session setting unit and the communication session setting unit when the first packet transmission method is selected by the packet transmission method selection unit. The gist is to set the first communication session and the second communication session on a wireless communication channel.

  A fifth feature of the present invention is according to the fourth feature of the present invention, wherein the wireless communication channel setting unit is configured to perform the first communication when the second packet transmission method is selected by the packet transmission method selection unit. The wireless communication channel dedicated to the session is set, and the communication session setting unit, on the wireless communication channel dedicated to the first communication session, when the second packet transmission method is selected by the packet transmission method selection unit The gist is to set the first communication session.

  A sixth feature of the present invention relates to the first feature of the present invention, wherein the packet of the specific type is a packet that requires a small transmission delay compared to a packet of a type different from the packet of the specific type. It is a summary.

  A seventh feature of the present invention is a radio base station (radio base station 200) that transmits / receives a plurality of types of packets including a packet of a specific type to / from a radio communication terminal (radio communication terminal 100). A first communication session, which is a logical communication path used for transmission of a packet, and a second communication session, which is a logical communication path used for transmission of a packet of a type different from the specific type of packet, between the wireless communication terminal and the wireless A wireless indicating a wireless quality between a communication session setting unit (control unit 210) set with a communication destination device of the communication terminal (for example, PDSN 300, SIP telephone 500, or SIP server 600) and the wireless communication terminal. Radio quality information acquisition unit (radio quality information acquisition unit 263) for acquiring quality information, and the radio quality acquired by the radio quality information acquisition unit Depending on the information, a first packet transmission method for adding a session identifier for identifying the transmission using the first communication session to the packet of the specific type, or adding the session identifier to the packet of the specific type When a packet transmission method selection unit (method selection unit 264) that selects one of the second packet transmission methods to be omitted and the first packet transmission method is selected by the packet transmission method selection unit, the session identifier is A session identifier adding unit (control unit 210) for adding to the packet of the specific type, and the session identifier adding unit, when the second packet transmission method is selected by the packet transmission method selection unit, The main point is to omit the addition of the session identifier to the packet of

  According to such a feature, when a plurality of communication sessions are set, it is possible to provide a radio base station that can select a packet transmission method according to radio communication quality.

  An eighth feature of the present invention is a packet communication method for transmitting and receiving a plurality of types of packets including a specific type of packet via a radio base station between a radio communication terminal and a communication destination device of the radio communication terminal. A first communication session which is a logical communication path used for transmission of the packet of the specific type, and a second communication session which is a logical communication path used for transmission of a packet of a type different from the packet of the specific type, Obtained by setting between the radio communication terminal and the communication destination device, obtaining radio quality information indicating radio quality between the radio communication terminal and the radio base station, and obtaining A session identifier for identifying transmission using the second communication session is added to the packet of the specific type according to the radio quality information The first packet transmission method is selected by the step of selecting either the first packet transmission method or the second packet transmission method that omits the addition of the session identifier to the specific type of packet, and the selecting step. If the second packet transmission method is selected by the step of adding the session identifier to the packet of the specific type and the step of selecting, the step of omitting the addition of the session identifier to the packet of the specific type It is a summary to provide.

  According to such a feature, it is possible to provide a packet communication method capable of selecting a packet transmission method according to wireless communication quality when a plurality of communication sessions are set.

  According to the present invention, it is possible to provide a radio communication terminal, a radio base station, and a packet communication method capable of selecting a packet transmission method according to radio communication quality when a plurality of communication sessions are set. .

  Next, a communication system according to an embodiment of the present invention will be described with reference to the drawings. In the description of the drawings in the following embodiments, the same or similar parts are denoted by the same or similar reference numerals.

  In the following, (1) Overview of communication system, (2) Configuration of communication system, (3) Channel sharing method and channel occupation method, (4) Packet configuration in each service instance, (5) Packet flow control processing, ( 6) Communication frame configuration and adaptive modulation, (7) Detailed operation of communication system, (8) Operation and effect, (9) Other embodiments will be described in this order.

(1) Overview of Communication System First, a schematic configuration of a communication system according to the present embodiment will be described with reference to FIGS. Specifically, (1.1) overall configuration of communication system, (1.2) schematic operation of communication system, and (1.3) protocol stack will be described.

(1.1) Overall Configuration of Communication System FIG. 1 is an overall schematic configuration diagram of a communication system 10 according to the present embodiment. In the present embodiment, a communication system 10 applied to a VoIP (Voice over Internet Protocol) application will be described.

  As shown in FIG. 1, a communication system 10 according to this embodiment includes a radio communication terminal 100, a radio base station 200, a PDSN (Packet Data Serving Node) 300, the Internet 400, a SIP (Session Initiation Protocol: RFC 3261 IETF) telephone. 500 and a SIP server 600.

  The radio communication terminal 100 and the radio base station 200 have a configuration based on an iBurst (registered trademark) system that is a radio communication system capable of high-speed communication (for iBurst, “High Capacity-Spatial Division Multiple Access (HC- SDMA) ”ATIS-PP-0700-004.2007 (ATIS / ANSI)). In the iBurst system, TDMA and SDMA / TDD communication systems are used.

  The wireless communication terminal 100, the wireless base station 200, and the PDSN 300 are connected to the X. It corresponds to the QoS control according to S0011-004-D. X. In S0011-004-D, the QoS of the packet flow transmitted and received by the real-time application is guaranteed by a bandwidth reservation mechanism.

  X. In the QoS control in S0011-004-D, a plurality of service instances are configured in one PPP (Point to Point Protocol) connection. In this embodiment, a service instance is an abstract example of a propagation path that carries a packet flow. In S0011-004-D, service option (SO) types each having a different function are made.

  In this way, fine QoS control is realized by setting a plurality of service instances and giving different QoS for each service instance.

(1.2) Schematic Operation of Communication System FIG. 2 is a functional block configuration diagram for explaining a schematic operation of the communication system 10. In FIG. 2, the wireless communication terminal 100 includes a SIP client unit 151 and a G729A codec 152. The SIP telephone 500 has a G729A codec 551.

  First, the wireless communication terminal 100 requests the wireless base station 200 for wireless connection. The radio base station 200 accepts a radio connection request from the radio communication terminal 100.

  Then, the radio communication terminal 100 and the radio base station 200 set a radio communication channel CH. The radio communication channel CH is configured using at least one physical channel. In this embodiment, the time slot corresponds to a physical channel.

  The radio base station 200 has a function of relaying a packet flow transmitted and received between the radio communication terminal 100 and the PDSN 300. In addition, the radio base station 200 sets an A10 connection with the PDSN 300 using the A11 signaling protocol.

  The radio communication terminal 100, the radio base station 200, and the PDSN 300 establish a main service instance (second communication session) MSI between the radio communication terminal 100 and the PDSN 300 after setting the radio communication channel CH and the A10 connection. .

  The wireless communication terminal 100 first establishes a main service instance MSI at the start of communication such as when the power is turned on. In the present embodiment, the main service instance MSI is established on one physical channel when the PPP connection between the wireless communication terminal 100 and the PDSN 300 is established.

  When the service instance is established in a state where the wireless communication terminal 100 has not established a service instance, the wireless communication terminal 100, the wireless base station 200, and the PDSN 300 recognize the established service instance as the main service instance MSI.

  There is only one main service instance MSI per PPP connection. The main service instance MSI is used for transmission of all packet flows that do not pass through other service instances.

  Specifically, the radio communication terminal 100 and the radio base station 200 store the association between the main service instance MSI and the radio communication channel CH. The radio base station 200 and the PDSN 300 store the association between the main service instance MSI and the A10 connection.

  Then, the radio communication terminal 100 transmits a PPP connection request to the PDSN 300 via the main service instance MSI.

  The PDSN 300 has a function as a PPP server, accepts a PPP connection request from the wireless communication terminal 100, and assigns a global IP address to the wireless communication terminal 100.

  As a result, the wireless communication terminal 100 can communicate with a network device connected to the Internet 400 using the global IP address allocated from the PDSN 300. In the present embodiment, the wireless communication terminal 100 executes a SIP phone 500 and a SIP phone.

  When starting a SIP phone, the wireless communication terminal 100 negotiates with the SIP server 600. Then, the wireless communication terminal 100 transmits the X. It negotiates with the PDSN 300 in accordance with RSVP (Resource reSerVation Protocol) defined by S0011-004-D, and establishes an auxiliary service instance (first communication session) ASI.

  Specifically, when the wireless communication terminal 100, the wireless base station 200, and the PDSN 300 have established an additional service instance from a state in which the main service instance MSI has already been established, the service instance is replaced by the auxiliary service instance ASI. Recognize that there is. In this case, the radio communication terminal 100 does not exchange information for establishing PPP with the PDSN 300 and acquire a global IP address.

  A packet type selection method and a transmission method negotiated by RSVP are applied to the auxiliary service instance ASI. As the packet type selection method, for example, contents such as the IP address of the SIP telephone 500, the UDP port number to be used, and the RTP payload being G729A (8 Kbps) are negotiated. As a transmission method, for example, it is negotiated to apply ROHC (RObust Header Compression: RFC 3095 IETF).

  In this way, by limiting the packet types that flow to the auxiliary service instance ASI, a special QoS can be given to the packet flow transmitted and received by the real-time application.

  The radio communication terminal 100 and the radio base station 200 store the association between the auxiliary service instance ASI and the radio communication channel CH. The radio base station 200 and the PDSN 300 store the association between the auxiliary service instance ASI and the A10 connection.

  When the auxiliary service instance ASI is established, the SIP server 600 establishes an RTP session for the SIP telephone between the wireless communication terminal 100 and the SIP telephone 500. SIP is a protocol for connecting a packet stream using the RTP / UDP / IP protocol between arbitrary Internet nodes. When the RTP session is established, the wireless communication terminal 100 can execute the SIP telephone with the SIP telephone 500.

  In the auxiliary service instance ASI, since the type is negotiated in advance for each packet flow, overhead specific to the packet flow can be omitted. For example, X. In the service option 67 (SO67) in S0011-004-D, the auxiliary service instance ASI transmits only a packet to which ROHC is applied in the PPP flow. In SO67, the overhead of PPP is omitted.

(1.3) Protocol Stack Next, a protocol stack in the communication system 10 will be described with reference to FIGS. 3 and 4.

  FIG. 3 is a diagram showing a protocol stack applied to the main service instance MSI in the communication system 10. FIG. 4 is a diagram illustrating a protocol stack applied to the auxiliary service instance ASI in the communication system 10.

  Since the main service instance MSI is used for transmission of all packet flows that do not pass through the auxiliary service instance ASI, ROHC compression is not performed, and no special processing is performed in a layer higher than PPP.

  On the other hand, the auxiliary service instance ASI uses UDP (RFC 768 IETF) and RTP (RFC 1889 IETF) with IP (RFC 791 IETF) as a lower layer to transmit media packets such as voice and moving images. Further, the overhead of the PPP header is removed between the radio communication terminal 100 and the radio base station 200.

  The radio communication terminal 100 and the PDSN 300 are equipped with ROHC. ROHC compresses the total 40 bytes of the RTP / UDP / IP packet header to a minimum of 2 bytes. In voice communication using VoIP, two G729A (8 Kbps) codec packets are stored in one RTP / UDP / IP packet.

  A service instance between the radio base station 200 and the PDSN 300 is realized by an A10 connection in accordance with the GRE (Generic Routing Encapsulation RFC 2784) protocol. A plurality of service instances are established between the radio base station 200 and the PDSN 300 by establishing a plurality of A10 connections in one PPP connection.

(2) Configuration of Communication System Next, configurations of the radio communication terminal 100, the radio base station 200, and the PDSN 300 that configure the communication system 10 will be described with reference to FIGS.

(2.1) Configuration of Radio Communication Terminal FIG. 5 is a functional block configuration diagram of the radio communication terminal 100. As illustrated in FIG. 5, the wireless communication terminal 100 includes an antenna 101, a wireless communication unit 102, a keypad 103, a microphone 104, a speaker 105, a G729A codec 152, and a control unit 110.

  In the present embodiment, the control unit 110 functions as a communication session setting unit that sets a main service instance MSI (second communication session) and an auxiliary service instance ASI (first communication session). In addition, the control unit 110 functions as an identifier adding unit that adds an identifier for identifying the auxiliary service instance ASI to the packet.

  Further, the control unit 110 includes a reception data buffer 111, a reception flow control unit 112, a ROHC expansion unit, an IP protocol stack management unit 114, an RTP / UDP / IP packet management unit 115, an RSVP client unit 116, a PPP client unit 117, DHCP. The client unit 118, the SIP protocol management unit 119, the ROHC compression unit 120, the L4 packet construction units 121 and 122, the transmission flow control unit 123, the radio quality information acquisition unit 163, and the method selection unit 164 are included.

  The radio communication unit 102 sets a radio communication channel CH with the radio base station 200. Further, the radio communication unit 102 performs adaptive modulation (link adaptation) based on the received SINR.

  The transmission flow control unit 123 has a function of negotiating with the radio base station 200. The transmission flow control unit 123 stores and holds contexts such as a packet context, service option type, and flow ID of the auxiliary service instance ASI.

  The radio quality information acquisition unit 163 acquires radio quality information indicating radio quality with the radio base station 200 from the radio communication unit 102. The method selection unit 164 selects either a channel sharing method or a channel occupation method described later according to the radio quality information.

  The G729A codec 152 samples the audio data from the microphone 104 and converts it into a codec payload.

  The converted voice data is compressed by the ROHC compression unit 120 via the RTP / UDP / IP packet management unit 115. The RTP / UDP / IP packet subjected to ROHC compression is transmitted via the L4 packet construction unit 121 and the transmission flow control unit 123.

  At that time, the radio communication unit 102 transmits to the radio base station 200 using the radio communication channel CH corresponding to the auxiliary service instance ASI.

  When the wireless communication unit 102 receives a packet from the wireless communication channel CH corresponding to the auxiliary service instance ASI, the received packet is input to the reception flow control unit 112 via the reception data buffer 111.

  The reception flow control unit 112 controls whether the received packet is input to the ROHC expansion unit 113 or the IP protocol stack management unit 114 according to the type of service instance associated with the wireless communication channel CH.

  The G729A codec 152 converts G729A (8 Kbps) audio data received from the radio base station 200 into audio data, and outputs the audio data from the speaker 105.

  The detailed operation of each buffer (data queue) will be described later.

(2.2) Configuration of Radio Base Station 200 FIG. 6 is a functional block configuration diagram of the radio base station 200. As illustrated in FIG. 6, the radio base station 200 includes an antenna 201, a radio communication unit 202, an A10 / GRE communication unit 203, and a control unit 210.

  The control unit 210 includes a reception packet buffer 211, a reception flow control unit 212, an A10 / GRE packet construction unit 213, 214, transmission buffers 215, 216, a reception flow control unit 217, an L4 packet construction unit 218, 219, and a transmission flow control. Part 220.

  The A10 / GRE communication unit 203 is a functional block that realizes an interface with the PDSN 300. A received packet from the A10 / GRE communication unit 203 is sent to the reception flow control unit 217.

  The transmission flow control unit 220 transmits the received packet to the transmission buffer for the radio communication channel CH associated with the main service instance MSI according to the service instance type associated with the A10 connection, or supports the auxiliary service instance ASI. The transmission is switched to the transmission buffer for the attached radio communication channel CH.

  In addition, the transmission flow control unit 220 negotiates with the wireless communication terminal 100 and stores and holds the packet context of the auxiliary service instance ASI.

  The wireless communication unit 202 is a functional block that establishes a wireless communication channel CH with the wireless communication terminal 100 and realizes an interface with the wireless communication terminal 100.

  The reception flow control unit 212 transmits the reception packet to the transmission buffer for the A10 connection channel associated with the main service instance MSI according to the service instance type associated with the radio communication channel CH, or sends the reception packet to the auxiliary service instance ASI. Whether to transmit to the transmission buffer for the associated A10 connection channel is switched.

(2.3) Configuration of PDSN 300 FIG. 7 is a functional block configuration diagram of the PDSN 300. As illustrated in FIG. 7, the PDSN 300 includes an A10 / GRE communication unit 301, an LL / PL transmission / reception unit 302, and a control unit 310.

  The LL / PL transmission / reception unit 302 is a functional block that implements an interface with the Internet 400 at the link layer (LL) and physical layer (PL) levels. The A10 / GRE communication unit 301 is a functional block that realizes an interface with the radio base station 200.

  The control unit 310 includes a reception packet buffer 313, a reception flow control unit 314, an A10 / GRE packet removal unit 315, 316, an IP protocol stack management unit 317, a PPP server unit 318, an RSVP server unit 319, a DHCP server unit 320, and ROHC expansion. Unit 321, transmission buffer 322, reception packet buffer 323, packet filter 324, ROHC compression unit 325, A10 / GRE packet construction units 326 and 327, and transmission flow control unit 328.

  Packets from the LL / PL transmission / reception unit 302 are distributed by the packet filter 324 in accordance with the standard negotiated with the wireless communication terminal 100 by RSVP. Specifically, the packet filter 324 sends the packet to either the A10 / GRE packet construction unit 326 associated with the auxiliary service instance ASI or the A10 / GRE packet construction unit 327 associated with the main service instance MSI. Distribute.

  Further, the transmission flow control unit 328 negotiates with the PDSN 300 using the RSVP protocol with the wireless communication terminal 100, and stores and holds contexts such as service options and flow IDs.

  Among the received packets from the A10 / GRE communication unit 301, packets included in the main service instance MSI include packets such as PPP and RSVP from the radio communication terminal 100 to the PDSN 300, for example. The reception flow control unit 314 inputs a packet for the PDSN 300 to the IP protocol stack management unit 317.

  Packets other than those addressed to the PDSN 300 via the main service instance MSI are sent to the LL / PL transmission / reception unit 302 after the A10 / GRE packet removal units 315 and 316 remove the A10 / GRE header.

  When the reception flow control unit 314 receives a packet that has passed through the auxiliary service instance ASI among the received packets, the reception flow control unit 314 inputs the packet to the ROHC expansion unit 321 after removing A10 / GRE. The ROHC expansion unit 321 restores the IP packet by ROHC expansion, and then sends the IP packet to the LL / PL transmission / reception unit 302.

(3) Channel Sharing Method and Channel Occupancy Method Next, the channel sharing method and the channel occupation method will be described with reference to FIG. Specifically, a specific method for setting a service instance in wireless communication between the wireless communication terminal 100 and the wireless base station 200 will be described.

(3.1) Channel sharing method (first packet transmission method)
As shown in FIG. 8, in the channel sharing scheme, the radio communication terminal 100 and the radio base station 200 set a main service instance MSI and an auxiliary service instance ASI on one radio communication channel CH.

  For this reason, in the channel sharing method, an identifier for identifying the service instance is embedded as an overhead in the header of the packet P1 transmitted via the auxiliary service instance ASI. In the present embodiment, the identifier is referred to as a service instance flow ID (session identifier).

  In this way, a plurality of service instances can share one radio communication channel CH in exchange for overhead. When the bandwidth of the radio communication channel CH is wide and the overhead is sufficiently small, the reduction in bandwidth due to such overhead is not dominant.

  Therefore, according to the channel sharing method, the radio communication terminal 100 and the radio base station 200 can effectively use the bandwidth when the bandwidth of the radio communication channel CH is wide. In the present embodiment, it is assumed that the channel sharing method is selected when communication between the radio communication terminal 100 and the radio base station 200 is started.

  Furthermore, the packet P1 for other uses with lower priority can be transmitted using the main service instance MSI. At this time, since only one radio communication channel CH is used, other radio communication channels CH can be used for other purposes, and radio communication resources can be used effectively.

  On the other hand, when the wireless communication terminal 100 is located at a cell edge, for example, there may be a case where only a very narrow bandwidth can be secured. Therefore, the bandwidth reduction caused by the overhead due to the service instance flow ID may be relatively non-negligible.

  Further, in the channel sharing method, when the radio band becomes extremely low, it becomes impossible to transmit packets with low priority. Alternatively, if the packet is transmitted, the throughput of the packet P1 having a high priority is reduced.

  Note that the packet P2 having a low priority order is often large because it is not compressed by ROHC or the like. In the case of data packets such as FTP and HTTP, even if the frequency is low, the band that is temporarily used tends to increase.

  Further, in the channel sharing method, it is difficult to perform fine QoS control closely to the physical layer for each service instance.

(3.2) Channel occupation method (second packet transmission method)
In the channel occupation method, the radio communication terminal 100 and the radio base station 200 set a radio communication channel CH2 dedicated to the auxiliary service instance ASI. Then, the radio communication terminal 100 and the radio base station 200 set the auxiliary service instance ASI on the radio communication channel CH2 dedicated to the auxiliary service instance ASI.

  According to the channel occupation method, since the overhead common to the packet P1 transmitted via the auxiliary service instance ASI is obvious, the overhead by the service instance flow ID for identifying the auxiliary service instance ASI is omitted. Is possible.

  Furthermore, since another radio communication channel CH1 can be assigned to the main service instance MSI, a packet P2 having a low priority can be transmitted using the main service instance MSI.

  On the other hand, it becomes difficult to use the bandwidth that is the remaining capacity of the radio communication channels CH1 and CH2. That is, instead of occupying the radio communication channel CH2, the advantage of omitting overhead is obtained, so that the surplus bandwidth of the radio communication channels CH1 and CH2 is sacrificed.

(3.3) Switching process between channel sharing method and channel occupation method The radio communication terminal 100 switches between the channel sharing method and the channel occupation method according to the radio quality with the radio base station 200. Specifically, the wireless communication terminal 100 compares the wireless quality with a threshold value, and selects either the channel sharing method or the channel occupation method according to the comparison result. Specific examples of communication quality criteria will be described later.

  The radio communication terminal 100 selects the channel sharing method when the radio quality is improved, and selects the channel occupation method when the radio quality is deteriorated.

  If the radio quality is good and there is enough surplus bandwidth even if a service instance is assigned to one radio communication channel CH, the radio communication terminal 100 selects the channel sharing method. In the channel sharing method, the excess throughput can be used for other applications where priority is lowered.

  On the other hand, when the radio quality is poor and it is difficult to secure the bandwidth, the radio communication terminal 100 selects the channel occupation method. In the channel occupation method, the overhead can be minimized and the bandwidth that the auxiliary service instance ASI can use can be guaranteed as much as possible.

  In the channel sharing method, there is a portion where QoS becomes common, but since the bandwidth is sufficient, sufficient packet transmission quality can be ensured without giving so close QoS control.

  On the other hand, in the channel occupation method, the radio communication channel CH2 is occupied by the auxiliary service instance ASI having a high priority that requires QoS control, thereby closely contacting the physical layer and L2 (corresponding to the second layer of the OSI reference model). Detailed QoS control can be performed individually. Therefore, it is possible to carefully care for a narrow band, and it is possible to ensure sufficient transmission quality.

  However, since the resources are limited, it is not always possible to assign the radio communication channel CH2 to the radio communication terminal 100 in the channel occupation method.

  On the other hand, in the channel sharing method, since the logical channel is divided, the resource limit can be relaxed much more. For this reason, it is highly possible that the radio communication channel CH can be allocated in accordance with a request from the radio communication terminal 100.

  Therefore, when the channel sharing method is selected at the start of communication, it is possible to avoid the inability to establish a VoIP session due to the inability to allocate resources.

(4) Packet Configuration in Each Service Instance Next, the packet configuration in each service instance will be described with reference to FIGS.

(4.1) Packet Configuration in Main Service Instance FIG. 9 is a table showing payload and header sizes in the main service instance MSI.

  In FIG. 9, the PPP header is a header defined by RFC1662: PPP in HDLC-like Framing.

  As described above, the service instance flow ID is an identifier for identifying a service instance, and is determined by negotiation between the radio base station 200 and the radio communication terminal 100 when each service instance is established.

  Note that the L3 delimiter is a delimiter tag for extracting an L3 packet from an octet string carried in an octet stream in a higher layer than the physical layer and L2, and displays the position of the next delimiter tag.

  The octet stream from the physical layer is rearranged in the order intended by the transmission side by the function of ARQ (automatic retransmission control) in L2, and passed to the upper layer.

  However, since it is passed as an octet stream, a mechanism for extracting the L3 packet is required. The L3 delimiter designates the position up to the next delimiter and becomes an overhead for clearly indicating the delimiter of the L3 packet, and the receiving side realizes clipping of the L3 packet based on the delimiter.

(4.2) Packet Configuration in Auxiliary Service Instance (When Channel Sharing Method) FIG. 10 is a table showing payload and header sizes in the auxiliary service instance ASI (when channel sharing method).

  In FIG. 10, the meaning of each overhead is the same as in the case of the main service instance, but since the service option 67 (SO67) is selected as the auxiliary service instance ASI, the overhead of the PPP header is omitted. Instead, the protocol distributed in the upper layer is limited to ROHC.

  In the auxiliary service instance ASI, overhead in the PPP header is omitted. Context information such as a protocol field is implicitly transmitted by being negotiated between the PDSN 300 and the wireless communication terminal 100 by the RSVP protocol.

  A field having a fixed value is supplemented with a fixed value on the receiving side as implicit transmission. The FCS field is also implicitly transmitted, and the receiving side complements the data by calculating the data length using the L3 delimiter and then recalculating the FCS.

(4.3) Packet Configuration in Auxiliary Service Instance (at Channel Occupancy Mode) FIG. 11 is a table showing the payload and header sizes in the auxiliary service instance ASI (at channel occupation mode).

  In FIG. 11, the meaning of each overhead is the same as in the case of the main service instance. Since the channel is occupied, the service instance flow ID is self-explanatory and is omitted.

(5) Packet Flow Control Processing Next, packet flow control processing executed in the radio communication terminal 100 and the radio base station 200 will be described.

  When the UDP protocol is used in the VoIP application, data retransmission in the upper layer is not performed. The CODEC payload that misses the playback opportunity due to the delay is discarded by the application.

  Therefore, in the VoIP application, in order to ensure the transmission reliability of the delayed data, rather than causing the arrival delay of the subsequent data, the packet that is delayed beyond the tolerance is positively discarded, and the subsequent data is transmitted in real time. It may be more effective to maintain the subjective voice quality to improve the possibility of arriving at.

  Therefore, if retransmission of a packet delayed beyond the limit is suppressed, a transmission path suitable for a VoIP application can be provided.

  Transmission of data from the radio communication terminal 100 to the radio base station 200 and data from the radio base station 200 to the radio communication terminal 100 may be delayed due to radio quality degradation.

  In such a case, the transmission data is stored in the transmission buffer on the transmission side, and waits until the wireless quality is improved and transmission is possible. However, there may be a case where the wireless quality is not improved. In that case, the transmission buffer overflows due to the arrival of subsequent data, and older data must be discarded.

  Since the packet transmitted via the auxiliary service instance ASI is RTP / UDP / IP using G729A voice data as the RTP payload, real time arrival is ensured even if the packet is discarded rather than improving the reliability of arrival by retransmission. It can be said that the subjective voice quality is better.

  Therefore, the radio communication terminal 100 and the radio base station 200 control the auxiliary service instance ASI so as to reduce the size of the transmission buffer and positively discard past packets for about 3 seconds or more.

  On the other hand, for the main service instance MSI, the radio communication terminal 100 and the radio base station 200 prepare a relatively large transmission buffer in consideration of the distribution of important data for maintaining the SIP telephone. As a result, control is performed so that packet discarding does not occur as much as possible.

  Due to the difference in transmission buffer size between the main service instance MSI and the auxiliary service instance ASI, the main service instance MSI is given a QoS that avoids packet loss and improves the data arrival reliability. QoS that increases the accuracy of arrival will be given.

(5.1) Packet Flow Control Processing in Channel Sharing Method FIG. 12 is a diagram for explaining packet flow control processing in the channel sharing method. Each functional block shown in FIG. 12 is provided in each transmission flow control unit, each reception flow control unit, and each buffer shown in FIGS.

  As shown in FIG. 12A, at the time of transmission, packets flowing through all service instances are temporarily stored in transmission data queues 801A and 801B prepared independently for each service instance. Corresponding service instance flow ID is added. Furthermore, in the case of the auxiliary service instance ASI, the PPP header is removed.

  Thereafter, the flow control unit 802 transfers the packet to the queue 804 to L3 according to the priority order in accordance with the flow rate. If there is enough bandwidth, all packets are transferred to the queue 804 to L3.

  When the bandwidth is narrow, the bandwidth control unit 803 preferentially transfers the auxiliary service instance ASI to the queue 804 to L3. When the bandwidth is further narrowed, the bandwidth control unit 803 performs control of discarding packets that remain in the data queue of the auxiliary service instance ASI in order from the oldest.

  As shown in FIG. 12B, at the time of reception, the L4 flow separation unit 606 distributes the packet from L3 to each service instance using the service instance / flow ID as a mark. For the auxiliary service instance ASI, the flow control unit 802 reconstructs the PPP header from the context information for each auxiliary service instance ASI, and reconstructs the upper data packet.

(5.2) Packet Flow Control Processing in Channel Occupancy Method FIG. 13 is a diagram for explaining packet flow control processing in the channel occupation method. Each functional block shown in FIG. 13 is provided in each transmission flow control unit, each reception flow control unit, and each buffer shown in FIGS.

  As shown in FIG. 13A, the bandwidth controller 803 discards only packets that flow through the auxiliary service instance ASI. The other points are the same as in FIG.

  As shown in FIG. 13B, for the auxiliary service instance ASI, the distribution using the identification information (specifically, the time slot number) of the wireless communication channel and the related information of the flow ID of the auxiliary service instance ASI. Is done. The other points are the same as in FIG.

(6) Communication Frame Configuration and Adaptive Modulation Next, the communication frame configuration and adaptive modulation will be described using FIG. 14 and FIG.

(6.1) Communication Frame Configuration FIG. 14 is a frame configuration diagram of a communication frame used for radio communication between the radio communication terminal 100 and the radio base station 200.

  In response to a wireless connection request from the wireless communication terminal 100, the wireless base station 200 establishes a wireless communication channel CH using one time slot (physical channel) according to TDMA-TDD.

  In FIG. 14, the uplink (the direction from the radio communication terminal 100 to the radio base station 200) and the downlink (the direction from the radio base station 200 to the radio communication terminal 100) are multiplexed by the TDMA scheme.

  The time slot has an asymmetric configuration between the uplink and the downlink. An uplink slot and a downlink slot with time slot number 1 are paired and assigned to one wireless communication terminal 100.

  The main service instance MSI is established on the time slot of slot number 1, and 1 is assigned as the service instance flow ID.

(6.2) Adaptive Modulation FIG. 15 is a diagram illustrating modulation classes of adaptive modulation executed in the radio communication terminal 100 and the radio base station 200.

  The radio communication terminal 100 and the radio base station 200 support a modulation class represented by a combination of a plurality of modulation schemes and coding rates. The throughput in FIG. 15 indicates the physical channel throughput per physical channel.

  The required SINR is defined in the modulation class. The higher the required SINR, the higher the throughput. The lower the required SINR, the smaller the throughput.

  When the received SINR exceeds the required SINR, the radio communication terminal 100 and the radio base station 200 ensure high throughput by selecting the highest possible modulation class.

  When the received SINR is low, the radio communication terminal 100 and the radio base station 200 perform control so that communication can be continued by selecting a lower modulation class.

  When the auxiliary service instance ASI is the channel occupation method, the radio communication terminal 100 monitors the modulation class used for transmission and reception. When one of the modulation classes is less than 3, the radio communication terminal 100 determines that the transmission capacity of the physical channel is not sufficient, and continues the channel occupation method.

  When both of the modulation classes are 3 or more, the wireless communication terminal 100 determines that the transmission capacity of the physical channel is sufficient, and changes from the channel occupation method to the channel sharing method.

  As a result, under a situation where a modulation class having high throughput is selected, it is possible to perform a suitable VoIP by allocating a band to the auxiliary service instance ASI using the channel sharing method. On the other hand, under a situation where low throughput is predominantly selected, the channel occupation method is used to reduce the overhead to the limit.

(7) Detailed Operation of Communication System Next, detailed operation of the communication system 10 will be described with reference to FIGS.

(7.1) Service Instance Setting Operation FIG. 16 is a sequence diagram showing a service instance setting operation in the communication system 10.

  In step S102, the radio communication terminal 100 and the radio base station 200 establish a radio communication channel CH using the time slot of slot number 0.

  In step S104, the radio communication terminal 100 transmits a main service instance assignment request message to the radio base station 200. At this time, the wireless communication terminal 100 designates a flow profile. Since the specified profile is the main service instance, the flow ID is 1, the service option is SO59, and new and shared are specified as additional attributes.

  In step S105, the radio base station 200 requests the PDSN 300 to establish a main service instance using the A11 signaling protocol according to the content of the profile requested from the radio communication terminal 100.

  In step S106, the PDSN 300 transmits a response message to the request in step S105 to the radio base station 200.

  In step S107, the radio base station 200 transmits a main service instance assignment response message to the radio communication terminal 100.

  In step S108, the main service instance MSI is established among the radio communication terminal 100, the radio base station 200, and the PDSN 300.

  In step S <b> 109, the wireless communication terminal 100 executes a PPP connection establishment sequence with the PDSN 300. In the PPP connection establishment sequence, the PDSN 300 assigns a global IP address to the wireless communication terminal 100.

  In step S110, a PPP connection is established among the radio communication terminal 100, the radio base station 200, and the PDSN 300.

In steps S111 to S117, the wireless communication terminal 100 recognizes the use of the SIP telephone by the user, and performs the following using the main service instance MSI.
-Message exchange for SIP call with SIP server 600-Context exchange of auxiliary service instance ASI by RSVP with PDSN 300-Message for establishment of auxiliary service instance ASI with radio base station 200 Exchange

  Since the auxiliary service instance ASI between the radio communication terminal 100 and the radio base station 200 is not established at this time, it is established by the channel sharing method. Specifically, the auxiliary service instance ASI is allocated in such a manner that the physical channel of slot number 1 is shared. At this time, the wireless communication terminal 100 designates a flow profile.

  In step S113, since the profile to be specified is the auxiliary service instance ASI, the wireless communication terminal 100 sets the flow ID to a unique number of 2 or more, sets the service option to SO67, and specifies new and shared as additional attributes.

  In step S114, the radio base station 200 requests the PDSN 300 to establish an auxiliary service instance ASI using the content of the profile requested from the radio communication terminal 100 using the A11 signaling protocol. In step S115 and step S116, a response message is transmitted to the wireless communication terminal 100.

  In step S117, an auxiliary service instance ASI is established among the radio communication terminal 100, the radio base station 200, and the PDSN 300. Thereafter, the wireless communication terminal 100 exchanges packet contexts with the PDSN 300 by RSVP.

  With the above sequence, the main service instance and the auxiliary service instance ASI are established among the radio communication terminal 100, the radio base station 200, and the PDSN 300. The service instance flow ID, the slot number, and the context of the service instance are stored in association with each other in the radio base station 200 and the radio communication terminal 100.

  Note that the auxiliary service instance ASI between the radio communication terminal 100 and the radio base station 200 is realized by a channel sharing method.

(7.2) Switching Operation from Channel Sharing Method to Channel Occupation Method FIG. 17 is a sequence diagram showing switching operation from the channel sharing method to the channel occupation method.

  Here, the auxiliary service instance ASI by the channel sharing method is established so as to be shared with the main service instance on the physical channel of slot number 1. The service instance / flow ID is assigned a unique number of 2 or more.

  In step S <b> 201, the radio communication terminal 100 establishes a physical channel with slot number 2 with the radio base station 200.

  In step S202, the radio communication terminal 100 transmits an auxiliary service instance allocation request message to the radio base station 200. At this time, in the specified profile, the service instance flow ID and the service option number are set to the same values as those already assigned to the auxiliary service instance ASI. The radio communication terminal 100 designates the time slot number as 2 and designates switching and occupation as additional attributes.

  In step S203, the radio base station 200 transmits a flow assignment response message to the radio communication terminal 100.

  In step S204, the auxiliary service instance ASI is switched in the radio communication terminal 100, the radio base station 200, and the PDSN 300. Specifically, the auxiliary service instance ASI is cut out from the physical channel (wireless communication channel) of time slot number 1 to the physical channel (wireless communication channel) of time slot number 2.

  In step S205 and step S206, the packet is transmitted using the auxiliary service instance ASI after switching.

  With the above sequence, switching from the channel sharing method to the channel occupation method is realized.

(7.3) Switching Operation from Channel Occupation Method to Channel Sharing Method FIG. 18 is a sequence diagram showing a switching operation from the channel occupation method to the channel sharing method.

  Here, the auxiliary service instance ASI based on the channel occupation method is always established with a slot number other than 1, and a unique number of 2 or more is assigned to the service instance flow ID.

  In step S301, the radio communication terminal 100 transmits an auxiliary service instance assignment request message to the radio base station 200. In the profile, the time slot number is designated as 1, and switching and sharing are designated as additional attributes.

  After the switching of the auxiliary service instance ASI is completed, in step S304, the radio communication terminal 100 and the radio base station 200 disconnect an unnecessary physical channel of slot number 2. PDSN 300 is not particularly related to this sequence.

(8) Operation and Effect According to the present embodiment, the wireless communication terminal 100 that transmits and receives a plurality of types of packets including RTP packets to and from the PDSN 300 via the wireless base station 200 is a logical communication path used for transmission of RTP packets. And an auxiliary service instance ASI and a main service instance MSI, which is a logical communication path used for transmission of a packet of a type different from the RTP packet, are set between the PDSN 300.

  The radio communication terminal 100 acquires modulation class identification information for identifying a modulation class corresponding to radio quality with the radio base station 200 as communication quality information.

  Then, the wireless communication terminal 100 uses a channel sharing method for adding a service instance flow ID for identifying transmission using the auxiliary service instance ASI to the RTP packet according to the communication quality information, or a service instance for the RTP packet. -Select one of the channel occupation methods that omits the addition of the flow ID.

  When the channel sharing method is selected, the wireless communication terminal 100 adds a service instance / flow ID to the RTP packet. On the other hand, when the channel occupation method is selected, the wireless communication terminal 100 omits the addition of the service instance / flow ID to the RTP packet.

  Therefore, when a plurality of service instances are set, it is possible to provide radio communication terminal 100 that can select a packet transmission scheme according to radio communication quality.

  According to the present embodiment, the radio communication terminal 100 determines whether or not the radio quality is improved based on the radio quality information, and when it is determined that the radio quality is improved, the channel sharing scheme is set. select. In the channel sharing method, the radio communication terminal 100 sets the auxiliary service instance ASI and the main service instance MSI on the same radio communication channel CH.

  Further, according to the present embodiment, the radio communication terminal 100 determines whether or not the radio quality has deteriorated based on the radio quality information, and determines that the channel occupancy method is used when it is determined that the radio quality has deteriorated. select. In the channel occupation method, the radio communication terminal 100 sets the auxiliary service instance ASI on the radio communication channel CH dedicated to the auxiliary service instance ASI.

  Therefore, it is possible to achieve both the effective use of the surplus bandwidth when the radio quality is good, the overhead reduction when the radio quality is bad, and the fine QoS control closely adhered to the physical layer.

(9) Other Embodiments As described above, the present invention has been described according to the embodiment. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

(9.1) Example of Changing Communication Quality Information In the above-described embodiment, a method of comparing a modulation class selected with a threshold value serving as a switching criterion is used as a switching criterion between the channel occupation method and the channel sharing method. It was.

  However, as a finer control method, it is also effective to provide a means for measuring the data throughput that passes through L2 and a table for storing a threshold value for comparison with this throughput, and perform switching by comparing the two. .

  Although the modulation class used is high, the situation where there are many FERs frequently occurs in actual operation. In such a case, a better result can be obtained by taking into account how much throughput is actually obtained.

(9.2) Modification Example of Auxiliary Service Instance FIG. 19 is a diagram illustrating a modification example of the auxiliary service instance. As shown in FIG. 19, there may be a plurality of auxiliary service instances ASI.

  In the case of an application such as a videophone, the voice packet flow and the image packet flow generally differ greatly in conditions such as the effect at the time of loss and the size of data, and the required QoS is usually different.

  For this reason, it is possible to provide a videophone with better quality as a whole by using different auxiliary service instances and applying different QoS to each.

In the case of such a QoS request, as shown in FIG. 19, a method of assigning separate independent auxiliary service instances ASI ₁ and ASI ₂ to the voice packet flow P1 and the image packet flow P3 can be considered. For example, immediately after the start of the videophone session, the main service instance MSI and the auxiliary service instances ASI ₁ and ASI ₂ are established by the channel sharing method.

When the radio wave condition deteriorates and the modulation class falls and it becomes difficult to secure the throughput, first, the auxiliary service instance ASI ₁ carrying the voice packet flow P1 is switched to the channel occupation method to prevent voice loss. Can do.

  Even if image data is lost, the image is only stopped by the processing of the videophone application. On the other hand, lack of audio data usually results in noise accompanied by discomfort. For this reason, the control for protecting the audio data first is effective.

Of course, the auxiliary service instance ASI ₂ carrying the image packet flow may also be controlled to switch to the channel occupation method if necessary. If the radio wave condition improves, the modulation class increases, and the throughput is sufficient, if you switch back to the channel sharing method, the excess band that could not be used by the channel occupation method can be used for other purposes. .

(9.3) Modification Example of Radio Communication Channel CH In the above-described embodiment, the example in which the physical channel is the radio communication channel CH that carries the service instance as it is has been described.

  In recent years, a channel aggregation technique has been realized in which a plurality of physical channels are combined into one radio communication channel CH.

  When using channel aggregation technology, it is also effective to first aggregate physical channels from slot numbers 1 to 3 and establish multiple service instances as a single radio communication channel CH using the channel sharing method. It is.

  When the radio quality has deteriorated, the physical channel of slot number 3 is removed from the radio communication channel CH, re-established as an independent radio communication channel CH, and an auxiliary service instance ASI is established in this channel using the channel occupation method.

  As a result, it is possible to provide a channel that can secure a wide band when the radio wave condition is good, and at the same time guarantee the minimum throughput of the auxiliary session when the radio wave condition deteriorates.

(9.4) Modification Example of Radio Communication Terminal and Radio Base Station In the embodiment described above, the radio base station 200 may appropriately execute various processes described as being executed by the radio communication terminal 100. In this case, the method selection unit 264 shown in FIG. 6 uses the radio quality information acquisition unit 263 to select either the channel occupation method or the channel sharing method.

  Thus, it should be understood that the present invention includes various embodiments and the like not described herein. Therefore, the present invention is limited only by the invention specifying matters in the scope of claims reasonable from this disclosure.

1 is an overall schematic configuration diagram of a communication system according to an embodiment of the present invention. It is a functional block block diagram for demonstrating schematic operation | movement of the communication system which concerns on embodiment of this invention. It is a figure which shows the protocol stack applied to main service instance MSI in the communication system which concerns on embodiment of this invention. It is a figure which shows the protocol stack applied to auxiliary service instance ASI in the communication system which concerns on embodiment of this invention. It is a functional block block diagram of the radio | wireless communication terminal which concerns on embodiment of this invention. It is a functional block block diagram of the radio base station which concerns on embodiment of this invention. It is a functional block block diagram of PDSN which concerns on embodiment of this invention. It is a conceptual diagram for demonstrating the channel sharing system and channel occupation system which concern on embodiment of this invention. It is a table | surface which shows the size of the payload in the main service instance which concerns on embodiment of this invention, and a header. It is a table | surface which shows the size of the payload and header in the auxiliary service instance (at the time of a channel sharing system) which concerns on embodiment of this invention. It is a table | surface which shows the size of the payload and header in the auxiliary service instance (at the time of a channel occupation system) which concerns on embodiment of this invention. It is a figure for demonstrating the packet flow control process in the channel sharing system which concerns on embodiment of this invention. It is a figure for demonstrating the packet flow control process in the channel occupation system which concerns on embodiment of this invention. FIG. 3 is a frame configuration diagram of a communication frame used for wireless communication between a wireless communication terminal and a wireless base station according to an embodiment of the present invention. It is a figure which shows the modulation class of the adaptive modulation performed in the radio | wireless communication terminal and radio | wireless base station which concern on embodiment of this invention. It is a sequence diagram which shows the setting operation | movement of the service instance in the communication system which concerns on embodiment of this invention. FIG. 6 is a sequence diagram showing a switching operation from the channel sharing method to the channel occupation method according to the embodiment of the present invention. It is a sequence diagram which shows the switching operation from the channel occupation method to the channel sharing method according to the embodiment of the present invention. It is a figure which shows the example of a change of the auxiliary service instance which concerns on embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 100 ... Wireless communication terminal, 101 ... Antenna, 102 ... Wireless communication part, 103 ... Keypad, 104 ... Microphone, 105 ... Speaker, 110 ... Control part, 111 ... Reception data buffer, 112 ... Reception flow control part, 113 ... ROHC Deployment unit 114 ... IP protocol stack management unit 115 ... Packet management unit 116 ... RSVP client unit 117 ... PPP client unit 118 ... DHCP client unit 119 ... SIP protocol management unit 120 ... ROHC compression unit 121 DESCRIPTION OF SYMBOLS 122 ... L4 packet construction part, 123 ... Transmission flow control part, 151 ... SIP client part, 152 ... G729A codec, 162 ... Service instance setting part, 163 ... Radio quality information acquisition part, 164 ... Method selection part, 200 ... Wireless base Station, 202 ... wireless communication unit, 03 ... A10 / GRE communication unit, 201 ... antenna, 210 ... control unit, 211 ... reception packet buffer, 212 ... reception flow control unit, 213,214 ... A10 / GRE packet construction unit, 215,216 ... transmission buffer, 217 ... Reception flow control unit, 218, 219 ... L4 packet construction unit, 220 ... transmission flow control unit, 263 ... radio quality information acquisition unit, 264 ... method selection unit, 300 ... PDSN, 301 ... communication unit, 302 ... LL / PL transmission / reception 310, control unit, 313 ... reception packet buffer, 314 ... reception flow control unit, 315, 316 ... A10 / GRE packet removal unit, 317 ... IP protocol stack management unit, 318 ... PPP server unit, 319 ... RSVP server unit 320 ... DHCP server unit, 321 ... ROHC expansion unit, 322 ... transmission buffer 323: Receive packet buffer, 324 ... Packet filter, 325 ... ROHC compression unit, 326, 327 ... A10 / GRE packet construction unit, 328 ... Transmission flow control unit, 400 ... Internet, 500 ... SIP telephone, 551 ... G729A codec , 600 ... SIP server

Claims (8)

A wireless communication terminal that transmits and receives a plurality of types of packets including a specific type of packet to and from a communication destination device via a wireless base station,
A first communication session that is a logical communication path used for transmission of the packet of the specific type and a second communication session that is a logical communication path used for transmission of a packet of a type different from the packet of the specific type A communication session setting unit to be set with the destination device;
A radio quality information acquisition unit for acquiring radio quality information indicating radio quality with the radio base station;
A first packet transmission method for adding a session identifier for identifying a transmission using the first communication session to the specific type of packet according to the wireless quality information acquired by the wireless quality information acquisition unit; Or a packet transmission method selection unit that selects one of the second packet transmission methods that omits the addition of the session identifier to the specific type of packet;
A session identifier adding unit that adds the session identifier to the specific type of packet when the first packet transmission method is selected by the packet transmission method selection unit;
The session identifier adding unit is a wireless communication terminal that omits the addition of the session identifier to the specific type of packet when the second packet transmission method is selected by the packet transmission method selection unit. The packet transmission method selection unit includes:
Based on the radio quality information, determine whether the radio quality has improved,
The wireless communication terminal according to claim 1, wherein the first packet transmission method is selected when it is determined that the wireless quality is improved. The packet transmission method selection unit includes:
Based on the radio quality information, determine whether the radio quality has deteriorated,
The radio communication terminal according to claim 1, wherein the second packet transmission method is selected when it is determined that the radio quality has deteriorated. A wireless communication channel setting unit configured to set a wireless communication channel configured using at least one physical channel defined by physical resources with the wireless base station;
The communication session setting unit sets the first communication session and the second communication session on the same wireless communication channel when the first packet transmission method is selected by the packet transmission method selection unit. The wireless communication terminal according to 1. The wireless communication channel setting unit sets the wireless communication channel dedicated to the first communication session when the second packet transmission method is selected by the packet transmission method selection unit;
5. The communication session setting unit sets the first communication session on the radio communication channel dedicated to the first communication session when the second packet transmission method is selected by the packet transmission method selection unit. The wireless communication terminal described in 1.   The wireless communication terminal according to claim 1, wherein the packet of the specific type is a packet that requires a small transmission delay compared to a packet of a type different from the packet of the specific type. A wireless base station that transmits and receives a plurality of types of packets including a specific type of packet with a wireless communication terminal,
A first communication session that is a logical communication path used for transmission of the packet of the specific type, and a second communication session that is a logical communication path used for transmission of a packet of a type different from the packet of the specific type. A communication session setting unit set between a communication terminal and a communication destination device of the wireless communication terminal;
A radio quality information acquisition unit that acquires radio quality information indicating radio quality with the radio communication terminal;
A first packet transmission method for adding a session identifier for identifying a transmission using the first communication session to the specific type of packet according to the wireless quality information acquired by the wireless quality information acquisition unit; Or a packet transmission method selection unit that selects one of the second packet transmission methods that omits the addition of the session identifier to the specific type of packet;
A session identifier adding unit that adds the session identifier to the specific type of packet when the first packet transmission method is selected by the packet transmission method selection unit;
The session identifier adding unit is a radio base station that omits the addition of the session identifier to the packet of the specific type when the second packet transmission method is selected by the packet transmission method selection unit. A packet communication method for transmitting and receiving a plurality of types of packets including a specific type of packet between a wireless communication terminal and a communication destination device of the wireless communication terminal via a wireless base station,
A first communication session that is a logical communication path used for transmission of the packet of the specific type, and a second communication session that is a logical communication path used for transmission of a packet of a type different from the packet of the specific type. Setting between the communication terminal and the communication destination device;
Obtaining radio quality information indicating radio quality between the radio communication terminal and the radio base station;
A first packet transmission method for adding a session identifier that identifies transmission using the second communication session according to the wireless quality information acquired in the acquiring step, to the specific type of packet; or Selecting one of the second packet transmission schemes that omits the addition of the session identifier to a specific type of packet;
Adding the session identifier to the specific type of packet when the first packet transmission method is selected by the selecting step;
And a step of omitting the addition of the session identifier to the specific type of packet when the second packet transmission method is selected in the selecting step.

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