Distributed indoor digital multiple-access cellular telephone system

• US 5,903,834 A
• Filed: 10/06/1995
• Issued: 05/11/1999
• Est. Priority Date: 10/06/1995
• Status: Expired due to Term

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Hedberg, Bo Gosta, Forsen, Anders Borje, Kronestedt, Carl Fredric Ulf, Wallstedt, Yngve Kenneth, Frodigh, Carl Magnus, Dannelind, John Tomas Robert
• Primary Examiner(s): Faile, Andrew I.
• Assistant Examiner(s): Boccio, Vincent F.
• Application Number:
  US08/540,326
• Time in Patent Office: 1,313 Days
• Field of Search: 455/33.1, 455/33.4, 455/54.1, 455/56.1, 455/33.2, 455/53.1, 455/51.1, 455/422, 455/442-444, 455/502, 455/503, 455/517, 455/524-525, 455/562, 455/132 , 455/445, 379/59, 379/60
• US Class Current: 455/422.1
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 40/02 Communication route or path selection, e.g. power-based or shortest path routing
• CPC Class Codes: H04W 74/00 Wireless channel access
• CPC Class Codes: H04W 88/085 Access point devices with remote components
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A communication network, and associated method, permitting wireless communication with a mobile unit in an indoor environment. Transceivers are positioned at spaced-apart locations and are coupled to a centralized, control device. The transceivers include transmitter portions and wideband receiver portions. Uplink signals transmitted by a mobile unit are received by receiver portions of transceivers within the range of the uplink signal. Downlink signals are generated by at least two transmitter portions of at least two transceivers. The control device controls selection of which transmitter portions and which receiver portions of the plurality of transceivers are utilized to effectuate two-way communication with the mobile unit. Control signals can also be transmitted by the transmitter portions of all of the transceivers such that a mobile unit positioned anywhere within the area of the communication network receives the control signals.

Claims

1. A communication network for permitting wireless communication with a mobile unit movably positionable to a selected location within at least one cell defined by an area encompassed by said network, said communication network comprising:

a plurality of spaced-apart transceivers, each of said transceivers respectively defining a subcell, said subcells collectively forming the at least one cell, said transceivers for selectively transmitting downlink signals to the mobile unit; and

a control device coupled to each of said transceivers for controlling operation of said transceivers such that a first said transceiver defining the subcell in which the mobile unit is positioned and a second said transceiver defining a subcell adjacent thereto concurrently transmit a downlink signal on a selected downlink channel to the mobile unit and such that the mobile unit is permitted uninterrupted reception of the downlink signal by remaining tuned to the selected downlink channel as the mobile unit is moved between the adjacent subcells and such that uplink signals transmitted by the mobile unit in response to downlink signals transmitted by a transmitter portion of one said transceiver are permitted to be routed through a receiver portion of another said transceiver regardless of whether said another transceiver transmitted the downlink signals to which the mobile unit is responding.

2. The communication network of claim 1 wherein the mobile unit is operable to transmit said uplink signals on a selected uplink channel of a set of uplink channels and wherein said transceivers are each tuned concurrently to all of the uplink channels of the set of uplink channels.

3. The communication network of claim 2 wherein said transceivers are operative to down-convert the uplink signals received by said transceivers to form first down-converted signals, and wherein the first down-converted signals formed by said transceivers are supplied to said control device.

4. The communication network of claim 3 wherein said control device further demodulates at least one of the first down-converted signals supplied thereto.

5. The communication network of claim 4 wherein said control device further selects which of the first-down converted signals supplied thereto are demodulated.

6. The communication network of claim 3 wherein said control device selects said first and second transceivers to transmit the downlink signal responsive, at least in part, to characteristics of uplink signals received at the transceivers.

7. The communication network of claim 6 wherein the characteristics of the uplink signals utilized by said control device comprises signal quality characteristics.

8. The communication network of claim 7 wherein the characteristics of the uplink signals utilized by said control device comprises at least energy levels of the uplink signals received at the transceivers.

9. The communication network of claim 2, wherein said transceivers each comprise a plurality of down-converters, said plurality of down-converters of each transceiver for down-converting uplink signals received on any of the uplink channels.

10. The communication network of claim 9 wherein said transceivers each comprise a plurality of up-converters and wherein said control device controls the operation of the transceivers by controlling selection of which of said transceivers and which of said up-converters thereof are utilized to form the downlink signals.

11. The communication network of claim 1 wherein said transceivers comprise antenna devices.

12. The communication network of claim 1 wherein at least two of said plurality of transceivers further simulcast a control signal on a control channel to the mobile unit.

13. The communication network of claim 12 wherein each of said plurality of transceivers simulcasts the control signal on the control channel to the mobile unit.

14. The communication network of claim 1 wherein said control device is further operative to assign identifiers to said transceivers.

15. The communication network of claim 14 wherein said plurality of spaced-apart transceivers includes at least one subsequently-added transceiver, said subsequently-added transceiver coupled to said control device subsequent to coupling of others of said plurality of transceivers to said control device, said subsequently-added transceiver operative to transmit to said control device indications of coupling of said subsequently-added transceiver to the control device, and wherein said control device assigns an identifier to said subsequently-added transceiver responsive to reception of the indications transmitted thereto by said subsequently-added transceiver.

16. The communication network of claim 14 wherein said transceivers are further operative to transmit authentication information to said control device and wherein said control device assigns identifiers to said transceivers by polling said transceivers and receiving the authentication information responsive thereto.

17. The communication network of claim 1 further comprising a bi-directional interface link for coupling said control device together with said transceivers.

18. The communication network of claim 1 wherein said cell defined by the area encompassed by said network overlaps with an alternate area of an alternate network having an alternate network mobile device moveably-positionable therein and capable of communication with both a transceiver of said plurality of spaced-apart transceivers and with a base station of the alternate network, and wherein said control device is further operative to control times in which the alternate network mobile device is permitted to communicate with at least one transceiver of said plurality of spaced-apart transceivers when the alternate network mobile device is being operated to communicate with the base station of the alternate network.

19. The communication network of claim 18 wherein the alternate network mobile device is permitted to communicate with at least one transceiver of the plurality of spaced-apart transceivers when the alternate network mobile device is positioned proximate to the selected transceiver.

20. A method for permitting wireless communication in a communication network with a mobile unit movably positionable to a selected location within at least one cell defined by an area encompassed by the network, said method comprising the steps of:

positioning a plurality of transceivers at spaced-apart locations throughout the at least one cell, each of the transceivers defining a subcell;

from a transceiver defining the subcell in which the mobile unit is positioned and from a transceiver defining a subcell adjacent thereto, concurrently transmitting a downlink signal on a selected downlink channel to the mobile unit such that the mobile unit is permitted uninterrupted reception of the downlink signal by remaining tuned to the selected downlink channel as the mobile unit is moved between the adjacent subcells; and

transmitting an uplink signal from the mobile unit in response to a downlink signal received from one of the transceivers, and routing the uplink signal through another of the transceivers regardless of whether said another transceiver transmitted the downlink signal to which the mobile unit is responding.

21. The method of claim 20 comprising the further steps of:

tuning the transceivers concurrently to every uplink channel of a set of uplink channels;

transmitting an uplink signal from the mobile unit upon a selected uplink channel of the set of uplink channels; and

receiving the uplink signal at transceivers of the plurality of transceivers within range of the mobile unit.

22. The method of claim 20 comprising the additional steps of:

transmitting polling requests to each transceiver requesting information regarding each transceiver;

receiving responses from each of the transceivers responsive to the polling requests; and

controlling communication with the mobile unit based in part upon the received responses.

23. The method of claim 22 further for adaptively configuring the network when an additional transceiver is installed therein, said method comprising the additional steps of:

transmitting signals from the additional transceiver to a control device to prompt the control device to poll the additional transceiver;

transmitting a polling request from the control device to the additional transceiver requesting additional information regarding the additional transceiver;

transmitting responses from the additional transceiver back to the control device responsive to the polling request; and

permitting the additional transceiver to form a portion of the network when the responses transmitted back to the control device are of selected values.

24. A communication network for permitting wireless communication with a mobile unit movably positionable to a selected location within at least one cell defined by an area encompassed by said network, said communication network comprising:

a plurality of spaced-apart transceivers respectively defining a plurality of subcells which collectively form the at least one cell, each of said transceivers having a transmitter portion and a receiver portion, said transmitter portions for selectively transmitting downlink signals on a selected downlink channel to the mobile unit tuned to the selected downlink channel, and each of said receiver portions tuned concurrently to every uplink channel of a set of uplink channels for receiving an uplink signal transmitted by the mobile unit on a selected uplink channel of the set of uplink channels; and

a control device coupled to each of said transceivers, said control device for controlling operation of said transceivers such that one said transceiver defining the subcell in which the mobile unit is located and another said transceiver defining an adjacent subcell concurrently transmit a downlink signal on the selected downlink channel.

25. The network of claim 24, wherein said control device controls operation of said transceivers such that uplink signals transmitted by the mobile unit in response to downlink signals transmitted by said transmitter portion of one said transceiver are permitted to be routed through said receiver portion of another said transceiver regardless of whether said another transceiver transmitted the downlink signals to which the mobile unit is responding.

26. A cellular telephone system having at least one cell defined in a specific geographic region, said system comprising:

a plurality of radio transceivers positioned throughout the at least one cell, each said radio transceiver for providing radio coverage within a portion of the cell, each portion defining a subcell of the at least one cell, the plurality of radio transceivers operable to broadcast a first information signal upon a common channel throughout each of the subcells defined by said plurality of radio transceivers, a first said radio transceiver and a second said radio transceiver adjacent thereto operable to broadcast a second information signal upon a selected channel throughout a first said subcell and a second said subcell respectively defined by the first radio transceiver and the second radio transceiver;

a mobile station operable to receive the first information signal when positioned within any of the subcells and operable to receive the second information signal when positioned within said first and second subcells, said mobile station responsive to a third information signal received from one of said radio transceivers for transmitting a fourth information signal to at least one of said radio transceivers; and

a controller coupled to said radio transceivers for permitting said fourth information signal to be routed through a further one of said radio transceivers other than said radio transceiver from which said third information signal was received regardless of whether said further radio transceiver transmitted said third information signal.

27. The cellular telephone system of claim 26 wherein the second information signal broadcast from the first radio transceiver is transmitted at a time offset relative to broadcast of the second information signal from the second radio transceiver, thereby to provide time dispersion.