Cellular mobile communication system having adjacent base stations each using same frequency for communication between base station and mobile terminals

• US 7,756,076 B2
• Filed: 05/05/2006
• Issued: 07/13/2010
• Est. Priority Date: 01/31/2006
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Nakano, Hiroyuki
• Primary Examiner(s): Pérez-Gutiérrez; Rafael
• Assistant Examiner(s): VIANA DI PRISCO, GERMAN
• Application Number:
  US11/429,002
• Publication Number:
  US 20070177539A1
• Time in Patent Office: 1,530 Days
• Field of Search: 370/328
• US Class Current: 370/328
• CPC Class Codes: H04W 16/30 Special cell shapes, e.g. doughnuts or ring cells
• CPC Class Codes: H04W 52/18 TPC being performed according to specific parameters
• CPC Class Codes: H04W 74/06 using polling

Abstract

The invention provides a cellular mobile communication system that efficiently performs high-speed communication with mobile terminals within the cell using a single frequency. The mobile communication system sequentially performs polling communication control to plural terminals within the own cell, based on a control of a base station positioned near the center of the cell. With this arrangement, the terminals within the cell can communicate with each other using a single frequency.

Claims

1. A cellular mobile communication method that sequentially performs polling communication control to a plurality of terminals within a cell, based on a control of a base station positioned near a center of the cell, thereby making it possible to communicate between the terminals using a single frequency, wherein

the base station generates a terminal attribute information table by obtaining terminal attribute information, including at least, a terminal name, reception power, a delay time and a reception direction therein, from the terminals at a start of communication, and sequentially performs the polling communication control of the terminals, starting from a terminal positioned nearest to the base station and ending with terminals positioned far from the base station,

the base station uses the table and classifies an area of the cell, in which terminals are present, into three concentric areas including a first area that is nearest to the base station, a second area that is farther from the base station, and a third area that is furthest from the base station and is located at an edge of the cell, and

each of other base stations of adjacent three cells sequentially increases transmission power from a center of a corresponding own cell towards an edge of said corresponding own cell, by shifting a phase by 120 degrees, synchronously with other cells, through communications between the base stations.

2. The cellular mobile communication method according to claim 1, wherein

the base station provides a first threshold value in a boundary between the first area and the second area, provides a second threshold value in a boundary between the second area and the third area, and

performs a communication start terminal control for increasing the transmission power in the adjacent three cells, by using pointers indicating a start point of the first area or the first or the second threshold value.

3. The cellular mobile communication method according to claim 2, wherein

when a number of terminals within the third area exceeds a predetermined number, the base station limits only one cell to be engaged among the adjacent three cells, in which one cell, the number of terminals within the third area exceeds the predetermined number.

4. A base station for communicating with mobile terminals within one cell of a cellular mobile communication system organised as a plurality of mutually-adjacent cells, each of the cells being classified into three concentric areas including a first area that is nearest to the base station, a second area that is farther from the base station, and a third area that is furthest from the base station and is located at an edge of the one cell, and each of other base stations of adjacent three cells sequentially increasing transmission power from a center of a corresponding own cell towards an edge of said corresponding own cell, by shifting a phase by 120 degrees, synchronously with other cells, through communications between the base stations, the base station comprising:

a first unit configured to communicate with each of the mobile terminals within the one cell;

a second unit configured to classify the mobile terminals in terms of their distance from the base station by detecting signals received from each mobile terminal; and

a third unit configured to coordinate with another base station in an adjacent cell to synchronize operations with the other base station;

wherein the base station is arranged to communicate with the mobile terminals classified as relatively distant from the base station at a same time as the other base station in the adjacent cell communicates with mobile terminals which are classified as relatively close to the other base station.

5. The base station of claim 4, wherein said second unit is operable to place the mobile terminals within the one cell in one of at least two classifications based on a threshold value of a received signal.

6. The base station of claim 5, wherein there are three classifications and said third unit is arranged to synchronize operations with other base stations in two adjacent cells so that communications with mobile terminals in respectively different ones of the three classifications are synchronized among the one cell and the two adjacent cells.