# US 2020/0288531 A1 · Enhanced machine type communications quick idle transition after connection release > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2020/0288531 A1 - Document ID: US20200288531A1 - Status: Published application - Kind: A1 - Application number: 16/495,059 - Filed: 2018-03-23 - Published: 2020-09-10 - Earliest claimed: 2017-04-26 - Assignees: QUALCOMM Incorporated - Applicants: QUALCOMM Incorporated - Inventors: Ashish Shankar IYER; Omesh Kumar HANDA; Chun-Hao HSU; Nitin PANT; Srinivasan RAJAGOPALAN; Liangchi HSU; Feilu LIU; Muthukumaran DHANAPAL; Alberto RICO ALVARINO; Zhibin DANG - Web page: https://patentgrep.com/patent/US20200288531A1 ## CPC - H04W 76/27: Transitions between radio resource control [RRC] states - H04W 76/34: Selective release of ongoing connections - H04L 1/18: Automatic repetition systems, e.g. Van Duuren systems - H04L 1/1812: Hybrid protocols; Hybrid automatic repeat request [HARQ] - H04W 4/70: Services for machine-to-machine communication [M2M] or machine type communication [MTC] - H04W 72/23: in the downlink direction of a wireless link, i.e. towards a terminal - H04W 76/30: Connection release - 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) ## Abstract Aspects of the present disclosure provide techniques to enable enhanced machine type communication (s) (eMTC) and/or narrowband Internet-of-Things (NB-IoT) devices to transition to idle mode after releasing a connection, such as a radio resource control (RRC) connection, more quickly than with previously known techniques. An example method includes determining, based on an indication received in a narrowband signal on a narrowband region of a bandwidth comprising a plurality of narrowband regions, whether to wait for a delay period, determined based on a configuration received from a network entity, before releasing a radio resource control (RRC) connection and releasing the RRC connection at a time in accordance with the determination. ## Claims ### Claim 1 A method for wireless communications by a user equipment (UE), comprising: determining, based on an indication received in a narrowband signal on a narrowband region of a bandwidth comprising a plurality of narrowband regions, whether to wait for a delay period, determined based on a configuration received from a network entity, before releasing a radio resource control (RRC) connection; and releasing the RRC connection at a time in accordance with the determination. ### Claim 2 (depends on 1) The method of claim 1, wherein: the narrowband signal comprises a command to release the RRC connection; the indication comprises an unset polling bit in a radio link control (RLC) layer portion of the narrowband signal; the determination is to not wait for the delay period; and the method further comprises: sending a hybrid automatic retransmission request (HARQ) acknowledgment (ACK) of the narrowband signal prior to releasing the RRC connection. ### Claim 3 (depends on 2) The method of claim 2, further comprising: powering down one or more radio components of the UE subsequent to releasing the RRC connection. ### Claim 4 (depends on 1) The method of claim 1, wherein: the narrowband signal comprises a command to release the RRC connection; the indication comprises a set polling bit in a radio link control (RLC) layer portion of the narrowband signal; the determination is to wait for the delay period, based on the polling bit; and the method further comprises: sending a hybrid automatic retransmission request (HARQ) acknowledgment (ACK) of the narrowband signal prior to releasing the RRC connection; receiving a first downlink control information (DCI) comprising an NO grant having a new data indicator (NDI) that is not toggled; and sending a layer 2 (L2) ACK of the narrowband signal, via transmission resources indicated in the NO grant, prior to releasing the RRC connection. ### Claim 5 (depends on 4) The method of claim 4, further comprising: receiving a second DCI comprising a request for a retransmission of the L2 ACK; and retransmitting the L2 ACK prior to releasing the RRC connection. ### Claim 6 (depends on 4) The method of claim 4, further comprising: determining, based on a coverage level of the UE, a length of the delay period. ### Claim 7 (depends on 6) The method of claim 6, wherein the determining the length of the delay period comprises: determining a length of a narrowband physical downlink control channel (NPDCCH) period based on a number of repetitions determined based on the coverage level; determining a number of the NPDCCH periods based on the coverage level; and calculating the delay period as the determined number of the NPDCCH periods. ### Claim 8 (depends on 4) The method of claim 4, further comprising: receiving a second DCI comprising another NO grant having an NDI that is toggled; and making a new determination, to not wait for the delay period before releasing the RRC connection, in response to receiving the second DCI. ### Claim 9 (depends on 7) The method of claim 7, wherein determining the number of the NPDCCH periods comprises selecting the number from a table of coverage levels, based on the coverage level. ### Claim 10 An apparatus for wireless communications, comprising: a processor configured to: determine, based on an indication received in a narrowband signal on a narrowband region of a bandwidth comprising a plurality of narrowband regions, whether to wait for a delay period, determined based on a configuration received from a network entity, before causing the apparatus to release a radio resource control (RRC) connection; and cause the apparatus to release the RRC connection at a time in accordance with the determination; and a memory coupled with the processor. ### Claim 11 (depends on 10) The apparatus of claim 10, wherein: the narrowband signal comprises a command to release the RRC connection; the indication comprises an unset polling bit in a radio link control (RLC) layer portion of the narrowband signal; and the processor is configured to: determine to not wait for the delay period; and cause the apparatus to send a hybrid automatic retransmission request (HARQ) acknowledgment (ACK) of the narrowband signal prior to releasing the RRC connection. ### Claim 12 (depends on 11) The apparatus of claim 11, wherein the processor is configured to: cause the apparatus to power down one or more radio components of the apparatus subsequent to releasing the RRC connection. ### Claim 13 (depends on 10) The method of claim 10, wherein: the narrowband signal comprises a command to release the RRC connection; the indication comprises a set polling bit in a radio link control (RLC) layer portion of the narrowband signal; the processor is further configured to: determine to wait for the delay period, based on the polling bit; cause the apparatus to send a hybrid automatic retransmission request (HARQ) acknowledgment (ACK) of the narrowband signal prior to releasing the RRC connection; cause the apparatus to receive a first downlink control information (DCI) comprising an NO grant having a new data indicator (NDI) that is not toggled; and cause the apparatus to send a layer 2 (L2) ACK of the narrowband signal, via transmission resources indicated in the N0 grant, prior to releasing the RRC connection. ### Claim 14 (depends on 13) The apparatus of claim 13, wherein the processor is further configured to: cause the apparatus to receive a second DCI comprising a request for a retransmission of the L2 ACK; and cause the apparatus to retransmit the L2 ACK prior to releasing the RRC connection. ### Claim 15 (depends on 13) The apparatus of claim 13, wherein the processor is further configured to: determine, based on a coverage level of the UE, a length of the delay period. ### Claim 16 (depends on 15) The apparatus of claim 15, wherein the determining the length of the delay period comprises: determining a length of a narrowband physical downlink control channel (NPDCCH) period based on a number of repetitions determined based on the coverage level; determining a number of the NPDCCH periods based on the coverage level; and calculating the delay period as the determined number of the NPDCCH periods. ### Claim 17 (depends on 16) The apparatus of claim 16, wherein the processor is further configured to: cause the apparatus to receive a second DCI comprising another NO grant having an NDI that is toggled; and make a new determination, to not wait for the delay period before releasing the RRC connection, in response to receiving the second DCI. ### Claim 18 (depends on 16) The apparatus of claim 16, wherein the processor is configured to determine the number of the NPDCCH periods by selecting the number from a table of coverage levels, based on the coverage level. ### Claim 19 An apparatus for wireless communications, comprising: means for determining, based on an indication received in a narrowband signal on a narrowband region of a bandwidth comprising a plurality of narrowband regions, whether to wait for a delay period, determined based on a configuration received from a network entity, before releasing a radio resource control (RRC) connection; and means for releasing the RRC connection at a time in accordance with the determination. ### Claim 20 A computer-readable medium for wireless communications including instructions, the instructions, when executed by a processor, cause the processor to perform operations comprising: determining, based on an indication received in a narrowband signal on a narrowband region of a bandwidth comprising a plurality of narrowband regions, whether to wait for a delay period, determined based on a configuration received from a network entity, before releasing a radio resource control (RRC) connection; and releasing the RRC connection at a time in accordance with the determination.