METHODS AND APPARATUS FOR MITIGATING INTERFERENCE BETWEEN CO-LOCATED COLLABORATING RADIOS

• US 20130170439A1
• Filed: 12/29/2011
• Published: 07/04/2013
• Est. Priority Date: 12/29/2011
• Status: Active Grant

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola Solutions, Inc.
• Inventors: HIBEN, BRADLEY M., ANDERSON, JEFF S., ANDERSON, HENRY W.
• Granted Patent: US 9,066,363 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04W 72/1215 for collaboration of different radio technologies
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network

Abstract

Methods and apparatus are provided for mitigating interference between spectrally distinct wireless communication networks employing co-located, collaborating radios. A first base station is in a first network and communicates with a first radio within a first frequency range, and a second base station is in a second network and communicates with a second radio in a second frequency range. The first and second radios are geographically co-located, for example, within a public safety vehicle. The first radio determines a maximum level of interference it will accept based on current operational parameters, and communicates a corresponding threshold value to the second radio through a data link. The second radio sends a request to its base station to employ interim scheduling constraints governing uplink transmissions from the second radio, to thereby limit out of band emissions received by the first radio to a range that is less than the threshold interference level.

Claims

1. A method of mitigating an interfering radio signal, that is received at a first mobile device configured to communicate with a first base station within a first frequency band, and which was transmitted by a second mobile device configured to communicate with a second base station within a second frequency band, the method comprising:

the first mobile device communicating information indicating a threshold value corresponding to a maximum received interference level to said second mobile device;

the second mobile device transmitting an interim scheduling request, based on said information, from said second mobile device to said second base station; and

the second base station rescheduling uplink transmissions from said second mobile device to said second base station in accordance with said interim scheduling request.

2. The method according to claim 1, further comprising said first mobile device determining a maximum interference level acceptable to said first mobile device, wherein said maximum value is based on the then current operational parameters associated with said first mobile device.

3. The method according to claim 2, wherein said operational parameters include at least one of:

frequency, bandwidth, TDM, and transmission power level.

4. The method according to claim 2, wherein determining a maximum interference level comprises determining an acceptable threshold level of out of band emissions.

5. The method according to claim 1, wherein said second mobile device and second base station are configured to communicate with each other using an OFDMA modulation scheme.

6. The method according to claim 1, wherein communicating comprises communicating said information over a collaborative link between co-located radios.

7. The method according to claim 6, wherein said data link is a dedicated data Link between the first and second mobile devices.

8. The method according to claim 6, wherein said data link comprises at least one of a Bluetooth™

compatable link and a USB connection.

9. The method according to claim 5, wherein said rescheduling comprises adjusting operational parameters associated with said uplink transmissions.

10. The method according to claim 5, wherein said rescheduling comprises pausing said uplink transmissions.

11. The method according to claim 1, wherein:

said first mobile device is a public safety land mobile radio device;

said first base station is a public safety land mobile radio base station; and

said first mobile device receives on a narrow band channel in the range of 769 to 775 megahertz.

12. The method according to claim 1, wherein said second base station is a broadband base station, and said second mobile device is a broadband public safety radio device.

13. The method according to claim 12, wherein said second mobile device transmits on a broadband channel in the range of 777 to 798 megahertz.

14. The method according to claim 1, wherein said first and second mobile devices are co-located in a vehicle.

15. The method according to claim 1, wherein said first and second mobile devices are co-located on a person.

16. The method according to claim 1, wherein said second mobile device comprises an LTE compliant subscriber modem.

17. The method according to claim 1, wherein at least one of said first and second mobile devices is a hand-held unit, and further wherein at least one of said first and second mobile devices is mountable in an emergency response vehicle.

18. A method of mitigating out of band emissions received at a first radio that communicates with a first base station within a first frequency band, and which was transmitted by a second radio configured to communicate with a second base station within a second frequency band, the method comprising:

transmitting a first control signal from said first base station to said first radio to alert said first radio that a subsequent transmission is forthcoming from said first base station to said first radio;

communicating a second control signal from said first radio to said second radio in response to said first control signal;

transmitting an interim scheduling request from said second radio to said second base station based on said second control signal; and

executing a mitigation protocol in response to said interim scheduling request.

19. The method according to claim 18, wherein said mitigation protocol comprises at least one of:

pausing uplink transmissions from said second mobile device to said second base station;

reducing the transmit power of said uplink transmissions; and

changing at least one of the bandwidth, frequency, and TDM of said uplink transmissions.

20. A system for mitigating radio interference from out of band emissions, comprising:

a first mobile device configured to communicate with a first base station in a frequency range of 769 to 805 megahertz;

a second mobile device co-located with said first mobile device and configured to communicate with a second base station in a frequency range of 777 to 798 megahertz using OFDMA modulation; and

a data link connecting said first and second mobile devices and configured to communicate information indicating a threshold interference value from said first mobile device to said second mobile device;

wherein said second mobile device is configured to send an interim scheduling request to said second base station upon receipt of said threshold interference value from said first mobile device.