System and method for mitigating interference when initializing links between cognitive radios

1. A spectrum management server, comprising:

a communications interface over which communications with a hub radio device are made, wherein spectrum access requests for a spoke radio device are received at the spectrum management server by way of the hub radio device; and

a processor that executes logical instructions to generate generic channel access credentials used by the spoke radio device to wirelessly communicate with the hub radio device before specific channel access credentials are supplied to the spoke radio device, the logical instructions configure the spectrum management server to:

determine a coverage area of the hub radio device and determine sub-regions of the coverage area;

determine a generic access transmit power limit for each sub-region of the coverage area for one or more channels on which the hub radio device has specific channel access credentials to engage in wireless communications; and

transmit the generic access transmit power level for each sub-region and channel combination to the hub radio device; and

wherein the sub-regions of the coverage area are segments of the coverage area defined by a first azimuth and a second azimuth relative to a location of the hub radio device.

2. A spectrum management server, comprising:

a communications interface over which communications with a hub radio device are made, wherein spectrum access requests for a spoke radio device are received at the spectrum management server by way of the hub radio device; and

a processor that executes logical instructions to generate generic channel access credentials used by the spoke radio device to wirelessly communicate with the hub radio device before specific channel access credentials are supplied to the spoke radio device, the logical instructions configure the spectrum management server to:

determine a coverage area of the hub radio device and determine sub-regions of the coverage area;

determine a generic access transmit power limit for each sub-region of the coverage area for one or more channels on which the hub radio device has specific channel access credentials to engage in wireless communications; and

transmit the generic access transmit power level for each sub-region and channel combination to the hub radio device; and

wherein the spectrum management server logically overlaps the coverage area with pixels of known geographic location and size;

wherein the spectrum management server determines, for each pixel, a maximum transmit power level; and

wherein the generic access transmit power limit for each sub-region and channel combination is determined by the spectrum management server by identifying the lowest maximum transmit power level for all pixels overlapping the sub-region of the coverage area.

3. The spectrum management server of claim 2 , wherein the maximum transmit power levels for the pixels are a function of operational characteristics of protected transmitters operating near the hub radio device.

4. A hub radio device, comprising:

radio circuitry configured to engage in wireless communications using specific channel access credentials, the hub radio device having a coverage area that is divided into sub-regions, and the specific channel access credentials acquired from a spectrum management server with which the hub radio device communicates over a communication medium that does not cause interference to protected radio devices; and

a control circuit that executes logical instructions to configure the hub radio device to:

receive a generic access transmit power limit for each sub-region of the coverage area for one or more of the channels in which the hub radio device has specific channel access credentials;

broadcast a beacon with the radio circuitry containing the generic access transmit power limit for each sub-region and channel combination; and

establish a communication link with a spoke radio device operating under generic channel access credentials that conform to the generic access transmit power limit for one of the sub-region and channel combinations specified in the beacon, the spoke radio device acquires specific channel access credentials for a location of the spoke radio device from the spectrum management server by way of the communication link, the hub radio device and the communication medium; and

wherein the beacon further contains an identification of a location of the hub and a geographic identification of each sub-region.

5. The hub radio device of claim 4 , wherein the sub-regions of the coverage area are segments of the coverage area defined by a first azimuth and a second azimuth relative to the location of the hub radio device.

6. A spoke radio device, comprising:

radio circuitry configured to engage in wireless communications, the wireless communications including establishing a link with a hub radio device using generic channel access credentials to support acquisition of specific channel access credentials from a spectrum management server; and

a control circuit that executes logical instructions to configure the spoke radio device to:

receive a beacon from the hub radio device containing the generic channel access credentials, the generic access credentials including a generic access transmit power limit for each of plural sub-regions of a coverage area of the hub radio device and for one or more of the channels for which the hub radio device has specific channel access credentials;

identify one of the sub-regions of the coverage area of the hub radio device in which the spoke radio device is located; and

select a channel from the beacon, and wherein the link is established using the generic access transmit power limit corresponding the selected channel and identified sub-region in which the spoke radio device is located; and

wherein the selected channel is the channel with the highest generic access transmit power limit for the identified sub-region in which the spoke radio device is located.

7. A spoke radio device, comprising:

radio circuitry configured to engage in wireless communications, the wireless communications including establishing a link with a hub radio device using generic channel access credentials to support acquisition of specific channel access credentials from a spectrum management server; and

a control circuit that executes logical instructions to configure the spoke radio device to:

receive a beacon from the hub radio device containing the generic channel access credentials, the generic access credentials including a generic access transmit power limit for each of plural sub-regions of a coverage area of the hub radio device and for one or more of the channels for which the hub radio device has specific channel access credentials;

identify one of the sub-regions of the coverage area of the hub radio device in which the spoke radio device is located; and

select a channel from the beacon, and wherein the link is established using the generic access transmit power limit corresponding the selected channel and identified sub-region in which the spoke radio device is located; and

wherein the spoke radio device identifies the sub-region in which the spoke radio device is located by identifying an azimuth between the hub radio device and the spoke radio device and comparing the identified azimuth to start and stop azimuths used to define each sub-region of the coverage area of the hub radio device.