# US 2014/0192691 A1 · Reliable delivery of data specified for transmission by multicasting in wireless networks > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0192691 A1 - Document ID: US20140192691A1 - Status: Published application - Kind: A1 - Application number: 13/735,051 - Filed: 2013-01-07 - Published: 2014-07-10 - Earliest claimed: 2013-01-07 - Assignees: GainSpan Corporation - Applicants: Gainspan Corporation - Inventors: Pankaj Vyas; Vishal Batra - Web page: https://patentgrep.com/patent/US20140192691A1 ## CPC - H04W 4/06: Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services - H04W 52/0212: {managed by the network, e.g. network or access point is leader and terminal is follower} - 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 An access point (AP) of a WLAN maintains a list of wireless clients in the WLAN that belong to a special class. The AP receives data to be transmitted to the wireless clients as a multicast packet, and examines the list to determine whether any wireless clients belong to the special class. If none of the wireless clients belongs to the special class, the AP transmits the data as a multicast packet. However, if one or more wireless clients belong to the special class, the AP transmits the data in the form of unicast packets to each wireless client of the special class in addition to transmitting the data as a multicast packet. ## Claims ### Claim 1 A method of reliably delivering data in a wireless local area network (WLAN), said WLAN comprising an access point (AP) and a plurality of wireless clients, said method being implemented in said AP, said method comprising: maintaining data indicating a list of wireless clients in said plurality of wireless clients that belong to a special class; receiving data, which is to be transmitted on said WLAN in the form of a multicast packet; examining said list to determine whether any wireless client is present in said special class; and if said examining determines that no wireless client is present in said special class, then transmitting said data as said multicast packet on said WLAN, but if said examining determines that wireless clients are present in said special class, then transmitting said data in the form of unicast packets on said WLAN to each wireless client of said special class in addition to transmitting said data as said multicast packet on said WLAN. ### Claim 2 (depends on 1) The method of claim 1, wherein membership to said special class is based on a requirement of a duration of a power-down interval of a wireless client operating in Power-Save Poll mode (PSPM), wherein a first client having a longer duration for said power-down interval is included in said list and a second client having a shorter duration for said power-down interval is not included in said list, wherein each of said first client and said second client is comprised in said plurality of clients. ### Claim 3 (depends on 2) The method of claim 2, wherein, prior to transmitting said data in the form of a first unicast packet, said AP transmits a first beacon frame indicating that said first unicast packet is available for delivery to a corresponding wireless client of said special class, wherein said corresponding wireless client transmits a PS-Poll frame in response to receipt of said first beacon frame, said AP transmitting said data in the form of said first unicast packet only upon receipt of said PS-Poll frame. ### Claim 4 (depends on 3) The method of claim 3, wherein, prior to transmitting said data as said multicast packet on said WLAN, said AP transmits a second beacon frame indicating that said multicast packet is available for delivery, said AP thereafter transmitting said multicast packet without waiting to receive a confirmation of availability from said wireless clients to receive said multicast packet. ### Claim 5 (depends on 4) The method of claim 4, wherein said multicast packet is an address resolution protocol (ARP) request packet. ### Claim 6 (depends on 2) The method of claim 2, wherein said first client requests for membership to said special class during association with said AP. ### Claim 7 (depends on 2) The method of claim 2, wherein said first client requests for membership to said special class in a vendor-specific information element (IE) of a probe request message transmitted to said AP. ### Claim 8 (depends on 2) The method of claim 2, wherein said AP indicates support for clients of said special class in one or both of a beacon frame and a vendor-specific information element (IE) of a probe response message. ### Claim 9 (depends on 2) The method of claim 2, wherein said AP is designed to be able to buffer data destined for said first client for a longer duration than data destined for said second client. ### Claim 10 (depends on 2) The method of claim 2, wherein said AP disables group key updates for wireless clients of said special class. ### Claim 11 A non-transitory machine readable medium storing one or more sequences of instructions for execution by one or more processors in an access point (AP) of a wireless local area network (WLAN), wherein said WLAN also includes a plurality of wireless clients, wherein execution of said one or more sequences of instructions by said one or more processors causes said AP to perform the actions of: maintaining data indicating a list of wireless clients in said plurality of wireless clients that belong to a special class; receiving data, which is to be transmitted on said WLAN in the form of a multicast packet; examining said list to determine whether any wireless client is present in said special class; and if said examining determines that no wireless client is present in said special class, then transmitting said data as said multicast packet on said WLAN, but if said examining determines that wireless clients are present in said special class, then transmitting said data in the form of unicast packets on said WLAN to each wireless client of said special class in addition to transmitting said data as said multicast packet on said WLAN. ### Claim 12 (depends on 11) The non-transitory machine readable medium of claim 11, wherein membership to said special class is based on a requirement of a duration of a power-down interval of a wireless client operating in Power-Save Poll mode (PSPM), wherein a first client having a longer duration for said power-down interval is included in said list and a second client having a shorter duration for said power-down interval is not included in said list, wherein each of said first client and said second client is comprised in said plurality of clients. ### Claim 13 (depends on 12) The non-transitory machine readable medium of claim 12, wherein, prior to transmitting said data in the form of a first unicast packet, said AP transmits a first beacon frame indicating that said first unicast packet is available for delivery to a corresponding wireless client of said special class, wherein said corresponding wireless client transmits a PS-Poll frame in response to receipt of said first beacon frame, said AP transmitting said data in the form of said first unicast packet only upon receipt of said PS-Poll frame. ### Claim 14 (depends on 13) The non-transitory machine readable medium of claim 13, wherein, prior to transmitting said data as said multicast packet on said WLAN, said AP transmits a second beacon frame indicating that said multicast packet is available for delivery, said AP thereafter transmitting said multicast packet without waiting to receive a confirmation of availability from said wireless clients to receive said multicast packet. ### Claim 15 (depends on 14) The non-transitory machine readable medium of claim 14, wherein said multicast packet is an address resolution protocol (ARP) request packet. ### Claim 16 An Access Point (AP) of a wireless local area network (WLAN), wherein said WLAN also includes a plurality of wireless clients, said AP comprising: a memory to store instructions; a processor to retrieve instructions from said memory and to execute said instructions, wherein execution of said retrieved instructions causes said AP to perform the actions of: maintaining data indicating a list of wireless clients in said plurality of wireless clients that belong to a special class; receiving data, which is to be transmitted on said WLAN in the form of a multicast packet; examining said list to determine whether any wireless client is present in said special class; and if said examining determines that no wireless client is present in said special class, then transmitting said data as said multicast packet on said WLAN, but if said examining determines that wireless clients are present in said special class, then transmitting said data in the form of unicast packets on said WLAN to each wireless client of said special class in addition to transmitting said data as said multicast packet on said WLAN. ### Claim 17 (depends on 16) The AP of claim 16, wherein membership to said special class is based on a requirement of a duration of a power-down interval of a wireless client operating in Power-Save Poll mode (PSPM), wherein a first client having a longer duration for said power-down interval is included in said list and a second client having a shorter duration for said power-down interval is not included in said list, wherein each of said first client and said second client is comprised in said plurality of clients. ### Claim 18 (depends on 17) The AP of claim 17, wherein, prior to transmitting said data in the form of a first unicast packet, said AP transmits a first beacon frame indicating that said first unicast packet is available for delivery to a corresponding wireless client of said special class, wherein said corresponding wireless client transmits a PS-Poll frame in response to receipt of said first beacon frame, said AP transmitting said data in the form of said first unicast packet only upon receipt of said PS-Poll frame. ### Claim 19 (depends on 18) The AP of claim 18, wherein, prior to transmitting said data as said multicast packet on said WLAN, said AP transmits a second beacon frame indicating that said multicast packet is available for delivery, said AP thereafter transmitting said multicast packet without waiting to receive a confirmation of availability from said wireless clients to receive said multicast packet. ### Claim 20 (depends on 16) The AP of claim 16, wherein said multicast packet is an address resolution protocol (ARP) request packet.