# US 9,439,091 B2 · Midpacket detection schemes for clear channel assessment (CCA) > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,439,091 B2 - Document ID: US9439091B2 - Status: Granted - Kind: B2 - Application number: 14/466,031 - Filed: 2014-08-22 - Published: 2015-03-12 - Granted: 2016-09-06 - Earliest claimed: 2013-09-06 - Assignees: QUALCOMM Incorporated - Applicants: QUALCOMM Incorporated - Inventors: Bin Tian; Eugene Jong-Hyon Baik; Sameer Vermani; Tao Tian - Web page: https://patentgrep.com/patent/US9439091B2 ## CPC - H04W 24/08: Testing, {supervising or monitoring} using real traffic - H04L 27/0006: {Assessment of spectral gaps suitable for allocating digitally modulated signals, e.g. for carrier allocation in cognitive radio (for spectrum sharing between different networks H04W16/14)} - H04W 52/0216: {using a pre-established activity schedule, e.g. traffic indication frame} - H04W 52/0229: {where the received signal is a wanted signal} - H04W 74/0825: {with collision detection} - H04L 5/001: {the frequencies being arranged in component carriers} - H04W 84/12: WLAN [Wireless Local Area Networks] - Y02D 30/70: in wireless communication networks - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - Y02D: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE ## Abstract Certain aspects of the present disclosure provide methods and apparatus for detecting ongoing transmissions and assessing channel state, based on midpacket detection. One example method generally includes receiving signals on a primary channel; detecting, based on the received signals, occurrence or non-occurrence of a first ongoing packet transmission on a primary channel; and generating at least one of a busy signal or an idle signal based on the detection. In this manner, collisions may be avoided. ## Claims ### Claim 1 An apparatus for wireless communications, comprising: a receiver configured to receive signals on a primary channel; and a processing system configured to: detect, based on the received signals, occurrence or non-occurrence of a first on-going packet transmission on the primary channel, wherein the processing system is further configured to detect occurrence or non-occurrence of a second on-going packet transmission on a secondary channel, and wherein a first detection level is used when performing detection for the primary channel and a second detection level is used when performing detection for the secondary channel; and generate at least one of a busy signal or an idle signal based on the detection. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the processing system is configured to perform the detection of occurrence or non-occurrence of the first on-going packet transmission as part of a clear channel assessment (CCA) of the primary channel. ### Claim 3 (depends on 1) The apparatus of claim 1, wherein the processing system is configured to perform the detection of occurrence or non-occurrence of the first on-going packet transmission on the primary channel upon waking up and subsequently during at least one of an interframe space period or a countdown period. ### Claim 4 (depends on 3) The apparatus of claim 3, wherein: the first detection level is used when performing detection of occurrence or non-occurrence of the first on-going packet transmission on the primary channel upon waking up; and a third detection level is used when performing detection of occurrence or non-occurrence of the first on-going packet transmission on the primary channel during the at least one of the interframe space period or the countdown period. ### Claim 5 An apparatus for wireless communications, comprising: means for receiving signals on a primary channel; means for detecting, based on the received signals, occurrence or non-occurrence of a first on-going packet transmission on the primary channel, wherein the means for detecting is further configured to detect occurrence or non-occurrence of a second on-going packet transmission on a secondary channel, and wherein a first detection level is used when performing detection for the primary channel and a second detection level is used when performing detection for the secondary channel; and means for generating at least one of a busy signal or an idle signal based on the detection. ### Claim 6 (depends on 5) The apparatus of claim 5, wherein the means for detecting is configured to perform the detection of occurrence or non-occurrence of the first on-going packet transmission as part of a clear channel assessment (CCA) of the primary channel. ### Claim 7 (depends on 5) The apparatus of claim 5, wherein the means for detecting is configured to perform the detection of occurrence or non-occurrence of the first on-going packet transmission upon waking up and subsequently during at least one of an interframe space period or a countdown period. ### Claim 8 (depends on 7) The apparatus of claim 7, wherein: the first detection level is used when performing detection of occurrence or non-occurrence of the first on-going packet transmission on the primary channel upon waking up; and a third detection level is used when performing detection of occurrence or non-occurrence of the first on-going packet transmission on the primary channel during the at least one of the interframe space period or the countdown period. ### Claim 9 A method for wireless communications, comprising: receiving signals on a primary channel; detecting, based on the received signals, occurrence or non-occurrence of a first on-going packet transmission on the primary channel, wherein detecting comprises detecting occurrence or non-occurrence of a second on-going packet transmission on a secondary channel, and wherein a first detection level is used when performing detection for the primary channel and a second detection level is used when performing detection for the secondary channel; and generating at least one of a busy signal or an idle signal based on the detection. ### Claim 10 (depends on 9) The method of claim 9, wherein the detecting of occurrence or non-occurrence of the first on-going packet transmission is performed as part of a clear channel assessment (CCA) of the primary channel. ### Claim 11 (depends on 9) The method of claim 9, wherein the detecting of occurrence or non-occurrence of the first on-going packet transmission is performed upon waking up and subsequently during at least one of an interframe space period or a countdown period. ### Claim 12 (depends on 11) The method of claim 11, wherein: the first detection level is used when performing detection of occurrence or non-occurrence of the first on-going packet transmission on the primary channel upon waking up; and a third detection level is used when performing detection of occurrence or non-occurrence of the first on-going packet transmission on the primary channel during the at least one of the interframe space period or the countdown period. ### Claim 13 A non-transitory computer-readable medium having instructions stored thereon for: receiving signals on a primary channel; detecting, based on the received signals, occurrence or non-occurrence of a first on-going packet transmission on the primary channel, wherein detecting comprises detecting occurrence or non-occurrence of a second on-going packet transmission on a secondary channel, and wherein a first detection level is used when performing detection for the primary channel and a second detection level is used when performing detection for the secondary channel; and generating at least one of a busy signal or an idle signal based on the detection. ### Claim 14 A wireless node, comprising: at least one antenna; a receiver configured to receive, via the at least one antenna, signals on a primary channel; and a processing system configured to detect, based on the received signals, occurrence or non-occurrence of a first on-going packet transmission on the primary channel and to generate at least one of a busy signal or an idle signal based on the detection, wherein the processing system is further configured to detect occurrence or non-occurrence of a second on-going packet transmission on a secondary channel, and wherein a first detection level is used when performing detection for the primary channel and a second detection level is used when performing detection for the secondary channel.