# US 2008/0186944 A1 · Method and System for Robust MAC Signaling > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2008/0186944 A1 - Document ID: US20080186944A1 - Status: Published application - Kind: A1 - Application number: 11/671,800 - Filed: 2007-02-06 - Published: 2008-08-07 - Earliest claimed: 2007-02-06 - Assignees: Research In Motion Limited - Inventors: Takashi Suzuki; Gordon Peter Young; James Earl Womack - Web page: https://patentgrep.com/patent/US20080186944A1 ## CPC - H04L 1/1812: Hybrid protocols; Hybrid automatic repeat request [HARQ] - H04L 1/1685: {the supervisory signal being transmitted in response to a specific request, e.g. to a polling signal} - H04L 1/1858: {Transmission or retransmission of more than one copy of acknowledgement message} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A method for indicating and interpreting robust MAC signaling, the indicating method having the steps of: checking whether a MAC-PDU contains control information; and if yes, providing an indication to use a robust configuration for a HARQ feedback transmission, and the interpreting method having the steps of: receiving a MAC-PDU; checking whether an indication for robust HARQ feedback transmission is provided; and if yes, utilizing robust HARQ feedback transmission. ## Claims ### Claim 1 A method for indicating robust Medium Access Control (MAC) signaling comprising the steps of: checking whether a MAC protocol data unit (MAC-PDU) contains control information; and if yes, providing an indication to use a robust configuration for a hybrid automatic repeat request (HARQ) feedback transmission. ### Claim 2 (depends on 1) The method of claim 1, wherein the indication comprises a reserved downlink shared control channel (DLSCCH), wherein the sending of a MAC-PDU that requires robust HARQ feedback transmission is signaled on a reserved DLSCCH and the sending of a MAC-PDU not requiring robust HARQ feedback transmission is signaled on a non-reserved DLSCCH. ### Claim 3 (depends on 2) The method of claim 2, wherein a MAC-PDU indicated on a reserved DLSCCH has a different format when compared to a MAC-PDU indicated on a non-reserved DLSCCH. ### Claim 4 (depends on 1) The method of claim 1, wherein the indication comprises the use of a one-bit indication on the DLSCCH, wherein normal HARQ feedback transmission is signaled when the bit is not toggled and robust HARQ feedback transmission is signaled when the bit is toggled. ### Claim 5 (depends on 1) The method of claim 1, wherein the indication comprises the use of a different Radio Network Temporary Identity (RNTI) for MAC-PDUs requiring robust HARQ feedback transmission from the RNTI for MAC-PDUs not requiring robust HARQ feedback transmission. ### Claim 6 (depends on 5) The method of claim 5, wherein two RNTIs are signaled to a User Equipment (UE) utilizing a Radio Resource Control (RRC) message. ### Claim 7 (depends on 5) The method of claim 5, wherein one RNTI is signaled to a User Equipment (UE) utilizing a Radio Resource Control signaling and the UE takes a compliment of the RNTI to use to determine the alternative RNTI. ### Claim 8 (depends on 1) The method of claim 1, wherein the indication is a field in a header of the MAC-PDU. ### Claim 9 (depends on 8) The method of claim 8, wherein the indication signals that a predefined increment, pre-configured by a Radio Resource Control (RRC), is used as the number to increase the number of repetitions of HARQ feedback transmission by. ### Claim 10 (depends on 8) The method of claim 8, wherein the indication is a repetition field, included in the header of the MAC-PDU. ### Claim 11 (depends on 10) The method of claim 10, wherein the repetition field is set to a delta value if the MAC-PDU contains the indication for robust HARQ feedback transmission, the delta value indicating a number to increase repetitions of HARQ feedback transmissions by. ### Claim 12 (depends on 10) The method of claim 10, wherein the repetition field is an absolute value indicating the number of repetitions of HARQ feedback expected. ### Claim 13 (depends on 9) The method of claim 9, further comprising the step of comparing the number of acknowledgements received with the number of non-acknowledgements and discontinuous transmissions (DTX) received. ### Claim 14 (depends on 13) The method of claim 13, wherein the MAC-PDU is retransmitted if the comparing step finds the number of acknowledgements is less than or equal to the number of non-acknowledgements and DTX. ### Claim 15 (depends on 13) The method of claim 13, wherein the MAC-PDU is retransmitted if the comparing step finds the number of acknowledgements is less than or equal to a configured threshold. ### Claim 16 (depends on 13) The method of claim 13, wherein the MAC-PDU is retransmitted if the number of acknowledgements and non-acknowledgements is less than an expected number of repetitions. ### Claim 17 (depends on 1) The method of claim 1, wherein the robust HARQ feedback transmission comprises one of: increasing transmission power for the HARQ feedback transmission; repeating acknowledgement or non-acknowledgement a pre-specified number of times; and adding a preamble and a post-amble to the acknowledgement and non-acknowledgment messages. ### Claim 18 (depends on 1) The method of claim 1, wherein the method is performed on an enhanced node B. ### Claim 19 A method for interpreting an indication of robust Medium Access Control (MAC) signaling comprising the steps of: receiving a MAC protocol data unit (MAC-PDU); checking whether an indication for robust hybrid automatic repeat request (HARQ) feedback transmission is provided; and if yes, utilizing robust hybrid automatic repeat request (HARQ) feedback transmission. ### Claim 20 (depends on 19) The method of claim 19, wherein the indication comprises a reserved downlink shared control channel (DLSCCH), wherein the sending of the MAC-PDU requiring robust HARQ feedback transmission is signaled on a reserved DLSCCH and the sending of a MAC-PDU that does not require robust HARQ feedback transmission is signaled on a non-reserved DLSCCH. ### Claim 21 (depends on 20) The method of claim 20, wherein a MAC-PDU indicated on a reserved DLSCCH has a different format when compared to a MAC-PDU indicated on a non-reserved DLSCCH. ### Claim 22 (depends on 21) The method of claim 21, wherein the format of bits is interpreted based on whether the sending of the MAC-PDU was indicated on a reserved DLSCCH or a non-reserved DLSCCH. ### Claim 23 (depends on 21) The method of claim 21, wherein the reserved DLSCCH is used as a default indication channel for UEs that are accessing the network in an unsynchronized manner. ### Claim 24 (depends on 19) The method of claim 19, wherein the indication comprises the use of a one bit indication on the DLSCCH, wherein normal HARQ feedback transmission is signaled when the bit is not toggled and robust HARQ feedback transmission is signaled when the bit is toggled. ### Claim 25 (depends on 19) The method of claim 19, wherein the indication comprises the use of a different Radio Network Temporary Identity (RNTI) for MAC-PDUs with requiring robust HARQ feedback transmission than the RNTI for MAC-PDUs not requiring robust HARQ feedback transmission. ### Claim 26 (depends on 25) The method of claim 25, wherein two RNTIs are signaled to the User Equipment (UE) utilizing a Radio Resource Control (RRC). ### Claim 27 (depends on 26) The method of claim 26, wherein one RNTI is signaled to the User Equipment (UE) utilizing a Radio Resource Control signaling and the UE takes a compliment of the RNTI to use in determining the alternative RNTI. ### Claim 28 (depends on 19) The method of claim 19, wherein the indication is in a header of the MAC-PDU. ### Claim 29 (depends on 19) The method of claim 19, wherein the indication signals that a predefined increment, pre-configured by a Radio Resource Control (RRC), is used as the number to increase the number of repetitions of HARQ feedback transmission by. ### Claim 30 (depends on 28) The method of claim 28, wherein the indication is a repetition field, included in the header of the MAC-PDU. ### Claim 31 (depends on 30) The method of claim 30, wherein the repetition field is set to a delta value if the MAC-PDU contains an indication requiring robust HARQ feedback transmission, the delta value indicating a number to increase repetitions of HARQ feedback transmissions by. ### Claim 32 (depends on 30) The method of claim 30, wherein the repetition field is an absolute value indicating the number of repetitions of HARQ feedback expected. ### Claim 33 (depends on 30) The method of claim 30, further comprising the step of sending the number of acknowledgements indicated by the repetition field if the MAC-PDU is decoded correctly. ### Claim 34 (depends on 19) The method of claim 19, wherein the robust HARQ feedback transmission comprises one of: increasing transmission power for the HARQ feedback transmission; repeating acknowledgement or non-acknowledgement a pre-specified number of times; and adding a preamble and a post-amble to acknowledgement and non-acknowledgment messages. ### Claim 35 (depends on 19) The method of claim 19 wherein the robust configuration for HARQ feedback transmission is signaled by a Radio Resource Control signaling during radio bearer configuration or re-configuration. ### Claim 36 An enhanced Node B (eNB) adapted to indicate robust Medium Access Control (MAC) signaling, characterized by: means for checking whether a MAC protocol data unit (MAC-PDU) contains control information; and means for providing an indication to use a robust configuration for a hybrid automatic repeat request (HARQ) feedback transmission. ### Claim 37 (depends on 36) The eNB of claim 36, wherein the indication comprises one of: a) a reserved downlink shared control channel (DLSCCH), wherein the sending of a MAC-PDU that requires robust HARQ feedback transmission is signaled on a reserved DLSCCH and the sending of a MAC-PDU that does not require robust HARQ feedback transmission is signaled on a non-reserved DLSCCH; b) a one bit indication on the DLSCCH, wherein normal HARQ feedback transmission is signaled when the bit is not toggled and robust HARQ feedback transmission is signaled when the bit is toggled; c) a different Radio Network Temporary Identity (RNTI) for MAC-PDUs requiring robust HARQ feedback transmission than the RNTI for MAC-PDUs not requiring robust HARQ feedback transmission; or d) a field in a header of the MAC-PDU. ### Claim 38 (depends on 36) The eNB of claim 36, further comprising means for checking the HARQ feedback received and comparing the number of feedback messages expected according to the associated robust HARQ indicator of the originally transmitted MAC-PDU. ### Claim 39 A User Equipment (UE) adapted to interpret an indication of robust Medium Access Control (MAC) signaling, characterized by: means for receiving a MAC protocol data unit (MAC-PDU); means for checking whether an indication for robust hybrid automatic repeat request (HARQ) feedback transmission is provided; and means for utilizing robust hybrid automatic repeat request (HARQ) feedback transmission. ### Claim 40 (depends on 39) The UE of claim 39, wherein the indication comprises one of: a) a reserved downlink shared control channel (DLSCCH), wherein the sending of the MAC-PDU requiring robust HARQ feedback transmission is signaled on a reserved DLSCCH and the sending of a MAC-PDU that does not require robust HARQ feedback transmission is signaled on a non-reserved DLSCCH; b) a one bit indication on the DLSCCH, wherein normal HARQ feedback transmission is signaled when the bit is not toggled and robust HARQ feedback transmission is signaled when the bit is toggled; c) a different Radio Network Temporary Identity (RNTI) for MAC-PDUs requiring robust HARQ feedback transmission than the RNTI for MAC-PDUs not requiring robust HARQ feedback transmission; or d) a field in a header of the MAC-PDU.