JP2000196668A - Router device, radio terminal, radio communication system and communicating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communicating method capable of making low power consumption at a radio terminal without lowering throughput even in an asymmetrical transmission line. SOLUTION: A narrow-band base station offering a narrow-band two-way radio channel is connected to a PCS network 303, a wideband one-way radio channel base station is connected to an ATM network 306, a hybrid router 304 connecting the Internet 307 and the networks 303 and 306 is installed, when a radio terminal 301 communicates with a server 308 on the Internet, a narrow- band radio channel is used in the direction from the radio terminal to the hybrid router and a wideband radio channel is used in the direction from the hybrid router to the radio terminal router, the terminal 301 also compresses the header part of data to transfer it to the router 304, and the hybrid router expands the compressed header part of the received data and transfers it to the server 308.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless terminal that communicates with a server on the Internet, for example, using different wireless sections for uplink and downlink, a router device for providing asymmetric wireless communication, and a router device and a router for providing asymmetric wireless communication. The present invention relates to a wireless communication system including a wireless terminal and a communication method thereof.

[0002]

2. Description of the Related Art When communicating with the Internet,
In a Web search or the like, the amount of data received by the terminal from the server is much larger than the amount of data transmitted by the terminal. In recent years, power consumption of mobile terminals that can be connected to the Internet while moving using wireless lines is a major issue. If the power consumption can be reduced, the battery mounted on the mobile terminal can be reduced in size and the terminal can be reduced in size and weight. Therefore, a great effect can be obtained by reducing power consumption by wireless transmission.

[0003] Reduction of power consumption by wireless transmission can be solved by using the asymmetry of the amount of data transmitted and received by the terminal as described above. By making use of the fact that the amount of data transmitted by the terminal is small, the transmission speed of the wireless channel transmitted by the terminal is made lower than the transmission speed of receiving data, whereby power consumption by wireless transmission can be reduced.

[0004] However, usually, Internet-based We
For the access of b, TCP is used as a transport layer. TCP does not support asymmetric transmission paths.
Therefore, if the transmission speed of the terminal is reduced in order to reduce the power consumption of the terminal, there is a problem that the throughput of TCP is reduced.

[0005] When an asymmetric transmission path is to be realized by a radio line, for example, an existing mobile phone line or PHS line is used for an uplink radio channel, and a broadband radio channel is used for a downlink channel. By doing so, initial investment in infrastructure such as base stations and networks can be reduced. However, in such a wireless circuit configuration, since the network of the up channel (direction from the terminal to the server) and the network of the down channel (direction from the server to the terminal) are different, there is a problem that the network cannot be directly connected to the server. is there.

[0006]

As described above, it is more effective to perform asymmetric transmission in order to reduce the power consumption of a terminal. However, TCP, which is a transport layer protocol, is used.
However, there is a problem that the throughput is reduced in an asymmetric transmission path.

When an asymmetric transmission line is to be realized by a wireless line, if the system is designed to reduce the initial introduction cost of the system, the line of the upstream channel and the line of the downstream channel are different, so that it is not possible to directly connect to the server. There is a problem.

[0008] The present invention has been made in view of the above circumstances, and a router device, a wireless device, and a wireless terminal capable of reducing the power consumption of a wireless terminal without reducing the throughput even on an asymmetric transmission line. An object is to provide a terminal, a wireless communication system, and a communication method.

[0009]

Means for Solving the Problems The present invention (claim 1) provides:
A first channel composed of at least a radio channel in the upstream direction (direction from the radio terminal to the transmission side) with a low transmission speed and a downlink direction in which the transmission speed is higher than at least the first channel (the radio terminal is connected to the reception side) Communication between a wireless terminal connected by a second channel constituted by a wireless channel of a certain direction and a node device connected via a predetermined network to a router device for performing a path control of data transferred. A method, wherein a header portion of data received from the wireless terminal via the first channel is compressed, decompressing the header portion, and adding the content of the header portion in the decompressed state. Routing the received data based on the received data and transmitting the data to the predetermined network. Preferably, when data addressed to the wireless terminal is received from the predetermined network side, a route control is performed for the wireless terminal without compressing a header portion of the received data, and the data is transmitted to the second terminal.
The transfer may be performed by using the channel of (1).

[0010] The present invention (Claim 3) provides a communication method using a first channel constituted by a radio channel and a router device connected by a second channel which is a radio channel having a higher transmission speed than the first channel. A communication method of a wireless terminal that communicates with a node device on a predetermined network, wherein when transmitting data to the router device, a header portion of the data is compressed and the data is transmitted using the first channel. It is characterized by transmitting. Preferably, from the router device, data whose header part is not compressed may be received through the second channel.

[0011] Preferably, a negotiation relating to compression and decompression of the header portion may be performed in advance between the wireless terminal and the router device.

Preferably, the header section to be compressed may be a network layer header section, a transport layer header section, or a network layer header section and a transport layer header section.

[0013] Preferably, the first channel is a bidirectional channel, and the second channel is a unidirectional channel.

Preferably, the predetermined network is the Internet, and the first channel is a PC
The second channel may be provided by a first base station connected to the S network, and the second channel may be provided by a second base station connected to the ATM network.

According to the present invention (claim 7), communication is performed by using a first channel constituted by a bidirectional wireless channel and a second channel which is a unidirectional wireless channel having a higher transmission speed than the first channel. A first base station providing a circuit and providing a first channel is connected to the PCS network, a second base station providing a second channel is connected to the ATM network, and the first base station and the first base station are connected to the ATM network. 2 base stations are connected via a router device, and the wireless terminal is connected to only the first channel or the first channel.
Channel and the second channel simultaneously, and the first channel
A communication method in a wireless communication system that communicates with a server device in a network only through a base station or through a first base station and a second base station and a router device. Compressing the header portion of the data to be transmitted, transmitting the compressed data of the header portion to the router device via the first base station, and the router device transmits the first base station from the wireless terminal. When the header part of the data received via the server is compressed, the header part is decompressed, and the received data is route-controlled based on the contents of the header part and transmitted to the server device. And

Preferably, when the router device receives normal data addressed to the wireless terminal from the server device, the router device performs route control for the wireless terminal without compressing a header portion of the received data. You may make it transmit to the said 2nd base station.

Preferably, when communicating with the server device, the wireless terminal compresses a header of transmission data and a header of reception data so as not to compress the header of the reception data with the router device in advance. Negotiation may be performed.

The present invention (claim 9) provides a wireless terminal connected by a first channel constituted by a wireless channel and a second channel which is a wireless channel having a higher transmission speed than the first channel, A router device for controlling a route of data transferred between a node device connected through a predetermined network, and a header portion of data received from the wireless terminal via the first channel. Means for compressing and decompressing the header portion when compressed, and means for transmitting data addressed to the wireless terminal received from the predetermined network side so as to pass through the second channel. It is characterized by the following.

According to the present invention (claim 10), a first channel constituted by a radio channel and a router device connected by a second channel which is a radio channel having a higher transmission speed than the first channel are provided. A wireless terminal that communicates with a node device on a predetermined network, wherein: a means for compressing a header portion of data transmitted to the node device; Means for transmitting to said router device using said channel.

Preferably, means for performing negotiation with the router in advance so that transmission data is compressed in its header and received data is not compressed in its header; Means for establishing the first channel for use in communication in the direction of the router device, and establishing the second channel for use in communication in the direction from the router device to the own terminal. .

According to the present invention (claim 11), a first network accommodating a first base station providing a first channel constituted by a bidirectional radio channel, and a transmission more than the first channel are provided. A second network accommodating a second base station that provides a second channel that is a high-speed downlink (a direction in which a wireless terminal is a receiving side) a first channel and a second network A router for connecting to a different third network, and the router from the first base station via the first network or from the second base station via the second network via the router. And a wireless terminal communicable with the node device connected to the third network, wherein the wireless terminal includes a header of data to be transmitted to the node device. And means for transferring the compressed data to the router device via the first network, wherein the router device is addressed to the node device by the wireless terminal received from the first network. Means for compressing and decompressing the header portion of the data of the above, and transferring the same to the node device via the third network; and the node device received from the third network and addressed to the wireless terminal. Means for transferring data to the wireless terminal via the second network.

According to the present invention, the header of the TCP packet from the wireless terminal to the router is compressed, decompressed by the router, and forwarded to the server or the like. Also,
The TCP packet from the server device is forwarded to the wireless terminal without being compressed or decompressed.

By doing so, on the transport layer, the degree of asymmetry on the radio line is reduced, and a decrease in TCP throughput can be prevented. Also, since the router device only needs to decompress the compression, the normal TC
No processing overhead is required compared to P / IP header compression (the transmission speed of the target data is slow, and there is no need for high-speed processing).

The same can be said for a wireless terminal. Since the wireless terminal only needs to perform TCP / IP compression, it does not require much overhead compared to normal TCP / IP header compression processing. The data transmission speed is slow and there is no need to process it at high speed.) In addition, the power consumption of the wireless terminal can be reduced.

Also, data from the wireless terminal is received by the router device via the PCS network, the data is forwarded to the server device, and the data from the server device is forwarded to the terminal device via the ATM network, so that the router device receives the data. The device can absorb networks having different uplink channels and downlink channels.

Note that the present invention is also established as a wireless communication system including the router device and the wireless terminal according to the present invention, and is also established as a communication method of the wireless communication system including the router device and the wireless terminal according to the present invention.

Further, the present invention relating to the apparatus is also realized as an invention relating to a method, and the present invention relating to a method is also realized as an invention relating to an apparatus.

Further, the present invention relating to an apparatus or a method is provided for causing a computer to execute a procedure corresponding to the present invention (or for causing a computer to function as means corresponding to the present invention, or a computer corresponding to the present invention). The present invention is also realized as a computer-readable recording medium in which a program for realizing the function of performing the above is recorded.

[0029]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of a network according to an embodiment of the present invention. As shown in FIG. 1, this network includes a wireless terminal (PS) 301, a narrowband wireless base station (CS) 302, a PCS network 303, a hybrid router 304, a broadband wireless base station (AP) 305, and an ATM network 306. , The Internet 307, and the server 308. The server 308 is, for example, an application such as a Web server or a server proxy server.

The wireless terminal 301 communicates with the narrowband wireless base station 302 through the narrowband bidirectional first wireless line.
The narrowband wireless base station 302 is connected via the PCS network 303 to
Connected to hybrid router 304.

The wireless terminal 301 communicates with the broadband wireless base station 305 via the second wireless line in a broadband unidirectional (direction toward the wireless terminal). Broadband wireless base station 3
05 is connected to the hybrid router 304 via the ATM network 306.

The hybrid router 304 is connected to the PCS network 3
The IP packet from the Internet 03 is forwarded to the Internet 307, and the IP packet from the Internet 307 is forwarded to the ATM network 306.

In such a network configuration, the transfer of the IP packet from the wireless terminal 301 to the server 308 and the transfer of the IP packet from the server 308 to the wireless terminal 301 are performed by different routes as follows. Will be

That is, the wireless terminal 301 connects to the narrow-band wireless base station 302 through a narrow-band wireless line, and further connects to the server 308 from the narrow-band wireless base station 302 via the PCS network 303, the hybrid router 304, and the Internet 307. Then, a Web search and a service request for other applications are performed.

On the other hand, an IP packet from the server 308 to the wireless terminal 301 is forwarded from the Internet 307 to the broadband wireless base station 305 via the hybrid router 304 and the ATM network 306, and transmitted to the wireless terminal 301 via the broadband wireless line. You.

In the present embodiment, when transferring an IP packet from the wireless terminal 301 to the hybrid router 304, the wireless terminal 301 compresses the header and transfers the header.
This is decompressed on the hybrid router 304 side. For example, the wireless terminal 301 and the hybrid router 304 perform a procedure of sharing a correspondence table (conversion table) between the content of the header to be omitted (all or part of the content of the header) and identification information capable of specifying the header, and The terminal 301 refers to the correspondence table, replaces the contents of the header of the IP packet with the corresponding identification information (compression processing), and transfers this. The hybrid router 304
When an IP packet in which the content of the header is omitted is received, the original header is restored (decompression process) by referring to the correspondence table and using the content corresponding to the identification information added to the packet. is there.

FIG. 2 shows a wireless terminal 30 according to this embodiment.
1 shows an example of a protocol stack of each of a hybrid router 304, a hybrid router 304, and a server 308. In FIG. 2, TC
An example is shown in which the P / IP header is compressed and decompressed. Also,
In FIG. 2, the protocol stack of the physical layer is omitted.

According to the present embodiment, it is possible to reduce the power consumption of the wireless terminal without lowering the throughput even with an asymmetric transmission line.

Hereinafter, the present embodiment will be described in more detail by taking as an example a case where the application of the wireless terminal 301 and the application of the server 308 communicate.

In the example of the protocol stack shown in FIG. 2, the header compression includes a method of compressing only one of the TCP header and the IP header, and a method of compressing both of them. And the IP header are both compressed.

First, the wireless terminal 301 uses TCP as the transport layer and uses IP as the three layers. 3
The packet is converted into an IP packet in the layer, and an IP address for the server 308 is added as a destination address.

Next, the wireless terminal 301 compresses the header of the IP packet and transmits it to the hybrid router 304 via the PCS network 303.

The hybrid router 304 receives the received I
If it turns out that the header of the P packet is compressed,
Perform header decompression. And I unzipped the header
The P packet is forwarded to the server 308 according to the destination address. At the time of forwarding, information of only an IP packet is used, and a message of the transport layer TCP is not assembled.

Since the IP packet arriving at the server 308 is not header-compressed, the server 308 uses a normal TCP
/ IP processing is performed.

On the other hand, an IP packet addressed to the wireless terminal 301 from the server 308 is transmitted to the hybrid router 304 by adding the IP address of the wireless terminal 301 as a destination address to the IP packet.

When the hybrid router 304 finds that the destination address of the IP packet is addressed to the wireless terminal 301, it forwards the IP packet to the wireless terminal 301. At the time of forwarding, TCP / IP header compression is not performed, and a forward destination interface is selected for the ATM network 306.

Since the IP packet received by the wireless terminal 301 from the ATM network 306 is not header-compressed, the wireless terminal 301 performs normal TCP / IP processing.

FIG. 3 shows TCP /
4 shows an example of an IP header compression procedure.

The wireless terminal 301 checks the IP address and port number of the IP packetized data, and determines whether a pair of the IP address and port number exists in the conversion table (FIG. 5A). Check (step S401). If a pair of an IP address and a port number is found in the conversion table, the header of the uncompressed IP packet is stored in that area (step S).
402). After that, the TCP / IP header is compressed (i
d number) (step S403), the PCS network 30
Send to port 3

On the other hand, if the pair of the IP address and the port number is not found in the conversion table in step S401, the table containing the oldest entry is selected (step S404), and the area in the selected table is set. The uncompressed TCP / IP header is stored (step S405). Thereafter, the compression of the TCP / IP header is not performed, and the IP packet as it is is
Send to the port for 03.

FIG. 4 shows an example of a TCP / IP header compression / decompression procedure in the hybrid router 304.

The hybrid router 304 is connected to the PCS network 3
When an IP packet is received from the IP address
It is checked whether or not the TCP / IP header of the P packet has been compressed (step S501). I
When it is found that the TCP / IP header of the P packet is compressed, the conversion table (FIG. 5B) is referred to from the added id number, and the uncompressed TCP stored in the conversion table is used. / IP header is extracted and replaced with the compressed TCP / IP header (step S502). In this way, the header is decompressed and passed to the IP layer.

On the other hand, if it is found in step S501 that the TCP / IP header of the IP packet is not compressed, the IP packet is passed to the IP layer as it is.

The procedure for sharing the conversion table between the wireless terminal 301 and the hybrid router 304 is as follows. For example, in step S401, the conversion table (FIG. 5A) on the wireless terminal 301 side stores the IP address, the port number, If no pair is found, the selected IP number is added to the IP packet as it is and passed from the wireless terminal 301 to the hybrid router 304. In step S401, the ID number is added to the packet having the uncompressed header. If there is, the uncompressed IP is stored in the corresponding area of the conversion table (FIG. 5B) on the hybrid router 304 side.
Save the packet header.

Alternatively, a special control packet for negotiating the correspondence between the contents of a certain IP header and the ID number may be exchanged between the wireless terminal 301 and the hybrid router 304.

FIG. 5 shows an example of the conversion table.
(A) is an example of a conversion table in the wireless terminal 301, and (b) is an example of a conversion table in the hybrid router 304.

Both tables are associated with each other by id, and a set of a source IP address, a destination IP address, and a port number in the tables,
Correspond one-to-one. When the wireless terminal 301 transmits a compressed IP packet, the correspondence is maintained by adding an id number.

The above-described compression, decompression, conversion table, and negotiation are merely examples, and various other methods are conceivable.

Next, a specific example of communication to which the present invention is applied will be described with reference to FIG.

The wireless terminal (PS) 301 establishes a wireless line with the narrowband wireless base station (CS) 302 (70).
1) Then, a request is made to asymmetrically compress the header with the hybrid router 304 to transmit the IP packet (702). That is, T transmitted on the uplink
The header of the CP / IP packet is compressed, and negotiation is performed so that the header of the TCP / IP packet transmitted on the downlink is not compressed. Finally, a downlink radio channel is established with the broadband radio base station (AP) 305 (7).
03). As a result, a point-to-point connection is established between the wireless terminal 301 and the hybrid router 304 that differs in the presence / absence of path / header compression in the upstream and downstream directions.

As described above, when the establishment of the line and the negotiation of the header compression are completed, the wireless terminal 30
1 transmits data to the server 308 on the Internet 307. At this time, the TCP / IP header is compressed (704) and transmitted via the hybrid router 304 (705).

Upon receiving the header-compressed packet from the wireless terminal 301, the hybrid router 304 compresses and decompresses the header (706), and forwards the packet to the server 308 according to the IP header (707). In the server 308, the data mounted on the received IP packet is passed to the corresponding application, and necessary processing is performed.

Next, when transmitting data from the server 308 to the wireless terminal 301, the data is transmitted to the hybrid router 304 without performing TCP / IP header compression (70).
8) The hybrid router 304 performs only forward of the packet according to the IP header (709), and transmits the packet to the wireless terminal 301 via the broadband wireless base station 305. In the wireless terminal 301, the data mounted on the received IP packet is passed to the corresponding application, and necessary processing is performed.

Next, specific examples of the TCP / IP header before and after compression will be described.

FIG. 7 shows an example of a normal (uncompressed) TCP / IP header format, and FIG.
4 shows an example of a P / IP header.

In the IP packet header portion, ver
“sion” is 4-bit version information, and “head”
er length is a 4-bit IP header length,
The type of field (TOS) is 8-bit service type information, the total length is a 16-bit packet length, and
Tion is a 16-bit identifier, and falses is 3
It is a flag of bit, and fragment off
t is a 13-bit fragment offset, ti
me to live is the survival time of 8 bits, p
protocol is 8-bit protocol information, h
The header checksum is a 16-bit header checksum, and the source IP address is
s is a 32-bit source IP address, and dest
Ination address is 32-bit destination I
P address.

In the TCP packet header, the source port number is 16 bi.
t is the source port number of t
The port number is a destination port number of 16 bits, and the sequence number is 32 bits.
Acknowledgm
“ent number” is a 32-bit response confirmation number, “header length” is a 4-bit TCP header length, “reserved” is a 6-bit reserved field, from URG to FIN are 6-bit code bits, and “window size” is 16-bit.
Window size, and TCP checksu
m is a 16-bit checksum, and
pointer is a 16-bit urgent pointer.

Note that option data may be added in addition to the above.

FIG. 7 shows an example of fields to be omitted by hatching. The omitted fields are shown in FIG.
Are stored in a one-to-one correspondence with the ids in the table, and the fields associated with the ids are added at the time of decompression. By such compression, conversion is performed as illustrated in FIG.

In the format example of FIG. 8, the first bit of the first octet is an identification bit indicating whether or not the TCP / IP header is compressed. For example, when the bit is 1, it indicates that compression is performed, and when the bit is 0, it indicates that compression is not performed. C of the second bit is a bit indicating the presence or absence of a connection ID field. I of the third bit is Δipid
This bit indicates the presence or absence of the field. P in the fourth bit indicates Push flag (PSH) of the TCP header. S in the fifth bit is a bit indicating the presence or absence of a field of Δseq. A of the sixth bit is a bit indicating the presence or absence of a field of Δack. 7th bit W
Is a bit indicating the presence or absence of a field of Δwin.
The eighth bit U indicates the presence or absence of the urgoff field, and indicates the URG bit in FIG.

.DELTA.win is the 16-bit value shown in FIG.
Corresponds to window size and the current window
This is the difference between the size and the previous window size. When the W bit is 0, it indicates that there is no change from the previous value. Δack is the 32-bit ackn of FIG.
The difference between the current response number and the previous response number is obtained in correspondence with the argument number.
When the A bit is 0, it indicates that the current value has not changed from the previous value. Δseq is the 32-bit seq of FIG.
The difference between the current sequence number and the previous sequence number corresponds to the sequence number. When the S bit is 0, it indicates that the current value has not changed from the previous value. Δipid is 16-bit ide
and the difference between the previous value and the current value. If the I bit is 0, it indicates that the current value is a value obtained by increasing the previous value by one.

As described above, TCP / IP header compression can be performed.

The items omitted in the header compression described above are merely examples, and various other omission methods are conceivable.

Next, a case where the compression of the TCP / IP header and the decompression of the compressed TCP / IP header are performed not by the IP process but by the user process will be described.

FIG. 9 shows that the hybrid router 304
An example of a mounting method of a header decompression processing unit (1004) for decompressing a compressed TCP / IP header will be described.

Normally, the TCP / IP processing is performed when the device driver 1003 converts an externally received IP packet into an IP packet.
To the process 1002 for IP processing,
This is performed by passing the data to the P processing process 1001 for TCP processing.

However, if the TCP / IP header is compressed, the IP packet cannot be directly passed to the IP processing process 1002.

Then, once, the device driver 1003
From the header decompression processing unit 100 processed in the user area
4 to pass the IP packet received from the outside.

The header decompression processing unit 1004 decompresses the received IP packet if necessary to decompress the TCP / IP header, and then executes the IP processing 1002
Pass to.

The IP processing process 1002 determines whether the
If the P packet is a packet to be forwarded, an appropriate output port is selected and passed to the device driver 1003. Even if the forward destination is the wireless terminal 303, the TCP /
The IP header is directly passed to the device driver 1003 without compression (1005).

Next, FIG. 10 shows that T
Header compression processing unit (10) for compressing the CP / IP header
14 shows an example of the implementation of 14).

In order to compress the TCP / IP header transmitted by the user, the TCP processing 1011 and the IP processing 1012 sequentially perform the TCP processing and the IP processing, and then pass it to the header compression processing unit 1014 in the user area. Then, TCP / IP header compression processing is performed. After that, it is passed to the device driver 1013 and transmitted.

On the other hand, when an IP packet is received, T
Since it is guaranteed that the compression of the CP / IP has not been performed, it is directly passed from the device driver 1013 to the IP processing process 1012 (1105).

Before starting the reception of the IP packet, the compression of the TCP / IP header is performed in advance only on the uplink channel,
The downlink channel does not compress the TCP / IP header,
And the hybrid router 304
Side only implements the decompression process of the TCP / IP header,
The wireless terminal 301 only needs to implement only the compression of the TCP / IP header, and the overhead due to the decompression / compression processing of the hybrid router 304 or the wireless terminal 301 can be minimized. Further, even if only the compression of the uplink channel is performed, the configuration of FIG.
The original performance of the CP can be obtained.

According to the present embodiment as described above, when the wireless terminal communicates with the server on the Internet, a narrowband wireless channel is used in the direction from the wireless terminal to the hybrid router, and the hybrid router communicates with the wireless terminal router. In the direction, a broadband wireless channel is used, and the wireless terminal compresses the header part of the data and passes it to the hybrid router, which decompresses the compressed header part of the received data and transfers it to the server. Therefore, even if the transmission path is asymmetric, the throughput does not decrease, and the power consumption of the wireless terminal can be reduced.

The above functions can also be realized as software.

The present embodiment is also directed to a computer which records a program for causing a computer to execute predetermined means (or for causing a computer to function as predetermined means, or for causing a computer to realize predetermined functions). It can also be implemented as a readable recording medium.

The present invention is not limited to the above-described embodiment, but can be implemented with various modifications within the technical scope.

[0090]

According to the present invention, header compression is performed in data transfer in the direction from the wireless terminal to the router device. Therefore, even if the transmission line is an asymmetric transmission line, the throughput is not reduced and the wireless communication is performed. It is possible to reduce the power consumption of the terminal.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration example of a network according to an embodiment of the present invention.

FIG. 2 shows an example of a protocol stack according to the embodiment.

FIG. 3 is a flowchart illustrating an example of a header compression procedure.

FIG. 4 is a flowchart showing an example of a header compression / decompression procedure.

FIG. 5 is a diagram showing an example of a conversion table for managing header compression.

FIG. 6 is a diagram showing an example of a data transmission / reception sequence.

FIG. 7 is a diagram showing a TCP / IP header format.

FIG. 8 is a diagram showing an example of a TCP / IP header format after header compression.

FIG. 9 is a diagram showing an example of a header decompression processing implementation of a router.

FIG. 10 is a diagram showing an example of a header compression processing implementation of a terminal.

[Explanation of symbols]

 301 ... Wireless terminal (PS) 302 ... Narrow band wireless base station (CS) 303 ... PCS network 304 ... Hybrid router 305 ... Broad band wireless base station (AP) 306 ... ATM network 307 ... Internet 308 ... Server 1001, 1011 ... TCP processing Process 1002, 1012 IP processing process 1003, 1013 Device driver 1004 Header decompression processing unit 1014 Header compression processing unit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5K030 HA08 HC09 HD03 JL01 JT02 KA23 LA07 LB05 5K033 AA03 BA11 CB06 DA05 DA19 DB12 DB16 DB18 DB25 EC04 5K051 AA03 BB02 CC07 DD05 DD15 FF16 GG02 HH27 JJ05 5K043 BB01 GG11 HH11 9A001 CC02 CC09 EE04 JZ25 JZ27

Claims (11)

[Claims] 1. A first channel comprising at least an uplink radio channel having a lower transmission rate and a second channel comprising at least a downlink radio channel having a transmission rate higher than the first channel. A communication method of a router device that performs path control of data transferred between a wireless terminal to be connected and a node device connected via a predetermined network, wherein the wireless terminal transmits the first channel. If the header portion of the data received via the communication device is compressed, the header portion is decompressed and decompressed. A communication method, wherein the data is transmitted to a network. 2. When data addressed to the wireless terminal is received from the predetermined network side, a route control is performed for the wireless terminal without compressing a header portion of the received data, and the data is transmitted to the wireless terminal. The communication method according to claim 1, wherein the transfer is performed using the second channel. 3. A method according to claim 1, further comprising the step of connecting a first channel constituted by a radio channel and a router connected by a second channel which is a radio channel having a higher transmission rate than the first channel. A communication method of a wireless terminal performing communication with a node device, wherein when transmitting data to the router device, a header portion of the data is compressed and transmitted using the first channel. Communication method. 4. The communication method according to claim 2, wherein data from which the header part is not compressed is received from the router device through the second channel. 5. The method according to claim 1, wherein the header section to be compressed is a network layer header section, a transport layer header section, or a network layer header section and a transport layer header section. The communication method according to claim 1. 6. The predetermined network is the Internet, the first channel is provided by a first base station connected to a PCS network, and the second channel is an AT.
The communication method according to any one of claims 1 to 5, wherein the communication method is provided by a second base station connected to the M network. 7. A communication line is provided by a first channel constituted by a bidirectional wireless channel and a second channel which is a unidirectional wireless channel having a transmission speed higher than that of the first channel. The first base station providing the second channel is connected to the PCS network and the second base station providing the second channel.
Is connected to the ATM network, the first base station and the second base station are connected via a router device, and the wireless terminal uses only the first channel or the first channel and the second channel. A communication method in a wireless communication system used simultaneously and communicating with a server device in a network only through a first base station or through a first base station and a second base station and a router device, The wireless terminal compresses a header portion of data to be transmitted, and transmits the compressed data of the header portion to the router device via the first base station. When the header portion of the data received via the first base station is compressed, the header portion is decompressed, and the route control of the received data is performed based on the contents of the header portion to direct the data to the server device. Send Communication method characterized by. 8. When the router device receives normal data addressed to the wireless terminal from the server device, the router device performs route control for the wireless terminal without compressing a header portion of the received data, and The communication method according to claim 11, wherein the transmission is performed to the second base station. 9. A wireless terminal connected via a predetermined network to a first channel constituted by a wireless channel and a wireless terminal connected by a second channel which is a wireless channel having a higher transmission rate than the first channel. A router device that performs route control of data transferred between the node device and the node device, wherein a header portion of data received from the wireless terminal via the first channel is compressed, A router device for compressing and decompressing the header portion, and a device for transmitting data addressed to the wireless terminal received from the predetermined network side so as to pass through the second channel. . 10. A network on a predetermined network via a first channel constituted by a radio channel and a router device connected by a second channel which is a radio channel having a higher transmission speed than the first channel. A wireless terminal that communicates with a node device, wherein: a means for compressing a header portion of data to be transmitted to the node device; and the router compressing the header portion using the first channel. Means for transmitting to the device. 11. A first device comprising a bidirectional wireless channel.
A first network accommodating a first base station that provides a first channel, and a second base station that provides a second channel that is a downlink radio channel having a higher transmission rate than the first channel. A second network to accommodate;
And a router device for connecting to a third network different from the second network, from the first base station via the first network or from the second base station via the second network And a wireless communication system comprising a wireless terminal capable of communicating with a node device connected to the third network via the router device, wherein the wireless terminal transmits data to be transmitted to the node device. Means for compressing a header portion and transferring the compressed packet to the router device via the first network, wherein the router device receives the node from the wireless terminal received from the first network. Means for compressing and decompressing a header portion of data addressed to the device, transferring the compressed data to the node device via the third network, and the third network. Wireless communication system; and a means for transferring data addressed to the wireless terminal in the node device onset received from the workpiece via the second network to the wireless terminal.