System for mutual synchronization and monitoring between base stations

• US 5,448,570 A
• Filed: 03/16/1994
• Issued: 09/05/1995
• Est. Priority Date: 03/17/1993
• Status: Expired due to Term

• Current Assignee: Kyocera Corporation
• Original Assignee: Kyocera Corporation
• Inventors: Yuda, Tetsuya, Toda, Yasushi
• Primary Examiner(s): Safourek, Benedict V.
• Application Number:
  US08/213,979
• Time in Patent Office: 538 Days
• Field of Search: 455/33.1, 455/49.1, 455/50.1, 455/51.1, 379/63, 371/42, 371/47.1, 370/29, 370/95.3, 370/103, 370/105.3, 307/107, 307/109, 340/825.2, 340/825.21
• US Class Current: 370/337
• CPC Class Codes: H04B 7/269 Master/slave synchronisation
• CPC Class Codes: H04J 3/0641 Change of the master or reference, e.g. take-over or failure of the master
• CPC Class Codes: H04J 3/0679 by determining clock distribution path in a network

Abstract

A communication system that performs time-division multiple access mobile communication using radio in a service area in which are disposed a plurality of base stations connected to a central station through a communication network. The central station selects and designates a master base station and a selected base station close to the master base station. The central station instructs the selected base station to synchronize a radio signal transmitted by the selected base station with a radio signal transmitted by the master base station. The central station further selects at least one additional base station close to the selected base station. The central station instructs the at least one additional base station to synchronize a radio signal transmitted by the additional base station with a radio signal transmitted by the selected base station. The process is repeated until all of the base stations are transmitting a synchronized radio wave. The central station also sequentially designates base stations to monitor each other, and further gives each base station criteria for judging an abnormality, thereby establishing a monitoring network.

Claims

1. A method of establishing mutual synchronization among base stations in a communication system that performs time-division multiple access mobile communication using radio in a service area in which are disposed a plurality of base stations that are connected to a communication network containing a central station that effects multiple-unit control, the method comprising:

(A) providing each of the plurality of base stations with transmission means for transmitting a radio signal, reception means for receiving a radio signal, synchronization means for controlling synchronization of a radio signal, and communication means for communicating with the central station,

(B) selecting, via the central station, one base station from among the plurality of base stations and designating the selected base station as a master base station,

(C) selecting, via the central station, at least one other base station from among the plurality of base stations and designating the selected base station as a selected base station, the selected base station being relatively closer to the master base station than any of the other base stations,

(D) instructing, via the central station, the synchronization means of the selected base station to synchronize a radio signal transmitted by the selected base station with a radio signal transmitted by the master base station and to thereby transmit a synchronized radio wave,

(E) selecting, via the central station, at least one additional base station from among the plurality of base stations, the at least one additional base station being relatively closer to the selected base station than any of the other base stations,

(F) instructing, via the central station, the synchronization means of the at least one additional base station to synchronize a radio signal transmitted by the additional base station with a radio signal transmitted by the selected base station and to thereby transmit a synchronized radio wave, and

(G) repeating steps (C) through (F) until substantially all of the plurality of base stations are transmitting a synchronized radio wave.

2. A method for effecting mutual monitoring among base stations in a communication system that performs time division multiple access mobile communication using radio in a service area in which are disposed a plurality of base stations which are connected to a communication network containing a central station that effects multiple-unit control, the method comprising:

providing each of the plurality of base stations with transmission means for transmitting a radio signal and communication means for communicating with the central station,

establishing a monitoring network by directing the central station to sequentially designate at least a first one of the plurality of base stations in the service area to monitor at least a second one of the base stations in the service area through the communication network,

providing, via the central station, each one of the plurality of base stations with a reference incoming level and a reference error generation rate as criteria for determining abnormality,

using the first base station to receive a radio signal from the second base station to thereby obtain an incoming level and an error generation rate,

informing the central station of an occurrence of an abnormality through the communication network when the incoming level and the error generation rate received by the first base station does not conform to at least one of the reference incoming level and the reference error generation rate, and

identifying, via the central station, an abnormal base station and a cause of failure based upon a comprehensive review of information received by the central station from all of the base stations.