JP2001036586A - Gateway device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce fluctuation in a arrival time of a reception acknowledgement signal at a sender and to prevent traffic in a radio channel from increasing. SOLUTION: A mobile exchange center 5 is provided with a gateway device 10 that has a packet relay processing means 11 that applies relay processing to a TCP packet and a re-transmission processing means 12 that applies re- transmission processing to a radio communication unit. The packet relay processing means 11 transmits a reception acknowledgement signal, with respect to an outgoing TCP packet, while being set to an incoming TCP packet. In the case that no incoming TCP packet is received until a prescribed timer expires, the packet relay processing means 11 transmits the reception acknowledgement signal with respect to the outgoing TCP packet on behalf of the radio communication unit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gateway device interposed between a wired communication line having a small number of bit errors and a wireless communication line having a large number of bit errors, and having means for retransmitting a communication packet to a wireless communication device. Things.

[0002]

2. Description of the Related Art Conventionally, a system including a gateway device and a communication device of this kind is disclosed in, for example, the following document. Literature; "Evolution of Wireless Data Services: IS-95
to cdma2000 '' IEEE Communication Magazine, October
1998, pp. 140-149. In FIG. 1 on page 144 of this document, the mobile switching center (M
obile Switching Center) includes the function of the gateway device. A communication device connected to a public data network (Public Data Network) and a wireless communication device (Mobile Station) connected to a wireless line are a relay device (Inter Working Functio) that functions as an access point of a public data network.
n), connected via a mobile switching center and a base station. Radio link protocol for mobile switching center M
(Radio Link protocol) is implemented, and a retransmission function between the mobile switching center and the base station as described in the section “The Burst Mechanism in IS-95-B” on page 144 of the above document. (ARQ: Automatic Repeat reQuest) provides reliable data transmission service. The retransmission function is a method in which the transmission side repeatedly sends the same data until a reception confirmation confirming that the transmitted data has correctly arrived at the destination arrives from the reception side to the transmission side. By doing so, high-quality data transmission is possible even on a communication line having many errors such as a wireless line.

[0003]

However, when a communication device connected to a public data network and a wireless communication device connected to a wireless line are communicating using the TCP / IP protocol, the wireless link protocol is used. In addition to the retransmission function, since the retransmission function in the TCP protocol is working, the timer of the TCP protocol times out during retransmission by the radio link protocol, and the retransmission is performed with the wireless communication device. In some cases, the same packet is retransmitted from a communication device connected to the public data network side, and there is a problem that traffic on a wireless line is unnecessarily increased. Further, due to retransmission in the wireless link protocol, the arrival time of the acknowledgment signal returned from the wireless communication device to the communication device connected to the public data network greatly fluctuates.
The timer value of the CP protocol was not set properly. Therefore, an object of the present invention is to provide a communication system for transmitting and receiving data using a communication packet of a transport layer having a field of a reception acknowledgment signal, such as a communication packet of a TCP protocol, and an arrival time of a reception acknowledgment signal at a transmission source. The present invention provides a gateway device that reduces fluctuations in traffic and prevents an increase in traffic on a wireless line. The gateway device includes a retransmission processing unit for a wireless communication device and relays a communication packet of a transport layer. This is achieved by providing a mobile switching center.

[0004]

SUMMARY OF THE INVENTION The present invention relates to a packet relay processing means interposed between a wired line network and a wireless line for relaying a communication packet of a transport layer having a field of an acknowledgment signal; The present invention relates to a gateway device having retransmission processing means for performing retransmission processing of a communication packet to a communication device in accordance with a predetermined procedure. According to the invention of claim 1, the packet relay processing means comprises:
A first relay processing function for generating a reception confirmation signal relating to a protocol of a communication packet on behalf of the wireless communication device, and a field of an reception confirmation signal for an upstream communication packet from the wireless communication device side generated by the packet relay processing means. And a second relay processing function for rewriting with the received acknowledgment signal and piggybacking on the upstream communication packet. According to a second aspect of the present invention, the packet relay processing means has a first relay processing function of creating a reception acknowledgment signal relating to a communication packet protocol in place of the wireless communication device and setting a timer when the reception acknowledgment signal is created. ing. Also, if an uplink communication packet from the wireless communication device has not arrived before the timer times out,
The reception acknowledgment signal created by this packet reception relay means is
A second relay processing function is provided for generating a communication packet included in the acknowledgment signal field and transmitting the generated communication packet to the wired network side. According to the first and second aspects of the present invention, the packet relay unit generates a reception acknowledgment signal for the communication device on the wired network in place of the wireless communication device. The return of the confirmation signal becomes possible, and the variation in the arrival time of the reception confirmation signal to the communication device on the wired network is reduced.

According to a third aspect of the present invention, the packet relay processing means has a first relay processing function of setting a delay processing timer for each downlink communication packet from the wired network and transferring the packet to the retransmission processing means. I have. Further, the acknowledgment information included in the uplink communication packet from the wireless terminal side is stored in a predetermined list, and the field of the acknowledgment signal of the communication packet is rewritten with the already set acknowledgment signal.
A second relay processing function for piggybacking on the upstream communication packet is provided. Furthermore, when the acknowledgment information for the downlink communication packet corresponding to this timer is accumulated in the list every time the delay processing timer times out,
Create and set a reception confirmation signal based on this confirmation information,
It has a third relay processing function. The invention of claim 4 is
The retransmission processing means has a function of limiting the number of retransmissions, and sets the time length of the delay processing timer of the packet relay processing means to a time required for retransmission of the number of retransmissions.
According to the third and fourth aspects, the reception acknowledgment signal is returned to the communication device on the side of the wired network with a fixed delay time, so that the variation in the arrival time of the reception acknowledgment signal is reduced,
The setting of the retransmission timer such as the P protocol is not adversely affected.

[0008] The invention of claim 5 is a packet retransmission processing means, wherein the packet relay processing means registers a down-link communication packet from the wired network in the retransmission communication packet registration unit and then transfers the packet to the retransmission processing means. When a downlink communication packet registered in the retransmission communication packet registration unit is received from the wired network side, a packet discard function for discarding the communication packet is provided. According to this configuration, when the same communication packet being retransmitted by the retransmission processing unit is retransmitted from the communication device on the wired network side, the packet relay processing unit discards the packet. In addition, the communication efficiency of the wireless line section is improved.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a configuration diagram showing an example of a system to which the present invention is applied. A communication device 1 and a wireless communication device 2 are composed of a wired line network 3, a relay device 4 functioning as an access point thereof, a mobile switching center 5, and They are connected via the base station 6, communicate using the TCP / IP protocol, and exchange data using communication packets (TCP packets) of the TCP protocol. The gateway device 10 includes a packet relay processing unit 11 and a retransmission processing unit 12, and is incorporated in the mobile switching center 5. Communication from the wired network 3 to the wireless network is called down, and communication from the wireless network to the wired network 3 is called up. The downstream TCP packet input to the mobile switching center 5 is transferred to the packet relay processing unit 11 via the transmission / reception interface on the wire network side, relayed by the packet relay processing unit 11, and transferred to the retransmission processing unit 12. The data is output via a transmission / reception interface on the wireless line side.
The retransmission processing unit 12 transmits an error-free TCP packet to the communication device 2 by retransmission processing with the communication device 2 connected to the wireless line, and receives an error-free TCP packet by retransmission processing. The upstream TCP packet is passed to the retransmission processing unit 12 via the transmission / reception interface on the radio line side in the mobile switching center 5, and a TCP packet free from errors is transferred to the packet relay processing unit 11 by the retransmission processing. The data is relayed at 11 and output to the wired network 3 via the transmission / reception interface on the wired network.

In this embodiment, it is assumed that the communication device 1 and the wireless communication device 2 are communicating using the TCP protocol as a protocol. The TCP protocol is originally a protocol between communication terminals, and will be described first. FIG. 2 shows a configuration diagram of the TCP packet. In FIG. 2, one row represents 32 bits (4 bytes). The TCP protocol is an acknowledgment type protocol. 32 is included in the TCP packet transmitted from the communication device 1.
An order number (sequence) consisting of bits is given. This sequence number indicates a byte position of data carried by the TCP packet to the wireless communication device 2. For example,
Now, assuming that the data up to the byte position “229” has already been correctly delivered from the communication device 1 to the wireless communication device 2, the wireless communication device 2 transmits the data at the byte position “2” in the next packet.
It is in a state of waiting for a TCP packet starting from 30. In this state, when the wireless communication device 2 correctly receives a TCP packet having a sequence number of "230" and a length of 250 bytes from the communication device 1, The wireless communication device 2 returns a reception acknowledgment signal (ACK signal) having the byte position 480 (= 230 + 250) of the head data of the TCP packet expected to be received next as the acknowledgment number to the communication device 1. If the sequence number of the received TCP packet is "310" and the length is 250 bytes, it means that the data at byte positions 230 to 309 has not yet arrived at the wireless communication device 2. The byte position of the first data of the TCP packet that the wireless communication device still expects to receive next is "
230 ", the acknowledgment number of the acknowledgment signal returned by the wireless communication device 2 is not" 560 "even if the TCP packet having the sequence number" 310 "and a data length of 250 bytes correctly arrives at the wireless communication device 2. After that, when the wireless communication device 2 receives the TCP packet having the sequence number “230” and the data length of 80 bytes, the wireless communication device 2 transmits a reception acknowledgment signal having “560” as the acknowledgment number to the communication device. This acknowledgment signal serves as acknowledgment of reception of two packets.The acknowledgment signal (ACK signal) is a TC transmitted from the wireless communication apparatus 2 to the communication apparatus 1.
Turn on the ACK bit at the 14th byte of the header of the P packet, and set the byte position of the data to be received next in the acknowledgment number field provided using 4 bytes from the 9th byte. Is done. AC
If there is data to be transmitted from the wireless communication device 2 to the communication device 1, the K signal is superimposed on a TCP packet for transmitting the data, and otherwise transmitted as a TCP packet without a data portion. A timer of the TCP protocol is set in the communication device 1. If the reception confirmation of the transmitted TCP packet is not received before the timer times out, the communication device 1 retransmits the TCP packet. The packet relay processing unit 11 of the gateway device according to the present embodiment performs processing related to reception confirmation that was originally performed by the wireless communication device.

Next, the processing of the packet relay processing unit 11 in the first embodiment will be described with reference to FIGS.
FIG. 3 is a state transition diagram of the packet relay processing unit 11. The packet relay processing unit 11 has three states of “idle”, “packet reception processing”, and “reception confirmation transmission processing”. Normally, it is in the “idle” state, and when a TCP packet is received from the transmission / reception interface or the retransmission processing unit 12 or a timeout occurs, the state transits to the “packet reception processing” state and the “acknowledgment transmission processing” state.
When the "packet receiving process" and the "acknowledgment transmitting process" are completed, the state returns to the "idle" state.

FIG. 4 is a flowchart for explaining the packet receiving process of the packet relay processing unit 11. Upon receiving the TCP packet, the packet relay processing unit 11 determines whether the received packet is a downlink TCP packet or an uplink TCP packet.
In the case of a downlink TCP packet, the sequence number of the packet is an internal variable ACK_N indicating the sequence number of the packet that the packet relay processing unit expects to receive next.
Check if it matches O. If they do not match, it means that a packet loss has occurred between the communication device 1 and the packet relay unit or that the order of the arriving packets has been reversed, so that ACK_NO is not updated and
The data indicating the packet consisting of a set of "sequence number and data length" is registered in the K packet memory,
After transferring the P packet to the retransmission processing unit 12, the process returns to the idle state. Sequence number of received packet and internal variable AC
If K_NO matches, ACK_NO is updated by newly setting the value of “sequence number + data length” of the packet to ACK_NO. For example, ACK_NO before update
If the sequence number of the received TCP packet is “230” and the data length is 250 bytes, ACK_NO is updated to “480”. Next, if there is an entry in the unacknowledged packet memory, there is a possibility that an acknowledgment signal for a packet whose acknowledgment has not been returned may be sent by receiving this packet. Check if it is in the ACK packet memory. ACK if there is
Update _NO. This operation is repeated until ACK_NO cannot be updated. For example, if there are two entries (480, 150) (630, 100) in the unacknowledged packet memory, ACK_NO is updated to "730". Next, if the timer T1 has not been set yet, the timer T1 is set. Timer T1 receives a reception confirmation signal (AC
K signal) means the maximum time for waiting for an upstream TCP packet for piggybacking. The ACK signal can be transmitted as a single TCP packet without uplink data. However, if there is a TCP packet including uplink data, it is more efficient to transmit a reception acknowledgment together with the TCP packet. . After setting the timer, the packet relay processing unit 11 transfers the received downstream TCP packet to the retransmission processing unit 12 and returns to the idle state. If the received TCP packet is an upstream TCP packet, first, the acknowledgment number field in the 4-byte field from the ninth byte of the TCP packet is set to the internal variable ACK_NO.
Replace with the value of This means that the ACK signal has been piggybacked on the upstream TCP packet. Because the carpool is going on,
The timer T1 is reset, and the TCP packet is transferred to the transmission / reception interface on the wired network side. When the transfer of the TCP packet is completed, the state returns to the idle state.

FIG. 5 is a flowchart for explaining the reception confirmation transmission processing of the packet relay processing unit 11. In the idle state, if the upbound TCP packet does not arrive even after the elapse of the timer T1, a timeout occurs.
In this case, the packet relay processing unit 11 generates a TCP packet in which the internal variable ACK_NO is set as the acknowledgment number, transfers the TCP packet to the transmission / reception interface on the wired line side, and simultaneously resets the timer T1 that has been set. . In this case, the TC returned to the communication device 1
The P packet includes only a reception acknowledgment signal (ACK signal) and does not include uplink data. Then, it returns to the idle state.

As described above, according to the first embodiment, the packet relay means generates the acknowledgment signal for the communication device on the wired network in place of the wireless communication device. A return of a reception acknowledgment signal which is not affected by the above can be made possible, and unnecessary TCP packets are not transmitted from the wired network during retransmission processing between the gateway device and the wireless communication device, thereby improving communication efficiency. In addition, since a reception acknowledgment signal that is not affected by the delay due to the retransmission processing is returned, the variation in the arrival time of the reception acknowledgment signal to the communication device on the wire line network side is reduced, and the TCP
The setting of the timer value for packet retransmission is not adversely affected.

Next, a second embodiment of the present invention will be described with reference to FIGS.
This will be described with reference to FIG. This embodiment has substantially the same configuration as that of the first embodiment, but differs in the packet reception processing when piggybacking on an upward TCP packet. That is, in the first embodiment, the upstream T
As soon as there is a CP packet, a reception confirmation signal of a downlink TCP packet is transmitted to the wire line network side with the uplink TCP packet, but in this embodiment, the retransmission processing unit 1
2, the number of retransmissions is limited, the return of the acknowledgment signal is delayed by the time required when the retransmission is performed the limited number of times, and the fluctuation of the delay time in the return of the acknowledgment signal is reduced. In the second embodiment, the retransmission processing unit 12 restricts the number of retransmissions and does not perform retransmission until the correct TCP packet is transmitted to the wireless communication device 2 over and over again until the correct transmission is performed. If the TCP packet cannot be correctly transmitted to the wireless communication device 2 even after performing the above, the retransmission operation is stopped, and the TCP packet is discarded by the gateway device 10.

FIG. 6 is a state transition diagram of the packet relay processing unit 11 in the second embodiment. The packet relay processing unit 11 has four states by adding “delay processing” to “idle”, “packet reception processing”, and “reception confirmation transmission processing”.
Usually, it is in an idle state, and transitions to each state when a TCP packet is received, a timer T1 times out, and a timer T2 times out. FIG. 7 is a flowchart illustrating a TCP packet reception process of the packet relay processing unit 11. Upon receiving the TCP packet, the packet relay processing unit 11 determines whether the received packet is a downlink TCP packet or an uplink T packet.
It is determined whether the packet is a CP packet. If the TCP packet received by the packet relay processing unit 11 is a downlink TCP packet, the sequence number and data length of the TCP packet are read, and a delay processing timer T2 using i = (sequence number + data length) as a parameter Set (i). In the timer T2 (i), a necessary time is set after the packet relay unit 11 transfers the TCP packet to the retransmission processing unit 12 when the retransmission processing unit 12 has performed the maximum number of retransmissions. After setting the timer T2 (i), the received downstream TCP
The packet is transferred to the retransmission processing unit 12 and returns to the idle state. When the TCP packet received by the packet relay processing unit 11 is an upstream TCP packet, first, it is checked whether or not the ACK bit is set in the TCP packet. If the ACK bit is not set, the TCP packet does not carry the acknowledgment number, so that the TCP
Forward the packet. If the ACK bit is set, check whether the value of the acknowledgment number field of the TCP packet is already registered in the OK packet list, and if not, register the value in the OK packet list. I do. The OK packet list is a list of acknowledgment numbers sent from the wireless communication device 2 that have not been sent to the communication device 1 yet. Second
In this embodiment, this list is provided in order to transmit the acknowledgment with a certain delay. Next, the value of the acknowledgment number field of the TCP packet is rewritten to the internal variable ACK_NO. ACK_NO is a value set by delay processing described later. Next, the timer T1 is reset, the TCP packet is transferred to the transmission / reception interface on the side of the wired network, and the state returns to the idle state.

FIG. 8 is a flowchart for explaining the delay processing. When one timer out of the plurality of timers T2 (i) having i as a parameter from the idle state times out, first, it is checked whether or not the parameter i of the timer that has timed out is registered in the OK packet list. If it is not registered in the OK packet list, the TCP packet corresponding to the parameter i has not been transmitted to the wireless communication device 2 correctly, so that the process returns to the idle state without doing anything. If the parameter i is registered in the OK packet list, i is set to the internal variable ACK_NO. As a result, when the packet relay processing unit receives an upcoming TCP packet that can be shared next, or when the timer T1 times out, an acknowledgment signal whose acknowledgment number is i is transmitted to the communication device 1.
Next, if the timer T1 has not been set yet, it is set, i is deleted from the OK packet list, and the process returns to the idle state. Thus, in this embodiment,
When the number of retransmissions of the retransmission processing unit is limited, the reception acknowledgment signal is returned to the communication device on the wired network side with a fixed delay time, so that the variation in the arrival time of the reception acknowledgment signal is reduced,
The setting of the retransmission timer of the TCP protocol is not adversely affected.

Next, a third embodiment of the present invention will be described with reference to FIGS.
This will be described with reference to FIG. FIG. 9 is a state transition diagram of the packet relay processing unit 11 in the third embodiment. The packet relay processing unit has three states of “idle”, “packet receiving processing”, and “retransmission registration deletion processing”. Normally, it is in the “idle” state, and transitions to the “packet reception processing” state and the “retransmission registration deletion processing” state when a TCP packet is received from the wired network or a retransmission processing end notification is sent from the retransmission processing unit 12. When the processing in each processing state ends, the state returns to the “idle” state.

FIG. 10 is a flowchart of a packet receiving process in the packet relay processing unit 11. When receiving the downlink TCP packet from the wired line side, the packet relay processing unit 11 in the “idle” state checks whether the TCP packet is registered. The transport layer protocol for communication between the communication devices 1 and 2 is T
Since it is a CP, a TCP packet can be uniquely specified by a pair of a transmission port number and a sequence number. Packet relay processing unit 1
The transmission port number and the sequence number of the downlink TCP packet currently undergoing retransmission processing by the retransmission processing unit 12 are registered in the retransmission packet registration unit 1. Packet relay processing unit 11
Then, the transmission port number and the sequence number of the downlink TCP packet received from the wired line side are read, and it is checked whether or not it is registered in the retransmission packet registration unit. If the TCP packet has been registered, the TCP packet is being retransmitted by the retransmission processing unit 12, so the TCP packet is discarded without being transferred to the retransmission processing unit 12, and returns to the idle state. If the TCP packet is not registered in the retransmission packet registration unit of the packet relay processing unit 11, the T
The pair of the transmission port number and the sequence number of the CP packet is first registered in the retransmission packet registration unit, and then the TCP packet is transferred to the retransmission processing unit 12. When the transfer is completed, it returns to the idle state.

FIG. 11 is a flowchart of a retransmission registration deletion process in the packet relay processing unit 11. Retransmission processing unit 1
When the retransmission process of the downlink TCP packet to the wireless communication device 2 ends, the retransmission processing end notification notifies the packet relay processing unit 11 of the retransmission process end notification. When the packet relay processing unit 11 receives the notification, the packet relay processing unit 11 deletes the information of the corresponding downlink TCP packet from the retransmission packet registration unit. As described above, according to the third embodiment, when the same TCP packet being retransmitted by the retransmission processing unit is retransmitted from the communication device on the wired network side, the packet relay processing unit
Since the P packets are discarded, the communication efficiency of the wireless line section is improved. In this embodiment, the transmission port number and the sequence number are used as information for registering a packet. However, other information can be used if a communication packet can be specified.

In the above embodiment, the communication packet of the transport layer communicated between the communication devices is the TC
RTP that uses P packets but requires real-time performance using UDP as a transport protocol
Packets can also be used. When relaying communication packets using a plurality of protocols, it is also possible to switch whether or not to delay the acknowledgment signal depending on the type of protocol. In the above embodiment, the unit of the retransmission processing in the retransmission processing unit is not particularly mentioned, but the retransmission processing unit does not necessarily need to be the entire communication packet received from the packet relay processing unit, and the communication packet is transmitted to a plurality of segments. It may be divided and used as a unit of retransmission processing. In this case, a retransmission processing end notification to the packet relay processing unit is notified from the retransmission processing unit when the retransmission processing for all the segments is completed. Further, in the above embodiment, the gateway device is incorporated in the mobile switching center. However, the gateway device can be incorporated in a relay device functioning as an access point of the wired network, and the connection between the other wired network and the wireless line can be established. Part can be provided.

[0020]

As described above, according to the present invention, in the process of relaying a communication packet in the transport layer, the retransmission function relating to the communication packet in the transport layer and the retransmission function in the radio line are separated, and The return of the acknowledgment signal for the communication packet of the above is piggybacked to the upstream communication packet as much as possible, so that the variation in the arrival time of the acknowledgment signal at the transmission source can be reduced, and the wireless line and the wired network This has the effect of preventing an increase in traffic in

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an example of a system to which the present invention is applied;

FIG. 2 is a configuration diagram of a TCP packet;

FIG. 3 is a state transition diagram of a packet relay processing unit according to the first embodiment.

FIG. 4 is a flowchart of a packet reception process performed by a packet relay processing unit according to the first embodiment;

FIG. 5 is a flowchart of a reception confirmation transmission process of a packet relay processing unit according to the first embodiment;

FIG. 6 is a state transition diagram of a packet relay processing unit according to the second embodiment;

FIG. 7 is a flowchart of a packet reception process performed by a packet relay processing unit according to the second embodiment;

FIG. 8 is a flowchart of delay processing of a packet relay processing unit according to the second embodiment;

FIG. 9 is a state transition diagram of a packet relay processing unit according to the third embodiment.

FIG. 10 is a flowchart of a packet reception process performed by a packet relay processing unit according to the third embodiment;

FIG. 11 is a flowchart illustrating a retransmission registration deletion process performed by a packet relay processing unit according to the third embodiment;

[Explanation of symbols]

 Reference Signs List 1 communication device 2 wireless communication device 3 wired circuit network 4 relay device 5 mobile switching center 6 base station 10 gateway device 11 packet relay processing unit 12 retransmission processing unit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) H04Q 7/22 7/24 7/26 7/30 F term (Reference) 5K014 AA03 AA04 DA02 EA01 FA03 FA08 FA14 HA05 5K030 GA12 HB18 JL07 JT03 KA21 LA02 LD18 MB10 5K033 AA06 BA15 CB04 CC01 DA05 DA12 DA19 DB18 EA04 EA06 5K067 AA11 BB21 DD24 DD30 EE02 EE10 EE16 HH28 9A001 BB02 BB04 CC05 CC02 DD10 EE02 JJ18 JJ56 JJ18

Claims (5)

[Claims] 1. A packet relay processing means interposed between a wired line network and a wireless line for relaying a communication packet of a transport layer having a field of an acknowledgment signal;
Retransmission processing means for performing a retransmission processing of a communication packet in accordance with a predetermined procedure for the wireless communication device, wherein the packet relay processing means, in place of the wireless communication device, of the communication packet A first relay processing function for generating a reception acknowledgment signal relating to a protocol, and rewriting a field of an acknowledgment signal of an uplink communication packet from the wireless communication device side with the reception acknowledgment signal created by the packet relay processing means; A second relay processing function for piggybacking on the upstream communication packet. 2. A packet relay processing means interposed between a wired line network and a wireless line for relaying a communication packet of a transport layer having a field of an acknowledgment signal;
Retransmission processing means for performing a retransmission processing of a communication packet in accordance with a predetermined procedure for the wireless communication device, wherein the packet relay processing means, in place of the wireless communication device, of the communication packet A first relay processing function for creating a reception acknowledgment signal related to the protocol and setting a timer when the reception acknowledgment signal is created; and an upstream communication packet from the wireless communication device arrives before the timer times out. If not, a second relay processing function of generating a communication packet having the reception acknowledgment signal created by the packet reception relay unit in a reception acknowledgment signal field and transmitting the communication packet to the wired network side. A gateway device. 3. A packet relay processing means interposed between a wired line network and a wireless line for relaying a transport layer communication packet having a field of a reception confirmation signal,
Retransmission processing means for performing retransmission processing of a communication packet in accordance with a predetermined procedure for the wireless communication apparatus, wherein the packet relay processing means comprises: for each downlink communication packet from the wired network side, A first relay processing function for setting a delay processing timer and transferring it to the retransmission processing means; and storing acknowledgment information included in an uplink communication packet from the wireless terminal side in a predetermined list, and A second relay processing function for rewriting the field of the reception confirmation signal of the above with the already set reception confirmation signal and piggybacking on the uplink communication packet, and for each time-out of each of the delay processing timers, If the acknowledgment information for the downlink communication packet obtained is stored in the list, the acknowledgment signal is stored based on the acknowledgment information. And a third relay processing function for creating and setting a number. 4. The retransmission processing means has a function of limiting the number of retransmissions, and sets a time length of a delay processing timer of the packet relay processing means to a time required for retransmission of the number of retransmissions. Item 4. The gateway device according to item 3. 5. A packet relay processing means interposed between a wired line network and a wireless line for relaying a communication packet of a transport layer having a field of an acknowledgment signal,
Retransmission processing means for performing retransmission processing of a communication packet according to a predetermined procedure for the wireless communication apparatus, wherein the packet relay processing means transmits a downstream communication packet from a wired network side. A retransmission packet registration function for registering the packet in the retransmission communication packet registration unit and then transferring the retransmission packet registration unit to the retransmission processing unit. A gateway device comprising: a packet discard function for discarding a packet.