JP2007074170A - Data transfer device and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a data transfer device and a data transfer method for, when a signal column whose pattern is the same as that of a control signal column for showing the end position of a packet exists in data to be transferred, suppressing the decrease of a transfer processing speed as much as possible when converting the signal column into another signal column. <P>SOLUTION: A user data conversion processing part 213 receives a pointer, and reads the pertinent data of the payload part of a reception RLC-PDU stored in an RLC-PDU storage part 214, and performs format conversion, and stores the data in a converted data storage part 215 so as to be connected to the previous data. A pointer generating part 216 manages the sequence number of the RLC-PDU to be converted the next, and judges whether or not the pertinent data exist in the PLC-PDU storage part 214 each time the data are connected. When the judgement result is positive, the pointer generating part 216 transfers the pointer showing the payload part of the RLC-PDU to a user data conversion processing part 213. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a data transfer apparatus and a data transfer method for transferring data between a plurality of communication networks, and more particularly to a variable-length packet in which a control signal sequence having a predetermined pattern for indicating this is arranged at an end position. The present invention relates to a data transfer apparatus and a data transfer method suitable for a case where a transmission network is a data transfer destination.

  In recent years, data transfer apparatuses that transfer data between a plurality of communication networks have been widely used, as represented by mobile phones that connect to both the Internet and personal computers and relay communication.

  FIG. 9 shows an example of the configuration of a communication system in which such a data transfer apparatus is used. In this communication system 101, a wireless base station 103 connected to the Internet 102 is arranged, and a data transfer device 104, which is a mobile phone, can connect to the Internet 102 by performing wireless communication with the wireless base station 103. It has become. In addition, a personal computer 105 is connected to the data transfer device 104, and data addressed to the personal computer 105 sent from the wireless base station 103 is transferred thereto. Further, the data sent from the personal computer 105 is transferred to the radio base station 103. As a result, the personal computer 105 can be connected to the Internet 102 via the data transfer device 104. Since the personal computer 105 that does not have the wireless communication function enables the Internet connection outdoors, such a data transfer device 104 is rapidly spreading.

  Both the wireless communication with the wireless base station 103 and the wired communication with the personal computer 105 performed by the data transfer device 104 are configured to packetize and transmit data to be transmitted. Different communication protocols are used. Therefore, the data transfer apparatus 104 extracts the data body (hereinafter referred to as transfer data) that is the original transfer target from the packet received from the radio base station 103 and packetizes it again for transmission to the personal computer 105. Protocol conversion processing is performed.

  Further, when the data to be transmitted cannot fit in one packet, the data is divided from the head into lengths that can be stored in the packet, and is sequentially packetized and transmitted to the network. Therefore, when each packet arrives at the data transfer apparatus 104 in the same order as the transmission order of the wireless base station 103, the data transfer apparatus 104 can finally connect the payload portions of the packets in the received order. This original transfer data can be restored.

  However, the wireless communication performed with the wireless base station 103 has a problem that a bit error is likely to occur in the packet due to noise or the like. Although the communication network to be connected here is a wireless communication network, a bit error, packet loss, or discard may occur in a wired communication network as well. When such a packet error occurs, it has been conventionally requested to retransmit the corresponding packet to the transmission source. At this time, the packet retransmission arrives late, Thus, if the payload portions of the packets are simply concatenated in the order of reception, the original transfer data cannot be correctly restored.

Therefore, it is conventionally performed to arrange the payload portions of the received packets after ordering them (see, for example, Patent Document 1). In this first proposal, each packet is sequentially received from the beginning based on the sequence number indicating the arrangement order in the original transfer data of the data stored in each packet attached to each packet on the transmission side. It is sequentially determined whether or not is received normally. And while receiving normally continuously, the payload part of each packet is concatenated in the order of reception, but in the case of discontinuity such as missing packets or errors in received packets The received packets after the discontinuous portion are temporarily stored in the memory, and the execution of the subsequent concatenation process is waited until the corresponding packet arrives by the retransmission process. As a result, the original transfer data can be correctly restored regardless of the order of the received packets and sent to the destination.
Japanese Unexamined Patent Publication No. 2000-134263 (paragraphs 0022 and 0023, FIGS. 2 and 3)

  However, there may be a problem if the restored transfer data is transferred to the personal computer 105 as it is. For example, communication such as that performed between the data transfer apparatus 104 of the communication system 101 shown in FIG. 9 and the personal computer 105 is compliant with RFC (Request For Comments) 1662 defined by Internet Engineering Task Force (ITEF). Many compliant communication protocols are used. This communication protocol is one of PPP (Point-to-Point Protocol), and a specific data string called a flag sequence is arranged at the start position and the end position of a packet to detect individual packets on the receiving side. It is like that. However, if the data sequence that matches the flag sequence happens to be present in the transfer data received from the radio base station 103, the personal computer 105 may perform erroneous packet detection.

  Therefore, in RFC (Request For Comments) 1662, it is checked whether or not the data to be transmitted includes a data string that matches the flag sequence, and if it is included, the data string is converted into another data string. It is stipulated that format conversion processing is performed. Since the flag sequence is expressed as “01111110” in binary notation, when there is a data string in which five or more values “1” continue consecutively, a value “0” is inserted for every five. Then, on the receiving side, when five values “1” continue, the value “0” immediately after that is determined to be removed. This prevents erroneous detection of the packet described above.

  However, such format conversion is usually slower than the reception speed and transmission speed of transfer data. For this reason, a processing delay occurs in the data transfer apparatus, and as a result, the transfer processing speed decreases. In order to realize a more comfortable communication environment for communication devices that communicate via a data transfer device, it is desirable to suppress such a decrease in transfer processing speed as much as possible.

  Therefore, an object of the present invention is to perform processing for converting a signal sequence into another signal sequence when the signal sequence having the same pattern as the control signal sequence for indicating the end position of the packet exists in the data to be transferred. It is an object of the present invention to provide a data transfer apparatus and a data transfer method that can suppress a decrease in transfer processing speed as much as possible.

  In the present invention, (a) a packet receiving means for receiving a packet from the first communication network, and (b) a control signal comprising a predetermined pattern for indicating that the packet received by the packet receiving means is at the end position. The divided data obtained by dividing the predetermined data to be transferred to the second communication network that transmits the variable-length packet in which the columns are arranged is sequentially added with the order information indicating the order from the top of the predetermined data. (C) divided data storage means for sequentially reading the divided data stored in the divided data storage means according to the order indicated by the order information; (D) Each time divided data is read from the divided data storage means, a plurality of divided data read by the divided data reading means are read. Specific signal sequence presence / absence determining means for determining whether or not there is a specific signal sequence as a signal sequence that matches a predetermined pattern in the data consisting of: (e) for data consisting of a plurality of divided data, A signal for performing processing for converting the specific signal sequence into a predetermined signal sequence determined in advance with the receiving side of the second communication network for the part where the specific signal sequence presence / absence determining unit determines that the specific signal sequence exists. Column conversion processing means, (f) divided data linking means for linking the divided data processed by the signal string conversion processing means in the order read by the divided data reading means, and (g) linked by the divided data linking means. The data transfer device is provided with data transmission means for converting the divided data into variable-length packets and sending them to the second network.

  That is, according to the present invention, a packet received from the first communication network is transferred to the second communication network that transmits a variable-length packet in which a control signal sequence having a predetermined pattern for indicating this is arranged at the end position. If the divided data obtained by dividing the target predetermined data is sequentially transmitted with the order information indicating the order from the head of the predetermined data added, the packet is stored in the divided data storage means. The stored divided data are sequentially read according to the order indicated by the order information, concatenated according to the read order, converted into variable-length packets, and sent to the second network. That is, the predetermined data is transferred from the first communication network to the second communication network. However, if a specific signal sequence that matches a predetermined pattern used as a control signal sequence indicating the end position of the packet in the second communication network is present in the predetermined data, the receiving end determines that this is the end of the packet. There is a risk of erroneous detection as a position. Therefore, it is determined whether or not the specific signal sequence exists in the data composed of a plurality of divided data read from the divided data storage means, and the specific signal sequence is determined for the portion determined to exist, for example, in the second communication. A process of converting into a predetermined signal sequence predetermined with the receiving side is performed, such as converting a signal sequence with a predetermined pattern on the receiving side of the network into a predetermined signal sequence. I have to. Thereby, the above-mentioned erroneous detection can be prevented. However, this conversion process may reduce the transfer processing speed.

  Therefore, every time the divided data is read, it is determined whether or not the specific signal sequence exists. As a result, it is possible to start a process of searching for a specific signal sequence and converting it into a predetermined signal sequence when the last divided data has not yet been received. That is, the conversion process is started earlier than the process of searching for a specific signal sequence and starting conversion to a predetermined signal sequence after receiving all of the divided data necessary for assembling the predetermined data, All necessary conversion processing can be completed earlier.

  In the present invention, (a) a packet reception step for receiving a packet from the first communication network, and (b) a control signal having a predetermined pattern for indicating that the packet received in the packet reception step is indicated at the end position. The divided data obtained by dividing the predetermined data to be transferred to the second communication network that transmits the variable-length packet in which the columns are arranged is sequentially added with the order information indicating the order from the top of the predetermined data. A divided data storage step for storing the packet in the divided data storage means, and (c) divided data for sequentially reading the divided data stored in the divided data storage means in the order indicated by the order information. A reading step; and (d) each time the divided data is read from the divided data storage means. A specific signal sequence presence / absence determining step for determining whether or not there is a specific signal sequence as a signal sequence that matches a predetermined pattern in the data composed of a plurality of divided data read out by (e), and (e) a plurality of divisions For data consisting of data, the specific signal sequence is determined in advance with the receiving side of the second communication network with respect to a portion where the specific signal sequence is determined to exist in the specific signal sequence search step. A signal sequence conversion processing step for performing processing for conversion into a signal sequence, and (f) a divided data concatenation step for concatenating the divided data processed by the signal sequence conversion processing step according to the order read in the divided data read step. (G) The data divided in this divided data concatenation step is converted into variable-length packets and sent to the second network. Is a transmitting step to the data transfer method.

  That is, according to the present invention, a packet received from the first communication network is transferred to the second communication network that transmits a variable-length packet in which a control signal sequence having a predetermined pattern for indicating this is arranged at the end position. If the divided data obtained by dividing the target predetermined data is sequentially transmitted with the order information indicating the order from the head of the predetermined data added, the packet is stored in the divided data storage means. Then, each divided data is sequentially read according to the order indicated by the order information. Each time the divided data is read, the data consisting of a plurality of read divided data is specified as a signal sequence that matches the predetermined pattern described above. It is determined whether or not a signal sequence exists, and for a portion determined to be present, the specific signal sequence is converted into the signal sequence having the predetermined pattern on the receiving side of the second communication network, for example. As in the case of a predetermined signal sequence, a process of converting into a predetermined signal sequence determined in advance with the receiving side is performed. Then, the divided data subjected to this processing are connected in accordance with the order read from the divided data storage means, converted into variable-length packets, and sent to the second network. As a result, it is possible to start a process of searching for a specific signal sequence and converting it into a predetermined signal sequence when the last divided data has not yet been received. That is, the conversion process is started earlier than the process of searching for a specific signal sequence and starting conversion to a predetermined signal sequence after receiving all of the divided data necessary for assembling the predetermined data, All necessary conversion processing can be completed earlier.

  As described above, according to the present invention, it is determined whether or not the specific signal sequence exists every time the divided data is read from the divided data storage means, and necessary conversion processing is performed. Thereby, the conversion process can be performed ahead of schedule, and all necessary conversion processes can be completed earlier. That is, it is possible to suppress a decrease in transfer processing speed as much as possible.

  Hereinafter, the present invention will be described in detail with reference to examples.

  FIG. 1 shows a configuration of a communication system in which a data transfer apparatus according to an embodiment of the present invention is used. In this communication system 201, a radio base station 203 connected to the Internet 202 and a mobile phone 204 that can be connected to the Internet 202 by performing radio communication with the radio base station 203 are arranged. A personal computer 206 is connected to the mobile phone 204 via a USB (Universal Serial Bus) cable 205.

  The wireless base station 203 and the mobile phone 204 perform wireless communication conforming to W-CDMA (Wideband-Code Division Multiple Access), which is a third generation mobile communication system standardized by 3GPP (3rd Generation Partnership Project). ing. In W-CDMA, packet retransmission in the data link layer is realized using a communication protocol called RLC (Radio Layer Control) protocol. Hereinafter, packets transmitted and received by the RLC protocol are referred to as RCL-PDU (RCL-Protocol Data Unit).

  Further, the cellular phone 204 uses a communication protocol called TLP-U (Terminal Link Protocol for U-plan) in a layer higher than the data link layer. In this layer, original user data is restored from the data stored in the RCL-PDU, and user data format conversion described later is performed so that the user data can be transferred to the personal computer 206. That is, the personal computer 206 is connected to the Internet 202 using the mobile phone 204 and can receive user data sent from the Internet 202 side.

  FIG. 2 shows the configuration of the mobile phone. The cellular phone 204 extracts the RCL-PDU from the signal received by the wireless communication processing unit 211 and the wireless communication processing unit 211 for performing wireless communication with the wireless base station 203 (FIG. 1) in the data link layer. An RLC-PDU reception processing unit 212 that performs reception processing is provided. In addition, a user data conversion processing unit 213 that performs restoration of user data and format conversion to generate converted data is provided. The RLC-PDU storage unit 214 for temporarily storing each RLC-PDU received by the RLC-PDU reception processing unit 212 and the converted data for storing the converted data by the user data conversion processing unit 213 A storage unit 215 is provided, and each is connected to a user data conversion processing unit 213. The cellular phone 204 is further provided with a pointer generation processing unit 216 that sequentially generates a pointer indicating an address on the RLC-PDU storage unit 214 of data to be subjected to format conversion and passes it to the user data conversion processing unit 213. The user data conversion processing unit 213 is connected. In addition, a USB communication processing unit 217 that performs communication with the personal computer 206 of FIG. 1 via the USB cable 205 is provided, and is connected to the user data conversion processing unit 213 and the post-conversion data storage unit 215.

  The mobile phone 204 includes a CPU (Central Processing Unit) (not shown), a storage medium such as a ROM (Read Only Memory) storing a control program, and a working memory such as a RAM (Random Access Memory), and receives RLC-PDU reception. The processing unit 212, the user data conversion processing unit 213, and the pointer generation processing unit 216 are realized by the CPU executing a control program. Although not shown, the wireless communication processing unit 211 includes a wireless communication circuit as existing hardware, and further converts received wireless data into a data format that can be processed by the CPU. Although not shown, the USB communication processing unit 217 also includes a communication circuit as existing hardware. Further, the RLC-PDU storage unit 214 and the post-conversion data storage unit 215 are realized by executing a control program and writing data to be stored in the RAM.

  The radio base station 203 stores the user data addressed to the personal computer 206 sent from the Internet 202 in the RLC-PDU and transmits it to the mobile phone 204. However, when the size of user data to be transmitted cannot be stored in one RLC-PDU, the user data is divided, stored in a plurality of RCL-PDUs, and transmitted to the mobile phone 204. ing.

FIG. 3 shows how user data is divided and stored in a plurality of RLC-PDUs. The RLC-PDU 221 is a 42-byte fixed-length packet, and the maximum data size that can be stored as a payload is 40 bytes. When the user data 222 to be transmitted to the mobile phone 204 is 40 bytes or more, the radio base station 203 divides 40 bytes from the head 223 of the data, stores each in the RLC-PDU 221, and stores each RLC-PDU 221. A sequence number starting from the value “1” is added to the header portion in ascending order. Here, it is assumed that certain user data 222 is divided into n pieces, stored in the order of division into RLC-PDUs 221 _{1 to} 221 _n of sequence numbers “1” to “n”, and transmission is performed. Note that the subscript “S” in the figure indicates the sequence number of each RLC-PDU 221.

  Returning to FIG. 2, the description will be continued. The RLC-PDU reception processing unit 212 of the mobile phone 204 stores each received RLC-PDU 221 in the RLC-PDU storage unit 214 and checks whether the sequence numbers of the RLC-PDUs are consecutive. , Loss of RLC-PDU 221 is detected. Further, on the radio base station 203 side, a packet data error is detected by CRC (Cyclic Redundancy Check) based on a check bit added to each RLC-PDU 221. When a data error or loss of the RLC-PDU 221 is detected, the sequence number is designated and a retransmission of the RLC-PDU 221 corresponding to the radio base station 203 is requested.

  The pointer generation processing unit 216 passes a pointer indicating the payload portion of each RLC-PDU 221 stored in the RLC-PDU storage unit 214 to the user data conversion processing unit 213 in the order of the sequence number by a process described later. Then, the user data conversion processing unit 213 reads the payload portion of the RLC-PDU 221 indicated by each pointer from the RLC-PDU storage unit 214 in the order of reception, and stores them in the converted data storage unit 215 in the form of sequential connection. Go. As a result, the original user data 222 is finally restored in the post-conversion data storage unit 215.

  The USB communication processing unit 217 of the mobile phone 204 communicates with the personal computer 206 using a communication protocol compliant with RFC1662 defined by ITEF. In this communication protocol, a specific data string called a flag sequence is arranged at the start position and end position of each data frame, and the receiving side detects the flag sequence to achieve frame synchronization. ing. This flag sequence is defined as “01111110” in binary notation. The USB communication processing unit 217 appropriately divides the user data 222 in the post-conversion data storage unit 215, stores it in a data frame, and transmits it. If this user data 222 happens to contain this data string “01111110” The personal computer 206 may erroneously detect this as the start position or end position of the data frame, which may hinder communication.

  Therefore, the user data conversion processing unit 213 performs format conversion conforming to RFC1662 when data is stored in the post-conversion data storage unit 215 so as to prevent such a problem from occurring. Specifically, it is checked whether there is a portion where the value “1” continues five or more continuously. If there is a portion, the value “0” is inserted for every five, and then the converted data storage unit 215 is inserted. To store. The USB communication processing unit 217 reads the converted data generated in this way from the converted data storage unit 215, stores it in a data frame, and transmits it to the personal computer 206. On the personal computer 206 side, when five values “1” continue, the value “0” inserted immediately after that is removed.

  As a result, there is no data string that matches the flag sequence in the transfer data, so that erroneous detection of the frame can be prevented and the original user data can be finally restored. Note that a portion where five or more values “1” continue may extend over a plurality of RLC-PDUs 221, but even if only the fifth is stored in the next RLC-PDU 221, for example, Since the value “0” has only to be inserted, there is no particular problem in such format conversion before connection.

  In addition, the format conversion processing speed is often slower than the data reception speed. Therefore, the received RLC-PDU 221 is temporarily stored in the RLC-PDU storage unit 214, and the user data conversion processing unit 213 reads out the payload portion of each RLC-PDU 221 from this, thereby performing such processing. It is designed to handle speed differences.

In addition, after all of the RLC-PDUs 221 _{1 to} 221 _{n having} the sequence numbers “1” to “n” are stored in the RLC-PDU storage unit 214, a pointer that specifies the address of the payload portion of each RLC-PDU 221 is used as the sequence number. If the data is transferred to the user data conversion processing unit 213 in ascending order, it takes time to complete the conversion, and the processing time until transmission to the personal computer 206 becomes long. Further, this processing time becomes longer as the size of the user data 222 becomes larger. On the other hand, if a pointer is passed before the RLC-PDU 221 having a data error or loss is retransmitted, a missing portion is generated in the user data.

  Therefore, the pointer generation processing unit 216 of this embodiment sequentially assigns appropriate pointers to the user data conversion processing unit 213 for the range that is continuously stored from the beginning of the sequence number even if all the storage is not completed. And let the conversion process be done as early as possible.

  FIG. 4 shows the flow of pointer generation processing of the pointer generation processing unit. It demonstrates with FIGS. 1-3. The pointer generation processing unit 216 first sets a value “1” as an initial value to the subsequent sequence number, which is a variable indicating the sequence number of the RLC-PDU 221 to be designated by the pointer (step S301). The pointer generation processing unit 216 sequentially monitors that the RLC-PDU reception processing unit 212 receives a new RLC-PDU 221 from the radio base station 203 and stores it in the RLC-PDU storage unit 214. When the RLC-PDU 221 is stored in the RLC-PDU storage unit 214 (step S302: Y), the sequence number and the address indicating the storage position in the RLC-PDU storage unit 214 of the payload portion are acquired. (Step S303).

  Then, the obtained sequence number is compared with the subsequent sequence number at that time (step S304). If they match (Y), it means that the RLC-PDU 221 to be next designated as a pointer is stored. . Accordingly, a pointer indicating the acquired address is passed to the user data conversion processing unit 213, and the value of the subsequent sequence number is incremented by 1 in order to move the processing to the next RLC-PDU 221 (step S305).

  If the acquired sequence number does not match the subsequent sequence number (step S304: N), this means that the RLC-PDU 221 is not to be designated as the next pointer designation target. Therefore, the sequence number and the address are associated with each other and stored in a storage area (not shown) (step S306), and the process returns to step S302 to wait for a new RLC-PDU 221 to be stored again. That is, the processing from step S302 to step S306 is repeated until the RLC-PDU 221 storing the data to be designated as the next pointer is received, and the sequence number and address of each received RLC-PDU 221 are successively received. Will be remembered.

  After passing the pointer to the user data conversion processing unit 213 in step S305, if the pointer has not been passed for all the RLC-PDUs 221 necessary to restore the original user data 222 (step S307), It is determined whether or not a sequence number that matches the subsequent sequence number is stored in the storage area (step S308). If not stored (N), the process returns to step S302 to wait for a new RLC-PDU 221 to be stored. If it has been stored (step S308: Y), the RLC-PDU 221 to be designated as the next pointer designation has already been stored in the RLC-PDU storage unit 214, so the process returns to step S305 to cope with it. A pointer indicating the stored address is passed to the user data conversion processing unit 213. At this time, the corresponding information may be deleted from the storage area so that the process of step S308 can be performed at higher speed.

  The RLC-PDU reception processing unit 212 notifies the pointer generation processing unit 216 of the last sequence number of the RLC-PDU 221 necessary for restoring the original user data 222. Based on this last sequence number, the pointer generation processing unit 216 determines whether or not the pointer has been passed for all the RLC-PDUs 221 necessary for restoring the original user data 222 (step S307). When all the RLC-PDUs 221 have been handed over (Y), the process returns to step S301 to initialize the subsequent sequence number and wait for the RLC-PDU 221 for the next user data to be stored in the RLC-PDU storage unit 214. (Return) In this way, the pointers chained in the correct order are passed from the pointer generation processing unit 216 to the user data conversion processing unit 213.

  FIG. 5 shows the flow of user data conversion processing of the user data conversion processing unit. This will be described with reference to FIGS. When the user data conversion processing unit 213 receives a pointer from the pointer generation processing unit 216 (step S321: Y), the user data conversion processing unit 213 reads data from the corresponding area of the RLC-PDU storage unit 214, performs format conversion, and stores the converted data. The data is stored in the unit 215 (step S322). That is, data is read from a 40-byte area starting from the address indicated by the pointer of the RLC-PDU storage unit 214. Further, the format conversion is a process of monitoring whether or not five or more values “1” continue as described above, and inserting a value “0” every fifth when the values are consecutive. Therefore, when the last bit of the payload portion of a certain RLC-PDU 221 has a value “1”, the number of consecutive “1” s including that bit is stored, and the next RLC- The format conversion is performed on the assumption that it is continuous before the payload portion of the PDU 221. That is, when all the last 4 bits of the data string read immediately before are the value “1” and the first 1 bit of the newly read data string is the value “1”, immediately after the 1 bit. The format conversion is performed in relation to the immediately preceding data string, such as inserting the value “0” into.

  If format conversion has not been completed for the entire range of user data (step S323: N), the process returns to step S321 and waits for reception of a pointer. When the format conversion of the entire range of user data is completed (step S323: Y), the corresponding converted data stored in the converted data storage unit 215 with respect to the USB communication processing unit 217 is transferred to the personal computer 206. (Step S324). Then, it waits for a pointer to be passed from the pointer generation processing unit 216 again for new user data (return). In some cases, a subsequent pointer is passed from the pointer generation processing unit while executing steps S322 and S323. For this reason, the user data conversion processing unit 213 is provided with a buffer memory (not shown) for sequentially storing the received pointers. In step S321, the pointers are acquired from the buffer memory.

Hereinafter, a state in which converted data is generated in the converted data storage unit based on each RLC-PDU stored in the RLC-PDU storage unit by the processing described above will be described. A predetermined time after the start of transmission of RLC-PDUs 221 _{1 to} 221 _n of sequence numbers “1” to “n” in the radio base station 203 is the first time, and a predetermined time after which the time has passed is the second Time.

FIG. 6 shows how converted data is generated in the converted data storage unit based on each RLC-PDU stored in the RLC-PDU storage unit. A description will be given with FIG. The sequence numbers “4”, “6”, and “1” between the start of transmission of RLC-PDUs 221 _{1 to} 221 _n of sequence numbers “1” to “n” in the radio base station 203 up to the first time. Assume that each RLC-PDU 221 up to sequence number “12” excluding 10 ”RLC-PDUs 221 ₄ , 221 ₆ , and 221 ₁₀ is stored in the RLC-PDU storage unit 214 in order from the smallest sequence number.

Since the RLC-PDUs 221 _{1 to} 221 _{3 with the} sequence numbers “1” to “3” are continuous, the processing of steps S302 to S305, S307, and S308 is repeated starting with step S301 in FIG. Therefore, the data stored in the RLC-PDUs 221 _{1 to} 221 ₃ with the sequence numbers “1” to “3” are sequentially converted.

However, the sequence number of the RLC-PDU 221 stored next to the sequence number “3” is “5” and does not match the subsequent sequence number “4” at that time (step S304: N in FIG. 4). The sequence number “5” and its address are stored in a storage area (not shown) without passing the pointer (step S306 in FIG. 4). For the subsequent RLC-PDU 221, the subsequent sequence number remains “4” and the processing from step S302 to step S306 is repeated in the same manner. Therefore, as shown in the figure, the converted data storage unit 215 generates converted data only for the portions corresponding to the RLC-PDUs 221 _{1 to} 221 ₃ with sequence numbers “1” to “3”.

FIG. 7 shows a state in which converted data is generated in the converted data storage unit when the time has passed from FIG. A description will be given with FIG. Until a second time has elapsed further time from the first time, the sequence number "4", "6" and "13" _{~ RLC-PDU221 4, 221 6} , 221 13 ~221 16 of "16" Assume that the storage is performed in this order. When the RLC-PDU 221 ₄ with the sequence number “4” is stored, it matches the subsequent sequence number “4” at that time (step S304: Y in FIG. 4), so that the pointer indicating the address is the user data conversion process The subsequent sequence number is “5” (step S305 in FIG. 4). The RLC-PDU221 ₅ of the sequence number "5" has already been stored, the sequence number "5" is because it is stored (step of FIG. 4 S308: Y), the pointer to the address that is associated and stored by the user The data is transferred to the data conversion processing unit 213, and the subsequent sequence number is “6” (step S305 in FIG. 4).

The following is stored RLC-PDU221 ₆ of the sequence number "6" is further subsequent sequence number "7" to "9" is stored in the storage area. Therefore, pointers indicating the addresses of the RLC-PDUs 221 _{6 to} 221 _{9 with} the sequence numbers “6” to “9” are successively passed to the user data conversion processing unit 213. Since the subsequent sequence number is "10", the sequence number "11" and "12" stored in the storage area becomes as the sequence number "13" is further stored to 221 ₁₃ to 221 ₁₆ each "16" The sequence number and address are also stored additionally. That is, format conversion is not yet performed. Therefore, as shown in the figure, the converted data storage unit 215 generates converted data only for the portions corresponding to the RLC-PDUs 221 _{4 to} 221 ₉ with the sequence numbers “4” to “9”. Thus, the format of the payload portion of each RLC-PDU 221 is quickly converted within the range continuously received from the sequence number “1”.

FIG. 8 shows a state in which converted data is generated in the converted data storage unit when conversion is started after all RLC-PDUs are stored in the RLC-PDU storage unit for reference. is there. The RLC-PDU 212 finally stores RLC-PDUs 221 _{1 to} 221 _n with sequence numbers “1” to “n” in the RLC-PDU storage unit 214 as shown in FIG. However, if the progress of reception of each RLC-PDU 221 and the format conversion processing speed are the same as those in FIGS. 6 and 7, the time when this state is reached is a time after the second time described above. If this time is the third time, this method starts format conversion from the third time. That is, RLC-PDUs 221 _{1 to} 221 ₃ with sequence numbers “1” to “3” at the _first time and RLC-PDUs 221 _{4 to} 221 ₉ with sequence numbers “4” to “9” at the second time, respectively. It is clear that the format conversion completion time is later than the method of the present embodiment in which the format conversion is started.

  As described above, in the present embodiment, each received RLC-PDU 221 is stored in the RLC-PDU storage unit 214, and a pointer is output in accordance with the sequence number order. The user data conversion processing unit 213 is in accordance with the output order. The data pointed to by the pointer is read out from the RLC-PDU storage unit 214. Then, the read data is subjected to format conversion and sequentially stored in the post-conversion data storage unit 215. As a result, the original user data subjected to format conversion is generated. As a result, it is possible to cope with the case where the processing speed of the format conversion is slower than the reception speed, and the user data is correctly assembled even when the reception order of each RLC-PDU 221 is changed by processing such as retransmission. be able to. Also, the sequence number of the RLC-PDU 221 to be designated as the next pointer designation is always managed, and whether or not it matches the sequence number of a newly received RLC-PDU or a previously received RLC-PDU. Is sequentially determined. If they match, a pointer indicating the address of the payload portion of the corresponding RLC-PDU is passed to the user data conversion processing unit 213. As a result, the payload portion of each RLC-PDU 221 stored in the RLC-PDU storage unit 214 is immediately converted within a range continuous from the sequence number “1” regardless of the reception status of the subsequent RLC-PDU 221. Can continue. In other words, the format conversion can be started before the reception of all the user data is completed, and the conversion process is completed more quickly than the format conversion is started after the reception of all the user data is completed. Is possible.

  In addition, although the case where it transmits after completing the restoration | restoration of the whole user data was demonstrated, when divided | segmented and stored in a some data frame, even if the whole restoration | restoration is not completed, a user Only the portion of the data that has been continuously restored from the beginning of the data may be transmitted first. Further, the subsequent sequence number may be directly searched in the RLC-PDU storage unit 214 without storing the sequence number or address of each RLC-PDU 221 stored in the RLC-PDU storage unit 214. In the embodiment, each received RLC-PDU is stored as it is, but only the respective payload portion may be stored. In addition, a mobile phone that receives RLC-PDU by wireless communication and converts the format to transmit user data stored in the RLC-PDU to a personal computer has been described as an example. Of course, the present invention can be applied to other various data transfer devices that perform conversion processing on transfer data.

1 is a system configuration diagram showing a configuration of a communication system in which a data transfer apparatus according to an embodiment of the present invention is used. It is a block diagram showing the structure of the mobile telephone by the Example of this invention. It is explanatory drawing showing a mode that the user data by the Example of this invention was divided | segmented and stored in several RLC-PDU. It is a flowchart showing the flow of the pointer production | generation process of the pointer production | generation part by the Example of this invention. It is a flowchart showing the flow of the user data conversion process of the user data conversion process part by the Example of this invention. It is explanatory drawing which represented typically a mode that the data after conversion were produced | generated in the data storage part after conversion based on each RLC-PDU stored in the RLC-PDU storage part by the Example of this invention. It is explanatory drawing which represented typically a mode that the data after conversion were produced | generated in the data storage part after conversion when time passed rather than FIG. 6 by the Example of this invention. It is explanatory drawing which represented typically a mode that the data after conversion were produced | generated in the data storage part after a conversion at the time of starting conversion after all the RLC-PDUs were stored in the RLC-PDU storage part. It is a system block diagram showing an example of the structure of the communication system in which the conventional data transfer apparatus is used.

Explanation of symbols

201 Communication System 202 Internet 203 Wireless Base Station 204 Mobile Phone 205 USB Cable 206 Personal Computer 211 Wireless Communication Processing Unit 212 RLC-PDU Reception Processing Unit 213 User Data Conversion Processing Unit 214 RLC-PDU Storage Unit 215 Post-conversion Data Storage Unit 216 Pointer Generation processing unit 217 USB communication processing unit

Claims (7)

Packet receiving means for receiving packets from the first communication network;
The packet received by the packet receiving means is predetermined data to be transferred to a second communication network that transmits a variable-length packet in which a control signal sequence having a predetermined pattern for indicating this is arranged at the end position. Divided data storage means for storing the packet, when the divided data is sequentially transmitted in a form to which the order information indicating the order from the beginning of the predetermined data is added,
Divided data reading means for sequentially reading each divided data stored in the divided data storage means in the order indicated by the order information;
Each time the divided data is read from the divided data storage means, there is a specific signal string as a signal string that matches the predetermined pattern in the data composed of a plurality of divided data read by the divided data reading means. Specific signal sequence presence / absence determining means for determining whether or not,
With respect to the data composed of the plurality of divided data, the specific signal sequence is determined between the reception side of the second communication network with respect to a portion where the specific signal sequence presence / absence determining unit determines that the specific signal sequence exists. Signal sequence conversion processing means for performing processing for conversion into a predetermined signal sequence determined in advance;
Divided data connecting means for connecting the divided data processed by the signal string conversion processing means in accordance with the order read by the divided data reading means;
A data transfer apparatus comprising: data transmitting means for converting the divided data connected by the divided data connecting means into the variable-length packet and sending it to the second network. Each time the divided data is stored in the divided data storage means or any of the divided data is read, it is determined whether or not the divided data to be read next is stored in the divided data storage means. Next divided data presence / absence determining means for performing
When the next divided data presence / absence determining means determines that the divided data to be read next is stored, the read instruction means for causing the divided data reading means to read the corresponding divided data. The data transfer apparatus according to claim 1, wherein: The order information is a sequence number described in a header part of each packet received by the packet receiving means,
Information acquisition means for acquiring the sequence number added to the divided data each time the divided data is stored in the divided data storage means;
Sequence number storage means for storing the sequence number acquired by the information acquisition means in association with area information indicating the storage area in the divided data storage means of the divided data to which the sequence number is added,
The next divided data presence / absence determining means comprises a next sequence number presence / absence determining means for determining whether or not a sequence number corresponding to the divided data to be read next is stored in the sequence number storage means.
The reading instructing means includes information output means for outputting area information corresponding to the sequence number when the next sequence number presence / absence determining means determines that the corresponding sequence number exists.
4. The data according to claim 3, wherein the divided data reading means is means for reading the divided data indicated by each of the area information output by the area information output means from the divided data storage means according to the output order. Transfer device. Error detection means for detecting when an error has occurred in the divided data sent from the first communication network;
2. The data transfer apparatus according to claim 1, further comprising: a divided data retransmission requesting unit that requests retransmission of the divided data to the transmission source of the divided data when the error detecting unit detects an error.   The data transfer apparatus according to claim 1, wherein the packet receiving means is means for receiving the packet by wireless communication.   3. The data transfer apparatus according to claim 1, wherein the data transmission means is means for performing transmission using a communication protocol compliant with RFC1662. Receiving a packet from the first communication network; and
Predetermined data to be transferred to a second communication network that transmits a variable-length packet in which a packet received in this packet receiving step is arranged with a control signal sequence having a predetermined pattern for indicating this at the end position Divided data storage step for storing the packet in the divided data storage means, when the divided data is sequentially transmitted in a form to which order information indicating the order from the beginning of the predetermined data is added,
A divided data reading step for sequentially reading each divided data stored in the divided data storage means in the order indicated by the order information;
Each time the divided data is read from the divided data storage means, there is a specific signal sequence as a signal sequence that matches the predetermined pattern in the data composed of a plurality of divided data read by the divided data reading step. A specific signal sequence presence / absence determination step for determining whether or not,
With respect to the data composed of the plurality of divided data, the specific signal sequence is determined between the receiving side of the second communication network with respect to a portion where the specific signal sequence is determined to exist in the specific signal sequence search step. A signal sequence conversion processing step for performing a process of converting into a predetermined signal sequence determined in advance;
A divided data concatenation step for concatenating the respective divided data processed by the signal sequence conversion processing step according to the order read in the divided data reading step;
A data transfer method comprising: a data transmission step of converting the divided data concatenated in the divided data concatenation step into the variable-length packet and transmitting the packet to the second network.

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