Mobile radio communications system

• US 5,901,144 A
• Filed: 04/09/1996
• Issued: 05/04/1999
• Est. Priority Date: 04/13/1995
• Status: Expired due to Fees

• Current Assignee: Hitachi Communication Technologies, Ltd. (Hitachi, Ltd.)
• Original Assignee: Hitachi, Ltd.
• Inventors: Maki, Takeshi, Suzuki, Toshiro, Aoyama, Kenichi, Fukai, Yuji
• Primary Examiner(s): Patel, Ajit
• Application Number:
  US08/631,301
• Time in Patent Office: 1,120 Days
• Field of Search: 370/310, 370/328, 370/329, 370/331, 370/332, 370/330, 370/436, 455/33.1, 455/33.2, 455/54.1, 455/54.2, 455/436, 455/437, 455/438, 455/439, 455/440, 455/441, 455/442, 379/59, 379/60
• US Class Current: 370/330
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 36/32 by location or mobility data, e.g. speed data
• CPC Class Codes: H04W 36/324 by mobility data, e.g. speed data
• CPC Class Codes: H04W 72/044 based on the type of the allocated resource
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA

Abstract

A mobile radio communications system having a plurality of base stations accommodating a plurality of mobile stations through radio transmission channels, each of the base stations being connected to a mobile communications exchanger through a plurality of signal lines. Each of the base stations is provided therein with a signal line allocating function unit for selecting a particular signal line from a plurality of signal lines and for allocating a communication slot for a mobile station dominated by the base station at a particular slot position on the selected signal line, a radio channel allocating function unit for allocating a communication slot for the mobile station dominated by the base station at a particular slot position on a radio transmission channel at a particular frequency, and a radio signal delay control unit for performing delay control for a timing at which the base station transmits a radio signal to the mobile station dominated by the base station.

Claims

1. A mobile radio communications system having a plurality of base stations which are installed along a moving direction of a plurality of mobile stations being accommodated through radio transmission channels, each of said mobile stations being connected with a mobile communications exchanger through a plurality of signal lines, each of said signal lines being connected in parallel to said plurality of base stations, wherein:

each one of said base stations autonomously allocates a frequency of one of said radio transmission channels and a time slot on the one radio transmission channel, used by one of said mobile stations dominated by said base station, in accordance with a lapse of a fixed time period calculated from a previously assumed moving speed of a mobile station under communication;

each one of said base stations allocates a signal line and a communication slot on said signal line, used by said one mobile station dominated by said one base station; and

said mobile station sequentially switches to one of said plurality of base stations installed along a moving direction of said moving mobile station under communication, by said base station allocating the same communication slot and the same frequency on the signal line by said mobile station dominated by the adjacent base station.

2. A mobile radio communications system according to claim 1, wherein each of said base stations comprises radio signal delay control means for variably setting a delay time for a transmission timing when each said base station transmits a signal to a mobile station accommodated in an associated radio zone associated with said base station, so that the phases of their time-division multiplexed channel slots transmitted to said mobile station mutually matches.

3. A method of switching a radio zone for a mobile radio communications system having a plurality of base stations which are installed along a moving direction of a plurality of mobile stations being accommodated through radio transmission channels, each of said mobile stations being connected with a mobile communications exchanger through a plurality of signal lines, each of said signal lines being connected in parallel to said plurality of base stations, said method comprising the steps of:

autonomously allocating, in each of said base stations, a frequency and a time slot on the radio transmission channel, used by a mobile station dominated by said base station, in accordance with a lapse of a fixed time period calculated from a previously assumed moving speed of a mobile station under communication;

allocating a signal line and a communication slot on said signal line used by said mobile station dominated by said base station; and

sequentially switching said moving mobile station under communication to one of plural radio zones each established by respective ones of said base stations, by said base station allocating the same communication slot and the same frequency on the signal line by said mobile station dominated by the adjacent base station, while said mobile station under communication passes by said plurality of base stations installed along a moving direction of said moving mobile station under communication.

4. A base station for a mobile radio communications system which is installed along a moving direction of a mobile station and is accommodated through radio transmission channels, said base station comprising:

a radio signal transmitter/receiver unit;

a radio signal delay control unit connected to said radio signal transceiver/receiver unit for providing a transmission timing with a delay of a previously set time period for a digital signal transmitted from said radio signal transmitter/receiver unit through said antenna to said mobile station dominated by said base station;

a radio channel allocating function unit connected to said radio signal delay control unit for selecting a particular frequency as a radio transmission channel for transmitting and receiving a radio signal to and from a mobile station through said radio signal delay control unit; and

a signal line allocating function unit connected to said radio channel allocating function unit for selecting a particular signal line from a plurality of signal lines as a signal line for transmitting and receiving a digital signal externally through said radio channel allocating function unit;

wherein said radio channel allocating function unit assigns the same frequency on the signal line by said mobile station dominated by the adjacent base station, and said signal line allocating function unit assigns the same communication slot on the signal line by said mobile station dominated by the adjacent base station.