Shared Radio Backhaul System

• US 20080181183A1
• Filed: 01/16/2008
• Published: 07/31/2008
• Est. Priority Date: 01/16/2007
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Gale, Simon, Urquhart, Andrew, Naden, James Mark
• Granted Patent: US 8,542,630 B2
• Time in Patent Office: Days
• US Class Current: 370/336
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• CPC Class Codes: H04B 1/0064 with separate antennas for the more than one band H04B1/0053 takes precedence
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 74/04 Scheduled access hybrid access H04W74/02
• CPC Class Codes: H04W 84/042 Public Land Mobile systems, e.g. cellular systems
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals
• CPC Class Codes: H04W 88/10 adapted for operation in multiple networks, e.g. multi-mode access points
• CPC Class Codes: H04W 92/20 between access points

Abstract

Embodiments of the invention relate to wireless communications networks, and more specifically to method and apparatus relating to wireless backhaul for cellular wireless systems. Increasing data capacity of cellular wireless systems places increasing demands on the capacity of the two way connection, known as backhaul, between a cellular base station and a telecommunications network such as the PSTN backhaul, since this is the connection that has to convey the wireless-originating traffic to its destination, often in an entirely different network. Known backhaul links include leased lines, microwave links, optical fibre links or radio resources for relaying backhaul traffic between base stations. The fixed line solutions are expensive to implement and maintain, while the radio solutions suffer from interference from transmissions between base stations with transmissions from user equipment to base stations which are not communicating with other base stations. In embodiments of the invention, the relaying of access data between base stations utilises radio resources other than radio resources used by transmissions from user equipment within an area of contiguous wireless coverage. The benefit of this approach is that it provides a means of avoiding interference between inter-base station transmissions and user equipment to base station transmissions.

Claims

1. A method of configuring a cellular wireless communications network comprising a first base station, a second base station, a further base station and a user equipment terminal, said network being located within an area of contiguous cellular wireless coverage, the method comprising:

configuring said first base station in a first transmission mode to transceive signals with a user equipment terminal according to a first frame format;

configuring said second base station in a second transmission mode to transceive signals with a user equipment terminal and with the further base station according to a second frame format; and

configuring said further base station in the second transmission mode so as to transceive signals with a user equipment terminal and with the second base station according to the second frame format,

in which the first frame format comprises a downlink portion for transmission of signals from the first base station to a user equipment terminal and an uplink portion for transmission of signals from said user equipment terminal to the first base station, and the transceiving of signals between said second and further base stations according to the second frame format occurs wholly within said downlink portion of the first frame format.

2. A method according to claim 1, including synchronizing the transceiving of signals between the first base station and a user equipment terminal with the transceiving of signals between the second base station and a user equipment terminal and/or with the further base station and a user equipment terminal.

3. A method according to claim 2, in which the second frame format comprises a first downlink portion for transmitting signals from the second base station to a user equipment terminal, a first uplink portion for transmitting signals from the user equipment terminal to the second base station, a second downlink portion for transmitting signals from the second base station to the further base station and a second uplink portion for transmitting signals from the further base station to the second base station, and the method further comprises adjusting the first and second uplink portions so as to synchronise the first uplink portion with said uplink portion associated with the first frame format.

4. A method according to claim 1, including:

configuring the second base station to transceive signals with a user equipment terminal and with the further base station according to a third frame format; and

configuring the further base station to transceive signals with a user equipment terminal and with a third base station according to the third frame format,

in which said transceiving of signals between the further base station and the third base station according to the third frame format occurs wholly within said downlink portion of the first frame format.

5. A method according to claim 4, in which the second base station transceives signals with the further base station in a different part of the downlink portion of the first frame format to that utilized for transceiving signals between the further base station and the third base station.

6. A method according to claim 1, in which the transceiving of signals between said second and further base stations according to the second frame format occurs wholly within timeslots allocated to transmissions between the first base station and user equipment terminal according to the first format.

7. A method according to claim 1, in which the transceiving of signals between said second and further base stations according to the second frame format occurs wholly within frequencies allocated to transmissions from the first base station to the user equipment terminal according to the first format.

8. A method according to claim 1, further comprising:

transmitting first signals between a user equipment terminal and the second base station by means of a first antenna system of a first type at the second base station; and

transceiving second signals between the second and further base stations by means of a second antenna system of a second type at the second base station, the second type of antenna system being different from the first type of antenna system.

9. A method according to claim 8, comprising connecting the first antenna system to a transceiver for transceiving the first signals and connecting the second antenna system to the transceiver for transceiving the second signals so as to selectively transceive said first and second signals.

10. A method according to claim 9, comprising:

decoding a message indicating a switching point with respect to a count value on a counter;

detecting a characteristic representing a power output of the transceiver as a function of time;

synchronising the counter with the characteristic; and

switching between the first antenna system and the second antenna system in dependence on the count value and the switching point.

11. A method according to claim 10, in which the first antenna system comprises an antenna array having a plurality of antenna elements and the second antenna system comprises a sub-set of said antenna elements, the method further comprising switching between said sub-set of antenna elements in dependence on the count value and the switching point.

12. A method according to claim 11, including applying a first set of amplitude and phase weighting values in respect of said first signals and applying a second, different, set of amplitude and phase weighting values in respect of said second signals.

13. A system for transceiving signals in a cellular wireless communications network, the cellular wireless communications network comprising a first base station, a second base station, a further base station and a user equipment terminal, said network being located within an area of contiguous cellular wireless coverage,

the system being arranged such that signals are transceived between the first base station and a user equipment terminal according to a first frame format and signals are transceived between the second base station and a user equipment terminal and the further base station according to a second frame format,

wherein the first frame format comprises a downlink portion for transmission of signals from the first base station to a user equipment terminal and an uplink portion for transmitting signals from said user equipment terminal to the first base station, and the transceiving of signals between said second and further base stations according to the second frame format occurs wholly within said downlink portion of the first frame format.

14. A system according to claim 13, wherein the system comprises:

a first antenna system of a first type at the second base station arranged to transceive signals between the second base station and a user equipment terminal; and

a second antenna system of a second type, different from the first type of antenna system, arranged to transceive signals between the second base station and the further base station.

15. A system according to claim 14, comprising a radio frequency switch for connecting the first antenna system to a transceiver during periods within the frame format that are allocated to transmissions between the second base station and the user equipment terminal and for connecting the second antenna system to the transceiver during periods within the second frame format that are allocated to transmissions between the second base station and the further base station.

16. A system according to claim 15, wherein the first antenna system comprises an antenna array having a plurality of antenna elements, and the second antenna system comprises a sub-set of said antenna elements.

17. A method of configuring a cellular wireless communications network comprising a first base station, a second base station, a third base station and a user equipment terminal, said network being located within an area of contiguous cellular wireless coverage, the method comprising:

receiving a first message apportioning radio resource for particular types of transmission at said first base station and said second base station;

receiving a second message apportioning radio resource for particular types of transmission at the third base station and the user equipment terminal;

transmitting first signals from said user equipment terminal to said third base station in a first radio resource allocation apportioned in said message; and

transceiving second signals between said first base station and said second base station in a second radio resource allocation apportioned in said message, where the second radio resource allocation does not overlap with the first radio resource allocation.

18. A method of configuring a cellular wireless communications network comprising a first base station, a second base station, and a user equipment terminal, said network being located within an area of contiguous cellular wireless coverage, the method comprising:

configuring said first base station in a first transmission mode to transceive signals with a user equipment terminal according to a first frame format; and

configuring said first base station in a second transmission mode to transceive signals with the user equipment terminal and a second base station according to a second frame format,

in which the first frame format comprises a downlink portion for transmission of signals from the first base station to a user equipment terminal and an uplink portion for transmission of signals from said user equipment terminal to the first base station, and the transceiving of signals between said first and second base stations according to the second frame format occurs wholly within said downlink portion of the first frame format.

19. A method according to claim 18, further comprising configuring a further base station to transceive signals with the second base station according to the second format when the first base station is operating in the first transmission mode.