Mobile communication system, radio base station, mobile terminal and delivery method

• US 20070171865A1
• Filed: 01/18/2007
• Published: 07/26/2007
• Est. Priority Date: 01/20/2006
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Kato, Shugo
• Granted Patent: US 7,710,917 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04L 12/185 with management of multicast group membership
• CPC Class Codes: H04L 12/189 in combination with wireless systems selective distribution or broadcast in wireless communication networks H04W4/06
• CPC Class Codes: H04L 45/16 Multipoint routing
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
• CPC Class Codes: H04W 72/30 Resource management for broadcast services

Abstract

A mobile communication system uses efficiently a radio band of a previously-connected base station, when a mobile terminal that executes multicast communication moves among radio base stations. The mobile communication system includes a layer-2 switch. Upon switching from one radio base station over to the other radio base station, the mobile terminal transmits a path formation request related to a multicast group via the connected radio base station. The path formation request reaches the wired port of the one radio base station through the layer-2 switch. Here, “leave” of the mobile terminal from the control of the one radio base station is detected, and the delivery of multicast is halted. The other radio base station, on the other hand, starts delivering the multicast.

Claims

1. A mobile communication system comprising:

a relay device capable of delivering data signals that are received to a network under control in response to data signals addressed to a predetermined multicast group transmitted from a transmitter, and of delivering various kinds of requests received from the network under control to a transmitter side and to the network under control;

a plurality of radio base stations connected to the relay device, and capable of delivering the data signals delivered from the relay device to the radio network under control; and

a mobile terminal that receives the data signals delivered from the radio base station, the mobile terminal including path formation request transmission means for transmitting a path formation request which includes group identification data for identifying a predetermined multicast group at the time of taking part in the predetermined multicast group and at the time of switching over a radio base station to which it is connected while receiving data signals transmitted being addressed to the predetermined multicast group, the path formation request further requesting formation of a path for receiving the delivery of the data signals,

wherein each of the radio base stations includes,

first request detection means for detecting various kinds of requests inclusive of the path formation request transmitted from the mobile terminal present under its control,

various-requests transmission means for transmitting various kinds of requests detected by the first request detection means to the relay device,

second request detection means for detecting various kinds of requests delivered from various-requests transmission means in another radio base station,

multicast delivery table managing means which registers the group identification data included in the path formation request to a multicast delivery table thereof when the first request detection means detects the path formation request transmitted from the mobile terminal present under its control, and deletes the group identification data included in the path formation request from the multicast delivery table thereof when the second request detection means detects the path formation request transmitted from the various-requests transmission means in the another radio base station, and

transmission control means which transmits a multicast packet received from the relay device to the radio network under its control only when the multicast packet received from the relay device is a multicast packet addressed to the multicast group which is the same as the multicast group registered to the multicast delivery table thereof as the group identification data.

4. The mobile communication system according to claim 1,

wherein each of the radio base stations include “

leave”

detection means for detecting the “

leave”

of the mobile terminal from its control based on connection strength to the mobile terminal, and

wherein the multicast delivery table managing means deletes, from the multicast delivery table thereof, the group identification data corresponding to the multicast group to which the mobile terminal is belonging when the “

leave”

detection means has detected the “

leave”

of the mobile terminal from its control.

5. The mobile communication system according to claim 1,

wherein the mobile terminal includes “

leave”

request transmission means for transmitting the “

leave”

request that includes group identification data corresponding to the multicast group to which the mobile terminal belongs and requests the “

leave”

from the multicast group based on an external instruction, and

wherein the multicast delivery table managing means in the radio base station deletes, from the multicast delivery table thereof, the group identification data included in the “

leave”

request even when the first request detection means has received the “

leave”

request transmitted from the mobile terminal present under its control.

6. The mobile communication system according to claim 1,

wherein the relay device includes a plurality of relay means connected in a tree form.

2. A mobile communication system comprising:

a relay device capable of delivering data signals that are received to a network under control in response to data signals addressed to a predetermined multicast group transmitted from a transmitter, and of delivering various kinds of requests received from the network under control to a transmitter side and to the network under control;

a plurality of radio base stations connected to the relay device, and capable of delivering the data signals delivered from the relay device to the radio network under control; and

a mobile terminal that receives the data signals delivered from the radio base station,

wherein the mobile terminal includes

path formation request transmission means for transmitting a path formation request which includes group identification data for identifying a predetermined multicast group at the time of taking part in the predetermined multicast group and at the time of switching over a radio base station to which it is connected while receiving data signals transmitted being addressed to the predetermined multicast group, the path formation request further requesting formation of a path for receiving the delivery of the data signals, and

departure notice transmission means which, at the time of switching over the radio base station to the another radio base station, transmits a departure notice expressing “

leave”

to the radio base station via the another radio base station which is connected after having been switched over, and

wherein each of the radio base stations includes,

first request detection means for detecting various kinds of requests inclusive of the path formation request and departure notice, and transmitted from the mobile terminal present under its control,

various-requests transmission means for transmitting various kinds of requests detected by the first request detection means to the relay device,

second request detection means for detecting various kinds of requests delivered from various-requests transmission means in another radio base station,

multicast delivery table managing means which registers the group identification data included in the path formation request to a multicast delivery table thereof when the first request detection means detects the path formation request transmitted from the mobile terminal present under its control, and deletes the group identification data included in the path formation request from the multicast delivery table thereof when the second request detection means detects the departure notice addressed thereto transmitted from the another radio base station, and

transmission control means which transmits a multicast packet received from the relay device to the radio network under its control only when the multicast packet received from the relay device is a multicast packet addressed to the multicast group which is the same as the multicast group registered to the multicast delivery table thereof as the group identification data.

3. The mobile communication system according to claim 2,

wherein the relay device includes

a multicast router capable of delivering the data signals that are received to the network under control in response to data signals addressed to the predetermined multicast group transmitted from the transmitter when the mobile terminal belonging to the multicast group is present under its control, and of transmitting the path formation request received through the network under control to a unit only that is connected to the transmitter side and of transmitting the departure notice that is received to a previously-connected radio base station;

and

a layer-2 switch arranged downstream of the multicast router and is capable of transmitting the data signals received via the multicast router to the network under control and of delivering the various requests received from the network under control to the transmitter side and to the network under control.

7. A base station for a mobile communication system, the mobile communication system including

a relay device capable of delivering data signals that are received to a network under control in response to data signals addressed to a predetermined multicast group transmitted from a transmitter, and of delivering various kinds of requests received from the network under control to a transmitter side and to the network under control,

a radio base station connected to the relay device, and capable of delivering the data signals delivered from the relay device to the radio network under control, and

a mobile terminal that receives the data signals delivered from the radio base station, and transmits a path formation request which includes group identification data for identifying a predetermined multicast group at the time of taking part in the predetermined multicast group and at the time of switching over a radio base station to which it is connected while receiving data signals transmitted being addressed to the predetermined multicast group, the path formation request further requesting formation of a path for receiving the delivery of the data signals,

the base station comprising:

first request detection means for detecting various kinds of requests inclusive of the path formation request transmitted from the mobile terminal present under its control;

various-requests transmission means for transmitting various kinds of requests detected by the first request detection means to the relay device;

second request detection means for detecting various kinds of requests delivered from various-requests transmission means in another radio base station;

multicast delivery table managing means which registers the group identification data included in the path formation request to a multicast delivery table thereof when the first request detection means detects the path formation request transmitted from the mobile terminal present under its control, and deletes the group identification data included in the path formation request from the multicast delivery table thereof when the second request detection means detects the path formation request transmitted from the various-requests transmission means in the another radio base station; and

transmission control means which transmits a multicast packet received from the relay device to the radio network under its control only when the multicast packet received from the relay device is a multicast packet addressed to the multicast group which is the same as the multicast group registered to the multicast delivery table thereof as the group identification data.

8. A radio base station for a mobile communication system, the mobile communication system including

a relay device capable of delivering data signals that are received to a network under control in response to data signals addressed to a predetermined multicast group transmitted from a transmitter, and of delivering various kinds of requests received from the network under control to a transmitter side and to the network under control,

a radio base station connected to the relay device, and capable of delivering the data signals delivered from the relay device to the radio network under control, and

a mobile terminal that receives the data signals delivered from the radio base station, transmits a path formation request which includes group identification data for identifying a predetermined multicast group at the time of taking part in the predetermined multicast group and at the time of switching over a radio base station to which it is connected while receiving data signals transmitted being addressed to the predetermined multicast group, the path formation request further requesting formation of a path for receiving the delivery of the data signals, and, at the time of switching over the radio base station to the another radio base station, transmits a departure notice expressing “

leave”

to the radio base station via the another radio base station which is connected after having been switched over,

the radio base station comprising;

first request detection means for detecting various kinds of requests inclusive of the path formation request and departure notice, and transmitted from the mobile terminal present under its control;

various-requests transmission means for transmitting various kinds of requests detected by the first request detection means to the relay device;

second request detection means for detecting various kinds of requests delivered from various-requests transmission means in another radio base station;

multicast delivery table managing means which registers the group identification data included in the path formation request to a multicast delivery table thereof when the first request detection means detects the path formation request transmitted from the mobile terminal present under its control, and deletes the group identification data included in the path formation request from the multicast delivery table thereof when the second request detection means detects the departure notice addressed thereto transmitted from the another radio base station; and

transmission control means which transmits a multicast packet received from the relay device to the radio network under its control only when the multicast packet received from the relay device is a multicast packet addressed to the multicast group which is the same as the multicast group registered to the multicast delivery table thereof as the group identification data.

9. The radio base station according to claim 8, further comprising:

“

leave”

detection means for detecting the “

leave”

of the mobile terminal from its control based on connection strength to the mobile terminal,

wherein the multicast delivery table managing means deletes, from the multicast delivery table thereof, the group identification data corresponding to the multicast group to which the mobile terminal is belonging when the “

leave”

detection means has detected the “

leave”

of the mobile terminal from its control.

10. A mobile terminal for a mobile communication system, the mobile communication system including

a relay device capable of delivering data signals that are received to a network under control in response to the data signals addressed to a predetermined multicast group transmitted from a transmitter, and of delivering various kinds of requests received from the network under control to the transmitter side and to the network under control,

a plurality of radio base stations connected to the relay device, to transmit various requests to the relay device when various requests from the network under control are detected, the various requests including group identification data for identifying the predetermined multicast group;

to register the group identification data included in the path formation request to the multicast delivery table thereof when the path formation request is detected requesting the formation of a path for receiving the delivery of the data signals, the group identification data including the group identification data corresponding to the multicast group to which it belongs transmitted from the transmitter side;

to delete the group identification data included in the notice or in the request from the multicast delivery table thereof when the departure notice is detected representing the “

leave”

of the mobile terminal from the under its control or when the “

leave”

request is detected requesting the “

leave”

from the multicast group to which it belongs; and

to transmit the multicast packet received from the relay device to the radio networks under its control only when the multicast packet received from the relay device is a multicast packet addressed to the multicast group which is the same as the multicast group that is registered in the multicast delivery table thereof as the group identification data, and

a mobile terminal for receiving data signals delivered from any one of the radio base stations;

the mobile terminal comprising;

path formation request transmission means for transmitting the path formation request at the time of taking part in the predetermined multicast group and at the time of switching over the radio base station to which it is connected while receiving data signals transmitted being addressed to the predetermined multicast group;

departure notice transmission means for transmitting the departure notice to the previously-connected base station via the radio base station connected after having been switched over at the time of switching over the radio base station to which it is connected; and

“

leave”

request transmission means for transmitting the “

leave”

request based on an external instruction.

11. A delivery method of a base station in a mobile communication system, the mobile communication system including

a relay device capable of delivering data signals that are received to a network under control in response to data signals addressed to a predetermined multicast group transmitted from a transmitter, and of delivering various kinds of requests received from the network under control to a transmitter side and to the network under control,

a radio base station connected to the relay device, and capable of delivering the data signals delivered from the relay device to the radio network under control, and

a mobile terminal that receives the data signals delivered from the radio base station, and transmits a path formation request which includes group identification data for identifying a predetermined multicast group at the time of taking part in the predetermined multicast group and at the time of switching over a radio base station to which it is connected while receiving data signals transmitted being addressed to the predetermined multicast group, the path formation request further requesting formation of a path for receiving the delivery of the data signals,

the delivery method comprising:

first request detection step for detecting various kinds of requests inclusive of the path formation request transmitted from the mobile terminal present under its control;

various-requests transmission step for transmitting various kinds of requests detected by the first request detection step to the relay device;

second request detection step for detecting various kinds of requests delivered from another radio base station;

multicast delivery table managing step for registering the group identification data included in the path formation request to a multicast delivery table thereof when the first request detection step detects the path formation request transmitted from the mobile terminal present under its control, and for deleting the group identification data included in the path formation request from the multicast delivery table thereof when the second request detection step detects the path formation request transmitted from the another radio base station; and

transmission control step for transmitting a multicast packet received from the relay device to the radio network under its control only when the multicast packet received from the relay device is a multicast packet addressed to the multicast group which is the same as the multicast group registered to the multicast delivery table thereof as the group identification data.

12. A delivery method of a radio base station in a mobile communication system, the mobile communication system including

a relay device capable of delivering data signals that are received to a network under control in response to data signals addressed to a predetermined multicast group transmitted from a transmitter, and of delivering various kinds of requests received from the network under control to a transmitter side and to the network under control,

a radio base station connected to the relay device, and capable of delivering the data signals delivered from the relay device to the radio network under control, and

a mobile terminal that receives the data signals delivered from the radio base station, transmits a path formation request which includes group identification data for identifying a predetermined multicast group at the time of taking part in the predetermined multicast group and at the time of switching over a radio base station to which it is connected while receiving data signals transmitted being addressed to the predetermined multicast group, the path formation request further requesting formation of a path for receiving the delivery of the data signals, and, at the time of switching over the radio base station to the another radio base station, transmits a departure notice expressing “

leave”

to the radio base station via the another radio base station which is connected after having been switched over,

the delivery method comprising;

first request detection step for detecting various kinds of requests inclusive of the path formation request and departure notice, and transmitted from the mobile terminal present under its control;

various-requests transmission step for transmitting various kinds of requests detected by the first request detection step to the relay device;

second request detection step for detecting various kinds of requests delivered from another radio base station;

multicast delivery table managing step for registering the group identification data included in the path formation request to a multicast delivery table thereof when the first request detection step detects the path formation request transmitted from the mobile terminal present under its control, and for deleting the group identification data included in the path formation request from the multicast delivery table thereof when the second request detection step detects the departure notice addressed thereto transmitted from the another radio base station; and

transmission control step for transmitting a multicast packet received from the relay device to the radio network under its control only when the multicast packet received from the relay device is a multicast packet addressed to the multicast group which is the same as the multicast group registered to the multicast delivery table thereof as the group identification data.

13. The delivery method according to claim 12, further comprising:

“

leave”

detection step for detecting the “

leave”

of the mobile terminal from its control based on connection strength to the mobile terminal,

wherein the multicast delivery table managing step deletes, from the multicast delivery table thereof, the group identification data corresponding to the multicast group to which the mobile terminal is belonging when the “

leave”

detection means has detected the “

leave”

of the mobile terminal from its control.