Mobile communication system and mobile station

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to a mobile communication system such as a cellular system and a mobile station, and more specifically, a multicast packet transmission function for transmitting one multicast packet transmitted from an IP (Internet Protocol) packet communication system to a plurality of mobile stations. It relates to a mobile communication system and a mobile station to have.

【0002】

[Conventional technology]

Conventionally, there is known a mobile data communication system that uses a wireless line of a mobile communication system to transmit a packet from a computer included in the fixed communication system to a mobile station in the mobile communication system. Some mobile data communication systems realize packet transmission by so-called tunneling in the mobile communication system.

【0003】

More specifically, this mobile communication system transmits packets by tunneling between a gateway device that functions as a gate to and from a fixed communication system and a support device that controls a location registration area in the mobile communication system. It is carried out. This tunneling is to transmit a packet on a logical transfer path (tunnel) established based on the position information of a mobile station. This enables packet transmission to moving mobile stations.

【0004】

On the other hand, in IP (Internet Protocol) packet communication systems represented by internet / intranet, so-called multicast communication has been conventionally performed. Multicast communication transmits multicast packets from one computer to multiple computers. As a usage pattern of multicast communication, there is a conference relay and the like.

【0005】

Multicast communication in IP packet communication is performed according to a control procedure called IGMP (Internet Group Management Protocol). In IGMP, the transmission destination of the multicast packet is managed by the router in the IP packet communication system. That is, when there are a plurality of transmission destinations, the router replicates the multicast packets by the number corresponding to the number of transmission destinations, and transmits the resulting multicast packets to each transmission destination.

【0006】

By the way, if this multicast communication can be used in a mobile data communication system, it is very convenient for the user. That is, even when you are out, you can watch the conference broadcast. Therefore, a technology that utilizes multicast communication in an IP packet communication system is also desired in a mobile data communication system.

【0007】

[Problems to be Solved by the Invention]

However, if the multicast communication in the IP packet communication system is applied as it is to the mobile data communication system as described above, the system efficiency such as the packet transmission efficiency, the control procedure efficiency, and the transmission efficiency in the wireless line may not be sufficient.

【0008】

Therefore, an object of the present invention is to provide a mobile communication system and a mobile station capable of improving system efficiency when multicast communication in a connectionless communication system such as an IP packet communication system is applied to mobile communication. Is.

【0009】

[Means for solving problems]

The present invention for achieving the above object includes a plurality of mobile stations, a plurality of base stations that communicate with the plurality of mobile stations, a base station control device that controls the plurality of base stations, and the plurality of mobile stations. It is provided with a relay connection device for setting an access link to and from the relay connection device, and a gateway device provided between the relay connection device and the connectionless packet communication system and communicating with the relay connection device by tunneling. A mobile communication system having a function of transmitting a multicast packet transmitted from a terminal provided in the connectionless packet communication system to a plurality of mobile stations via the access link, and the relay connection device is the multicast. By duplicating the packet, a means for creating a number of multicast packets corresponding to the number of mobile stations registered for distribution (hereinafter referred to as "delivery destination mobile station"), and the above-mentioned distribution destination mobile station using the created multicast packet. It is a mobile communication system characterized in that it includes a means for distributing via the access link.

【0010】

The present invention also includes means for requesting the relay connection device via the control channel to register the distribution of the multicast packet together with the location registration or the handover when the mobile station moves with the change of the service area. It is a mobile communication system characterized by being an invention.

【0011】

Further, the present invention includes means for the base station to notify a mobile station that has moved to a cell formed by the own station of information about a multicast packet delivered by the own station via a notification channel. Therefore, the mobile station has a means of determining whether or not the desired multicast packet is delivered based on the information about the multicast packet notified from the base station, and the desired multicast packet is not delivered. It is a mobile communication system including means for requesting the relay connection device to register the delivery of the desired multicast packet via the access link when it is determined.

【0012】

Furthermore, in the present invention, when a plurality of the relay connection devices are provided for each predetermined area and the mobile station requests distribution registration, whether or not the multicast packet corresponding to the request is distributed. Further includes a means for determining the above and a means for requesting the gateway device to register the distribution of the multicast packet when it is determined that the multicast packet corresponding to the above request has not been delivered. However, when there is a distribution registration request from the relay connection device, the mobile communication system includes means for delivering a multicast packet corresponding to the request to the relay connection device that has made the request.

【0013】

Further, in the present invention, the mobile communication system uses CDMA (Code Division Multiple Access) as a communication access method, and the base station control device allocates common radio resource information to a plurality of mobile stations. It includes means and means for notifying each base station to be controlled to deliver a multicast packet based on the assigned radio resource information, and the base station controls the base station. It is a mobile communication system including a means for delivering a multicast packet to a mobile station based on the radio resource information when the device receives the above notification.

【0014】

Furthermore, in the present invention, when the mobile station changes the jurisdiction area of the base station control device, the relay connection device changes from the base station control device immediately before the change to the base station control device immediately after the change. It further includes means for notifying each base station control device to secure a line by extension control, and each base station control device responds to the notification of the relay connection device and subscribes to the subscriber line. It is a mobile communication system characterized in that it includes means for securing a line by executing extension control.

【0015】

Further, in the present invention, the base station control device provides a means for transmitting a question signal to the base station confirming whether or not the multicast packet needs to be delivered, and a power measurement instruction signal for instructing reception power measurement. The base station includes means for transmitting to the base station, and the base station transmits the inquiry signal to the mobile station and transmits the power measurement instruction signal from the mobile station when the power measurement instruction signal is received. It includes means for measuring the received power of the response signal to be received and means for transmitting the measured received power value to the base station control device, and the mobile station responds to the reception of the question signal by the mobile station. Is included in the means for transmitting the above-mentioned to the base station, and when the above-mentioned base station control device delivers the means for holding the received power value transmitted from the above-mentioned base station and the multicast packet to the mobile station. The mobile communication system further includes means for controlling the transmission power of the base station based on the held received power value.

【0016】

Furthermore, the present invention receives a multicast packet from a terrestrial device created by duplicating the multicast packet transmitted by tunneling as many as the number of mobile stations registered based on the distribution registration request via an access link. It is a mobile station that includes a means for requesting distribution registration of a multicast packet via a control channel together with location registration or handover when moving with a change in the service area. ..

【0017】

Further, the present invention receives the multicast packet from the ground device created by duplicating the multicast packet transmitted by tunneling by the number of mobile stations registered based on the distribution registration request via the access link. When it is a mobile station and it is determined that the desired multicast packet is not delivered and the means for determining whether or not the desired multicast packet is delivered based on the information about the received multicast packet, the relevant is concerned. It is a mobile station including means for requesting distribution registration of a desired multicast packet.

【0018】

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

【0019】

The following embodiments 1 to 7 may have different system configurations, or may correspond to each function in one system.

【0020】

Embodiment 1. FIG. 1 is a block diagram showing a configuration of a mobile data communication system to which the mobile communication system according to the first embodiment of the present invention is applied. This mobile data communication system includes an IP (Internet Protocol) packet communication system 1 and a mobile communication system 10. This mobile data communication system simultaneously transmits a multi-packet transmitted from the IP terminal 2 in the IP packet communication system 1 to a plurality of mobile stations 11 in the mobile communication system 10.

【0021】

The IP packet communication system 1 is a connectionless packet communication system, and includes a plurality of IP terminals 2, a plurality of routers 3, and a gateway device (GW) 4. The IP terminal 2 is composed of a personal computer, a workstation, a server, and the like, and implements IP. The gateway device 4 functions as a gate on the IP packet communication system 1 side between the IP packet communication system 1 and the mobile communication system 10.

【0022】

The IP terminal 2 divides the transmission data into a plurality of packets and transmits the transmission data. Each packet consists of a header part and a data part. The header unit includes an IP address that identifies the mobile station 11 when transmitting transmission data to the mobile station 11. For example, the header section includes a unicast address that identifies one mobile station 11 or a multicast address that identifies one distribution group that includes two or more mobile stations 11. In the following, a packet containing a unicast address in the header portion will be referred to as a unicast packet, and a packet containing a multicast address in the header portion will be referred to as a multicast packet.

【0023】

The router 3 relays the packet sent from the IP terminal 2. The multicast packet sent from the router 3 is given to the gateway device 4. The gateway device 4 performs processing such as identifying the service area network from the destination IP address on the given packet, and then sends the packet to the mobile communication system 10.

【0024】

The mobile communication system 10 includes a mobile station 11 and a ground device 12. The mobile communication system 10 uses CDMA (Code Division Multiple Access) as a communication access method between the mobile station 11 and the ground device 12. That is, in the mobile station 11 and the base station 13 in the ground device 12, the transmission data is subjected to primary modulation by a predetermined primary modulation method such as QPSK (Quadrature Phase Shift-Keying) to create a primary modulation signal. After that, the created primary modulation signal is subjected to secondary modulation using a diffusion code unique to each user to create a secondary modulation signal. Then, a radio wave based on the created secondary modulation signal is radiated. In this way, communication between the mobile station 11 and the ground device 12 is achieved.

【0025】

The mobile station 11 has a portable computer terminal 11a such as a notebook personal computer and a mobile device 11b. The mobile device 11b is composed of a telephone capable of data communication. Specifically, the mobile device 11b is composed of a mobile phone, a PHS (Personal Handyphone System) phone, and the like. At the time of use, the mobile device 11b is connected to the computer terminal 11a. The mobile station 11 may be configured by itself capable of data communication.

【0026】

The ground device 12 includes a plurality of base stations 13, a plurality of base station control devices 14, a plurality of support devices 15, a gateway device (GW) 16, and a home position register 17. The base station 13 forms a cell composed of a plurality of (for example, three) sectors and communicates with the mobile station 11 existing in the cell. The base station control device 14 is connected to a plurality of base stations 13 and has jurisdiction over a jurisdiction area composed of cells formed by each of the connected base stations 13.

【0027】

The support device 15 is provided for each position registration area, which is the smallest unit for grasping the position of the mobile station 11, for example. The location registration area is composed of a plurality of cells. The support device 15 is connected to the home position register 17, the gateway device 16, and all the base station control devices 14 provided in the location registration area. The support device 15 has a function of setting an access link with the mobile station 11. A plurality of access links are logical communication paths for packet transmission between the support device 15 and the mobile station 11, and are set for each mobile station 11 and for each QOS (Quality Of Service) class. This access link has functions such as error control (for example, ARQ; error recovery by automatic retransmission) according to QOS.

【0028】

The support device 15 has a distribution registration table 15a. The distribution registration table 15a shows the correspondence between the access link, that is, the mobile station 11, and the logical communication path for forwarding the multicast packet requested to be distributed by the mobile station 11. The support device 15 identifies the distribution destination mobile station to which the multicast packet should be distributed by referring to the distribution registration table 15a. Further, the support device 15 updates the contents of the distribution registration table 15a by receiving a request / cancellation of the distribution registration from the mobile station 11.

【0029】

Registration to the distribution registration table 15a is performed, for example, by transmitting a distribution registration request signal from the mobile station 11 to the ground device 12. Specifically, the mobile station 11 transmits a distribution registration request signal to the base station 13. The base station 13 transfers the distribution registration request signal to the base station control device 14. The base station control device 14 transfers the received distribution registration request signal to the support device 15. The support device 15 associates the mobile station 11 (access link) requesting distribution registration with the multicast packet to be distributed and registers it in the distribution registration table 15a.

【0030】

The home position register 17 stores the subscriber data of the mobile station 11. The subscriber data includes a unique subscriber number, the current location of the mobile station and a distribution group table. The distribution group table shows the correspondence between the mobile station 11 and the distribution group.

【0031】

The gateway device 16 is connected to the gateway device 4 of the IP packet communication system 1. The gateway device 16 is also connected to the home position register 17. The gateway device 16 functions as a gate on the mobile communication system 10 side with the IP packet communication system 1. Specifically, the gateway device 16 routines the transmission destination of the packet transmitted from the IP packet communication system 1 based on the subscriber data stored in the home position register 17.

【0032】

The gateway device 16 and the support device 15 transmit data by so-called tunneling. More specifically, for example, when forwarding a multicast packet from the gateway device 16 to the support device 15, the gateway device 16 forms a logical forwarding path (tunnel) with the support device 15. Then, the multicast packet is transmitted on this formed transfer path. As described above, in the first embodiment, the gateway device 16 and the support device 15 are the start point and the end point of the tunnel, respectively.

【0033】

FIG. 2 is a flowchart showing the processing of the support device 15. In order to deliver the multicast packet to the mobile station 11, it is necessary to set an access link between the mobile station 11 and the support device 15. Therefore, the mobile station 11 requests the support device 15 of the ground device 12 to set the access link after the power is turned on. In response, the support device 15 establishes an access link with the mobile station 11 (step S1).

【0034】

When a multicast packet is sent from the IP terminal 2 in the IP packet communication system 1, the multicast packet is sent to the mobile communication system 10 via the router 3 and the gateway device 4.

【0035】

The multicast packet sent from the IP packet communication system 1 is received by the gateway device 16. The gateway device 16 determines a support device 15 to deliver the multicast packet based on the multicast address of the received multicast packet and the subscriber data stored in the home position register 17. Specifically, the gateway device 16 identifies which mobile station 11 is included in the distribution group corresponding to the multicast address by referring to the distribution group table.

【0036】

Further, the gateway device 16 recognizes the location registration area where the mobile station 11 included in the distribution group exists based on the current location data included in the subscriber data. After that, the gateway device 16 determines the support device 15 corresponding to the recognized location registration area as the transfer destination.

【0037】

The gateway device 16 forwards the multicast packet by tunneling to the support device 15 determined as the forwarding destination. In this case, when a plurality of support devices 15 are determined as transfer destinations, the gateway device 16 replicates the multicast packets by the number of the support devices 15 and forwards the replicated multicast packets to each support device 15 by tunneling. ..

【0038】

When the support device 15 receives a packet from the gateway device 16 (step S2), the support device 15 determines whether or not the received packet is a multicast packet (step S3). If it is a multicast packet, the support device 15 identifies the mobile station 11 included in the group to which the multicast packet should be delivered (step S4). Specifically, the support device 15 bases the distribution group and the mobile station 11 included in the distribution group based on the multicast address included in the transferred multicast packet and the distribution group table stored in the home position register 17. To identify.

【0039】

After that, the support device 15 refers to the distribution registration table 15a, and among the above-specified mobile stations 11, the mobile station registered in the distribution registration table 15a as wishing to be distributed (hereinafter referred to as distribution destination mobile station). ) 11 is identified (step S5). Then, the support device 15 replicates the received multicast packets in order to create a number of multicast packets corresponding to the number of distribution destination mobile stations 11 (step S6). That is, the multicast packet is replicated at the support device 15 which is the end point of the transfer path for tunneling and the access link is set with the mobile station 11.

【0040】

After that, each of the replicated multicast packets is transmitted to the delivery destination mobile station 11 on the access link (step S7). Specifically, the support device 15 identifies the base station control device 14 that has jurisdiction over the jurisdiction area in which the distribution destination mobile station 11 exists, and sends the replicated multicast packet to the specified base station control device 14. Send in frame units on the access link.

【0041】

The base station control device 14 transmits the transmitted multicast packet to the base station 13 forming the cell in which the delivery destination mobile station 11 exists on the access link. The base station 13 radiates a radio wave based on the transmitted multicast packet to the cell. As a result, the mobile station 11 can receive the multicast packet.

【0042】

In the determination process of step S3, if it is not a multicast packet, it is considered to be a unicast packet. Therefore, the support device 15 sends the unicast packet to the destination mobile station 11 via the access link. Send (step S8).

【0043】

As described above, according to the first embodiment, the support that is the end point of the transfer path when communicating with the gateway device 16 by tunneling and that a unique access link is set with the mobile station 11. The device 15 replicates the multicast packet.

【0044】

Therefore, the multicast packet to be transmitted is one not only in the IP packet communication system 1 but also in the transmission section between the gateway device 16 and the support device 15. Therefore, the multicast packet can be transmitted more efficiently than the case where the multicast packet is duplicated in the IP packet communication system 1. Therefore, it is possible to provide a mobile data communication system with improved system efficiency.

【0045】

Embodiment 2. FIG. 3 is a flowchart for explaining the distribution registration request processing of the mobile station 11 in the mobile data communication system to which the mobile communication system according to the second embodiment of the present invention is applied. In the following description, FIG. 1 will be referred to at the same time.

【0046】

In the second embodiment, the delivery registration request processing when the mobile station 11 moves to another location registration area while receiving the multicast packet will be described. When the mobile station 11 moves across the location registration area, it is necessary to request the support device 15 having jurisdiction over the location registration area of the destination again for distribution registration. In this case, it is conceivable that the mobile station 11 requests the ground device 12 for distribution registration via the communication channel.

【0047】

However, in this case, the ground device 12 must wait for the completion of the distribution registration and then start the distribution of the multicast packet, which may take a long time until the distribution of the multicast packet is performed. Therefore, in the second embodiment, in consideration of making a handover request using the control channel when the mobile station 11 moves between cells, the distribution registration is requested together with the handover request.

【0048】

More specifically, the base station control device 14 constantly instructs all the base stations 13 under its jurisdiction to provide the broadcast information. The broadcast information includes free channel information. The base station 13 radiates a radio wave including the received broadcast information toward the cell via the broadcast channel. In this way, the mobile station 11 moving to its own cell is constantly notified of the free channel.

【0049】

On the other hand, when the mobile station 11 receives the multicast packet, it constantly monitors whether or not to change the service area cell. Specifically, the mobile station 11 detects the quality of the received radio wave (for example, the reception level) (step T1). In addition, the mobile station 11 determines whether or not the detected quality has dropped below a predetermined threshold value (step T2). The threshold value is set to a value corresponding to the minimum reception quality required for communication. If the quality drops below the above threshold, it is considered that the cell boundary has been approached, and the mobile station 11 executes the carrier sense (step T3). Carrier sense is a process of detecting frequencies used in adjacent cells in order to obtain a good reception condition.

【0050】

When a frequency is detected, the mobile station 11 determines whether or not a channel corresponding to the detected frequency is available (step T4). Specifically, the mobile station 11 compares the channel corresponding to the detected frequency with the free channel of the received broadcast information. If the channel corresponding to the detected frequency is not an empty channel (NO in step T4), mobile station 11 re-executes the carrier sense in step T3 to identify another channel. On the other hand, if the channel corresponding to the detected frequency is a free channel (YES in step T4), the mobile station 11 sends a handover request signal to the destination base station 13 in order to switch the communication channel to this free channel. And transmit over the control channel (step T5). As a control channel, CCCH (Common Control Channel) or the like can be applied.

【0051】

The handover request signal includes distribution-related data as shown in FIG. Delivery-related data includes type data and address data. The type data specifies the request / cancellation of delivery. For the address data, specify the IP address (multicast address) for which distribution request / cancellation is desired. In addition, the handover request signal includes message type data, random access number data, jurisdiction area data, and location registration area data. The message type data specifies a handover request.

【0052】

The base station 13 transfers the received handover request signal to the base station control device 14 to which the base station 13 is connected. When the base station control device 14 receives the handover request signal, the base station control device 14 transfers the handover request signal to the support device 15 to which the own device is connected. As a result, the support device 15 receives the handover request signal.

【0053】

Upon receiving the handover request signal, the support device 15 recognizes the data included in the handover request signal. If the distribution-related data is not included, the support device 15 instructs the base station control device 14 that has transmitted the handover request signal to perform the handover.

【0054】

In accordance with this handover instruction, the base station control device 14 instructs the destination base station 13 to set the channel and also instructs the source base station 13 to release the channel. In this way, the handover is achieved.

【0055】

On the other hand, if distribution-related data is included, the support device 15 identifies the mobile station 11 that has transmitted the handover request signal based on which access link the handover request signal has been transmitted to. .. After that, the support device 15 accesses the distribution registration table 15a and registers the access link corresponding to the mobile station 11. In this way, distribution registration is achieved.

【0056】

As described above, according to the second embodiment, the mobile station 11 requests the distribution registration via the control channel at the same time as the request for handover. Therefore, the efficiency of packet transmission can be improved as compared with the case where the distribution registration request is made via the communication channel. Therefore, it is possible to provide a mobile data communication system with improved system efficiency.

【0057】

Embodiment 3. FIG. 5 is a flowchart for explaining a distribution registration request process of the base station control device 14 in the mobile data communication system to which the mobile communication system according to the third embodiment of the present invention is applied. In the following description, FIG. 1 will be referred to at the same time.

【0058】

In the second embodiment, it is assumed that the multicast packet is moved to another location registration area while being received. On the other hand, in the third embodiment, it is assumed that the user moves to another location registration area without receiving the multicast packet.

【0059】

In such a case, the mobile station 11 needs to request location registration in a new location registration area instead of handover. This location registration request is usually made using a control channel such as SCCH. Therefore, in such a case, the mobile station 11 makes a distribution registration request together with the location registration request.

【0060】

Specifically, the mobile station 11 transmits a location registration request signal to the base station 13 that has jurisdiction over the destination cell. As shown in FIG. 6, the location registration request signal includes a message type, a user ID, location registration area data, and distribution-related data. The message type specifies that location registration is requested. The distribution-related data includes the type data and the address data as well as the distribution-related data in the handover request signal shown in FIG.

【0061】

The base station 13 transfers the received location registration request signal to the base station control device 14 to which the base station 13 is connected. As a result, the base station control device 14 receives the location registration request signal (step U1). The base station control device 14 transfers the received location registration request signal to the support device 15 (step U2).

【0062】

The support device 15 accesses the home position register 17 and changes the current position of the mobile station 11 to a new position according to the position registration request. As a result, location registration is achieved. Further, the support device 15 accesses the distribution registration table 15a and registers the access link set with the mobile station 11. In this way, distribution registration is achieved.

【0063】

When the location registration and the distribution registration are performed, the support device 15 transmits a response signal indicating that the location registration and the distribution registration have been performed to the base station control device 14. When the base station controller 14 receives the response signal, the base station controller 14 includes the radio resource information necessary for delivering the multicast packet in the response signal (step U3). After that, the base station control device 14 transmits a response signal including the radio resource information to the base station 13 (step U4).

【0064】

The radio resource information includes the radio frequency, spread code and sector number used to deliver the multicast packet. In this case, the radio resource information is not individually assigned to the mobile station 11, but is commonly assigned to a plurality of mobile stations 11 that are registered for distribution regarding the same multicast packet. For example, if another mobile station 11 that has registered for distribution of the same multicast packet already exists in the location registration area of the destination, the radio resource information used for wireless communication with the other mobile station 11 To assign.

【0065】

When the base station 13 receives the response signal, the base station 13 executes transmission control of the radio section based on the radio resource information included in the received response signal. Specifically, the base station 13 creates a primary modulation signal based on the frequency included in the radio resource information, and further creates a secondary modulation signal based on the spread code included in the radio resource information, and then the radio resource. A radio wave based on the secondary modulation signal is emitted to the sector corresponding to the sector number included in the information.

【0066】

As described above, according to the third embodiment, the distribution registration request is made via the control channel. Therefore, it is possible to provide a mobile data communication system with improved system efficiency as compared with the case where a distribution registration request is made via a communication channel.

【0067】

In addition, when registering the distribution of multicast packets, radio resource information common to other mobile stations 11 is assigned. Therefore, effective use of wireless resources can be achieved. Therefore, it is possible to provide a mobile data communication system with improved system efficiency.

【0068】

Embodiment 4. FIG. 7 is a flowchart for explaining the distribution registration request processing of the mobile station 11 in the mobile data communication system to which the mobile communication system according to the fourth embodiment of the present invention is applied. In the following description, FIG. 1 will be referred to at the same time.

【0069】

In the fourth embodiment, the delivery registration request processing when the mobile station 11 moves between cells while receiving the multicast packet will be described. When the mobile station 11 moves between cells, it is unknown whether or not the same type of multicast packet as the multicast packet being received is delivered to the destination cell. Therefore, when moving between cells, it is conceivable that the mobile station 11 always requests the ground device 12 for distribution registration.

【0070】

However, if a mobile station 11 that is included in the same distribution group as the own station already exists in the destination cell, when a multicast packet of the same type as the multicast packet being received has already been distributed to the destination cell. There is. Therefore, in the fourth embodiment, in consideration of such a case, the mobile station 11 requests the ground device 12 to register the distribution only when the receiving multicast packet is not distributed to the destination cell. I try to do it.

【0071】

More specifically, when delivering the multicast packet, the base station 13 transmits the broadcast information signal toward the cell via the broadcast channel. As a result, the mobile station 11 that has moved to the cell is notified whether or not the multicast packet to be delivered is delivered to the cell.

【0072】

As the broadcast channel, BCCH (Broadcast Control Channel) or the like can be applied. BCCH in this case is not for notifying information about the entire system such as network ID, cell ID and logical channel configuration, but for notifying information about delivery of multicast packets.

【0073】

The broadcast information signal includes packet-related information as shown in FIG. 8 (a). As shown in FIG. 8B, the packet-related information includes each data of message type, information element length, location registration area, frequency band, spread information, and address information.

【0074】

The message type data specifies the type of message sent to the mobile station 11. Specifically, what kind of information element or information element group is included in the message transmitted to the mobile station 11 is specified. The information element length specifies the message length to be transmitted to the mobile station 11. Each data of the frequency band and the spread information specifies the frequency band and the spread information regarding the channel in the downlink direction (base station 13 mobile station 11) for delivering the multicast packet shared by a plurality of mobile stations 11. The address information specifies information about the multicast packet currently being delivered. The information includes address information and a packet ID for identifying a mobile station group (delivery group) that receives a multicast packet.

【0075】

In addition to the packet-related information, the broadcast information signal includes BCCH identification information, transmission power information, uplink interference amount, and CRC (Cyclic Redundancy Check), as shown in FIG. 8A.

【0076】

Returning to FIG. 7, when the mobile station 11 moves between cells while receiving the multicast packet, the mobile station 11 transmits the broadcast information signal transmitted from the base station 13 forming the destination cell via the broadcast channel. Receive (step V1). After that, the mobile station 11 confirms the packet-related information included in the received broadcast information signal (step V2), and the same multicast packet as the multicast packet being received by the own station is delivered from the destination base station 13. Determine if it is present (step V3).

【0077】

If it has not been distributed (NO in step V3), the mobile station 11 transmits a distribution registration request signal to the base station 13 (step V4). After that, as in the case of the second embodiment, the distribution registration request signal is transferred from the base station 13 to the support device 15 via the base station control device 14, and the distribution registration table 15a is updated in the support device 15. Delivery registration is achieved.

【0078】

On the other hand, if it is distributed (YES in step V3), the mobile station 11 does not transmit the distribution registration request signal. However, even in this case, it can be seen from the registration status of the distribution registration table 15a before the movement that the mobile station 11 desires distribution registration. Therefore, the mobile station 11 can continue to receive the same type of multicast packet as the multicast packet being received.

【0079】

As described above, according to the fourth embodiment, when the mobile station 11 moves between cells, the same type of multicast packet as the multicast packet received by the mobile station 11 is delivered from the destination base station 13. Only when there is no distribution registration request is made to the ground device 12. Therefore, the signal processing in the ground device 12 becomes simpler than the case where the distribution registration request is made even when the distribution has already been performed. Therefore, the efficiency of signal processing can be improved.

【0080】

When requesting distribution registration, as in the second embodiment, distribution registration may be requested via the control channel together with the handover request. In this case, the packet transmission efficiency can be improved as in the second embodiment.

【0081】

Embodiment 5. FIG. 9 is a flowchart for explaining a process at the time of distribution registration of the support device 15 in the mobile data communication system to which the mobile communication system according to the fifth embodiment of the present invention is applied. In the following description, FIG. 1 will be referred to at the same time.

【0082】

In the fifth embodiment, the processing of the support device 15 when the mobile station 11 requests the ground device 12 for distribution registration will be described. The mobile station 11 may move to another location registration area. In this case, since communication is performed with a different support device 15, the mobile station 11 needs to request the distribution registration of the multicast packet again.

【0083】

If a mobile station that wants to deliver the same type of multicast packet as its own station exists in the location registration area of the destination, the mobile station 11 simply makes the above delivery registration request and delivers the desired multicast packet. Can be received. That is, the desired multicast packet has already been delivered in the destination cell.

【0084】

On the other hand, if the mobile station 11 wishing to deliver the same type of multicast packet as the own station does not exist in the location registration area of the destination, the gateway device 16 multicasts to the support device 15 having jurisdiction over the location registration area. Not sending a packet. Therefore, the multicast packet is not delivered to any cell in the location registration area. Therefore, even if the support device 15 accepts the distribution registration from the mobile station 11, the support device 15 cannot distribute the multicast packet corresponding to the distribution request to the mobile station 11.

【0085】

Therefore, in the fifth embodiment, in consideration of such a case, the support device 15 checks the distribution status of the multicast packet so that the multicast packet can be distributed to the mobile station 11.

【0086】

More specifically, when the distribution registration request signal from the mobile station 11 is received (step W1), the support device 15 determines whether or not the multicast packet in response to the request is being distributed. Specifically, the support device 15 confirms the multicast packet requested by the mobile station 11 based on the address data included in the distribution-related data (step W2). Next, the support device 15 determines whether or not the mobile station 11 requesting distribution registration is registered in the distribution registration table 15a (step W3).

【0087】

If it is registered (YES in step W3), it is considered that the mobile station 11 has not moved from another location registration area, but has newly requested distribution registration in the same location registration area. Therefore, in this case, the support device 15 registers the mobile station 11 in the distribution registration table 15a as usual. As a result, the mobile station 11 can receive the multicast packet delivered from the support device 15. On the other hand, if it is not registered (NO in step W3), the support device 15 registers the mobile station 11 requesting distribution registration in the distribution registration table 15a (step W4).

【0088】

Next, the support device 15 determines whether or not the multicast packet corresponding to the distribution registration request is being distributed (step W5). If the multicast packet is delivered (YES in step W5), the support device 15 distributes the distributed multicast packet to the mobile station 11 that has requested the distribution registration, so that the base station controller 14 can distribute the multicast packet. Send to. On the other hand, if the multicast packet has not been delivered (NO in step W5), the support device 15 requests the gateway device 16 to deliver the multicast packet (step W6).

【0089】

When the support device 15 requests distribution, the gateway device 16 duplicates the multicast packet in response to the request and transmits the duplicated multicast packet to the support device 15 that has made the delivery request. As a result, the support device 15 can deliver the multicast packet in response to the request to the mobile station 11 that has requested the delivery registration.

【0090】

As described above, according to the fifth embodiment, when the mobile station 11 requests the distribution registration of the multicast packet, the support device 15 receives the multicast packet from the gateway device 16 only when the multicast packet is not distributed. Is requested from the gateway device 16.

【0091】

Therefore, assuming this case, the processing in the gateway device 16 and the support device 15 can be simplified as compared with the case where the gateway device 16 delivers the multicast packet to all the support devices 15 in advance. Therefore, it is possible to obtain a mobile data communication system with improved processing efficiency.

【0092】

Embodiment 6. FIG. 10 is a flowchart for explaining a process at the time of distribution registration of the support device 15 in the mobile data communication system to which the mobile communication system according to the sixth embodiment of the present invention is applied. In the following description, FIG. 1 will be referred to at the same time.

【0093】

In the sixth embodiment, when the mobile station 11 moves between cells while receiving a multicast packet, the support device 15 and the base station control device 14 perform the distribution registration when the mobile station 11 requests distribution registration. The subscriber line extension control will be described. When the mobile station 11 moves between cells while receiving a multicast packet, it is conceivable to simply set and release the line by handover. However, in this case, since the line is cut off even for a moment, packet loss may occur. Therefore, in the sixth embodiment, the channel switching is realized by the subscriber line extension control in which the line is not interrupted momentarily.

【0094】

More specifically, the mobile station 11 transmits a distribution registration request signal to the base station 13 when moving between cells. The base station 13 transfers the received distribution registration request signal to the base station control device 14. The base station control device 14 transfers the received distribution registration request signal to the support device 15. As a result, the support device 15 receives the distribution registration request signal (step X1).

【0095】

The support device 15 determines whether or not the base station control device 14 that has transmitted the distribution registration request signal is different from the base station control device 14 that has delivered the multicast packet to the mobile station 11 before the movement. (Step X2). If different (NO in step X2), the support device 15 determines whether or not the request is for the same type of multicast packet as the multicast packet delivered from the mobile base station 13 to the mobile station 11. (Step X3). If the multicast packets are of the same type, the support device 15 executes the subscriber line extension control to secure the line (step X4).

【0096】

Specifically, the support device 15 requires the base station control device 14 at the destination to connect a line to the base station control device 14 at the move source. Further, the support device 15 also requests the base station control device 14 of the movement source to connect a line to the base station control device 14 of the movement destination. The two base station control devices 14 requested to connect the line from the support device 15 mutually establish a line according to this request. In this way, the line connection by extending the subscriber line is achieved.

【0097】

On the other hand, when the base station controller 14 that sent the distribution registration request is the same as the base station controller 14 that delivered the multicast packet before the move (NO in step X2), and the multicast requested by the mobile station 11. If the packets are not of the same type, the support device 15 performs a normal handover. That is, a channel is set between the mobile station 11 and the destination base station 13, and the channel set between the mobile station 11 and the mobile source base station is released.

【0098】

As described above, according to the sixth embodiment, since the line connection is made by extending the subscriber line, it is possible to prevent packet loss when moving between cells, unlike the case where the line is set and released only by handover. it can. Therefore, the mobile station 11 can continuously receive the multicast packets. Therefore, the mobile station 11 can receive high-quality distribution data. Therefore, it is possible to provide a mobile data communication system with improved system efficiency.

【0099】

Embodiment 7. FIGS. 11 and 12 are flowcharts for explaining a transmission power control process in a mobile data communication system to which the mobile communication system according to the seventh embodiment of the present invention is applied. In the following description, FIG. 1 will be referred to at the same time.

【0100】

Even if the mobile station 11 is registered for distribution, distribution may not be required. This is determined by the user's will, but in this case, the delivery registration cancellation request is not always made. It is wasteful and inefficient to continue to deliver the multicast packet to the mobile station 11 which does not need to be delivered without the delivery registration being deleted. Therefore, in the seventh embodiment, the ground device 12 side periodically confirms with the mobile station 11 registered for distribution whether or not distribution is necessary.

【0101】

More specifically, the support device 15 periodically transmits a question signal to the base station control device 14 (step Y1 in FIG. 11). The question signal is for confirming whether or not distribution is necessary for the mobile station 11 registered in the distribution registration table 15a. When the base station control device 14 receives the interrogation signal, it transfers the interrogation signal to the base station 13 (step Y2). At this time, the base station control device 14 transmits the power measurement request signal to the base station 13 together with the question signal (step Y2). The power measurement request signal requests the measurement of the power when the response signal to the question signal is received at the base station 13.

【0102】

When the base station 13 receives the interrogation signal and the power measurement request signal, it transmits the interrogation signal out of the two received signals to each mobile station 11 in the cell (step Y3). Upon receiving the interrogation signal, the mobile station 11 transmits a response signal, which is a response to the interrogation signal, to the base station 13 (step Y4).

【0103】

When the base station 13 receives the response signal, it measures the power of the received response signal based on the received power measurement signal previously transmitted from the base station controller 14 (step Y5). After measuring the power, the base station 13 adds the measured power value to the response signal and transmits the response signal to the base station control device 14 (step Y5).

【0104】

The base station control device 14 receives the response signal transmitted from the base station 13. The base station controller 14 then determines whether the response signal is for a question signal for what type of multicast packet (step Y6).

【0105】

As mentioned above, the interrogation signal is transmitted periodically. Therefore, it is not always necessary to return the response signal for the same type of multicast packet to the support device 15, and the response signal for one type of multicast packet is sufficient only once. Therefore, the above-mentioned discrimination processing is performed.

【0106】

If it is a response signal to a previously received type of multicast packet (YES in step Y6), the base station controller 14 does not transmit the response signal to the support device 15. On the other hand, if it is a response signal for the type of multicast packet received for the first time (NO in step Y6), the base station control device 14 transmits the response signal to the support device 15 (step Y7).

【0107】

When the support device 15 receives the response signal, the support device 15 updates the distribution registration status of the distribution registration table 15a according to the response content. Specifically, in the case of a response signal that needs to be distributed, the support device 15 maintains the registration of the mobile station 11. In the case of a response signal that distribution is not necessary, the support device 15 deletes the registration of the mobile station from the distribution registration table 15a.

【0108】

The base station control device 14 also accumulates the received power value included in the response signal for each base station 13 (step Y8 in FIG. 12). The base station control device 14 determines whether or not response signals have been received from all the connected base stations 13 (step Y9). When the response signals are received from all the base stations 13, the base station controller 14 recognizes the lowest received power value among all the received power values (step Y10).

【0109】

After that, the base station control device 14 calculates the power value when the multicast packet is transmitted from the base station 13 based on the minimum received power value (step Y11). Specifically, since the base station control device 14 needs to receive the multicast packet with sufficient received power at the mobile station 11, the base station control device 14 calculates the transmission power value at which the minimum received power value is a predetermined received power value.

【0110】

After that, the base station controller 14 notifies all connected base stations 13 to deliver the multicast packet with the calculated transmission power value (step Y12). Upon receiving this notification, the base station 13 delivers the multicast packet with the above transmission power value.

【0111】

As described above, according to the seventh embodiment, the base station control device 14 collects the received power value in the base station 13 when confirming the necessity of distribution, and among the collected received power values. The transmission power of the base station 13 is controlled according to the minimum received power value. Therefore, all the mobile stations 11 existing in the jurisdiction area of the base station control device 14 can receive the multicast packet with sufficient received power. Therefore, high-quality multicast packet transmission can be realized. Therefore, it is possible to provide a mobile data communication system with improved system efficiency.

【0112】

Other Embodiments. The seven embodiments of the present invention have been described above. However, it goes without saying that the present invention may adopt other embodiments. For example, in the above-described first to seventh embodiments, a case where an IP packet communication system is applied as a connectionless packet communication system is described as an example. However, the present invention can be easily applied to other connectionless packet communication systems such as CLNP (Connection-Less Network Protocol) type packet communication systems.

【0113】

[Effect of the invention]

As described above, according to the present invention, when the multicast packet communication in the connectionless packet communication system is applied to the mobile communication system, the multicast packet is duplicated in the relay connection device. Therefore, in the connectionless packet communication system, even if there are a plurality of distribution destination mobile stations, only one multicast packet needs to be transmitted. Moreover, only one multicast packet needs to be transmitted between the gateway device and the relay connection device. Therefore, the multicast packet can be transmitted more efficiently than the case where the multicast packet is duplicated and transmitted in the connectionless packet communication system. Therefore, the system efficiency can be improved.

【0114】

Further, according to the present invention, when moving with a change in a service area such as a cell and a location registration area, the mobile station makes a distribution request for a multicast packet together with a location registration request or a handover request via a control channel. I am trying to do it. Therefore, the multicast packet can be transmitted to the mobile station more quickly than when the packet delivery request is made via the communication channel. In other words, the mobile station can receive the multicast packet quickly.

【0115】

More specifically, when a packet delivery request is made via a communication channel, the communication channel cannot be used for packet transmission, so it is necessary to make the packet transmission wait. However, by making the packet delivery request via the control channel instead of the communication channel, the packet transmission can be made without waiting for the packet delivery request. Therefore, the packet can be efficiently transmitted, and the mobile station can efficiently receive the packet.

【0116】

Further, according to the present invention, when the mobile station moves with the change of the service area cell, the base station concerned is limited to the case where the desired multicast packet is not delivered from the base station forming the cell immediately after the change. Request delivery registration. That is, when the multicast packet of the group in which the own station exists is delivered from the base station forming the cell immediately after the change, the multicast packet can be received. Therefore, the mobile station can receive the multicast packet without registering for distribution each time it moves. That is, in the mobile station, the efficiency of the distribution registration request can be improved. Therefore, useless signal processing in the mobile communication system can be omitted as compared with the case where distribution registration is requested every time the cell in the service area is changed. Therefore, it is possible to provide a system in which the efficiency of signal processing is improved.

【0117】

In the mobile communication system, when the mobile station moves with the change of the service area cell, so-called handover processing is performed. By executing this handover process, the base station can know that the mobile station has newly moved to the cell formed by the base station.

【0118】

Furthermore, according to the present invention, the multicast packet is delivered only to the relay connection device having jurisdiction over the area where the mobile station desired to be delivered exists. Therefore, the gateway device does not transmit the multicast packet to the relay connection device that does not need to be delivered. Therefore, the packet transmission efficiency can be improved. Therefore, the system efficiency can be improved.

【0119】

Further, according to the present invention, since the radio resource information is assigned to a plurality of mobile stations in common, the radio resources can be effectively used as compared with the case where the radio resource information unique to one mobile station is assigned. .. Therefore, it is possible to provide a mobile communication system with improved system efficiency.

【0120】

Furthermore, according to the present invention, when the mobile station changes the jurisdiction area of the base station control device, the line is secured by the subscriber line extension control. Therefore, even if the mobile station changes the jurisdiction area during communication, the line connection state is not interrupted. Therefore, even if the jurisdiction area is changed when the mobile station is receiving the multicast packet, the occurrence of packet loss can be prevented. Therefore, the communication quality can be improved.

【0121】

Further, according to the present invention, the base station control device can confirm the necessity of delivering the multicast packet of the mobile station. At the same time, transmission power control can be performed. Therefore, the mobile station can receive radio waves with sufficient power. Therefore, high quality communication can be realized. Therefore, the efficiency of the mobile data communication system can be improved.

[Simple explanation of drawings]

[Figure 1]

It is a block diagram which shows the structure of the mobile data communication system to which the mobile communication system which concerns on Embodiment 1 of this invention is applied.

[Figure 2]

It is a flowchart which shows the processing of a support device.

[Fig. 3]

It is a flowchart for demonstrating the distribution registration request processing of the mobile station in the mobile data communication system to which the mobile communication system which concerns on Embodiment 2 of this invention is applied.

[Fig. 4]

It is a conceptual diagram which shows the structure of the handover request signal.

[Fig. 5]

It is a flowchart for demonstrating the distribution registration request processing of the base station control apparatus in the mobile data communication system to which the mobile communication system which concerns on Embodiment 3 of this invention is applied.

[Fig. 6]

It is a conceptual diagram which shows the structure of the position registration request signal.

[Fig. 7]

It is a flowchart for demonstrating the distribution registration request processing of the mobile station in the mobile data communication system to which the mobile communication system which concerns on Embodiment 4 of this invention is applied.

[Fig. 8]

It is a conceptual diagram which shows the structure of the broadcast information signal.

[Fig. 9]

It is a flowchart for demonstrating the process at the time of distribution registration of the support apparatus in the mobile data communication system to which the mobile communication system which concerns on Embodiment 5 of this invention is applied.

[Fig. 10]

It is a flowchart for demonstrating the process at the time of distribution registration of the support apparatus in the mobile data communication system to which the mobile communication system which concerns on Embodiment 6 of this invention is applied.

[Fig. 11]

It is a flowchart for demonstrating transmission power control processing in the mobile data communication system to which the mobile communication system which concerns on Embodiment 7 of this invention is applied.

[Fig. 12]

It is a flowchart for demonstrating the transmission power control processing in the mobile data communication system to which the mobile communication system which concerns on Embodiment 7 of this invention is applied, and shows the continuation processing of FIG.

[Explanation of symbols]

1 IP packet communication system 2 IP terminal 10 Mobile communication system 11 Mobile station 12 Ground equipment 13 base station 14 Base station controller 15 Support device 16 Gateway device