Spectrum sharing between wireless systems

• US 7,177,645 B2
• Filed: 03/10/2005
• Issued: 02/13/2007
• Est. Priority Date: 03/11/2004
• Status: Expired due to Fees

• Current Assignee: Sparkmotion Incorporated (Quarterhill Inc. (f/k/a Wi-LAN Inc.))
• Original Assignee: Alvarion Limited
• Inventors: Goldhamer, Mariana
• Primary Examiner(s): Feild, Joseph
• Assistant Examiner(s): PEREZ, JULIO R
• Application Number:
  US11/076,224
• Publication Number:
  US 20050202824A1
• Time in Patent Office: 705 Days
• Field of Search: 455/447, 455/448, 455/450, 455/452.1, 455/452.2, 455/454, 370/337, 370/341, 370/330, 370/280, 370/324, 370/468
• US Class Current: 455/447
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/541 using the level of interference

Abstract

In a wireless network, subjected to interferences caused by the operation of an adjacent network, a method and devices are provided to allow the allocation of time-sub-frames for operating at frequencies that are subjected to such interferences.

By the present invention, a time frame allocated for communication is divided into at least two time sub-frames. The links along which communications will be transmitted in each of these sub-frames are selected in such a way that during each sub-frame, none of the operative links will be subjected to interferences caused by communications transmitted during that sub-frame along any of the other links.

Also, the time frames allocated for communication along the channels that experience interferences are divided into at least two time sub-frames. One of the time sub-frames is reserved for communicating signals to/from subscriber terminals that are not subjected to interferences, while another time sub-frame is reserved for communicating radio signals to/from terminals that are subjected to interferences. The transmission and/or reception of radio signals along the interfered channels are scheduled in such a way that the interferences caused by the adjacent wireless network, will not have an impact on transmissions and/or receptions of the radio signals at either end of any link which is subjected to interference.

Claims

1. In a wireless system comprising a first plurality of wireless networks, each wireless network comprising at least one base station and at least one subscriber terminal associated therewith, wherein at least one of the communication links extending between at least one of a first plurality of base stations and one or more subscriber terminals adapted to communicate with said at least one base station, experiences interferences resulting from communications exchanged along at least one communication link comprised in a different wireless network, a method of allocating sub-frames within one or more communication time frames for eliminating said interferences, which method comprises:

for each wireless network, classifying each of the operative links extending between its base station and the subscriber terminals associated therewith by the interferences to which said link would be subjected due to transmissions of communications in at least one other wireless network;

allocating within one or more of the communication time frames designated for transmission and/or reception of communications along said first plurality of wireless networks, at least two sub-frames;

determining which of the links will be allowed to carry communications during each of said at least two sub-frames, wherein the determination is made to satisfy a selection condition whereby none of the links associated with a certain sub-frame be subjected to interferences caused by communications transmitted along any of the other links carrying communications during that sub-frame; and

communicating radio signals between each of the base stations and their respective one or more subscriber terminals during said at least two sub-frames, wherein the communication is carried in accordance with the determination step.

2. A method according to claim 1, wherein in case that in the determining step, one or more of the links cannot be is associated with any of said at least two sub-frames because of failing to satisfy said selection condition, at least one of the links that would cause interferences in communications along said one or more links, will not be transmitting communications during that sub-frame.

3. A method according to claim 1, wherein at least one of said at least two sub-frames is selected to allow transmission of communications along links operative in at least two different wireless networks out of said first plurality of wireless networks, and wherein each of said links is not subjected to any interferences caused by any of the other links along which communication is transmitted in said first plurality of wireless networks.

4. A method according to claim 1, further characterized in that at least one base station selected from among said first plurality of base stations is provided with an option to change one or more of its operating parameters while communicating with its associated one or more subscriber terminals within at least one sub-frame selected from among said at least two sub-frames, and wherein at least one member of the group comprising the remaining base stations and the plurality of subscriber terminals associated with said remaining base stations, is adapted to respectively change its operating parameters in order to ensure that no interferences are experienced along the communication link extending between said one base station and said one or more subscriber terminals communicating therewith, for the duration of said at least one sub-frame.

5. A method according to claim 1, further characterized in that at least one subscriber terminal selected from among a plurality of subscriber terminals associated with said first plurality of base stations, is provided with an option to change one or more of its operating parameters while communicating with its associated base station within at least one sub-frame selected from among said at least two sub-frames, and wherein at least one member of the group comprising the remaining base stations out of said first plurality of base stations and the plurality of subscriber terminals associated with said remaining base stations, is adapted to respectively change its operating parameters in order to ensure that no interferences are experienced along the communication link extending between said at least one subscriber terminal and the base station with which it communicates, for the duration of said at least one sub-frame.

6. A method according to claim 4, and wherein said one or more operating parameters is selected from the group consisting of transmission power, beam shape, bandwidth fraction, modulation, coding rate and any combination thereof.

7. A method according to claim 5, and wherein said one or more operating parameters is selected from the group consisting of transmission power, beam shape, bandwidth fraction, modulation, coding rate and any combination thereof.

8. A method according to claim 1, wherein the allocation of said at least two sub-frames is made in accordance with a repetitive pattern or scheme which is repeated every N consecutive time frames, where N being an integer, and wherein said repetitive pattern or scheme may vary from time to time.

9. A method according to claim 4, wherein a second plurality of base stations is selected from among said first plurality of base stations, and wherein each of said second plurality of base stations is provided with an option to change one or more of its operating parameters while communicating with its respective one or more subscriber terminals within at least one sub-frame, provided that no interferences to communications transmitted and/or received by any of said second plurality of base stations, is caused by communications transmitted and/or received by any other base station out of said second plurality of base stations.

10. A method according to the claim 1, further comprising incorporating at least one marking signal or at least one marking message designated for a recipient that is comprised in at least one other of said first plurality of wireless networks, indicating at least one member of the group consisting of:

a beginning of a time frame, a beginning of one or more sub-frames, end of a time frame, end of one or more sub-frames, duration of time frame, duration of a one or more sub-frames, and any combination thereof.

11. A method according to the claim 1, further comprising a step of transmitting at least one request signal or at least one request message in order to request a change in at least one of the following:

the duration of at least one time sub-frame during which communications may be transmitted and/or received along at least one other link belonging to another wireless network of said first plurality of wireless networks, and/or one or more operating parameters characterizing transmission and/or reception along at least one other link belonging to another wireless network out of said first plurality of wireless networks.

12. A method according to claim 11, wherein said at least one request signal or said at least one request message is generated based on a load of traffic to be transmitted by one or more base stations and/or by one or more subscriber terminals, or is generated based on the level of interference thereat.

13. A method according to claim 10, wherein said step of incorporating at least one marking signal or at least one marking message is carried by transmitting at least one energy carrying signal in at least one pre-defined sub-band of the signal transmitted.

14. A method according to claim 11, wherein said step of transmitting at least one request signal or at least one request message is carried by transmitting at least one energy carrying signal in at least one pre-defined sub-band of the signal transmitted.

15. A base station adapted to operate in a wireless network and comprising:

an interface operative to allow communication between said base station and plurality of subscriber terminals associated therewith;

at least one radio transceiver operative at at least one frequency and capable of transmitting communication traffic towards said plurality of subscriber terminals and receive communication traffic therefrom;

at least one processor adapted to;

determine the existence of interferences caused by communications transmitted between at least one other base station and at least one other subscriber terminal, at a frequency substantially the same or substantially adjacent to the frequency used for communication between said base station and one or more subscriber terminals out of said plurality of subscriber terminals;

divide at least one of the time frames allocated for transmission and/or reception of communications, into at least two time sub-frames, wherein each of said at least two sub-frames is characterized in that all of the links along which communication is being transmitted during said sub-frame are not subjected to interferences caused by any of said at least one other base station or said at least one other subscriber terminal, during that sub-frame.

16. A base station according to claim 15, wherein said at least one processor is further adapted to incorporate at least one marking signal or at least one marking message in a signal to be transmitted, indicating at least one member of the group consisting of:

a beginning of a time frame, a beginning of one or more sub-frames, end of a time frame, end of one or more sub-frames, duration of time frame, duration of a one or more sub-frames, and any combination thereof.

17. A base station according to claim 15, wherein said at least one processor is further adapted to associate at least one request signal or at least one request message in a signal to be transmitted, in order to request changing of at least one of the following:

the duration of at least one time sub-frame during which communications may be transmitted and/or received along at least one other link belonging to another wireless network, and/or at least one operating parameter characterizing transmission and/or reception along at least one other link belonging to another wireless network.

18. A subscriber terminal adapted to operate in a wireless network and comprising:

an interface operative to allow communication between said subscriber terminal and at least one base station;

at least one radio transceiver operative at at least one frequency and adapted to transmit communication traffic towards said at least one base station and receive communication traffic therefrom;

at least one processor adapted to;

determine the existence of interferences caused by radio transmissions at a frequency that is substantially the same or substantially adjacent to a frequency used by said subscriber terminal, and where the interferences occur during transmission to or reception of communication from said at least one base station; and

notifying said at least one base station of the interferences detected; and

wherein said at least one radio transceiver is adapted to receive radio transmissions within a time sub-frame allocated by said at least one base station for transmitting radio transmissions to subscriber terminals that experience interferences in their communication with said at least one base station, and wherein said at least one radio transceiver is further adapted to transmit radio transmissions within a time sub-frame allocated by said at least one base station for receiving radio transmissions from subscriber terminals that experience interferences in their communication with said at least one base station.

19. A subscriber terminal according to claim 18, wherein said at least one processor is further adapted to receive and/or incorporate in a signal to be transmitted, at least one marking signal or at least one marking message indicating at least one member of the group consisting of:

a beginning of a time frame, a beginning of one or more sub-frames, end of a time frame, end of one or more sub-frames, duration of time frame, duration of a one or more sub-frames, and any combination thereof.

20. A subscriber terminal according to claim 18, wherein said at least one processor is further adapted to receive and/or incorporate in a signal to be transmitted at least one request signal or at least one request message in order to request changing of at least one of the following:

the duration of at least one time sub-frame during which communications may be transmitted and/or received along at least one other link belonging to another wireless network, and/or one or more operating parameters characterizing transmission and/or reception along at least one other link belonging to another wireless network.