JP5520862B2 - COMMUNICATION SYSTEM AND METHOD, COMMUNICATION DEVICE - Google Patents

Description

  The present invention relates to a communication system and method for transmitting packets to a terminal capable of performing wireless communication simultaneously with a plurality of base stations using a plurality of wireless communication paths, and a communication apparatus, and more particularly, to a terminal at a certain base station. When a downlink packet that has failed to be transmitted to the terminal is transmitted to the terminal via another base station, a charging count based on whether the gateway has reached the terminal or not reached is calculated based on the discard information notified from each base station. The present invention relates to a communication system and method, a communication apparatus such as a base station and a gateway apparatus.

  In recent years, research and standardization activities for the 3.9th generation mobile communication system have been promoted as a method for realizing higher speed and higher quality of mobile radio communication. In LTE (Long Term Evolution), which is one of the 3.9th generation mobile communication systems, the gateway performs a billing count that counts either or both of the number of packets and the number of bytes of a packet to be billed, and sends it to the billing server. By notifying the result of the charging count, a specification for charging based on either or both of the number of packets and the number of bytes of the packet to be charged is defined. As a parameter for notifying the charging server of the charging count result of the gateway, Non-Patent Document 1 includes Act-Output-Packets, Act-Output-Octets, Act-Input-Packets, and Act-Input-Octets for each service unit. Each is defined. Act-Output-Packets and Act-Output-Octets are parameters for notifying the billing server of the number of packets and the number of bytes, respectively, of the packets to be billed among the downlink packets transmitted from the service providing server to the terminal. It is. Act-Input-Packets and Act-Output-Octets are parameters for notifying the billing server of the number of packets and the number of bytes, respectively, of the packets to be billed among the uplink packets transmitted from the terminal to the service providing server. It is.

  In LTE, as one of means for realizing high speed and high quality, standardization activities are underway for a method in which a terminal communicates with a plurality of radio base stations simultaneously. By communicating simultaneously with a plurality of radio base stations, even if the radio state deteriorates at a certain base station, the packet is transmitted to the terminal via the other base station having a relatively good radio state, so that the packet It is thought that the delay can be lowered at the same time as the probability of not reaching the threshold is reduced. Non-Patent Document 2 discusses a method for realizing a function of communicating and connecting to a service providing server with a terminal simultaneously with a plurality of radio base stations.

JP 2000-083036 A

3GPP TS29.061 V9.3.0, (2010-6), Technical Specification 3GPP TS 23.861 V1.3.0, (2010-2), Technical Specification

  When performing the billing counting of the downlink packet, it is necessary to count only the packets that have reached the terminal as a billing target, and to count the packets discarded at the gateway or base station before reaching the terminal. If charging is counted for a packet that is discarded before reaching the terminal, an erroneous charging for charging a service that is not actually received by the user using the terminal occurs. However, the standard provisions shown in Non-Patent Document 1 and the like do not stipulate how to exclude packets discarded at the base station before reaching the terminal from the charging count of the gateway. The method is to be implemented independently for each vendor that provides the communication device.

  As a method for preventing erroneous charging, the method shown in the fourth embodiment of Patent Document 1 is applied to LTE, and when the base station detects a missing packet, it is discarded and not charged. By notifying the gateway of the information on either or both of the number of packets and the number of bytes, it is possible to exclude either or both of the number of packets and bytes discarded at the base station from the gateway billing count . However, in the method shown in the fourth embodiment of Patent Document 1, it is assumed that there is one node corresponding to the base station, and there are a plurality of nodes corresponding to the base station. The case where the corresponding nodes communicate with each other at the same time was not considered.

  When communicating simultaneously with a plurality of base stations, a case is considered where the same packet is transmitted from the gateway to the plurality of base stations. This is performed for a packet that requires a low delay or a low discard rate, or in a transition period in which a base station that mainly performs communication is switched. In this case, the packet is successfully transmitted to the terminal via a certain base station, but may be discarded before the packet is transmitted to the terminal in another base station. At this time, if it is attempted to prevent erroneous billing by the method shown in the fourth embodiment of Patent Document 1, the packet is not subject to the billing count of the gateway when a discard occurrence notification is received from a certain base station. However, since the packet is actually a packet that reaches the terminal via another base station, an erroneous charge that excludes the packet that reaches the terminal from the charge count target occurs. Therefore, a configuration that avoids this problem is necessary.

  In view of the above points, the present invention, in a wireless communication system, when each gateway transmits the same packet to a plurality of base stations, based on the identifier of the discarded packet notified from each base station, The purpose is to avoid erroneous charging by excluding only one or both of the number of packets and the number of bytes of packets that have been discarded by all base stations and have not reached the terminal.

  The wireless communication system of the present invention provides a terminal (MS) that performs wireless communication simultaneously with a plurality of base stations (BS), a gateway (GW) that communicates with the terminal via the plurality of base stations, and a service that communicates with the gateway When a gateway performs charging counting of the number of charging target packets and the number of charging target bytes in a wireless communication network composed of servers (SS), the gateway compares the identifiers of discarded packets notified from a plurality of base stations. Thus, one of the characteristics is that only one or both of the number of packets and the number of bytes of packets discarded at all base stations are excluded from the charge count and excluded from the charge count.

  Also, the wireless communication system of the present invention is configured such that a result obtained by excluding a packet count and / or the number of packets discarded by a gateway from all base stations from the charge count is excluded from the charge count. ) Is one of the features.

  In addition, the wireless communication system of the present invention is characterized in that the base station notifies the gateway of the discarded packet identifier.

  According to the present invention, in the wireless communication system, when the gateway transmits the same packet to each of the plurality of base stations, erroneous charges can be avoided.

A gateway device having a billing count function in which the gateway compares the discard notifications from each base station in a case where the same packet is transmitted from the gateway to a plurality of base stations, and only discards the packets discarded by all the base stations. And an example of a base station having the discard notification function. An example of a block diagram of a gateway. An example of the block diagram of the memory part of a gateway. An example of the block diagram of the process part of a gateway. In the case where the same packet is transmitted from the gateway to a plurality of base stations, the gateway has a charging count function that compares the discard notification from each base station and only discards the packets discarded by all the base stations. An example of the table (transmission packet information table) to hold | maintain. An example of the block diagram of a base station. An example of the block diagram of the process part of a base station. An example of the block diagram of the process part of the base station of the modification in which a base station has a billing byte count function of a discard packet. An example of a processing flowchart when the gateway in the charging count function of the gateway transmits the same packet to a plurality of base stations.

1. Overview FIG. 1 shows a mobile radio having a function of avoiding erroneous charging by excluding only one or both of the number of packets and the number of bytes of a packet that has been discarded by all base stations and did not reach the terminal. It is an example of a communication system.

  One mobile radio communication system according to an embodiment of the present invention includes a radio terminal (hereinafter, MS: Mobile Station) 5 that performs radio communication simultaneously with a plurality of base stations (hereinafter, BS: Base Station) 4, and a plurality of base stations (hereinafter, MS: Mobile Station). A gateway device that communicates with the MS 5 via the BS 4 (hereinafter, also simply referred to as a gateway in the present specification; hereinafter referred to as GW: Gateway) 2 and a service providing server that communicates with the GW 2 (hereinafter, SS: Service Server). 1). GW2 compares the identifiers of discarded packets notified from each of a plurality of BSs 4 when counting the number of charging target packets and the number of charging target bytes in the wireless communication network, and is discarded by all BSs 4 Only one or both of the number of packets and the number of bytes of the packet are excluded from the charge count and excluded from the charge count.

2. Embodiment of the Present Invention In the embodiment of the present invention, when the GW 2 transmits the same packet to each of a plurality of BSs 4, all the packets are discarded based on the discarded packet identifiers notified from the respective BS 4. The present invention relates to a function for avoiding erroneous charging by excluding only one or both of the number of packets and the number of bytes of the packets discarded by BS4 and not reaching MS5. GW2 charging count for MS5 is corrected based on message transmission including identifier of discarded packet from BS4 to GW2 due to packet transmission failure from BS4 to MS5, and discard notification from BS4 from GW2 to CS3 An example of message transmission including the charged count result is shown in FIG. GW2 transmits the same packet to BS4 # 1, BS4 # 2, and BS4 # 3, as shown by a in FIG. BS4 # 1, BS4 # 2, and BS4 # 3 each transmit the packet received at a to MS5. As shown in FIG. 1b ', packets transmitted from BS4 # 1 and BS4 # 3 are received by MS5, but as shown in FIG. 1b, packets transmitted from BS4 # 2 do not reach MS5 and are discarded. The When the transmission of the packet from the BS 4 # 2 to the MS 5 fails, the BS 4 # 2 transmits a message including the discarded packet identifier to the GW 2 as shown in c. The GW 2 transmits to the CS 3 a message (d in FIG. 1) including the billing count result corrected based on the discard notification from the BS 4 # 2 to the CS 3.

  Further, as a modified example of the present embodiment, a case where the BS 4 transmits the number of bytes of the discarded packet to the GW 2 in addition to the identifier of the discarded packet is shown.

2-1. System Configuration [Example of Architecture of Mobile Radio Communication System of this Embodiment]
An example of the architecture of the mobile radio communication system of the present embodiment is as described in the overview.

2-2. Device configuration 2-2-1. GW2
[Example of GW2 of this embodiment]
FIG. 2 shows an example of a functional block diagram of the GW 2 used in the present embodiment.

  The GW 2 includes, for example, an SS interface unit 21, a BS interface unit 22, a CS interface unit 23, a memory unit 24, and a processing unit 25.

  The SS interface unit 21 is an interface with SS1. The SS interface unit 21 allows the GW 2 to transmit and receive IP packets with the SS 1.

  The BS interface unit 22 is an interface with the BS 4. The GW 2 transmits and receives IP packets to and from the BS 4 through the BS interface unit 22. In the present embodiment, the GW 2 uses the BS interface unit 22 to transmit a packet that gives an identifier to the BS 4 or information indicating that a notification of the identifier of the packet is requested when the packet is discarded by the BS 4. , A message indicating the discard of the packet may be received from the BS 4.

  The CS interface unit 23 is an interface with CS3. By the CS interface unit 23, the GW 2 transmits and receives IP packets to and from the CS 3. In the present embodiment, the GW 2 transmits, to the CS 3 by the CS interface unit 23, either or both of the number of packets and the number of bytes counted for the MS 5 unit or MS 5 and the service unit, or a response from the CS 3 to the charging count transmission. You may receive. Further, the accounting count to be transmitted may be a value calculated by excluding either or both of the number of packets / bytes discarded at BS4 by GW2, or either the number of packets / bytes discarded at BS4 or Both values themselves can be used.

  The memory unit 24 stores information such as IP packets to be transmitted / received, addresses of SS1, CS3 and BS4 to be connected, one or both of the number of packets / bytes counted for each MS5 or MS5 and service, and a transmission packet information table. Store and manage as necessary. The processing unit 25 performs management of information held in the memory unit 24, IP packet transmission / reception processing such as construction and analysis of IP packets, and the like.

  FIG. 3 shows an example of a block diagram of the memory unit of the gateway. FIG. 4 shows an example of a block diagram of the processing unit of the gateway.

  For example, as shown in FIG. 3, the memory unit 24 has a transmission packet information table 241, and includes identifiers for each packet, the number of charged bytes for each packet, an identifier for the service to which each packet belongs, and the destination BS 4 that has transmitted each packet. Information such as identifiers and timeout times of packets can be managed. Details of the table will be described later.

  For example, as shown in FIG. 4, the processing unit 25 includes a memory management unit 251 that manages information stored in the memory unit 24, a transmission / reception processing unit 252 that performs IP packet transmission / reception processing such as construction and analysis of IP packets, and the like. Then, management of information held in the memory unit 24, IP packet transmission / reception processing such as construction and analysis of IP packets, and the like are performed. Further, as shown in FIG. 4, for example, the processing unit 25 transmits the same packet to a plurality of BSs 4, assigns an identifier to each packet to be transmitted to the BS 4, and identifies an identifier of the packet when the packet is discarded by the BS 4. A billing count processing unit 253 that performs the addition of information indicating that a request for notification is requested, the calculation of the billing count when the packet discard is notified from the BS4, and the like, transmission of the same packet to a plurality of BS4, Assignment of an identifier to each packet to be transmitted to BS4, addition of information indicating that notification of the identifier of the packet is requested when the packet is discarded by BS4, and charging when a packet discard is notified from BS4 Count calculation and so on. Further, as shown in FIG. 4, for example, the processing unit 25 includes a time measuring unit 254 that measures a time-out time at which the GW 2 deletes information related to a packet from the transmission packet information table 241, and the GW 2 includes the transmission packet information table 241. Time-out time for deleting information related to a certain packet is measured.

[An example of information held in the memory unit of the GW 2 of the present embodiment]
FIG. 5 shows a transmission packet information table as an example of information held in the memory unit of the GW 2 in the case of the present embodiment. The transmission packet information table stores, for example, the identifier of each packet, the number of charged bytes of each packet, the identifier of the service to which each packet belongs, the identifier of the destination BS 4 that transmitted each packet, and the timeout time of each packet.

  The packet identifier is an identifier of a packet transmitted from the GW 2 to the BS 4. As the packet identifier, for example, information originally included in the packet such as a UDP header sequence number set by the GW 2 may be used, or a field or header for setting the identifier may be newly added by the GW 2. Good.

  The number of charging bytes is the number of bytes that the GW 2 includes in the charging count when the packet is to be charged. As the number of charged bytes, for example, the total number of bytes of a packet including all headers such as an IP header may be counted, or only the number of bytes of a payload part excluding a specific header such as an IP header may be counted. .

  The service identifier is used to determine which service is excluded from the charge count when the charge count is performed for each user and service in GW2 and the packet is discarded without being transmitted to the terminal. Identifier. As the service identifier, for example, the identifier of SS1 which is the server that provides the service may be used, or the identifier of the communication path divided for each service may be used. In addition, this information can be omitted when the accounting count is a user unit (MS5 unit) or when the service can be identified from the header of the packet discard message transmitted from the BS4.

  The identifier of the destination BS 4 is the identifier of the BS 4 to which the GW 2 has transmitted the packet. As the identifier of the destination BS4, for example, the IP address of the BS4 may be used, or an identifier associated with the IP address of the BS4 may be defined and used. Although FIG. 5 shows an example where the combination of identifiers of the destination BS4 is the same for all packets, the combination of identifiers of the destination BS4 may be different for each packet. In the transmission packet information table, for each identifier of the transmission destination BS4, it can be set in the table whether or not a message notifying the discard of the packet has been received from the BS4 corresponding to the identifier of the BS4. For example, in the example of FIG. 5, regarding the packet whose packet identifier is “11”, the BS4 whose destination BS4 identifier is “BS4 # 2” and the BS4 whose destination BS4 identifier is “BS4 # 3” The message indicating that the packet whose packet identifier is “11” has been discarded is stored.

  The time-out time of the packet is a time at which the GW 2 may delete the information on the packet from the table. As the timeout time, for example, the standard time of the place where the GW 2 is installed or the standard time set by the operator managing the GW 2 may be used, or the number of seconds elapsed from a certain reference time may be used as a numerical value. May be.

  In addition, the transmission packet information table may include a service identifier or the like for each user and each service when the accounting is performed for each user and each service.

  These pieces of information can be updated by, for example, the value of the packet received from SS1 or the value acquired via BS4.

2-2-2. BS4
[An example of BS4 of this embodiment]
FIG. 6 shows an example of a functional block diagram of the BS 4 used in the present embodiment. FIG. 7 shows an example of a block diagram of the processing unit of the base station.

  The BS 4 includes, for example, a GW interface unit 41, an MS interface unit 42, a memory unit 43, and a processing unit 44.

  The GW interface unit 41 is an interface with the GW 2. By the GW interface unit 41, the BS 4 transmits and receives IP packets to and from the GW 2. In the present embodiment, the BS 4 transmits a message indicating that the packet is discarded to the GW 2 by the GW interface unit 41, or the packet to which the identifier is given from the GW 2 or the identifier of the packet when the packet is discarded by the BS 4. Information indicating that a notification is requested may be received. The message indicating the discard of the packet transmitted to the GW 2 includes the identifier of the BS 4 that is the transmission source of the message, the identifier of the discarded packet, and the like. Furthermore, when the GW2 billing count is performed on an MS5 and service basis, a service identifier may be included.

  The MS interface unit 42 is an interface with the MS 5. The MS interface unit 42 causes the BS 4 to transmit and receive IP packets with the MS 5.

  The memory unit 43 stores and manages information such as IP packets to be transmitted / received, the address of the GW 2 to be connected, and the address of the MS 5 to be connected as necessary.

  For example, as shown in FIG. 7, the processing unit 44 includes a memory management unit 441 that manages information held in the memory unit 43, a transmission / reception management unit 442 that performs IP packet transmission / reception processing such as construction and analysis of IP packets, and the like. Then, management of information held in the memory unit 43, IP packet transmission / reception processing such as construction and analysis of IP packets, and the like are performed. Further, detection of whether or not the packet is discarded at the BS 4 is performed by the transmission / reception management unit 442, for example.

[An example of BS4 in a modification of the present embodiment]
The BS 4 used in the modified example of the present embodiment is that the message indicating the discard of the packet transmitted to the GW 2 by the GW interface unit 41 includes the number of charged bytes of the packet, and an example of a block diagram of the processing unit 44 Is the same as BS 4 of the present embodiment except that FIG. The processing unit 44 of the BS 4 used in the modification of the present embodiment, for example, as shown in FIG. 8, in addition to the memory management unit 441 and the transmission / reception management unit 442 mentioned in the present embodiment, The accounting byte count unit 443 for calculating the accounting byte count is used to calculate the accounting byte count of the packet received from the GW 2.

2-3. Charging count of packets discarded by BS4 [Example of charging count by GW2 when BS4 according to this embodiment does not transmit the charging byte count of discarded packets to GW2]
In FIG. 9, as an example of GW2 processing in the accounting count of packets discarded by BS4, the same packet is simultaneously transmitted to three BS4 (hereinafter referred to as BS4 # 1, BS4 # 2, and BS4 # 3, respectively). The processing when transmitting is shown.

  When the processing unit 25 of the GW 2 transmits the same packet to a plurality of BSs 4 in step S201, the identifier is set in the packet and is transmitted to each BS.

  In step S202, the processing unit 25 of the GW 2 stores the identifier of the packet transmitted to each BS 4 in S201, the number of charging bytes related to the packet, the identifier of the service, the identifier of the destination BS 4 and the timeout time in the transmission packet information table 241. to add. The service identifier can be omitted if it is not necessary. The packet can include information indicating that a request for notification of the identifier of the packet is requested to the GW 2 when the packet is discarded by the BS 4. For example, depending on whether the sequence number of the UDP header is a value included in a specific range agreed with BS4, whether to request BS4 to notify the identifier of the packet to GW2 when the packet is discarded It may be specified whether or not, or a flag indicating whether or not to make a request for a newly added field or header may be set. The timeout time may be set according to the setting policy of GW2. For example, a timer value until timeout may be set in advance in the GW 2, and a time when the timer value has elapsed from the current time may be set as the timeout time.

  In step S203, the processing unit 25 of the GW 2 refers to the transmission packet information table 241 and determines whether a message indicating the discard of the packet has been received from the BS 4 before the timeout time of the packet. The message indicating the discard of the packet includes the identifier of the BS 4 that is the transmission source of the message, the identifier of the discarded packet, and the like.

  When the timeout time is reached without receiving the message indicating that the packet is discarded, the processing unit 25 of the GW 2 determines in step S204N that the MS 5 has successfully received the packet, and the transmission packet information table 241 relates to the packet. All information is deleted and the process is terminated. The packet is determined to be a chargeable packet, and either or both of the number of packets and the number of bytes of the packet are included in the charge count.

  When the message indicating the discard of the packet is received before the time-out time is reached, the processing unit 25 of the GW 2 determines that the identifier of the BS 4 that is the transmission source of the received message is the packet of the packet information table 241 in step S204Y. It is determined whether it is included in the identifier of the destination BS4.

  If the identifier of the BS4 that is the source of the received message is not included in the identifier of the destination BS4 of the packet, the processing unit 25 of the GW2 discards the received message and continues the processing from step S203 in step S205N. .

  If the identifier of the BS4 that is the transmission source of the received message is included in the identifier of the transmission destination BS4 of the packet, the processing unit 25 of the GW2 updates the transmission packet information table 241 in step S205Y and transmits the packet. The fact that the discard notification has been received is added to the identifier of the destination BS4. Note that the timeout time of the packet in the transmission packet information table 241 may be updated when the discard notification is received. The update of the time-out time may be performed, for example, only when the first discard notification is received for the packet, or may be performed at all triggers when the discard notification is received.

  In step S206, the processing unit 25 of the GW 2 determines whether or not a discard notification has been received from all the transmission destination BSs 4 of the packet.

  If BS4 that has not yet received the discard notification remains in the transmission destination BS4 of the packet, the processing unit 25 of the GW2 continues the processing from step S203 in step S207N.

  When the discard notification is received from all the transmission destination BSs 4 of the packet, the processing unit 25 of the GW 2 determines in step S207Y that the MS 5 has failed to receive the packet, and stores all the information related to the packet in the transmission packet information table 241. Delete and finish the process. The packet is excluded from the charge target packet, and either or both of the packet number and the byte number of the packet are excluded from the charge count.

[Example of discard notification to GW 2 by BS 4 when BS 4 according to this embodiment does not transmit the number of charged bytes of the discarded packet to GW 2]
An example of the process of BS4 in the discard notification to GW2 regarding the packet discarded by BS4 is shown.

  When the packet for which the discard notification is requested to the GW 2 is discarded, the processing unit 44 of the BS 4 transmits a message indicating the discard of the packet to the GW 2 that is the transmission source of the packet. In the message indicating the discard of the packet, the identifier of the BS 4 that is the transmission source of the message, the identifier of the discarded packet, and the like are set. In addition, when a billing count is performed for each user and service, a service identifier or the like may be further included.

[Example of charging count by GW2 when BS4, which is a modification of the present embodiment, notifies GW2 of the number of charging bytes of the discarded packet]
When BS4 notifies the GW2 of the number of charged bytes of the discarded packet, the GW2 counts the number of charged bytes of the discarded packet instead of holding the number of charged bytes for each packet, and notifies the GW2. The point of use of FIG. 8 instead of FIG. 7 and the reference source of the number of charging bytes included in the charging count in S204N and the number of charging bytes excluded from the charging count in S207Y are received from BS4 instead of the transmission packet information table 241. The only difference is the message, and the GW2 billing count process is performed in the same manner as in the above flow. When the number of charged bytes of the packet notified from each BS 4 is different from each other, for example, a majority vote may be adopted, an average value of the notified number of charged bytes may be adopted, or a notification will be received. Alternatively, the number of charging bytes notified from the BS 4 may be adopted according to the order or the priority determined in advance for each BS 4.

3. Effects of this embodiment According to the above-described embodiment, when the gateway transmits the same packet to a plurality of base stations, the gateway compares the discard notifications from the respective base stations and is discarded by all the base stations. Since only packets are not charged, one or both of the number of packets and the number of bytes that have actually reached the terminal can be charged for each user or for each user and service at the gateway.

  Further, when the above embodiment and the modification are compared, in the above embodiment, the amount of information necessary for the message transmitted from the BS 4 to the GW 2 is small, and the traffic reduction in the uplink direction and the message transmission processing of the BS 4 The load of message reception processing of GW2 can be reduced. On the other hand, in the modified example, since it is not necessary to store the number of bytes for each packet in the GW2, the memory capacity of the GW2 can be reduced.

  The present invention can be used, for example, in a charging system when transmitting a packet to a wireless terminal via a plurality of base stations.

  Further, the present invention can be applied to various communication devices other than GW and BS.

1 Service Providing Server 2 Gateway Step S201 to Step S207 Step 21 of Gateway Billing Count Processing Flow when Gateway Transmits Same Packet to Multiple Base Stations SS Interface Unit 22 BS Interface Unit 23 CS Interface Unit 24 Memory Unit 241 Transmission Packet Information table 25 processing unit 251 memory management unit 252 transmission / reception management unit 253 accounting count processing unit 254 timing unit 3 accounting server 4 base station 41 GW interface unit 42 MS interface unit 43 memory unit 44 processing unit 441 memory management unit 442 transmission / reception management unit 443 Billing byte count unit 5 Terminal

Claims (10)

The same packet including the packet identifier is transmitted to a plurality of base stations, the identifiers of the discarded packets notified from the respective base stations are compared, and the packets discarded by all the base stations that transmitted the same packet are not charged. A communication device that determines the target and notifies the billing server;
A base station that notifies a communication device of an identifier of a packet that has been discarded by the base station and has not reached the terminal.   2. The base station according to claim 1, wherein the base station counts the number of charged bytes of a packet received from the communication apparatus and has not reached the terminal, and notifies the identifier of the packet and the number of charged bytes to the communication apparatus. The wireless communication system described. The communication device
Packet identifiers included in the same packet transmitted to a plurality of base stations, identifiers indicating each destination base station that transmitted the packet, and each packet is discarded at each source base station corresponding to each packet identifier Holding a transmission packet information table including at least the transmission status of whether or not
The non-billing target packet is determined by referring to a transmission state indicating whether or not a packet including the identifier held in the transmission packet information table is discarded at each transmission source base station. Item 2. The wireless communication system according to Item 1.   When the communication device is notified of the identifier of the packet that has been discarded by the base station and has not reached the terminal, the transmission state of the packet indicated by the packet identifier corresponding to the base station that has transmitted the notification is discarded. The wireless communication system according to claim 3, wherein the wireless communication system is updated to information indicating the fact.   The transmission packet information table stores a timeout time corresponding to the identifier of each packet, and when the transmission status does not indicate discarding to each base station corresponding to the packet identifier after the timeout time elapses, 4. The wireless communication system according to claim 3, wherein the packet of the identifier is included in the charging count.   Determining that the packet indicated by the identifier is a non-chargeable packet when all the transmission states at each transmission source base station corresponding to the identifier held in the transmission packet information table indicate discarding The wireless communication system according to claim 3. Send the same packet with the packet identifier to multiple base stations,
Receiving from the base station information including the identifier of the packet that was discarded at the base station and did not reach the terminal;
A communication apparatus that compares identifiers of discarded packets notified from the respective base stations, determines packets discarded by all base stations that transmitted the same packet as non-chargeable objects, and notifies a charging server. The communication device
Packet identifiers included in the same packet transmitted to a plurality of base stations, identifiers indicating each destination base station that transmitted the packet, and each packet is discarded at each source base station corresponding to each packet identifier Holding a transmission packet information table including at least the transmission status of whether or not
The non-billing target packet is determined by referring to a transmission state indicating whether or not a packet including the identifier held in the transmission packet information table is discarded at each transmission source base station. Item 8. The communication device according to Item 7.   The transmission packet information table stores a timeout time corresponding to the identifier of each packet, and when the transmission status does not indicate discarding to each base station corresponding to the packet identifier after the timeout time elapses, The communication apparatus according to claim 8, wherein the packet of the identifier is included in the accounting count.   Determining that the packet indicated by the identifier is a non-chargeable packet when all the transmission states at each transmission source base station corresponding to the identifier held in the transmission packet information table indicate discarding The communication apparatus according to claim 8, characterized in that:

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