US 6,311,065 B1Granted

Mobile communication system for predicting a transfer location of a mobile station

AssigneeFujitsu Limited

InventorsKazumasa Ushiki, Mitsunori Fukazawa

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Abstract

A mobile communication system which performs a handover operation with high-reliability, while the system can flexibly cope with various circumstances in which a mobile station is used, without changing a hardware structure. A plurality of radio base stations form respective radio communication cells. Each of the radio base stations performs a radio channel setting control including a handover with respect to a call originated for the mobile station located in one of the cells. An exchange is connected to each of the radio base stations via a communication link so that the exchange performs a call process of the call in association with the radio channel setting control performed by the radio base stations. After the call becomes a completed call and prior to a handover operation, a movement of the mobile station from one of the cells in which the mobile station is located to another one of the cells adjacent to the one of the cells is predicted based on at least one of procedures of the radio channel setting control and the call process. When the movement is predicted so as to select candidate cells which are candidates of a transferee of the completed call, a free radio channel of the cells is acquired. A path connected to the acquired free radio channel is formed in the communication link.

Claims63

Dependent claims

A mobile communication system comprising:

a plurality of radio base stations forming respective radio communication zones according to one of a small zone structure and a sector structure, each of said radio base stations performing a radio channel setting control including a handover with respect to a call originated for a mobile station located in one of said radio communication zones;
and
an exchange connected to each of said radio base stations via a communication link so that said exchange performs a call process of said call in association with the radio channel setting control performed by said radio base stations,
said mobile communication system further comprising:
a movement predicting unit which predicts, after said call becomes a completed call and prior to a handover operation, a movement of said mobile station from one of said radio communication zones in which said mobile station is located to another one of said communication zones adjacent to said one of said radio communication zones, a prediction of said movement being performed based on at least one of procedures of the radio channel setting control and the call process;
a candidate zone selecting unit which is activated when said movement is predicted by said movement predicting unit so as to select candidate radio communication zones which are candidates for transferring said completed call to, based on said predicted movement, said candidate zone selecting unit forming a communication path to said candidate radio communication zones, said communication path to be connected to a radio channel in said communication link prior to initiation of a handover to a radio communication zone from among said candidate radio communication zones, wherein an asynchronous transfer mode is applied to said communication link, and said candidate zone selecting unit logically forms a path without occupying a transmission band of said communication link,
wherein said radio base station and said exchange include means for acquiring a transmission band of a path formed by said candidate zone selecting unit with respect to the candidate radio communication zone which corresponds to a radio communication zone selected for handover of the completed call based on procedures of the radio channel setting control and the call process.

4 more elements

A mobile communication system comprising:

a plurality of radio base stations forming respective radio communication zones according to one of a small zone structure and a sector structure, each of said radio base stations performing a radio channel setting control including a handover with respect to a call originated for a mobile station located in one of said radio communication zones;
and
an exchange connected to each of said radio base stations via a communication link so that said exchange performs a call process of said call in association with the radio channel setting control performed by said radio base stations,
said mobile communication system further comprising:
a movement predicting unit which predicts, after said call becomes a completed call and prior to a handover operation, a movement of said mobile station from one of said radio communication zones in which said mobile station is located to another one of said communication zones adjacent to said one of said radio communication zones, a prediction of said movement being performed based on at least one of procedures of the radio channel setting control and the call process;
and
a candidate zone selecting unit which is activated when said movement is predicted by said movement predicting unit so as to select candidate radio communication zones which are candidates for transferring said completed call to, based on said predicted movement, said candidate zone selecting unit forming a communication path corresponding to said communication link to said candidate radio communication zones,
wherein each of said radio base stations includes means for determining whether or not a radio communication zone selected for handover corresponds to one of said radio communication zones during a process of a handover of said completed call, and for acquiring a free radio channel of said one of said candidate radio communication zones when a result of a determination is affirmative and after initiation of a handover to said one of said radio communication zones, said means connecting said acquired free radio channel to the communication link formed by said candidate zone selecting unit.

5 more elements

A mobile communication system comprising:

a mobile station which can be located in one of a plurality of radio communication zones according to a small zone structure or a sector structure;
a plurality of radio base stations forming said respective radio communication zones, each of said radio base stations performing a radio channel setting control including a handover with respect to a call originated for said mobile station located in one of said radio communication zones;
and
an exchange connected to each of said radio base stations via a communication link so that said exchange performs a call process of said call in association with the radio channel setting control performed by said radio base stations,
said mobile communication system further comprising:
a candidate zone notification unit which selects, after said call becomes a completed call, candidate radio communication zones which are candidates for transferring the completed call to so as to announce the candidate radio communication zones to said mobile station;
and
a candidate zone selecting unit which forms a communication path in said communication link to said candidate radio communication zones and acquires a free radio channel of the candidate radio communication zones selected by said candidate zone selecting unit when a request is provided from said mobile station and after initiation of a handover, and connects a communication path to said free radio channel,
wherein said mobile station includes a movement predicting unit which predicts a movement of said mobile station from one of said radio communication zones in which said mobile station is located to another one of said radio communication zones adjacent to said one of said radio communication zones, and when a result of a prediction indicates one of the candidate radio communication zones announced by said candidate zone notification unit, said movement predicting unit provides the result to said candidate zone selecting unit as said request.

6 more elements

A mobile communication system comprising:

a mobile station which can be located in one of a plurality of radio communication zones according to a small zone structure or a sector structure;
a plurality of radio base stations forming said respective radio communication zones, each of said radio base stations performing a radio channel setting control including a handover with respect to a call originated for said mobile station located in one of said radio communication zones;
and
an exchange connected to each of said radio base stations via a communication link so that said exchange performs a call process of said call in association with the radio channel setting control performed by said radio base stations,
said mobile communication system further comprising:
a candidate zone notification unit which selects, after said call becomes a completed call, candidate radio communication zones which are candidates for transferring the completed call to so as to announce the candidate radio communication zones to said mobile station;
and
a candidate zone selecting unit which selects the candidate radio communication zones selected by said candidate zone notification unit when a request is provided from said mobile station, and forms a communication link to the radio base station in said candidate radio communication zones,
wherein said mobile station includes a movement predicting unit which predicts a movement of said mobile station from one of said radio communication zones in which said mobile station is located to another one of said radio communication zones adjacent to said one of said radio communication zones, and when a result of a prediction indicates one of the candidate radio communication zones announced by said candidate zone notification unit, said movement predicting unit provides the result to said candidate zone selecting unit as said request;
and
each of said radio base stations includes means for determining whether or not a radio communication zone selected for handover corresponds to one of said radio communication zones during a process of a handover of said completed call, and for acquiring a free radio channel of said one of said candidate radio communication zones when a result of a determination is affirmative and after initiation of a handover sequence to said one of said radio communication zones, said means connecting said acquired free radio channel to the communication link formed by said candidate zone selecting unit.

8 more elements

Dependencies are inferred from the claim text.