Communications system

• US 5,682,256 A
• Filed: 02/26/1996
• Issued: 10/28/1997
• Est. Priority Date: 11/11/1988
• Status: Expired due to Term

• Current Assignee: NextG Networks
• Original Assignee: British Telecommunications PLC (BT Group PLC)
• Inventors: Motley, Andrew James, Chadney, Anthony Gerard
• Primary Examiner(s): Marcelo, Melvin
• Assistant Examiner(s): BACARES, RAFAEL D
• Application Number:
  US08/607,199
• Time in Patent Office: 610 Days
• Field of Search: 359/117, 359/118, 359/135, 359/136, 359/145, 359/151, 359/167, 359/172, 359/152, 455/16, 455/53.1, 455/54.1, 455/56.1, 455/11.1, 455/33.1, 455/33.4, 379/56, 379/59
• US Class Current: 398/115
• CPC Class Codes: H04B 10/25754 Star network topology
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 88/085 Access point devices with remote components

Abstract

A communications system has a base center with radio transceivers for providing a number of radio frequency (RF) communications links and a plurality of fixed radio ports through which RF signals can be transmitted and received over the air. A fiber optic network interconnects the RF transceivers and the fixed radio ports and carries the RF signals by means of optical signals. There is a plurality of radio/optical interfaces by which RF signals can be modulated onto and demodulated from one or more optical signals, between the RF transceivers and the fiber optic network, and between the fiber optic network and the fixed radio ports. A matrix switch selectively interconnects the transceivers and the radio ports through the fiber optic network.

Claims

1. A communications system comprising:

a base centre having a plurality of independently operated radio frequency (RF) transceivers at the base centre for providing a plurality of radio frequency (RF) communications links;

a plurality of fixed radio ports through which RF signals can be transmitted and received over the air;

a fibre optic network for selectively interconnecting the RF transceivers and the fixed radio ports, and for carrying the RF signals by means of optical signals;

a plurality of radio/optical interfaces by which RF signals can be modulated onto and demodulated from one or more optical signals, which interfaces are between the RF transceivers and the fibre optic network, and between the fibre optic network and the fixed radio ports.

8. A communications system as claimed in claim 1 wherein there is multiplexing/demultiplexing of the optical signals in the fibre optic network.

9. A communications system as claimed in claim 1 wherein the fibre optic network incorporates wavelength routing of optical signals.

10. A communication system as described in claim 1 which call handover is between radio ports is controlled in the base centre through switching the radio transceiver from one radio port to another radio port by a matrix switch.

11. A communication system as claimed in claim 10 in which diversity operation is provided by combining or switching between two or more radio points in the matrix switch.

12. A communication system as claimed in claim 1 in which dynamic channel allocation is controlled in the base centre.

2. A communications system comprising:

a base centre having a plurality of independently operated radio frequency (RF) transceivers for providing a plurality of radio frequency (RF) communications links;

a plurality of fixed radio ports through which RF signals can be transmitted and received over the air;

a fibre optic network for selectively interconnecting the RF transceivers and the fixed radio ports, and for carrying the RF signals by means of optical signals;

a plurality of radio/optical interfaces by which RF signals can be modulated onto and demodulated from one or more optical signals, which interfaces are between the RF transceivers and the fibre optic network, and between the fibre optic network and the fixed radio ports; and

a matrix switch for selectively interconnecting the transceivers and the radio ports through the fibre optic network.

3. A communications system as claimed in claim 2 wherein the RF links are frequency division multiplexed.

4. A communications system as claimed in claim 2 wherein the RF links are time division multiplexed.

5. A communications system as claimed in claim 2, wherein there is means for combining RF signals to or from one or more of the RF ports.

7. A communications system as claimed in claim 2 wherein the matrix switch is for switching RF signals, and between the RF matrix switch and the fibre optic network there are one or more RF/optical interfaces.

16. A communications system as in claim 2 wherein there is multiplexing/demultiplexing of the optical signals in the fibre optic network.

17. A communications system as in claim 2 wherein the fibre optic network incorporates wavelength routing of optical signals.

18. A communication system as in claim 2 wherein call handover between radio ports is controlled in the base centre through switching the radio transceiver from one radio port to another radio port by the matrix switch.

19. A communication system as in claim 2 wherein diversity operation is provided by combining or switching between two or more radio points in the matrix switching.

20. A communication system as in claim 2 wherein dynamic channel allocation is controlled in the base centre.

6. A communications system comprising:

a base centre having a plurality of radio transceivers for providing a number of radio frequency (RF) communications links;

a plurality of fixed radio ports through which RF signals can be transmitted and received over the air;

a fibre optic network for interconnecting the RF transceivers and the fixed radio ports, and for carrying the RF signals by means of optical signals;

a plurality of radio/optical interfaces by which RF signals can be modulated onto and demodulated from one or more optical signals, which interfaces are between the RF transceivers and the fibre optic network, and between the fibre optic network and the fixed radio ports; and

a matrix switch for selectively interconnecting the transceivers and the radio ports through the fibre optic network;

wherein the matrix switch is for switching optical signals and between the optical matrix switch and the plurality of RF transceivers there are one or more RF/optical interfaces.

13. A communications system comprising:

a base centre having a plurality of independently operated radio frequency (RF) transceivers at the base centre for establishing at least one radio frequency (RF) communication link;

a plurality of remotely located, fixedly situated, radio frequency (RF) communication ports for transceiving radio frequency (RF) signals via the air;

an optical fibre network selectively connecting said base centre with each of said remote RF communication ports;

an RF/optical signal interface at said base center connected between said optical fibre network and said radio frequency transceivers for converting RF-modulated optical signals to RF electrical signals and for converting RF electrical signals to RF-modulated optical signals; and

an RF/optical signal interface at each of said RF communication ports connected to said optical fibre network for converting RF-modulated optical signals to RF electrical signals and for converting RF electrical signals to RF-modulated optical signals.

14. A cellular communications system for interfacing with plural portable or mobile RF transceivers via plural fixed RF communication ports, said system comprising:

a plurality of trunked RF communication channels including a plurality of independently operated RF transceivers accessible at a base centre location;

an optical fibre network selectively interconnecting said base centre location to said fixed RF communication ports; and

an RF/optical signal interface at both said base centre and said fixed RF communication ports for converting RF electrical signals to RF-modulated optical signals and for converting RF-modulated optical signals to RF electrical signals so that communications between the base centre and the fixed RF communication ports is via RF-modulated optical signals,

whereby RF transceiver resources may be concentrated and commonly located at the base centre for servicing a plurality of fixed RF communication ports.

15. A cellular communications system having trunked RF communication channels at a base station interfacing with plural portable or mobile RF transceivers via plural fixed RF communication ports distributed among overlapping cellular communication zones, said system comprising:

an optical fibre network selectively interconnecting said base station and its trunked RF communication channels with said fixed RF communication ports; and

an RF/optical signal interface at each end of the fibre network for converting RF electrical signals to RF-modulated optical signals and vice versa.