Method and system for connecting cells and microcells in a wireless communications network

• US 5,890,055 A
• Filed: 07/28/1995
• Issued: 03/30/1999
• Est. Priority Date: 07/28/1995
• Status: Expired due to Fees

• Current Assignee: AT&T Corporation (AT&T, Inc.)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Erceg, Vinko, Vannucci, Giovanni, Roman, Robert Stephen, Clark, Martin V., Rustako, Anthony Joseph Jr., Greenstein, Lawrence Joel, Driessen, Peter Frank, Chu, Ta-Shing
• Primary Examiner(s): Chin, Wellington
• Assistant Examiner(s): SOBUTKA, PHILIP
• Application Number:
  US08/508,858
• Time in Patent Office: 1,341 Days
• Field of Search: 455/7, 455/14, 455/15, 455/16, 455/17, 455/20, 455/23, 455/25, 455/33.1, 455/56.1, 455/422, 455/446, 455/447, 455/448, 455/524, 455/562, 455/561, 455/60, 333/137, 333/126
• US Class Current: 455/16
• CPC Class Codes: H04B 7/2606 Arrangements for base station coverage control, e.g. by using relays in tunnels
• CPC Class Codes: H04W 16/26 Cell enhancers or enhancement, e.g. for tunnels, building shadow
• CPC Class Codes: H04W 88/085 Access point devices with remote components

Abstract

A wireless communications system includes a number of clusters of repeaters wherein all repeaters within a cluster arc connected to a common hub via respective millimeter-wave radio links. Wireless signals received by the repeaters from end-user devices are transparently carried by the millimeter-wave radio links to respective hubs that act as concentrators for the repeaters. The hubs may be linked to a wireless network base station (in an outdoor setting) or alternatively to a server or a PBX (in an indoor environment) via a high-speed transmission facility, such as a fiber optic cable that is thus shared by all the repeaters.

Claims

1. A transmission system for use in a wireless communications network, said system comprising

at least one cluster of repeaters wherein each one of said repeaters receives a) wireless signals from wireless end-user devices via respective wireless links to produce communications signals destined for a networking device of said communications network;

and b) information signals from said networking device to deliver wireless signals to at least one of said wireless end-user devices; and

at least one hub wherein each hub communicates with a) said networking device via a transmission link, and b) repeaters that are associated with a single cluster, and that are within line-of-sight of each hub, said communication with said associated repeaters being carried out via respective radio links which provide respective communications paths for said communications signals and said information signals to be exchanged between said associated repeaters, said each hub and said networking device, said hub further including a polarization duplexer which uses orthogonal polarization to associate each received communications signal to a particular repeater which transmitted thereto said communication signal.

2. The invention of claim 1 wherein said at least one hub is also a repeater which communicates with wireless end-user devices within said hub'"'"'s vicinity.

3. The invention of claim 1 wherein one of said repeaters within the cluster is not within line-of-sight of other repeaters within the cluster.

4. The invention of claim 1 wherein said radio link is a millimeter-wave link.

5. The invention of claim 1 wherein said repeater further includes

a first antenna for communications with said at least one wireless end-user device;

and

a second antenna for communications with said hub, said second antenna being placed within line of sight of a corresponding antenna connected to said hub.

6. The invention of claim 1 wherein said hub further includes

at least one duplexer a) which separates information signals transmitted to a particular one of said associated repeaters from communications signals received from said particular one of said associated repeaters, and b) separates information signals transmitted to different ones of said associated repeaters.

7. The invention of claim 1 wherein at least one of said repeaters receives a plurality of said wireless signals from a plurality of wireless end-user devices operative at different air interfaces and wherein said at least one repeater receives said plurality of wireless signals as a block of spectrum in aggregate form.

8. The invention of claim 1 wherein said networking device is selected from a group of devices which include a) a base station b) a processor and c) a wireless private branch exchange.

9. The invention of claim 1 wherein said at least one hub further includes

a first processor which receives said information signals from said networking device and converts said information signals into a format suitable for transmission over said respective radio link;

and

a second processor which a) receives said communications signals via said respective radio link and b) modulates said communications signals for transmission to a transceiver which terminates a facility connected to said networking device.

10. The invention of claim 1 wherein said at least one hub is co-located with said networking device.

11. The invention of claim 1 wherein at least one of said repeaters includes

a first signal processor which processes said wireless signals received from said wireless end-user devices to produce said communications signals destined for said networking device;

and

a second signal processor which processes information signals received from i) said networking device via a hub associated with said repeater, and ii) said respective radio link in order to output said wireless signals to said at least one wireless end-user device.

12. The invention of claim 11 wherein said first signal processor further includes

a frequency converter which converts said received wireless signals into intermediate frequency signals;

and

a modulator which frequency-modulates said intermediate frequency signals onto a carrier to generate said communications signals transmitted to said hub via said respective radio link.

13. The invention of claim 11 wherein said second signal processor further includes

a frequency converter which converts said information signals received from said hub into respective intermediate frequency signals of lower frequency;

and

a frequency-modulated signal detector which recovers from said respective intermediate frequency signals a baseband signal that is further processed to generate said wireless signals transmitted to said at least one wireless end-user device.

14. A wireless communications network comprising

at least one repeater which a) receives at least one wireless signal from at least one nearby wireless end-user device, b) converts said at least one received wireless signal to an intermediate frequency signal, and c) frequency-modulates said intermediate frequency signal onto a carrier for transmission over a radio link operative at a selected frequency range;

and

at least one hub which a) receives via said radio link said frequency-modulated signal from said at least one repeater that is placed within line-of-sight of said at least one hub, and b) demodulates said frequency-modulated signal to produce a demodulated near baseband signal that is subsequently up converted to a selected carrier frequency for communication to a transceiver which terminates a transmission link connected to a communications device of said wireless communications network, said hub including a polarization duplexer that uses orthogonal polarizations to associate each received communications signal to a particular repeater which transmitted thereto said communications signal.

15. The invention of claim 14 wherein said wireless communications network includes more than one of said hubs wherein each one of said hubs communicates via respective radio links to more than one repeater.

16. The invention of claim 15 wherein said at least one repeater receives more than one wireless signal from more than one wireless end-user device, in aggregate form as a block of spectrum.

17. A transmission system for wireless communications network comprising

a plurality of hubs wherein each one of said hubs a) receives communications signal from an associated networking device and b) converts said communications signal to a near baseband signal that is subsequently frequency-modulated for transmission over a radio link operative at a selected frequency range, each of said hubs including a polarization duplexer that uses orthogonal polarizations to associate each received communications signal to a particular repeater which transmitted thereto said communications signal;

and

a plurality of repeaters grouped into clusters wherein repeaters within a cluster are located with line-of-sight of an associated one of said hubs and wherein said repeaters within a cluster a) receive said frequency-modulated signal from said associated hub via said radio link and b) demodulate said respective frequency-modulated signal to produce a demodulated signal that is subsequently frequency-translated to at least one wireless carrier frequency for transmission to at least one nearby wireless end-user device operative at one or more air interfaces.

18. The invention of claim 17 wherein said radio link is a millimeter-wave link.

19. A method of communicating wireless information in a wireless communications network, said method comprising the steps of:

receiving in at least one repeater a wireless signal from a wireless end-user device at a first frequency range, and a communications signal at a second frequency range;

processing in said at least one repeater a) said wireless signals to produce frequency-modulated signals that are transmitted over a radio link operative at said second frequency range, and b) said communications signals to produce said wireless signal that is transmitted to said wireless end-user devices at said first frequency range;

receiving in a hub located within line-of-sight of said at least one repeater a) a data signal from a networking device of said wireless communications network, and b) said frequency-modulated signal from said at least one repeater, said hub including a polarization duplexer that uses orthogonal polarizations to associate such received communications signal to a particular repeater that transmitted thereto said communications signal;

processing at said hub a) said data signal to generate said commnications signal that is transmitted to said at least one repeater via said radio link, and b) said frequency-modulated signal that is demodulated to be subsequently modulated at a selected carrier frequency for communication to a transceiver which terminates a wired transmission link connected to said communications device.

20. The method of claim 19 wherein said radio link is a millimeter wave link.

21. The method of claim 19 wherein said networking device is selected from a group of devices which include a) a base station b) a processor, and c) a wireless private branch exchange.

22. The method of claim 19 wherein said hub is also a repeater which receives wireless signals from nearby wireless end-user devices.

23. A system for communicating wireless information in a wireless communications network, said method comprising the steps of:

at least one repeater which a) receives a wireless signal from a wireless end-user device at a first frequency range, and a communications signal at a second frequency range, and b) processes i) said wireless signal to produce a frequency-modulated signal that is transmitted over a radio link operative at said second frequency range, and ii) said communications signal to produce said wireless signal that is transmitted to said wireless end-user device at said first frequency range;

a hub that is located within line-of-sight of said at least one repeater and a) receives a data signal from a networking device of said wireless communications network, and said frequency-modulated signal from said at least one repeater b) processes i) said data signal to generate said communications signals that are transmitted to said at least one repeater via said radio link, and ii) said frequency-modulated signal that is demodulated to be subsequently modulated at a selected carrier frequency for communication to a transceiver which terminates a wired transmission link connected to said communications device, said hub including a polarization duplexer that uses orthogonal polarizations to associate each received communications signal to a particular repeater that transmitted hereto said communications signal.

24. The invention of claim 23 wherein said radio link is a millimeter wave link.

25. The invention of claim 23 wherein said networking device is selected from a group of devices which include a) a base station b) a processor, and c) a wireless private branch exchange.

26. The invention of claim 23 wherein said hub is also a repeater which receives a wireless signal from a nearby wireless end-user device.

27. A wireless communications network comprising

at least one cluster of repeaters wherein each one of said repeaters within said cluster simulcasts a respective individual version of a common wireless information signal received from a wireless end-user device, and destined for a networking device;

a hub which a) receives at first frequency range said common wireless signal from said wireless end-user device, and at a second frequency range each said individual version of said common wireless signal from each one of said repeaters via respective radio links b) adds said common wireless signal received therein to a total of each said received individual version received from each one of said repeaters to generate a composite signal which is transmitted to said networking device, and c) transmits to each one of said repeaters a common wireless communications signal that is received from said networking device in order to allow each repeater to act as a different port of a distributed antenna.

28. The invention of claim 27 wherein each one of said repeaters is placed at a given distance of said hub in order to increase the range of coverage of said wireless communications network.

29. The invention of claim 27 wherein said networking device is selected from a group of devices which include a) a base station b) a processor and c) a wireless private branch exchange.

30. The invention of claim 27 wherein said addition of said common wireless signal to said total of each individual version of said common wireless signal is performed at said networking device.

31. A hub for use in a wireless communications network, said hub comprising

an antenna which a) a receives modulated communications signals as a block of spectrum from a plurality of repeaters via respective radio links, said repeaters being placed within line-of-sight of said hub, and arranged to receive from nearby mobile end-users devices wireless end-user signals that are processed in said repeaters to produce said modulated communications signals, and b) transmits to said repeaters via said radio links information signals received from a networking device of said wireless communications network;

a polarization duplexer that uses orthogonal polarizations to associate each received communications signal to a particular repeater that transmitted thereto said communications signal;

a first processor which converts said information signals into a format suitable for transmission over said respective radio links; and

a second processor which demodulates said modulated communications signals to produce demodulated near baseband signals that are subsequently up converted to a selected carrier frequency for communication to a transceiver which terminates a transmission link connected to said networking device.

32. The invention of claim 31 wherein said hub further includes:

at least one duplexer a) which separates information signals transmitted to a particular one of said repeaters from communications signals received from said particular one of said repeaters, and b) separates information signals transmitted to different ones of said repeaters.

33. The invention of claim 31 wherein said carrier frequency is selected such that frequencies of third order intermodulation products for said near baseband signals fall in parts of the spectrum of said transmission link where no signals are present.