Managing spectrum resources using channel maps and predicted noise floor
A central registration system provides channel maps of available spectrum channels to radio devices. The channel map indicates relative noise floor amounts among the available channels. For this purpose, an amount of predicted interference caused by high-power protected transmitters on each channel available to the requesting radio device for wireless communications is determined, where interference from primary channel and out-of-band emissions of the transmitters is considered.
1. A system for providing channel maps of available spectrum to radio devices, comprising:
an interface to communicate with the radio devices over a network; and
a processor that executes a spectrum resource function that is stored in a memory and, by execution of the spectrum resource function, the system configured to:
receive a request for a channel map from one of the radio devices;
determine channels that are available to the requesting radio device for wireless communications;
determine, for each channel determined to be available, a predicted noise floor amount caused by high-power protected transmitters that are known to the system prior to receipt of the request, wherein the determination of predicted noise floor is made using a path loss model for a location of the requesting radio device, and wherein, for each predicted noise floor, interference from primary channel and out-of-band emissions of the transmitters is considered; and
transmit a channel map of the available channels to the requesting radio device, the channel map indicating relative predicted noise floor amount among the available channels.
2. The system of claim 1 , wherein the request is a whitespace channel map request.
3. The system of claim 1 , wherein the available channels in the channel map are ranked in order of noise floor from least to most to indicate the relative noise floor amount among the available channels.
4. The system of claim 1 , wherein the channel map includes the determined noise floor amount for each available channel.
5. The system of claim 1 , wherein transmitters considered as contributors to the predicted noise floor amounts are transmitters that are within a predetermined distance from the requesting radio device.
6. The system of claim 1 , wherein transmitters considered as contributors to the predicted noise floor amounts are transmitters that have a field strength at the transmitter's primary channel that is above a predetermined threshold.
7. The system of claim 1 , wherein transmitters considered as contributors to the predicted noise floor amounts are transmitters that have either one of a primary channel matching one of an available channel for the requesting radio device or a channel adjacent an available channel for the requesting radio device by a predetermined number of channel increments above or below the available channel.
8. The system of claim 1 , wherein the predicted interference is determined by:
for each transmitter considered, identify an interference contribution for the transmitter on the transmitter's primary channel and out-of-band emissions for adjacent channels that are a predetermined number of channel increments above or below the primary channel; and
for each available channel, sum the corresponding interference contributions from each transmitter.
9. The system of claim 8 , for each channel for which sensed interference data is available, the system further includes the sensed interference data in the sum of the interference contributions from each transmitter.
10. The system of claim 8 , wherein the predicted noise floor amount for each available channel is adjusted for antenna characteristics of the requesting radio device.
11. The system of claim 8 , wherein the interference contribution for the transmitter's primary channel is determined using a path loss model and the distance between the transmitter and the requesting radio device.
12. The system of claim 11 , wherein the interference contribution for the channels adjacent the transmitter's primary channel is determined by reducing the interference contribution for the transmitter's primary channel by a predetermined amount corresponding to the number of channel increments from the primary channel.
13. A method of providing channel maps of available spectrum to radio devices, comprising:
receiving a request for a channel map from one of the radio devices;
determine channels that are available to the requesting radio device for wireless communications;
determining, for each channel determined to be available, a predicted noise floor amount caused by high-power protected transmitters that are known to the system prior to receipt of the request, wherein the determination of predicted noise floor is made using a path loss model for a location of the requesting radio device, and wherein, for each predicted noise floor, interference from primary channel and out-of-band emissions of the transmitters is considered; and
transmitting a channel map of the available channels to the requesting radio device, the channel map indicating relative predicted noise floor amount among the available channels.
14. The method of claim 13 , wherein the request is a whitespace channel map request.
15. The method of claim 13 , wherein the available channels in the channel map are ranked in order of noise floor from least to most to indicate the relative noise floor amount among the available channels.
16. The method of claim 13 , wherein the channel map includes the determined noise floor amount for each available channel.
17. The method of claim 13 , wherein transmitters considered during the determining of the predicted noise floor amounts are transmitters that are within a predetermined distance from the requesting radio device.
18. The method of claim 13 , wherein transmitters considered during the determining of the predicted noise floor amounts are transmitters that have a field strength at the transmitter's primary channel that is above a predetermined threshold.
19. The method of claim 13 , wherein transmitters considered during the determining of the predicted noise floor amounts are transmitters that have either one of a primary channel matching one of an available channel for the requesting radio device or a channel adjacent an available channel for the requesting radio device by a predetermined number of channel increments above or below the available channel.
20. The method of claim 13 , wherein the predicted interference is determined by:
for each transmitter considered, identify an interference contribution for the transmitter on the transmitter's primary channel and out-of-band emissions for adjacent channels that are a predetermined number of channel increments above or below the primary channel; and
for each available channel, sum the corresponding interference contributions from each transmitter.
21. The method of claim 20 , for each channel for which sensed interference data is available, further including the sensed interference data in the sum of the interference contributions from each transmitter.
22. The method of claim 20 , wherein the predicted noise floor for each available channel is adjusted for antenna characteristics of the requesting radio device.
23. The method of claim 20 , wherein the interference contribution for the transmitter's primary channel is determined using a path loss model and the distance between the transmitter and the requesting radio device.
24. The method of claim 23 , wherein the interference contribution for the channels adjacent the transmitter's primary channel is determined by reducing the interference contribution for the transmitter's primary channel by a predetermined amount corresponding to the number of channel increments from the primary channel.