MOBILE COMMUNICATION SYSTEM

• US 20100272004A1
• Filed: 12/12/2008
• Published: 10/28/2010
• Est. Priority Date: 12/17/2007
• Status: Active Grant

• Current Assignee: Miics&Partners Japan Company Limited
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Mochizuki, Mituru, Maeda, Miho, Iwane, Yasushi, Saegusa, Taiga
• Granted Patent: US 8,811,252 B2
• Time in Patent Office: Days
• US Class Current: 370/312
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 65/611 for multicast or broadcast systems for broadcast or conference H04L12/18; arrangements for broadcast or distribution combined with broadcast H04H20/00; arrangements for broadcast applications with a direct linkage to broadcast information or to broadcast space-time H04H60/00; selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS], H04W4/06
• CPC Class Codes: H04W 48/12 using downlink control channel
• CPC Class Codes: H04W 68/12 Inter-network notification
• CPC Class Codes: H04W 72/0466 the resource being a scrambling code
• CPC Class Codes: H04W 72/30 Resource management for broadcast services

Abstract

A communication system has three types of cells including, in addition to an MBMS dedicated cell, a unicast cell to and from which a mobile terminal can transmit and receive individual communication data, and a unicast/MBMS-mixed cell which can provide both a service provided by the unicast cell and a service provided by the MBMS dedicated cell. While receiving the broadcast type data transmitted from the MBMS dedicated cell, the mobile terminal makes a notification of an MBMS receiving state via the unicast cell or the unicast/MBMS-mixed cell to transmit information for identifying the MBMS dedicated cell, and the communication system transmits a paging signal to the mobile terminal currently receiving the broadcast type data transmitted from the MBMS dedicated cell on the basis of a tracking area (Tracking Area) in which the mobile terminal is tracked, the tracking area being determined on the basis of the information transmitted.

Claims

1. A communication system which uses an OFDM (Orthogonal Frequency Division Multiplexing) method as a downlink access method, and also uses an SC-FDMA (Single Career Frequency Division Multiple Access) method as an uplink access method, and which can transmit broadcast type data for providing an MBMS (Multimedia Broadcast Multicast Service) which is a point-to-multipoint broadcast communication service to a mobile terminal and can also transmit point-to-point dedicated communication data to said mobile terminal,

wherein said communication system has three types of cells including a unicast cell to and from which a mobile terminal can transmit and receive said dedicated communication data, an MBMS dedicated cell from which said mobile terminal can receive said broadcast type data, but to and from which said mobile terminal cannot transmit and receive said dedicated communication data, and a unicast/MBMS-mixed cell which can provide both a service provided by said unicast cell and a service provided by said MBMS dedicated cell, and

while receiving said broadcast type data transmitted from said MBMS dedicated cell, said mobile terminal makes a notification of an MBMS receiving state via said unicast cell or said unicast/MBMS-mixed cell to transmit information for identifying said MBMS dedicated cell which is transmitting said broadcast type data which said mobile terminal is receiving, and said communication system transmits a paging signal destined for said mobile terminal currently receiving said broadcast type data transmitted from said MBMS dedicated cell on a basis of a tracking area (Tracking Area) in which said mobile terminal is tracked, the tracking area being determined on a basis of the information transmitted from said mobile terminal.

2. The mobile communication system according to claim 1, wherein the paging signal is transmitted via a multicast control channel which is provided in a downlink direction from a base station to the mobile terminal in the MBMS dedicated cell, and which is used to transmit control information for controlling a receiving process of said mobile terminal.

3. The communication system according to claim 2, wherein the multicast control channel includes an indicator for making a distinction between presence and absence of the paging signal, and an indicator for making a distinction between presence and absence of the control information.

4. A communication system which uses an OFDM (Orthogonal Frequency Division Multiplexing) method as a downlink access method, and also uses an SC-FDMA (Single Career Frequency Division Multiple Access) method as an uplink access method, and which can transmit broadcast type data for providing an MBMS (Multimedia Broadcast Multicast Service) which is a point-to-multipoint broadcast communication service to a mobile terminal and can also transmit point-to-point dedicated communication data to said mobile terminal, wherein

said communication system has an MBSFN (Multimedia Broadcast multicast service Single Frequency Network) synchronization area comprised of a plurality of MBMS dedicated cells from each of which said mobile terminal can receive said broadcast type data, but to and from each of which said mobile terminal cannot transmit and receive said dedicated communication data, the plurality of MBMS dedicated cells being synchronized with one another at a single frequency, and

an MBMS dedicated cell which constructs the MBSFN synchronization area discontinues transmission of MBMS data to said mobile terminal during a predetermined time period to provide a reception discontinuous time period during which said mobile terminal does not receive said MBMS data.

5. The communication system according to claim 4, wherein said communication system further has a unicast cell to and from which the mobile terminal can transmit and receive said dedicated communication data, and a unicast/MBMS-mixed cell which can provide both a service provided by said unicast cell and a service provided by said MBMS dedicated cell, and the mobile terminal which is using an MBMS service in the MBMS transmission dedicated cell carries out a process of measuring said unicast cell and said unicast/MBMS mixed cell during the reception discontinuous time period in order to carry out a location registration process and a cell selection process.

6. The communication system according to claim 5, wherein the reception discontinuous time period has a length which is equal to a minimum of that of each of periods at which the mobile terminal carries out the process of measuring the unicast cell and the unicast/MBMS mixed cell, or a common factor of the minimum.