JP2005124077A - Wireless lan system, its communication control method, transmitting station, and receiving station - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wireless LAN system capable of transmitting IPv6 packets by high transmission efficiency over an IPv4 network. <P>SOLUTION: When an access point 1 receives an encapsulated packet from a network 7 (#a), it converts the packet into a packet having a compressed header made by compression of the encapsulated header of the encapsulated packet to transmit to a wireless LAN terminal 2. When the wireless LAN terminal 2 receives the packet having the compressed header from the access point 1, it restores the encapsulated packet from the packet having the compressed header to transmit a network (#b) 7 connected to the own terminal. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a wireless LAN system, a communication control method for the wireless LAN system, a transmitting station for the wireless LAN system, and a receiving station for the wireless LAN system.

  In conventional Internet communication, packet communication based on the IPv4 (Internet Protocol version 4) protocol is performed. For the purpose of responding to the increase in the number of addresses in recent years, the introduction of the IPv6 (Internet Protocol version 6) protocol has been introduced. Progressing. However, the IPv6 protocol and the IPv4 protocol have different header formats and other protocol formats. When an IPv6 protocol packet (hereinafter referred to as an IPv6 packet) is communicated on an existing IPv4 protocol network, tunneling or A conversion technique called encapsulation is used.

  As a technique for performing this encapsulation conversion, for example, there is a technique called “6to4” (see, for example, Non-Patent Document 1).

  This specification encapsulates an IPv6 packet and transmits it over an IPv4 protocol network, and transmits an IPv6 packet as if it were an IPv4 packet on an IPv4 protocol network (hereinafter referred to as an IPv4 network). It is.

  FIG. 13 is a configuration diagram of a wireless LAN system that communicates IPv6 packets from a server with clients on a wireless LAN connected to an IPv4 network using this encapsulation.

  In FIG. 13, the wireless LAN system includes an access point 1x, a wireless LAN terminal 2x, an IPv4 network 7x, an IPv6 network 8x, an encapsulation unit 9x, a server 10x, an encapsulation unit 99x, and a client 21x. The access point 1x has a wireless transmission unit 31x, and the wireless terminal 2x has a wireless transmission unit 32x.

  FIG. 14 is a diagram showing a configuration of a packet transmitted in the wireless LAN system. FIG. 14A shows a packet that the access point 1x transmits / receives to / from the IPv4 network 7x. The wired LAN MAC header 14x, IPv4 header 11x, and IPv6 header of a wired LAN represented by Ethernet (registered trademark) or IEEE802.3. 12x and payload 13x.

  FIG. 14B shows a packet that the access point 1x transmits and receives to and from the wireless LAN terminal 2x, and includes a wireless LAN MAC header 16x, an IPv4 header 11x, an IPv6 header 12x, and a payload 13x. The detailed structure of the wired LAN MAC header 14x is defined in IEEE standard specification IEEE 802.3, and the detailed structure of the wireless LAN MAC header 16x is defined in IEEE 802.11a, IEEE 802.11b, and the like. The operation of the conventional wireless LAN system will be described below with reference to FIGS.

  In FIG. 13, it is assumed that the server 10x performs packet communication in which an address or the like is set in the IPv6 format to the client 21x connected to the wireless LAN terminal 2x. The IPv6 packet transmitted by the server 10x is transmitted to the encapsulation unit 9x via the IPv6 network 8x. Upon receiving the IPv6 packet, the encapsulation unit 9x converts the packet into an encapsulated packet with an IPv4 header added thereto. Then, the encapsulated packet is further transmitted to the access point 1x via the IPv4 network 7x.

  When the access point 1x receives the encapsulated packet via the IPv4 network 7x, the access point 1x converts the wired LAN MAC header 14x of the packet into the wireless LAN MAC header 16x, and transmits the encapsulated packet to the wireless LAN terminal 2x.

  When receiving the encapsulated packet, the wireless LAN terminal 2x removes the wireless LAN MAC header 16x, newly sets the wired LAN MAC header 14x, and further transmits the packet to the encapsulation unit 99x. Then, the encapsulation unit 99x unencapsulates the packet, restores it to an IPv6 packet, and transmits it to the client 21x. Note that this procedure is reversed for packet transmission from the client 21 to the server 10.

  FIGS. 15 and 16 show the header structure of IPv4 packet and IPv6 packet, respectively. Details of the correspondence between the IPv4 header and the IPv6 header can be found in RFC (Request For Comment) 2460 of IETF (Internet Engineering Task Force). is described.

  In FIG. 15, the packet length of the IPv4 packet is 20 bytes in the minimum unit excluding option m and padding n.

  Further, in FIG. 16, since the source IP address G and the destination IP address H are each represented by 128 bits (16 bytes) in the IPv6 protocol, it is shown that the IPv6 header has a fixed length of 40 bytes. Although not shown in FIG. 16, the IPv6 header is used for setting routing (route information), authentication for QOS, encrypted payload, etc., following the basic header of fixed length 40 bytes shown in the figure. An extension header may be set.

  By the way, the IPv6 header 12x indicating information such as an address accompanying the IPv6 packet is longer than that of the IPv4 header 11x, and the IPv4 header 11x encapsulates the header of the IPv6 packet, so the packet length becomes long. In the wireless LAN system, header information specific to the wireless LAN for wireless communication control is further added.

  Therefore, in the communication section of the wireless LAN, there is a problem that the above various header lengths are summed up to become a long header, resulting in a decrease in throughput.

For example, since the IPv4 header 11x is 20 bytes or more and the IPv6 header 12x is a 40-byte header, the above-described encapsulation results in a minimum 60-byte header. In Ethernet (registered trademark), which is a typical IP packet transmission means, the length of the payload 13x in which the IP packet is contained is 64 bytes at the minimum setting value. Accordingly, when an encapsulated packet is transmitted with the minimum specified value, most of the payload 13x is occupied by the IP header, so that a reduction in transmission efficiency is a significant problem.
IETF RFC 3056 (Internet Engineering Task Force Request For Comments 3056).

  Conventionally, in a wireless LAN system connected to an IPv4 network, when an IPv6 packet is encapsulated, the header becomes longer and a MAC address header of the wireless LAN is added, so that the header length occupied in the packet is increased and transmitted. There was a problem that efficiency decreased.

  An object of the present invention is to realize a wireless LAN system capable of transmitting IPv6 packets with high transmission efficiency on an IPv4 network and a communication control method thereof.

  In order to achieve the above object, the wireless LAN system of the present invention has a packet transmitted from a first client via a first network according to a protocol of a second network different from the first network. A wireless LAN system comprising a transmitting station that receives a packet converted into an encapsulated packet via the second network, and a receiving station wirelessly connected to the transmitting station, wherein the transmitting station A first translation table for storing compressed information in association with a combination of a plurality of addresses based on a protocol of one network, and a capsule composed of first header information and second header information of the encapsulated packet And at least a part of the encrypted header is compressed into compressed header information based on the first conversion table, and the wireless communication head Conversion means for converting into a wireless communication packet to which is added, and transmission means for wirelessly transmitting the wireless communication packet to the receiving station, wherein the receiving station has a plurality of addresses based on the protocol of the first network. A second conversion table storing compressed information in association with each other according to the combination; and receiving the wireless communication packet, at least a part of the compressed header information is based on the second conversion table based on the first and second conversion tables. Transmission means for restoring to the encapsulated packet comprising the header information of 2 and transmitting to the second client.

  In the wireless LAN system of the present invention, a packet transmitted from a first client via a first network is converted into an encapsulated packet according to a second network protocol different from the first network. A wireless LAN system comprising a transmitting station that receives the data via the second network and a receiving station that is wirelessly connected to the transmitting station, wherein the transmitting station conforms to the protocol of the first network. A first conversion table storing compressed information in association with each other in accordance with a combination of a plurality of addresses based on the first header information and at least a part of the encapsulated header including the second header information of the encapsulated packet Is compressed into compressed header information based on the first conversion table, and a wireless communication header and a compressed header packet are compressed. Conversion means for converting into a wireless communication packet to which certain identification information is added, and transmission means for wirelessly transmitting the wireless communication packet to the receiving station, wherein the receiving station is based on a plurality of protocols based on the protocol of the first network A second conversion table that stores compressed information in association with each other according to a combination of addresses, and when the wireless communication packet is received and determined to be the compressed header packet based on the identification information, Transmitting means for restoring at least a part of the compressed header information to the encapsulated packet including the first and second header information based on the second conversion table and transmitting the packet to the second client. It is characterized by.

  In the wireless LAN system of the present invention, a packet transmitted from a first client via a first network is converted into an encapsulated packet according to a second network protocol different from the first network. A wireless LAN system comprising a transmitting station that receives the data via the second network and a receiving station that is wirelessly connected to the transmitting station, wherein the transmitting station conforms to the protocol of the first network. A first conversion table in which compression information is associated and stored in accordance with a combination of a plurality of addresses, and a combination of a plurality of addresses included in the first header information of the encapsulated packet in the first conversion table Is stored, the capsule comprising the first header information and the second header information of the encapsulated packet At least a part of the header is compressed into compressed header information based on the first conversion table, converted to a first wireless communication packet with a wireless communication header added thereto, and the first packet is encapsulated in the first conversion table. Conversion means for converting to a second wireless communication packet in which the wireless communication header is added to the encapsulated packet when the combination of the plurality of addresses included in the first header information is not stored; Or transmitting means for wirelessly transmitting a second wireless communication packet to the receiving station, wherein the receiving station is associated with compression information in accordance with a combination of a plurality of addresses based on the protocol of the first network. And storing the second conversion table to be stored and the first wireless communication packet, at least a part of the compressed header information is stored in the second Transmission means for restoring the encapsulated packet including the first and second header information based on a conversion table and transmitting the encapsulated packet to the second client when the second radio packet is received; It is characterized by having.

  The transmitting station of the wireless LAN system of the present invention is wirelessly connected to the receiving station, and a packet transmitted from the first client via the first network is a second network different from the first network. A transmitting station that receives the packet converted into the encapsulated packet according to the protocol via the second network, and supports compression information according to a combination of a plurality of addresses based on the protocol of the first network. A conversion table that is attached and stored, and at least a part of an encapsulation header including the first header information and the second header information of the encapsulated packet is compressed into compressed header information based on the conversion table, and wireless Conversion means for converting the packet into a wireless communication packet with a communication header added thereto; and receiving the wireless communication packet. Characterized by comprising a transmitting means for wireless transmission to the station.

  Further, the receiving station of the wireless LAN system of the present invention can encapsulate the packet transmitted from the first client via the first network according to the second network protocol different from the first network. A receiving station that is wirelessly connected to a transmitting station that receives the converted data via the second network, and compression information corresponds to a combination of a plurality of addresses based on the protocol of the first network A radio including a conversion table attached and stored, compressed header information in which at least a part of an encapsulation header including the first header information and the second header information of the encapsulated packet is compressed, and a radio communication header Receiving means for receiving a communication packet from the transmitting station; and before the wireless communication packet received by the receiving means At least a portion of the compressed header information based on the conversion table to restore the encapsulated packet consisting of the first and second header information, and a sending means for sending to the client.

  According to the present invention, even when IPv6 packets of different protocols are encapsulated and transmitted on the IPv4 network, the encapsulated header can be compressed and communication with a short header length can be performed on the wireless LAN. Efficiency can be improved.

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

  FIG. 1 is a block diagram showing the configuration of a first embodiment of a wireless LAN system according to the present invention.

  1, the wireless LAN system includes an access point 1, a wireless LAN terminal 2, an IPv4 network (#a, #b) 7, an IPv4 terminal 7t, an IPv6 network (#a, #b) 8, an encapsulation unit 9, and a capsule. The configuration unit 99, the server 10, and the client 21 are configured. The access point 1 has a wireless unit 31, a header processing unit 51, and a conversion table 61. The wireless LAN terminal 2 has a wireless unit 32, a header processing unit 52, and a conversion table 62. The client 21 is composed of a personal computer PC or a portable information terminal.

  FIG. 2 is a diagram illustrating a configuration of a packet transmitted by the wireless LAN system according to the first embodiment. FIG. 2A shows a packet that the access point 1 transmits / receives to / from the wired LAN IPv4 network (#a) 7. The wired LAN MAC header 14 represented by Ethernet (registered trademark), the IPv4 header 11, and the IPv6 header. 12 and a payload 13. FIG. 2B shows a packet that the access point 1 transmits / receives to / from the wireless LAN terminal 2 and includes a wireless LAN MAC header 16, a compression header 15, and a payload 13. Note that FIG. 2A is also a packet transmitted and received between the wireless LAN terminal 2 and the IPv4 network (#b) 7.

  In FIG. 1, the server 10 transmits a packet in which an IPv6 address is set to the client 21. The IPv6 packet transmitted by the server 10 is transmitted to the encapsulation unit 9 via the IPv6 network (#a) 8.

  In the following description, the operation is described by taking the case where the server 10 transmits an IPv6 packet from the IPv6 network (#a) 8 as an example. However, instead of the server 10, the IPv6 packet is transmitted from a client (not shown). The operation is the same even if it is transmitted.

  The encapsulation unit 9 is also called a relay router, and converts it into an encapsulated packet to which an IPv4 header 11 indicating the entrance and exit of the IPv4 network (#a, #b) 7 is added. The encapsulated packet from the encapsulating unit 9 is transmitted to the access point 1 via the IPv4 network (#a) 7.

  As shown in FIG. 2A, this encapsulated packet is added to the packet having the IPv4 header 11 in the IPv4 header 11 in the IPv4 network (#a, #b) 7 which is the transmission section of the wired LAN. The header part is a long packet. The IPv6 packet transmitted by the server 10 may be considered as the IPv6 header 12 and the payload 13 excluding the IPv4 header 11 from FIG. On the wired network connecting the server 10 and the access point 1, a signal is transmitted by adding a wired LAN MAC header 14 by the server 10, and on the wireless network between the access point 1 and the wireless terminal 2. Then, a signal with the wireless LAN MAC header 16 added is transmitted by the access point 1.

  When the access point 1 receives the encapsulated packet (FIG. 2A) via the IPv4 network (#a) 7, the header processing unit 51 removes the wired LAN MAC header 14, and further, the header part (IPv4) of the encapsulated packet. The header 11 and the IPv6 header 12) are converted into the compressed header 15 according to the conversion table 61. Then, a signal with the wireless LAN MAC header 16 added ((b) in FIG. 2) is generated and transmitted to the wireless LAN terminal 2.

  On the other hand, the header processing unit 52 of the wireless LAN terminal 2 removes the wireless LAN MAC header 16 from the received packet, further restores the header part according to the conversion table 62, and generates a packet with the wired LAN MAC header 14 added thereto. To the IPv4 network (#b) 7. That is, the signal transmitted from the wireless LAN terminal 2 to the IPv4 network (#b) 7 is the same as that shown in FIG. When receiving the packet, the encapsulating unit 99 connected to the IPv4 network (#b) 7 unencapsulates the packet, deletes the IPv4 header 11 and restores the IPv6 packet to restore the IPv6 network (#b) 8. To the client 21 via

  The client 21 receives this packet from the IPv6 network (#b) 8 and performs necessary signal processing. When a packet is transmitted from the client 21 to the server 10, the conversion process is performed by following this reverse course, and the packet is transmitted.

  FIG. 3 is a configuration diagram of the header (address) portion of the encapsulated packet converted by the encapsulating unit 9.

  In FIG. 3, the capsule header has a configuration in which an IPv6 header (reference characters A to H) is connected to an IPv4 header (reference characters a to n). The source IP address k (for example, “11.33.55.77”) in the IPv4 header portion of the encapsulated packet is displayed in decimal. The source IP address G in the IPv6 header part starts with an IPv6 prefix called “2002”.

  When the encapsulation unit 99 on the packet receiving side confirms that this IPv6 prefix exists following the IPv4 header, it can determine that the packet is an encapsulated packet. Further, in the IPv6 header, a source address “0b21: 374d: 1 :: 1—” is set after the IPv6 prefix.

  In the compression of the header part, the combination of the source IP address G and the destination IP address H of the IPv6 header and, if necessary, the field of the flow label C or other IPv6 header or the extension header are set. A compression number can be set by appropriately combining conditions such as encryption information.

  FIG. 4 is an example of a conversion table for converting an encapsulated header into a compressed header. This conversion table is set as a conversion table 61 and a conversion table 62 in the internal memory of the header processing unit 51 of the access point 1 and the header processing unit 52 of the wireless LAN terminal 2, respectively. The conversion table is composed of a source IP address G, a destination IP address H, other combination items, header detailed data, and the like in an IPv6 header corresponding to the compression number. Note that FIG. 4 shows a conversion table in the case of setting a compression number corresponding to a source IP address G and a destination IP address H of an IPv6 header assumed in advance, but other combinations may be made as necessary as described above. Necessary items (parameters) may be added.

  Various header detailed data necessary for restoring the compressed header described in the encapsulated header is stored in the conversion table 61 and the conversion table 62 by means such as initial setting.

  FIG. 5 shows an example of the structure of the compressed header portion of the compressed header packet converted by the header processing unit 61 of the access point 1.

  In FIG. 5, the compressed header 15 is composed of a compressed header display field x1, a compressed number field x2, and a spare field x3. In order to indicate that the packet transmitted / received between the access point 1 and the wireless LAN terminal 2 is a compressed packet, here, the portion corresponding to the field indicating the version a of the IPv4 header is used as the compressed header display field x1. , “1111”.

  In the compression number field x2 set in the compression header, a compression number based on FIG. 4 is set from a combination based on the combination of the source IP address G and the destination IP address H of the IPv6 header. These describe the setting contents in the portion corresponding to the fields assigned to the header length b, service type c and total length d of the IPv4 header. (Use of portions corresponding to other fields of the IPv4 header may be appropriately set by the system as necessary.)

  For example, in the setting of the compression number field x2, the compression number is set only by the combination of the source IP address G and the destination IP address H of the IPv6 header using the 10th bit from the head of the header length b of the IPv4 header. Then, it becomes the compression number of 512 combinations at maximum. That is, in the past, a header of at least 60 bytes was used for encapsulation, but here it is a compressed header compressed to 4 bytes or less. In this case, the 10th bit and thereafter are reserved x3.

  The compression number field x2 can be set by generating a compression number based on a combination of a combination of the source IP address G and the destination IP address H of the IPv6 header and other connection-related conditions. However, since the number of bits required for the header information is only the number of description bits corresponding to the number of connections that meet these conditions, the degree of compression becomes very high.

  As a method for indicating that the header of the compressed packet is a compressed header when transmitting the compressed packet, the identifier “1111” is provided in the compressed header in the above description. You may carry out by other methods, such as describing in the LANMAC header 16. FIG.

  FIG. 6 is a configuration example of a packet transmitted on the wireless LAN between the wireless unit 31 of the access point 1 and the wireless unit 32 of the wireless LAN terminal 2. In FIG. 6, a wireless LAN packet includes a PLC frame preamble pa, a PLCP header ph, which is header information unique to the wireless LAN, a MAC frame mf corresponding to the wireless LAN MAC header 16, a data frame df on which a compressed header and payload data are mounted. It consists of an FCS frame ff for error correction.

  For identifying whether this wireless LAN packet is a compressed header or a header that is not a compressed header, header type information is provided in the MAC frame mf in FIG. 6. For example, if it is “11”, it is a compressed header packet. It shows that.

  FIG. 7 is a flowchart showing an operation procedure when the access point 1 transmits an encapsulated packet to and from the wireless LAN terminal 2.

  In FIG. 7, the left column indicates the operation of the access point 1 that transmits the encapsulated packet, and the right column indicates the operation of the wireless LAN terminal 2 that receives the packet.

  First, in the access point 1 and the wireless LAN terminal 2, initial settings are made in advance in the conversion table 61 and the conversion table 62 in order to create a compressed header corresponding to the encapsulated header. (Steps s1 and s1-1). For this initial setting, for example, a personal computer is connected to the access point 1 and the wireless LAN terminal 2, and predetermined setting information may be input by an input device such as a keyboard, for example, corresponding to the compression number in FIG. . Alternatively, a method may be used in which wireless LAN communication is performed between the access point 1 and the wireless LAN terminal 2, a personal computer is connected to one of them, and setting information is input to both using the communication. .

  When the access point 1 receives a packet ((a) in FIG. 2) from the IPv4 network (#a) 7 (step s2), the header processing unit 51 reads the wired LAN MAC header 14 and uses the packet addressed to itself. If there is, this is taken in, the wired LAN MAC header 14 is removed, and the IPv4 header 11 and the IPv6 header 12 are read.

  When the header processing unit 51 determines the IPv6 prefix “2002” in the IPv6 header 12, the header processing unit 51 determines that the header is an encapsulated header transmitted from the server 10 to the client 21 (when step s3 is Yes). . And the header part is collated with the conversion table 61 (step s5).

  For example, if the source IP address of the IPv6 header 12 is “c001: 0203 :: 48” and the destination IP address is “09fe: fdfc :: 48”, the compression number corresponding to the combination is shown in FIG. (Step s6 is Yes), the compression number (in this example, “2” is applicable) for the combination is read out.

  Subsequently, the header processing unit 51 adds “1111” in the compressed header display field x1 to the compressed header information in the compressed header 15 of the packet to be transmitted to the wireless LAN terminal 2, that is, the compressed header, and the compressed number. “2” is written in the compression number field x2 (step s7).

  The header processing unit 51 further generates a compressed header packet (FIG. 2B) to which the wireless LAN MAC header 16 in which the device destination address (for example, DA) of the wireless LAN terminal 2 is written is added to the wireless unit 31. Output. Then, the access point 1 transmits this compressed header packet to the wireless LAN terminal 2 via the wireless unit 31 (step s8).

  When receiving the compressed header packet (step s10), the wireless unit 32 of the wireless LAN terminal 2 outputs the packet to the header processing unit 52. The header processing unit 52 reads the device destination address (DA) from the wireless LAN MAC header 16 and captures the packet. Then, the wireless LAN MAC header 16 is removed, and the compressed header display field x1 “1111” of the compressed header 15 is read to determine that the header is a compressed header (Yes in step s11).

  Then, the header processing unit 52 collates the compression header with the conversion table 62, and from the compression number “2” of the compression number field x2, the transmission source IP address G “c001: 0203 of the IPv6 header of the corresponding packet corresponding thereto. :: 48 ”and the destination IP address H“ 09fe: fdfc :: 48 ”and other header detailed data are read from the conversion table 62 (step s12) and restored to the encapsulated packet of the IPv4 network (#b) 7 (Step s13).

  When these processes are completed, the wireless LAN terminal 2 generates an encapsulated packet (FIG. 2A) to which a wired LAN MAC header for transmission to the IPv4 network (#b) 7 is added, toward the client 21. The encapsulated packet is transmitted via the IPv4 network (#b) 7 (step s14).

  In step s3, if the packet received from the IPv4 network (#a) 7 is not an encapsulated packet (step s3 is No), the access point 1 is an IPv4 packet transmitted from, for example, the IPv4 terminal 7t. Judge. That is, it is determined that the data communication is from a client directly connected to the IPv4 network (#a) 7 that does not pass through the encapsulation unit 9. Then, the access point 1 adds the wireless LAN MAC header 16 addressed to the wireless LAN terminal 2 to the IPv4 packet and transmits it (step s4).

  When receiving the IPv4 packet (step s10), the wireless unit 32 of the wireless LAN terminal 2 outputs it to the header processing unit 52. The header processing unit 52 removes the wireless LAN MAC header 16, reads that the content of the header of this packet is not “1111”, and determines that the header is not a compressed header (No in step s11).

  Subsequently, when it is determined that there is no IPv6 prefix “2002” in the IPv6 header (No in step s15 in FIG. 7), the received IPv4 packet is transmitted to the client via the IPv4 network (#b) 7 (FIG. 7). 7 step s18). The client in this case is a partner connected to the IPv4 network (#b) 7.

  If it is determined in step s6 that the packet is an encapsulated packet for which no compression number is set in the conversion table 61 (No in step s6), the header processing unit 51 keeps the packet as an encapsulated header. The wireless LAN MAC header 16 is added and transmitted to the wireless LAN terminal 2 (step s9).

  Upon receiving this encapsulated packet, the wireless unit 32 of the wireless LAN terminal 2 outputs it to the header processing unit 52. The header processing unit 52 removes the wireless LAN MAC header 16 and determines that it is not a compressed header because the head of the header part is not “1111” (No in step s11). Further, an IPv6 prefix “2002” is added to the IPv4 header. Whether the packet is an encapsulated packet is determined based on whether or not it continues.

  Here, since the IPv6 prefix “2002” continues, the header processing unit 52 determines that the packet is an encapsulated packet (Yes in step s15). Then, an encapsulated packet with a wired LAN MAC header 14 for transmission to the IPv4 network (#b) 7 is generated and transmitted to the client 21 via the IPv4 network (#b) 7 and the encapsulation unit 99 ( Step s14).

  The above is the basic form of the first embodiment, but some of the steps of the above operation may be performed by a certain component or may be substituted.

  FIG. 8 is a modification of the wireless LAN system according to the first embodiment.

  This wireless LAN system is the same as the first embodiment in FIG. 1 except that the client 21 is directly connected to the wireless LAN terminal 2. With this connection configuration, it is possible to change the burden on the functional elements that perform header restoration processing.

  In this wireless LAN system, the encapsulated packet may be transmitted from the wireless LAN terminal 2 to the client 21, or the restored IPv6 packet may be transmitted from the wireless LAN terminal 2 instead of the encapsulated packet.

  For example, when the client 21 has a relay router function, the client 21 restores the encapsulated packet transmitted from the wireless LAN terminal 2 to an IPv6 packet. Then, the restored IPv6 packet may be transmitted from the client 21 to an IPv6 network connected to the client 21 or an IPv6 terminal.

  Further, when the client 21 is a host or a computer terminal having an encapsulation restoration function, the client 21 converts the encapsulation packet transmitted from the wireless LAN terminal 2 into an IPv6 packet, and interprets the header content. Required signal processing, application execution, and the like.

  Further, the wireless LAN terminal 2 may have a function of a relay router that converts the encapsulated packet into an IPv6 packet and transmits it instead of the encapsulating unit 99. In this case, the compressed header packet is restored to an IPv6 packet in step s13 in FIG. 7, and the IPv6 packet is transmitted in step s14.

  If the packet is an encapsulated packet in step s15, the wireless LAN terminal 2 that has received the encapsulated packet generates an IPv6 packet and transmits it to the client 21.

  Next, a case where an IPv6 packet is transmitted from the wireless LAN terminal 2 to the access point 1 will be described. Here, in order to avoid complicated explanation, the operation will be described assuming that the client 21 is directly connected to the wireless LAN terminal 2.

  FIG. 9 is a flowchart showing an operation procedure for transmitting a packet from the wireless LAN terminal 2 to the access point 1.

  In FIG. 9, the left column indicates the operation of the wireless LAN terminal 2 that transmits a packet, and the right column indicates the operation of the access point 1 that receives the packet. In this wireless LAN communication, the transmission direction is opposite to that in the first embodiment, but the description will focus on differences from the flowchart of FIG.

  The header processing unit 52 of the wireless LAN terminal 2 receives the encapsulated packet from the client 21 (step p3 is Yes), and if the compressed header information corresponding to the encapsulated packet is set in the conversion table 62 (step p5). Yes), a compressed header packet having a compressed header in which a predetermined compression number is set based thereon is generated. For example, a combination in which the description data of the destination IP address G and the destination IP address H in the IPv6 header in FIG. 4 are reversed (here, for example, the source IP address G “09fe: fdfc :: 48” and the destination IP address H “ c001: 0203 :: 48 ”), the compression number“ 2 ”is set. Then, the header processing unit 52 generates a compressed header packet to which the wireless LAN MAC header 16 is added, and transmits the packet to the access point 1 via the wireless unit 32 (step p8).

  When the access point 1 receives the compressed header packet via the wireless unit 31, the access point 1 outputs the packet to the header processing unit 51.

  If the packet received by the access point 1 is a compressed header packet (step p11 is Yes), the header processing unit 51 refers to the conversion table 61 and starts from the compression number “2” of the packet to the transmission source IP address, The destination IP address or the like is read (step p12), and a predetermined encapsulated packet set in the IPv4 header and IPv6 header is generated (step p13). Then, the encapsulated packet with the wired LAN MAC header added (the same configuration as in FIG. 2A) is transmitted to the server 10 via the IPv4 packet network (#a) 7 (step p14).

  However, in step p6, when the information regarding the server 10 is not set in the conversion table 62 (step p6 is No), the header processing unit 52 performs the encapsulation as it is and encapsulates it in the access point 1 via the radio unit 32. A packet is transmitted (step p9).

  When the wireless unit 31 of the access point 1 receives the encapsulated packet that is not the compressed header (No in step p11 and Yes in step p15), the wireless unit 31 outputs the packet to the header processing unit 51. The header processing unit 51 transmits the encapsulated packet to the server 10 via the IPv4 packet network (#a) 7 (step p14).

  If the access point 1 has a relay router function and the packet received by the wireless LAN terminal 2 from the client 21 is an IPv6 packet (No in step p3), the wireless LAN terminal 2 directly receives IPv6. The packet is transmitted to the access point 1 (step p4).

  When the header processing unit 51 of the access point 1 determines that the received packet is an IPv6 packet (No in step p11, No in step p15, Yes in step p16), it encapsulates the IPv6 packet (step p13), and IPv4. It transmits to the network (#a) 7 (step p14).

  This encapsulated packet is received by the encapsulating unit 9 from the IPv4 packet network (#a) 7, where the encapsulated packet is unwound and converted into an IPv6 packet. The encapsulation unit 9 transmits this IPv6 packet to the server 10 via the IPv6 network (#a) 8. When the server 10 receives the packet, the server 10 reads the header and payload data and executes a predetermined application.

  The compression method or algorithm for the encapsulated header is not limited to the table formation as in the above example, but may use a conversion rule (specification) such as RFC 2085 of IETF.

  In the second embodiment, an encapsulated packet in which the compression number of the combination of the source IP address G and the destination IP address H of the IPv6 header is not set in the conversion table 61 and the conversion table 62 is transferred to the access point 1 and the wireless LAN terminal 2. When the communication is performed, wireless LAN communication is performed by additionally setting a compression number corresponding to this combination in the conversion table 61 and the conversion table 62.

  FIG. 10 is a flowchart illustrating an operation procedure according to the second embodiment. In FIG. 10, the left column indicates the operation of the access point 1 that transmits a packet, and the right column indicates the operation of the wireless LAN terminal 2 that receives the packet.

  The operation of the second embodiment will be described with a focus on differences from the first embodiment. The description will be made assuming that the client 21 is connected to the wireless LAN terminal 2.

  When the access point 1 receives the encapsulated packet (similar to FIG. 2A) from the IPv4 network (#a) 7 (step s52), the header processing unit 51 reads the wired LAN MAC header 14 and sends it to its own device. Is read, and the IPv4 header 11 which is the head of the encapsulated header is read out.

  When the IPv6 header 12 subsequent to the IPv4 header 11 is an encapsulated header in which the IPv6 prefix “2002” is set (step s53 is Yes), the header processing unit 51 converts the header of the encapsulated packet and The table 61 is collated (step s55), and the combination of the source IP address G “c001: 0203 :: 48” and the destination IP address H “09fe: fdfd :: 48” in the IPv6 header of the packet is converted into the conversion table 61. Assume that it is determined that there is no such (No in step s56).

  Then, the header processing unit 51 additionally stores the source IP address G “c001: 0203 :: 48” and the destination IP address H “09fe: fdfd :: 48” in the conversion table 61 from the IPv6 header of the encapsulated packet. . Then, a compression number (here, “16”) corresponding to this combination is generated, and the compression number “16”, the IP address, etc. are stored in the conversion table 61 as shown in FIG. Then, the conversion table 61 is reset (step s59).

  Subsequent to this setting, the header processing unit 51 generates an encapsulated packet to which the wireless LAN MAC header 16 is added and transmits it to the wireless LAN terminal 2 via the wireless unit 31 (step s59-1).

  When this encapsulated packet is transmitted, it is compressed in the field of option m (see FIG. 3) of the IPv4 header of the encapsulated packet in the next and subsequent transmissions in accordance with the reconfigured conversion table 61. A mark (for example, the last 5 bits are set to “01111”) indicating that the packet is an encapsulated packet in the header is set and transmitted.

  When receiving the encapsulated packet (step s51-2), the wireless unit 32 of the wireless LAN terminal 2 outputs it to the header processing unit 52. Then, the header processing unit 52 removes the wireless LAN MAC header 16 and determines that it is not a compressed header because the head of the header portion is not “1111”, and reads the contents of the header portion of the encapsulated packet. That is, it is determined whether the packet is an encapsulated packet from the IPv6 prefix “2002” of the IPv6 header (Yes in step s51-7).

  Furthermore, when the header processing unit 52 reads the mark “01111” from the option m field of the IPv4 header, the header processing unit 52 determines that the packet is to be transmitted as a compressed header packet next time (Yes in step s51-8). Then, the source IP address G “c001: 0203 :: 48” and the destination IP address H “09fe: fdfd :: 48” of the IPv6 header are additionally stored in the conversion table 62 from the encapsulated header (step s51-9). .

  Then, the compression number “16” corresponding to this combination is stored in the conversion table 62, and the conversion table 62 is reset. As the compression number of the conversion table 62, the same compression number as the conversion table 61 of the access point 1 must be set. For this reason, for example, the compression number is set as a serial number, and the compression number is set in the option m field of the IPv4 header on the access point 1 side by adding the compression number every time the compression number is added. Adopts a method such as reading this compression number.

  The addition of these marks and the notification of the compression number may be performed by a method such as setting in the MAC frame of the wireless LAN MAC header 16 in addition to the above method.

  The header processing unit 52 adds a wired LAN MAC header connected to the IPv4 network to generate an encapsulated packet, and the wireless LAN terminal 2 transmits the encapsulated packet to the client 21.

  If the mark “01111” is not deciphered in step s51-8, the header processing unit 52 generates an encapsulated packet in which the wired LAN MAC header is added to the encapsulated packet, and the wireless LAN terminal 2 transmits to the client 21. The encapsulated packet is transmitted (step s51-6).

  Therefore, even if the header processing unit 52 receives an encapsulated header packet that does not store a compression number in the initial setting, and subsequently receives the same encapsulated header packet, it transmits it as a compressed header packet. I can do it.

  In step s51-7, if the packet is not an encapsulated packet but an IPv4 packet (No in step s51-7), the wireless LAN terminal 2 transmits an IPv4 packet to the client 21 (step s51-10).

  The method of additionally registering the source IP address and the destination IP address in the conversion tables 61 and 62 is based on the source IP address G that may be compressed and communicated when the conversion tables 61 and 62 are further initialized. The destination IP address H may be registered as a compressed header application candidate. Then, only when an encapsulated packet having the registered IP address is received, it may be transmitted as a packet for compressing the header. This method of attaching a mark has an effect of saving the capacity of the compression tables 61 and 62 because the number of clients to be subjected to compression header processing can be limited.

  In addition, when performing the initial setting for registration of the above candidates, the information to be entered is only the IP address information, and other than that, for example, the header detailed data described in FIG. 4 is not inputted. Also good. In this case as well, since the header detailed data is read when the encapsulated packet is received, if the header detailed data is automatically copied and stored in the conversion tables 61 and 62, the header detailed data is set by default. It is possible to reduce the work of inputting.

  On the other hand, a method of additionally setting the compression number and the combination in the conversion tables 61 and 62 may be adopted for all the combinations that have received the combination of the source IP address and the destination IP address without attaching this mark. The method of not adding a mark is effective when the access point 1 and the wireless LAN terminal 2 perform an inter-LAN bridge function. However, in this method, the amount of data set in the conversion tables 61 and 62 becomes enormous, so it is desirable to clear and update the combination of the source IP address and the destination IP address and the compression number as appropriate.

  Also in the second embodiment, as in the first embodiment applied to the configuration shown in FIG. 8, it is possible to adopt a modification such as restoring the IPv6 packet to the wireless LAN terminal 2. In this case, in FIG. 10, step s51-5 is converted into a compressed header packet or encapsulated packet into an IPv6 packet, and step s51-6 is read so that the IPv6 packet is transmitted to the client.

  FIG. 11 is a flowchart illustrating an operation when a packet is transmitted from the wireless LAN terminal 2 to the access point 1 in the second embodiment.

  In FIG. 11, the left column indicates the operation of the wireless LAN terminal 2 that transmits a packet, and the right column indicates the operation of the access point 1 that receives the packet.

  In this case, the operation of transmitting packets from the access point 1 to the wireless LAN terminal 2 in FIG. 10 may be replaced with the flowchart of transmitting packets from the wireless LAN terminal 2 to the access point 1. If the access point 1 has a relay router function, step p51-11 is added, and the operation is as follows.

  If the packet received from the client 21 by the wireless LAN terminal 2 is an IPv6 packet (No at step p53), the IPv6 packet is transmitted from the wireless LAN terminal 2 to the access point 1 (step p54).

  In this case, if the header processing unit 51 of the access point 1 is not a packet of a compressed header and is not an encapsulated packet (No in step p51-3, No in step p51-7), the header processing unit 51 receives the packet in step p51-11. It is determined whether the received packet is an IPv6 packet. When it is determined that the packet is an IPv6 packet (step p51-11 is Yes), the IPv6 packet is encapsulated (step p51-5) and transmitted to the IPv4 network (#a) 7 (step p51-6). As a result, the access point 1 can convert the IPv6 packet into an encapsulated packet.

  The third embodiment is one of means for communicating between the access point 1 and the wireless LAN terminal 2 an encapsulated packet in which the compressed header information of the encapsulated packet is not described in the conversion table 61 and the conversion table 62. When the packet transmission side has the function of a relay router, wireless LAN communication is performed using packets in the IPv6 header for wireless communication therebetween.

  FIG. 12 is a flowchart illustrating the operation procedure of the third embodiment. In FIG. 12, the left column indicates the operation of the access point 1 that transmits a packet, and the right column indicates the operation of the wireless LAN terminal 2 that receives the packet. The operation of the third embodiment will be described with a focus on differences from the second embodiment shown in FIG.

  In the following, the encapsulated packet received by the access point 1 is a combination of IP addresses whose compression numbers are not set in the conversion table 61, and one of the IP addresses is registered as a candidate IP address to be transmitted in the compressed header. The operation will be described taking the case of a capsule packet as an example.

  Now, the header processing unit 51 of the access point 1 reads the received encapsulated packet and, for example, the transmission source IP address G “c001: 0203: 48” and the destination IP address H “09fe: fdfb :: 48”. Is not included in the conversion table 61 (No in step s56), but the source IP address G “c001: 0203 :: 48” is registered as an IP address candidate to be transmitted in the compressed header (step s56-1). Yes).

  The determination of the presence / absence of registration is performed by, for example, a method in which an identification field of the source IP address G of the conversion table 61 is provided and whether or not “1” meaning registration is initially set there. .

  Therefore, the header processing unit 51 determines that the received combination of IP addresses will be transmitted in the compressed header from the next time. Then, the source IP address G “c001: 0203 :: 48”, the destination IP address H “09fe: fdfb :: 48”, and the compression number “17” corresponding to the combination thereof are added to the conversion table 61 (step) s59).

  Then, the access point 1 converts the received encapsulated packet into an IPv6 packet, sets a mark “01111” indicating that it will be transmitted as a compressed header packet from the next time on, and sets the extension header of the IPv6 header to the wireless LAN terminal 2. (Step s59-2). The extension header is an option setting field set subsequent to the destination IP address H field of the IPv6 header.

  If the header processing unit 52 of the wireless LAN terminal 2 determines that the received packet is an IPv6 packet (Yes in step s60), the extension header of the received packet is read, and the next and subsequent IPv6 packets are compressed. When the mark “01111” for indicating “” is read, it corresponds to the source IP address G “c001: 0203 :: 48” and the destination IP address H “09fe: fdfb :: 48” read from the IPv6 header, and combinations thereof The compression number “17” is added to the conversion table 62 and reset (step s61).

  The compression number of this conversion table 62 is the same as that of the conversion table 61 of the access point 1 as in the second embodiment.

  On the other hand, when the IP address of the received encapsulated packet is not registered in the IP address candidate to be transmitted by the compressed header (No in step s56-1), the encapsulated pad is transmitted as it is to the wireless LAN terminal 2 (step s56). -2). Then, the wireless LAN terminal 2 transmits the packet as an encapsulated packet to the client 21 (step s51-7 is Yes, s51-6).

  If the encapsulated packet is transmitted to the wireless LAN terminal 2 by a method that does not register that the IP address is a candidate for transmission in the compressed header, steps s56-1, 56-2, and s51-7 are omitted.

  That is, for a capsule packet having no IP address combination in the conversion table 61, the IP address combination is added to the conversion table 61 (step s59). Then, the encapsulated packet is converted into an IPv6 packet and transmitted from the access point 1 to the wireless LAN terminal 2 (step s59-2).

  In the wireless LAN terminal 2, a combination of IP addresses is read from the received IPv6 packet and added to the conversion table 62 (step s61).

  Further, when the encapsulated packet is transmitted from the wireless LAN terminal 2 to the access point 1, the relationship between the access point 1 and the wireless LAN terminal 2 in FIG. 12 is switched.

  Also in the third embodiment, it is possible to adopt a modification in which the wireless LAN terminal 2 restores an IPv6 packet and transmits it to the client 21 as in the first and second embodiments.

  The present invention is not limited to the above embodiments, and in a wireless LAN system that transmits encapsulated packets for communication using two or more protocols, header compression is performed for packet transmission in a wireless communication section. Applies to

  For example, the access point is connected to an IPv4 network, the wireless LAN terminal is connected to an IPv6 network or an IPv6 client, and the wireless LAN terminal communicates with the IPv4 protocol and performs an operation that combines compression and decompression of the encapsulated packet. May be.

  On the other hand, the wireless LAN terminal is connected to the IPv4 network, the access point is connected to the IPv6 network or the IPv6 client, and the access point communicates with the IPv4 protocol and performs the operation that combines compression and decompression of the encapsulated packet. Also good.

  Furthermore, the present invention is applicable not only to communication between an access point and a wireless LAN terminal but also to communication in an ad hoc mode in which communication is performed between a wireless LAN terminal and another wireless LAN terminal. In this case, the access point 1 described above may be read as the wireless LAN terminal 1 (# 2) and the wireless LAN terminal 1 as the wireless LAN terminal 1 (# 1).

  Further, the above description of the present invention is applied to a wireless LAN system that transmits a packet obtained by encapsulating an IPv6 packet by the IPv4 protocol on the IPv4 network. However, the present invention is based on the IPv6 protocol. You may apply to the wireless LAN system which transmits the packet which encapsulated on the IPv6 network.

The block diagram of the Example of the wireless LAN system which concerns on this invention. The figure which shows the structure of the packet transmitted with the wireless LAN system which concerns on the Example of this invention. An example of a structure of the IPv4 / IPv6 encapsulated packet header based on the Example of this invention. The example of the table which converts the encapsulation header which concerns on the Example of this invention into a compression header. The example of the structure of the compression header based on the Example of this invention. The block diagram of the packet transmitted with the wireless LAN which concerns on the Example of this invention. 5 is a flowchart showing a transmission operation procedure from an access point to a wireless LAN terminal in Embodiment 1 of the present invention. The block diagram of the other Example of the wireless LAN system structure which concerns on this invention. 5 is a flowchart showing a transmission operation procedure from the wireless LAN terminal to the access point according to the first embodiment of the present invention. 9 is a flowchart showing a transmission operation procedure from an access point to a wireless LAN terminal in Embodiment 2 of the present invention. The flowchart which shows the transmission operation | movement procedure from the wireless LAN terminal in Example 2 of this invention to an access point. 9 is a flowchart showing a transmission operation procedure from an access point to a wireless LAN terminal in Embodiment 3 of the present invention. The block diagram of the conventional wireless LAN system. The figure which shows the structure of the packet transmitted with the conventional wireless LAN system. The block diagram of an IPv4 packet header. The block diagram of an IPv6 packet header.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Access point 2 Wireless LAN terminal 31, 32 Wireless part 51, 52 Header processing part 61, 62 Conversion table 7 IPv4 network 7t IPv4 terminal 8 IPv6 network 9 Encapsulating device 10 Server 11 IPv4 header 12 IPv6 header 13 Payload 14 Wired LAN MAC header 15 Compressed header
16 Wireless LAN MAC header

Claims (17)

The packet transmitted from the first client through the first network is converted into the encapsulated packet according to the protocol of the second network different from the first network through the second network. A wireless LAN system comprising a transmitting station that receives the data and a receiving station that is wirelessly connected to the transmitting station,
The transmitting station is
A first conversion table for storing compressed information in association with a combination of a plurality of addresses based on the protocol of the first network;
Wireless communication in which at least a part of an encapsulation header composed of first header information and second header information of the encapsulated packet is compressed into compressed header information based on the first conversion table, and a wireless communication header is added Conversion means for converting into packets;
Transmitting means for wirelessly transmitting the wireless communication packet to the receiving station;
The receiving station is
A second conversion table for storing compressed information in association with a combination of a plurality of addresses based on the protocol of the first network;
When the wireless communication packet is received, at least a part of the compressed header information is restored to the encapsulated packet including the first and second header information based on the second conversion table, and is sent to the second client. A wireless LAN system, comprising: a transmission means for transmitting. The packet transmitted from the first client through the first network is converted into the encapsulated packet according to the protocol of the second network different from the first network through the second network. A wireless LAN system comprising a transmitting station that receives the data and a receiving station that is wirelessly connected to the transmitting station,
The transmitting station is
A first conversion table for storing compressed information in association with a combination of a plurality of addresses based on the protocol of the first network;
Compress at least a part of the encapsulated header composed of the first header information and the second header information of the encapsulated packet into compressed header information based on the first conversion table, and a radio communication header and a compressed header packet A conversion means for converting the wireless communication packet to which identification information is added;
Transmitting means for wirelessly transmitting the wireless communication packet to the receiving station;
The receiving station is
A second conversion table for storing compressed information in association with a combination of a plurality of addresses based on the protocol of the first network;
When the wireless communication packet is received and determined to be the compressed header packet based on the identification information, at least a part of the compressed header information is based on the second conversion table and the first and second A wireless LAN system, comprising: a transmission unit that restores the encapsulated packet including the header information of the client and transmits the packet to the second client. The packet transmitted from the first client through the first network is converted into the encapsulated packet according to the protocol of the second network different from the first network through the second network. A wireless LAN system comprising a transmitting station that receives the data and a receiving station that is wirelessly connected to the transmitting station,
The transmitting station is
A first conversion table for storing compressed information in association with a combination of a plurality of addresses based on the protocol of the first network;
When a combination of a plurality of addresses included in the first header information of the encapsulated packet is stored in the first conversion table, from the first header information and the second header information of the encapsulated packet, And compressing at least a part of the encapsulation header into compressed header information based on the first conversion table, converting the compressed header information to a first wireless communication packet to which a wireless communication header is added, and adding the capsule to the first conversion table. Conversion means for converting to a second wireless communication packet in which the wireless communication header is added to the encapsulated packet when the combination of the plurality of addresses included in the first header information of the encrypted packet is not stored;
Transmitting means for wirelessly transmitting the first or second wireless communication packet to the receiving station;
The receiving station is
A second conversion table for storing compressed information in association with a combination of a plurality of addresses based on the protocol of the first network;
When receiving the first wireless communication packet, at least a part of the compressed header information is restored to the encapsulated packet including the first and second header information based on the second conversion table, and the second A wireless LAN system comprising: a transmission means for transmitting the encapsulated packet to the second client when the wireless packet is received.   The second client is directly connected to the receiving station or a second network different from the first network and the second network to which the first client is connected from the receiving station 4. The wireless LAN system according to claim 1, wherein the wireless LAN system is connected via the first network.   The wireless LAN system according to any one of claims 1 to 3, wherein the plurality of addresses based on the protocol of the first network are a source IP address and a destination IP address.   The first header information is header information based on a protocol of the first network, and the second header information is header information based on a protocol of the second network. The wireless LAN system according to any one of claims 1 to 3.   When the transmitting station receives the encapsulated packet from the second network, the transmitting station removes the wired communication header added to the packet, and transmits the wireless communication packet to the receiving station. The wireless LAN system according to any one of claims 1 to 3, wherein the wireless LAN system is added.   When the receiving station receives the wireless communication packet, the receiving station removes the wireless communication header added to the wireless communication packet, and when the receiving station transmits the packet to the second client, the second client is connected. The wireless LAN system according to any one of claims 1 to 3, wherein a wired communication header corresponding to a network is added.   When determining that the packet from the transmitting station is a packet that is not the compressed header packet based on the identification information and determining that the packet is the encapsulated packet from the first header information, the encapsulated packet The wireless LAN system according to claim 2, wherein the wireless LAN system is transmitted to the second client.   The transmitting station, when the combination of the plurality of addresses included in the first header information of the encapsulated packet is not stored in the first conversion table, the plurality of addresses in the first conversion table The wireless LAN system according to claim 3, wherein the combination and the compression information thereof are stored.   When the transmitting station does not store the combination of the plurality of addresses included in the first header information of the encapsulated packet in the first conversion table, the transmitting station transmits the encapsulated packet to the receiving station. The wireless LAN system according to claim 10, wherein a mark is set in the first header information and transmitted.   When receiving the encapsulated packet in which the mark is set, the receiving station converts the combination of the plurality of addresses included in the first header information of the encapsulated packet and the compression information thereof into the second conversion. The wireless LAN system according to claim 11, which is stored in a table. The packet transmitted from the first client through the first network is converted into the encapsulated packet according to the protocol of the second network different from the first network through the second network. A wireless LAN system communication control method comprising: a transmitting station that receives the data; and a receiving station that is wirelessly connected to the transmitting station,
The transmitting station is
Comprising a first conversion table for storing compressed information in association with a combination of a plurality of addresses based on the protocol of the first network;
Wireless communication in which at least a part of an encapsulation header composed of first header information and second header information of the encapsulated packet is compressed into compressed header information based on the first conversion table, and a wireless communication header is added Converted into packets and wirelessly transmitted to the receiving station,
The receiving station is
Comprising a second conversion table for storing compressed information in association with a combination of a plurality of addresses based on the protocol of the first network;
When the wireless communication packet is received, at least a part of the compressed header information is restored to the encapsulated packet including the first and second header information based on the second conversion table, and is sent to the second client. A communication control method for a wireless LAN system, characterized by comprising: The packet transmitted from the first client through the first network is converted into the encapsulated packet according to the protocol of the second network different from the first network through the second network. A wireless LAN system communication control method comprising: a transmitting station that receives the data; and a receiving station that is wirelessly connected to the transmitting station,
The transmitting station is
Comprising a first conversion table for storing compressed information in association with a combination of a plurality of addresses based on the protocol of the first network;
It is a radio communication header and a compressed header packet by compressing at least a part of the encapsulated header composed of the first header information and the second header information of the encapsulated packet into compressed header information based on the first conversion table. Converted into a wireless communication packet with identification information added and wirelessly transmitted to the receiving station,
The receiving station is
Comprising a second conversion table for storing compressed information in association with a combination of a plurality of addresses based on the protocol of the first network;
When the wireless communication packet is received and determined to be the compressed header packet based on the identification information, at least a part of the compressed header information is based on the second conversion table and the first and second A communication control method for a wireless LAN system, wherein the packet is restored to the encapsulated packet comprising the header information and transmitted to the second client. The packet transmitted from the first client through the first network is converted into the encapsulated packet according to the protocol of the second network different from the first network through the second network. A wireless LAN system communication control method comprising: a transmitting station that receives the data; and a receiving station that is wirelessly connected to the transmitting station,
The transmitting station is
Comprising a first conversion table for storing compressed information in association with a combination of a plurality of addresses based on the protocol of the first network;
When a combination of a plurality of addresses included in the first header information of the encapsulated packet is stored in the first conversion table, from the first header information and the second header information of the encapsulated packet Compressing at least part of the encapsulated header into compressed header information based on the first conversion table, and converting the compressed header information to a first wireless communication packet with a wireless communication header added thereto,
A second radio in which the radio communication header is added to the encapsulated packet when the combination of the plurality of addresses included in the first header information of the encapsulated packet is not stored in the first conversion table; Converted into communication packets,
Wirelessly transmitting the first or second wireless communication packet to the receiving station;
The receiving station is
Comprising a second conversion table for storing compressed information in association with a combination of a plurality of addresses based on the protocol of the first network;
Upon receiving the first wireless communication packet, at least a part of the compressed header information is restored to the encapsulated packet composed of the first and second header information based on the second conversion table,
When the second wireless packet is received, the encapsulated packet is transmitted to the second client. A packet wirelessly connected to a receiving station and transmitted from a first client via a first network, converted into an encapsulated packet according to a second network protocol different from the first network A transmitting station for receiving via the second network,
A conversion table in which compression information is stored in association with a combination of a plurality of addresses based on the protocol of the first network;
Based on the conversion table, at least a part of the encapsulated header composed of the first header information and the second header information of the encapsulated packet is compressed into compressed header information and converted into a radio communication packet with a radio communication header added. Conversion means to
Transmitting means for wirelessly transmitting the wireless communication packet to the receiving station. The packet transmitted from the first client through the first network is converted into the encapsulated packet according to the protocol of the second network different from the first network through the second network. A receiving station that is wirelessly connected to the receiving station
A compression table in which compression information is associated and stored according to a combination of a plurality of addresses based on the protocol of the first network; and
Reception of receiving from the transmitting station a wireless communication packet including compressed header information in which at least a part of an encapsulation header including the first header information and second header information of the encapsulated packet is compressed and a wireless communication header. Means,
At least a part of the compressed header information of the wireless communication packet received by the receiving unit is restored to the encapsulated packet composed of the first and second header information based on the conversion table, and transmitted to the client A wireless LAN system receiving station.

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