# US 8,787,962 B2 · Transmit opportunity detection > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,787,962 B2 - Document ID: US8787962B2 - Status: Granted - Kind: B2 - Application number: 13/260,698 - Filed: 2010-03-26 - Published: 2012-05-31 - Granted: 2014-07-22 - Earliest claimed: 2009-03-27 - Assignees: Regents of the University of Minnesota - Applicants: Nikhil Kundargi; Ahmed H. Tewfik - Inventors: Nikhil Kundargi; Ahmed H. Tewfik - Web page: https://patentgrep.com/patent/US8787962B2 ## CPC - H04W 52/343: {taking into account loading or congestion level} - H04W 52/241: {taking into account channel quality metrics, e.g. SIR, SNR, CIR or Eb/lo} - H04W 52/362: {Aspects of the step size} - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract The present application discusses, among other things, apparatus and methods for detecting and using a excess capacity on a wireless network medium. A method embodiment includes calculating a differential metric based on a first metric and a second metric for a primary network. The primary network can have a medium shared with a secondary network. The first metric can be based on a first distribution of traffic on the primary network and can correspond to absence of a perturbation of the medium. The second metric can be based on a second distribution of traffic on the primary network and can correspond to a perturbation of the medium from a node of the secondary network. The method can include selecting a transmission power for the node based on the differential metric. ## Claims ### Claim 1 A method comprising: calculating a differential metric using a processor of a node on a secondary network, the differential metric based on a first metric and a second metric for a primary network, the primary network having a medium shared with the secondary network, the first metric based on a first distribution of traffic on the primary network and corresponding to absence of a perturbation of the medium, the second metric based on a second distribution of traffic on the primary network and corresponding to a perturbation of the medium from the node; and selecting a transmission power for the node based on the differential metric. ### Claim 2 (depends on 1) The method of claim 1, further including determining at least one of the first metric and the second metric using the processor of the node and a distributional divergence metric. ### Claim 3 (depends on 1) The method of claim 1, further including iteratively estimating the second metric using the processor of the node. ### Claim 4 (depends on 1) The method of claim 1, wherein selecting the transmission power includes determining a power level that provides a minimum signal-to-noise ratio (SNR) of a node on the primary network using the processor of the node. ### Claim 5 (depends on 4) The method of claim 4, wherein selecting a transmission power includes incrementally increasing the transmission power if the differential metric meets a threshold criteria indicative of an insubstantial divergence between the first distribution and the second distribution. ### Claim 6 (depends on 4) The method of claim 4, wherein selecting a transmission power includes reducing the transmission power if the differential metric does not meet a threshold criteria indicative of an insubstantial divergence between the first distribution and the second distribution. ### Claim 7 (depends on 1) The method of claim 1, wherein calculating the differential metric includes implementing a goodness-of-fit (GOF) test with respect to the first distribution using primary network samples corresponding to the second distribution. ### Claim 8 (depends on 7) The method of claim 7, wherein implementing the GOF test includes executing a sequential Kolmogorov-Smirnov algorithm. ### Claim 9 (depends on 8) The method of claim 8, wherein selecting a transmission power includes incrementally increasing the transmission power if the differential metric meets a threshold criteria indicative of an insubstantial divergence between the first distribution and the second distribution. ### Claim 10 (depends on 8) The method of claim 8, wherein selecting a transmission power includes reducing the transmission power if the differential metric does not meet a threshold criteria indicative of an insubstantial divergence between the first distribution and the second distribution. ### Claim 11 An apparatus comprising: a receiver configured to receive information corresponding to a primary network, the primary network having a medium shared with a secondary metric; a service module to generate a first service metric corresponding to a signal to noise ratio (SNR) of the received information in absence of a perturbation on the medium and to generate a second service metric corresponding to a SNR of the received information in view of a perturbation generated by the apparatus on the network; a processor configured to generate a result based on a first comparison of the first service metric and the second service metric and configured to select a transmission parameter based on the result; and a transmitter configured to transmit information using the secondary network and using the transmission parameter, the transmitter configured to provide the perturbation. ### Claim 12 (depends on 11) The apparatus of claim 11, wherein the processor is configured to operate using a Media Access Control (MAC) layer, the MAC layer including the service module. ### Claim 13 (depends on 11) The apparatus of claim 11, wherein the transmission parameter includes a transmission power parameter. ### Claim 14 (depends on 13) The apparatus of claim 13, wherein the processor is configured to incrementally increase the transmission power parameter based on a second comparison of the result and a predetermined criteria. ### Claim 15 (depends on 13) The apparatus of claim 13, wherein the processor is configured to reduce the transmission power parameter based on a second comparison of the result and a predetermined criteria.