# US 2014/0192712 A1 · Methods and apparatus for controlling access points coupled to a common power source > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0192712 A1 - Document ID: US20140192712A1 - Status: Published application - Kind: A1 - Application number: 13/737,828 - Filed: 2013-01-09 - Published: 2014-07-10 - Earliest claimed: 2013-01-09 - Assignees: QUALCOMM Incorporated - Applicants: Qualcomm Incorporated - Inventors: Junyi Li; Vincent D. Park; Jin-Der Wang - Web page: https://patentgrep.com/patent/US20140192712A1 ## CPC - H04W 52/0206: {in access points, e.g. base stations} - H04W 52/346: {distributing total power among users or channels} - H04W 52/143: {Downlink power control} - H04W 52/40: during macro-diversity or soft handoff - 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) - 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 Power efficient methods and apparatus for detecting wireless terminals in a relatively small geographic area are described. Wireless terminals transmit discovery signals and/or other signals which may be detected by an access point. Various described methods and apparatus are well suited for embodiments where multiple access points, which obtain power from a common power source and/or via a common power bus, with limited power delivery capability. To address power constraints, access points are controlled by a gateway device coupled to the access points so that one or more access points perform monitoring at different times with one or more access points having their receivers powered off while another access point monitors for wireless terminal signals. Power consumption from the common power source is managed by controlling power consumption associated with monitoring operations performed by one or more access points coupled to a common power source. ## Claims ### Claim 1 A method of operating a gateway device, the method comprising: controlling a first subset of access points, in a plurality of access points, which obtain power from a common power source, to monitor for a signal from a wireless terminal during a first period of time during which at least some access points in said plurality of access points do not monitor for wireless terminal signals, said first subset of access points including one or more access points, said first subset of access points including a first access point; receiving a signal from said first access point indicating detection of a signal from a wireless terminal; controlling, in response to receiving said signal indicating detection of a wireless terminal, at least a second access point in said plurality of access points to switch from a non-monitoring mode of operation to a monitoring mode of operation; and controlling at least the second access point to monitor for wireless terminal signals during a second period of time while said first access point does not monitor for wireless terminal signals. ### Claim 2 (depends on 1) The method of claim 1, further comprising: selecting access points in said plurality of access points to be included in said first subset of access points based on a first common power source power budget; and communicating to access points in said first subset of access points that they are to operate in a monitoring mode of operation during said first period of time. ### Claim 3 (depends on 2) The method of claim 2, wherein selecting access points to be included in said first subset of access points includes selecting a first plurality of access points distributed over a large area to monitor for wireless terminal signals. ### Claim 4 (depends on 3) The method of claim 3, further comprising: selecting access points in said plurality of access points to be included in a second subset of access points based on a second common power source power budget, and wherein said selecting access points to be included in a second subset of access points includes excluding from consideration for possible selection said first access point. ### Claim 5 (depends on 4) The method of claim 4, wherein said selecting access points to be included in a second subset of access points includes basing the selection of the second subset of access points on the location of said first access point. ### Claim 6 (depends on 5) The method of claim 5, wherein said selecting access points to be included in a second subset of access points includes applying a preference for selecting access points for inclusion in said second subset of access points which were not included in said first subset of access points. ### Claim 7 (depends on 5) The method of claim 5, wherein said selecting access points to be included in a second subset of access points includes selecting a cluster of access points in proximity to said first access point. ### Claim 8 (depends on 2) The method of claim 2, further comprising: selecting access points from said plurality of access points to be included in a third subset of access points based on said first common power source power budget; and communicating to access points in said third subset of access points that they are to operate in a monitoring mode of operation during a third period of time. ### Claim 9 A gateway device comprising: means for controlling a first subset of access points, in a plurality of access points, which obtain power from a common power source, to monitor for a signal from a wireless terminal during a first period of time during which at least some access points in said plurality of access points do not monitor for wireless terminal signals, said first subset of access points including one or more access points, said first subset of access points including a first access point; means for receiving a signal from said first access point indicating detection of a signal from a wireless terminal; means for controlling, in response to receiving said signal indicating detection of a wireless terminal, at least a second access point in said plurality of access points to switch from a non-monitoring mode of operation to a monitoring mode of operation; and means for controlling at least the second access point to monitor for wireless terminal signals during a second period of time while said first access point does not monitor for wireless terminal signals. ### Claim 10 (depends on 9) The gateway device of claim 9, further comprising: means for selecting access points in said plurality of access points to be included in said first subset of access points based on a first common power source power budget; and means for communicating to access points in said first subset of access points that they are to operate in a monitoring mode of operation during said first period of time. ### Claim 11 (depends on 10) The gateway device of claim 10, wherein said means for selecting access points to be included in said first subset of access points includes means for selecting a first plurality of access points distributed over a large area to monitor for wireless terminal signals. ### Claim 12 (depends on 11) The gateway device of claim 11, further comprising: means for selecting access points in said plurality of access points to be included in a second subset of access points based on a second common power source power budget, and wherein said means for selecting access points to be included in a second subset of access points includes means for excluding from consideration for possible selection said first access point. ### Claim 13 (depends on 12) The gateway device of claim 12, wherein said means for selecting access points to be included in a second subset of access points includes means for basing the selection of the second subset of access points on the location of said first access point. ### Claim 14 (depends on 13) The gateway device of claim 13, wherein said means for selecting access points to be included in a second subset of access points includes means for applying a preference for selecting access points for inclusion in said second subset of access points which were not included in said first subset of access points. ### Claim 15 A computer program product for use in a gateway device, the computer program product comprising: a non-transitory computer readable medium comprising: code for causing at least one computer to control a first subset of access points, in a plurality of access points, which obtain power from a common power source, to monitor for a signal from a wireless terminal during a first period of time during which at least some access points in said plurality of access points do not monitor for wireless terminal signals, said first subset of access points including one or more access points, said first subset of access points including a first access point; code for causing said at least one computer to receive a signal from said first access point indicating detection of a signal from a wireless terminal; code for causing said at least one computer to control, in response to receiving said signal indicating detection of a wireless terminal, at least a second access point in said plurality of access points to switch from a non-monitoring mode of operation to a monitoring mode of operation; and code for causing said at least one computer to control at least the second access point to monitor for wireless terminal signals during a second period of time while said first access point does not monitor for wireless terminal signals. ### Claim 16 A gateway device comprising: at least one processor configured to: control a first subset of access points, in a plurality of access points, which obtain power from a common power source, to monitor for a signal from a wireless terminal during a first period of time during which at least some access points in said plurality of access points do not monitor for wireless terminal signals, said first subset of access points including one or more access points, said first subset of access points including a first access point; receive a signal from said first access point indicating detection of a signal from a wireless terminal; control, in response to receiving said signal indicating detection of a wireless terminal, at least a second access point in said plurality of access points to switch from a non-monitoring mode of operation to a monitoring mode of operation; and control at least the second access point to monitor for wireless terminal signals during a second period of time while said first access point does not monitor for wireless terminal signals; and memory coupled to said at least one processor. ### Claim 17 (depends on 16) The gateway device of claim 16, wherein said at least one processor is further configured to: select access points in said plurality of access points to be included in said first subset of access points based on a first common power source power budget; and communicate to access points in said first subset of access points that they are to operate in a monitoring mode of operation during said first period of time. ### Claim 18 (depends on 17) The gateway device of claim 17, wherein said at least one processor is configured to select a first plurality of access points distributed over a large area to monitor for wireless terminal signals, as part of being configured to selecting access points to be included in said first subset of access points. ### Claim 19 (depends on 18) The gateway device of claim 18, wherein said at least one processor is further configured to: select access points in said plurality of access points to be included in a second subset of access points based on a second common power source power budget, and wherein said at least one processor is configured to exclude from consideration for possible selection said first access point, as part of being configured to select access points to be included in a second subset of access points. ### Claim 20 (depends on 19) The gateway device of claim 19, wherein said at least one processor is configured to base the selection of the second subset of access points on the location of said first access point, as part of being configured to select access points to be included in a second subset of access points.