# US 2020/0404704 A1 · Immediate retransmission scheme for real time applications > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2020/0404704 A1 - Document ID: US20200404704A1 - Status: Published application - Kind: A1 - Application number: 16/584,821 - Filed: 2019-09-26 - Published: 2020-12-24 - Earliest claimed: 2019-06-18 - Assignees: Sony Corporation - Applicants: Sony Corporation - Inventors: Liangxiao Xin; Mohamed Abouelseoud; Kazuyuki Sakoda - Web page: https://patentgrep.com/patent/US20200404704A1 ## CPC - H04L 1/1887: {Scheduling and prioritising arrangements} - H04W 74/0808: using carrier sensing, e.g. carrier sense multiple access [CSMA] - H04L 1/0003: {by switching between different modulation schemes} - H04L 1/1819: {with retransmission of additional or different redundancy} - H04L 1/1877: {for semi-reliable protocols, e.g. for less sensitive applications like streaming video (buffer level management for video bitstream control arrangements H04N21/44004)} - H04L 1/1896: {ARQ related signaling} - H04L 5/0055: {Physical resource allocation for ACK/NACK (for physical mapping arrangements in ARQ protocols H04L1/1861)} - H04L 5/0023: {Time-frequency-space} - H04L 5/0091: {Signalling for the administration of the divided path, e.g. signalling of configuration information} - H04W 84/12: WLAN [Wireless Local Area Networks] - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract A wireless communication circuit configured for communicating over a wireless local area network (WLAN) in its reception area to communicate real-time application (RTA) packets as well as non-real time (non-RTA) packets. RTA packet retransmission is performed with lower latency in response to performing an immediate retransmission scheme that can bypass the need to contend for channel access, and/or without waiting for notifications back from a receiver before channel access. In other instances the RTA packets contend for retransmission access without a contention time window increase. ## Claims ### Claim 1 An apparatus for wireless communication in a network, the apparatus comprising: (a) a wireless communication circuit configured for wirelessly communicating with at least one other wireless local area network (WLAN) station in its reception area; (b) a processor coupled to said wireless communication circuit within a station configured for operating on the WLAN; and (c) a non-transitory memory storing instructions executable by the processor; (d) wherein said instructions, when executed by the processor, perform one or more steps comprising: (i) operating said wireless communication circuit as a WLAN station configured to support communicating real-time application (RTA) packets that are sensitive to communication delays as well as non-real time packets; (ii) distinguishing real-time application (RTA) packets from non-real-time application (non-RTA) packets by prior negotiation, or packet header information, or a combination of prior negotiation and packet header information; (iii) performing retransmissions for non-real time application (non-RTA) packets using carrier sense multiple access/collision avoidance (CSMA/CA); and (iv) performing retransmissions for at least a portion of real time application (RTA) packets in response to bypassing a process of contending for channel access, and/or without waiting for notifications back from a receiver before channel access. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein said instructions, when executed by the processor, perform one or more steps comprising receiving notifications back from a receiver on packet success or packet error. ### Claim 3 (depends on 2) The apparatus of claim 2, wherein said instructions, when executed by the processor, perform said bypassing the process of contending for channel access in response to immediately retransmitting the real time application (RTA) packet without contending for channel access upon receiving a notification from a receiver of the real time application (RTA) packet. ### Claim 4 (depends on 2) The apparatus of claim 2: wherein station is operating as an access point (AP) on the network; and wherein said instructions, when executed by the processor, perform one or more steps comprising assigning subsets of subcarriers to multiple individual users. ### Claim 5 (depends on 4) The apparatus of claim 4, wherein said instructions, when executed by the processor, perform said assigning subsets of subcarriers by utilizing orthogonal frequency-division multiple access (OFDMA). ### Claim 6 (depends on 5) The apparatus of claim 5, wherein said instructions, when executed by the processor, perform orthogonal frequency-division multiple access (OFDMA) and embed retransmission scheduling information into notifications. ### Claim 7 (depends on 4) The apparatus of claim 4, wherein said instructions, when executed by the processor, performing orthogonal frequency-division multiple access (OFDMA) utilizes separate resource blocks as assigned by an AP. ### Claim 8 (depends on 1) The apparatus of claim 1, wherein said instructions, when executed by the processor, perform one or more steps comprising terminating retransmissions of a real-time application (RTA) packet when the packet lifetime has expired. ### Claim 9 (depends on 1) The apparatus of claim 1, wherein said notifications comprise an acknowledgement (ACK) indicating the packet was received correctly, and a negative acknowledgment (NACK) indicating the packet was received with error. ### Claim 10 (depends on 1) The apparatus of claim 1, wherein said instructions, when executed by the processor, perform one or more steps comprising transmitting a real-time application (RTA) packet multiple times without waiting for notifications back from the receiver. ### Claim 11 (depends on 1) The apparatus of claim 1, wherein said instructions, when executed by the processor, perform one or more steps comprising scheduling retransmission of a real-time application (RTA) packet after initial transmission of said RTA packet. ### Claim 12 (depends on 1) The apparatus of claim 1, wherein said instructions, when executed by the processor, perform steps further comprising retransmitting a real-time application (RTA) packet using a lower bit rate modulation and coding scheme (MCS) than when initial transmitted. ### Claim 13 (depends on 1) The apparatus of claim 1, wherein said instructions, when executed by the processor, perform steps further comprising performing retransmissions for a second portion of real time application (RTA) packets in response to performing collision avoidance without increasing contention time window length. ### Claim 14 An apparatus for wireless communication in a network, the apparatus comprising: (a) a wireless communication circuit configured for wirelessly communicating with at least one other wireless local area network (WLAN) station in its reception area; (b) a processor coupled to said wireless communication circuit within a station configured for operating on the WLAN; and (c) a non-transitory memory storing instructions executable by the processor; (d) wherein said instructions, when executed by the processor, perform one or more steps comprising: (i) operating said wireless communication circuit as a WLAN station configured to support communicating real-time application (RTA) packets that are sensitive to communication delays as well as non-real time packets; (ii) transmitting a packet to a receiver and receiving notifications back from the receiver on packet success or packet error; (iii) distinguishing real-time application (RTA) packets from non-real-time application (non-RTA) packets by prior negotiation, or packet header information, or a combination of prior negotiation and packet header information; (iv) performing retransmissions for non-real time application (non-RTA) packets using carrier sense multiple access/collision avoidance (CSMA/CA); (v) performing retransmissions for at least a portion of real time application (RTA) packets in response to bypassing a process of contending for channel access, and/or without waiting for notifications back from a receiver before channel access; and (vi) terminating retransmissions of a real-time application (RTA) packet when the packet lifetime has expired. ### Claim 15 (depends on 14) The apparatus of claim 14, wherein said instructions, when executed by the processor, perform said bypassing the process of contending for channel access in response to immediately retransmitting the real time application (RTA) packet without contention upon receiving a notification from a receiver of the real time application (RTA) packet error. ### Claim 16 (depends on 15) The apparatus of claim 15: wherein station is operating as an access point (AP) on the network; and wherein said instructions, when executed by the processor, perform one or more steps comprising assigning subsets of subcarriers to multiple individual users. ### Claim 17 (depends on 16) The apparatus of claim 16, wherein said instructions, when executed by the processor, perform said assigning subsets of subcarriers by utilizing orthogonal frequency-division multiple access (OFDMA). ### Claim 18 (depends on 17) The apparatus of claim 17, wherein said instructions, when executed by the processor, perform orthogonal frequency-division multiple access (OFDMA) and embeds retransmission scheduling information into notifications. ### Claim 19 (depends on 16) The apparatus of claim 16, wherein said instructions, when executed by the processor, performing orthogonal frequency-division multiple access (OFDMA) utilizes separate resource blocks as assigned by an AP. ### Claim 20 (depends on 14) The apparatus of claim 14, wherein said notifications comprise an acknowledgement (ACK) indicating the packet was received correctly, and a negative acknowledgment (NACK) indicating the packet was received with error. ### Claim 21 (depends on 14) The apparatus of claim 14, wherein said instructions, when executed by the processor, perform one or more steps comprising transmitting a real-time application (RTA) packet multiple times without waiting for notifications back from the receiver. ### Claim 22 (depends on 14) The apparatus of claim 14, wherein said instructions, when executed by the processor, perform one or more steps comprising scheduling retransmission of a real-time application (RTA) packet after initial transmission of said RTA packet. ### Claim 23 (depends on 14) The apparatus of claim 14, wherein said instructions, when executed by the processor, perform steps further comprising retransmitting a real-time application (RTA) packet using a lower bit rate modulation and coding scheme (MCS) than when initial transmitted. ### Claim 24 (depends on 14) The apparatus of claim 14, wherein said instructions, when executed by the processor, perform steps further comprising performing retransmissions for a second portion of real time application (RTA) packets in response to performing collision avoidance without increasing contention time window length. ### Claim 25 A method of performing wireless communication, comprising: (a) operating a wireless communication circuit as a WLAN station configured to support communicating real-time application (RTA) packets that are sensitive to communication delays as well as non-real time packets; (b) distinguishing real-time application (RTA) packets from non-real-time application (non-RTA) packets by prior negotiation, or packet header information, or a combination of prior negotiation and packet header information; (c) performing retransmissions for non-real time application (non-RTA) packets using carrier sense multiple access/collision avoidance (CSMA/CA); and (d) performing retransmissions for at least a portion of real time application (RTA) packets in response to bypassing a process of contending for channel access, and/or without waiting for notifications back from a receiver before channel access.