Communication method and apparatus for a radio local area network system using macrodiversity

• US 7,095,711 B1
• Filed: 02/06/1997
• Issued: 08/22/2006
• Est. Priority Date: 07/18/1996
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Arai, Koji
• Primary Examiner(s): To, Doris H.
• Assistant Examiner(s): Nguyen, Phuongchau Ba
• Application Number:
  US08/796,752
• Time in Patent Office: 3,484 Days
• Field of Search: 370/338, 370/465, 370/468, 370/542.X, 370/543, 370/544, 370/315, 370/336, 370/339, 370/360, 370/538, 370/536, 370/540, 370/217, 370/220, 370/242, 370/243, 370/328, 370/329, 370/545, 375/299, 455/101, 455/561, 341/337, 341/61
• US Class Current: 370/217
• CPC Class Codes: H04B 7/022 Site diversity; Macro-diversity using two or more spaced independent antennas H04B7/04
• CPC Class Codes: H04W 28/22 Negotiating communication rate
• CPC Class Codes: H04W 4/18 Information format or content conversion, e.g. adaptation by the network of the transmitted or received information for the purpose of wireless delivery to users or terminals
• CPC Class Codes: H04W 52/40 during macro-diversity or soft handoff
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/08 Access point devices
• CPC Class Codes: H04W 88/181 Transcoding devices; Rate adaptation devices

Abstract

A communication method for a radio LAN system provides communication at a first transmission rate. In the method, a first signal of the first transmission rate is time-divisionally distributed into n−1 second signals (n=3, 4, . . . ). The n−1 second signals are respectively converted into n−1 third signals of a second transmission rate less than the first transmission rate. The n−1 third signals of the second transmission rate are also transmitted through radio transmission paths between n−1 radio base stations and a terminal station connected to at least one terminal unit.

Claims

1. A communication method for a radio LAN system providing communication at a first transmission rate, said method comprising:

time-divisionally distributing a first signal of said first transmission rate into n−

1 second signals, wherein n is an integer≧

3;

respectively converting said n−

1 second signals into n−

1 third signals of a second transmission rate less than said first transmission rate;

transmitting said n−

1 third signals of said second transmission rate through radio transmission paths between n−

1 radio base stations and a terminal station connected with at least one terminal unit, wherein said radio LAN system further comprises at least one redundant radio base station n;

transmitting a fourth signal through a radio transmission path between said terminal station and said at least one redundant radio base station n, data of said fourth signal having a given relationship with data in signals transmitted between at least, wherein k≦

n−

1, radio base stations of said n−

1 radio base stations and said terminal station; and

compensating, when at least one transmission path between said at least k radio base stations and said terminal station is interrupted, data of the signal to be transmitted through an interrupted transmission path based on said data of said fourth signal transmitted between said at least one redundant radio base station n and said terminal station.

2. A communication method for a radio LAN system providing communication at a first transmission rate, said method comprising:

time-divisionally distributing a first signal of said first transmission rate into n−

1 second signals, wherein n is an integer≧

3;

respectively converting said n−

1 second signals into n−

1 third signals of a second transmission rate less than said first transmission rate; and

transmitting said n−

1 third signals of said second transmission rate through radio transmission paths between n−

1 radio base stations and a terminal station connected with at least one terminal unit, wherein said radio LAN system further comprises at least one redundant radio base station n;

transmitting a fourth signal through a radio transmission path between said terminal station and said at least one redundant radio base station n, data of said fourth signal having a given relationship with data in signals transmitted between at least k, wherein k≦

n−

1, radio base stations of said n−

1 radio base stations and said terminal station; and

compensating, when at least one transmission path between said at least k radio base stations and said terminal station is interrupted, data of the signal to be transmitted through an interrupted transmission path based on said data of said fourth signal transmitted between said at least one redundant radio base station n and said terminal station, where said given relationship when transmitting the fourth signal is that said data of said fourth signal transmitted between said at least one redundant radio base station n and said terminal station is a summation of data of the signals transmitted between said at least k radio base stations and said terminal station for each given time slot.

3. A communication method for a radio LAN system providing communication at a first transmission rate, said method comprising:

time-divisionally distributing a first signal of said first transmission rate into n−

1 second signals, wherein n is an integer≧

3;

respectively converting said n−

1 second signals into n−

1 third signals of a second transmission rate less than said first transmission rate;

transmitting said n−

1 third signals of said second transmission rate through radio transmission paths between n−

1 radio base stations and a terminal station connected with at least one terminal unit, wherein said radio LAN system further comprises at least one redundant radio base station n for transmission of data obtained by summing said n−

1 signals;

monitoring interruption of transmission paths between said n−

1 radio base stations and said terminal station; and

compensating, when one of said transmission paths is interrupted, data of an interrupted transmission path by transmitting said data of the interrupted transmission path between said at least one redundant radio base station n and said terminal station.

4. A communication apparatus for a radio LAN system providing communication at a first transmission rate, said apparatus comprising:

rate-conversion-and-distribution means for time-divisionally distributing a first signal of said first transmission rate into n−

1 second signals, wherein n is an integer≧

3 and respectively converting said n−

1 second signals into n−

1 third signals of a second transmission rate less than said first transmission rate;

n−

1 radio base stations transmitting said n−

1 third signals of said second transmission rate to a terminal station connected with at least one terminal unit through radio transmission paths;

at least one summation means for generating a fourth signal by summing data of at least, wherein k≦

n−

1, signals of said n−

1 third signals of said second transmission rate every timeslots for compensating data of the interrupted path between one of the radio stations transmitting said k signals and the terminal; and

at least one redundant radio base station n transmitting said fourth signal generated in said at least one summation means to said terminal station.

5. A communication apparatus for a radio LAN system providing communication at a first transmission rate, said apparatus comprising:

rate-conversion-and-distribution means for time-divisionally distributing a first signal of said first transmission rate into n−

1 second signals, wherein n is an integer≧

3 and respectively converting said n−

1 second signals into n−

1 third signals of a second transmission rate less than said first transmission rate;

n−

1 radio base stations transmitting said n−

1 third signals of said second transmission rate to a terminal station connected with at least one terminal unit through radio transmission paths;

at least one redundant radio base station n transmitting a signal to said terminal station for transmission of data obtained by summing said n−

1 signals;

line monitoring means for monitoring interruption of transmission paths between said n−

1 radio base stations and said terminal station; and

switching means, when at least one of said transmission paths is interrupted, for forwarding a signal to be transmitted through an interrupted transmission path to said at least one redundant radio base station n.

6. A terminal station used in a radio LAN system having rate-conversion-and-distribution means for time-divisionally distributing a first signal of a first transmission rate into n−

1 second signals, wherein n is an integer≧

3 and respectively converting said n−

1 second signals into n−

1 third signals of a second transmission rate less than said first transmission rate, n−

11 radio base stations transmitting said n−

1 third signals of said second transmission rate to said terminal station connected with at least one terminal unit through radio transmission paths, at least one first summation means for generating a fourth signal by summing data of at least k, wherein k≦

n−

1, signals of said n−

1 third signals of said second transmission rate for every timeslot, and at least one redundant radio base station n transmitting said fourth signal generated in said at least one first summation means to said terminal station, said terminal station comprising;

a receiver receiving said third signals of said second transmission rate transmitted from said n−

1 radio base stations;

rate-conversion-and-multiplex means for converting and multiplexing received third signals of said second transmission rate into signals of said first transmission rate;

line monitoring means for monitoring interruption of transmission paths between said n−

1 radio base stations and said terminal station;

at least one second summation means, when at least one of said transmission paths is interrupted, for generating a fifth signal by summing data of every timeslots of at least k signals of signals transmitted from said n−

1 radio base stations except for a signal to be transmitted through an interrupted transmission path;

at least one subtraction means for generating subtraction data between data of the signal transmitted from said redundant radio base station n and data of said fifth signal generated in said second summation means; and

switching means for providing said subtraction data generated in said subtraction means to said rate-conversion-and-multiplex means instead of providing data of an interrupted signal detected in said monitoring means;

wherein even when at least one of signals transmitted from said n−

1 radio base stations is interrupted, data of the interrupted signal is compensated.

7. A terminal station used in a radio LAN system having rate-conversion-and-distribution means for time-divisionally distributing a first signal of a first transmission rate into n−

1 second signals, wherein n is an integer≧

3 and respectively converting said n−

1 second signals into n−

1 third signals of a second transmission rate less than said first transmission rate, n−

1 radio base stations transmitting said n−

1 third signals of the second transmission rate to said terminal station connected with at least one terminal unit through radio transmission paths, at least one redundant radio base station n transmitting a signal obtained by summing said n−

1 third signals to said terminal station, first line monitoring means for monitoring interruption of transmission paths between said n−

1 radio base stations and said terminal station, and first switching means, when at least one of said transmission paths is interrupted, for forwarding a signal to be transmitted through an interrupted transmission path to said at least one redundant radio base station n;

said terminal station comprising;

a receiver receiving said third signals of the second transmission rate transmitted from said n−

1 radio base stations;

rate-conversion-and-multiplex means for converting and multiplexing received third signals of the second transmission rate into signals of said first transmission rate;

second line monitoring means for monitoring interruption of transmission paths between said n−

1 radio base stations and said terminal station; and

second switching means, when at least one of said transmission paths is interrupted, for providing the signal transmitted from said redundant radio base station to said rate-conversion-and-multiplex means instead of providing a signal to be transmitted through an interrupted transmission path;

wherein even when at least one of signals transmitted from said n−

1 radio base stations is interrupted, data of the interrupted signal is compensated.