Uplink HARQ Procedure for MTC Operation

Abstract

A terminal in a wireless communication network receives a grant for uplink transmission from a network node. The grant indicates a first number of repetitions. The terminal transmits on an uplink shared channel according to the first number of repetitions and monitors a downlink control channel for a message a first number of subframes after the transmitting on the uplink shared channel. The terminal performs, based on a result of the monitoring, uplink retransmission according to a retransmission format received from the network node.

What is claimed is: 
     
         1 . A method performed by a terminal in a wireless communication network, the method comprising:
 receiving a grant for uplink transmission from a network node of the wireless communication network, the grant indicating a first number of repetitions;   transmitting on an uplink shared channel according to the first number of repetitions;   monitoring a downlink control channel for a message a first number of subframes after the transmitting on the uplink shared channel according to the first number of repetitions; and   performing, based on a result of the monitoring, uplink retransmission according to a retransmission format received from the network node.   
     
     
         2 . The method of  claim 1 , wherein:
 the result of the monitoring comprises detecting the message, correctly decoding the message, and determining that the message requests retransmission;   performing the uplink retransmission according to the retransmission format received from the network node comprises performing adaptive uplink retransmission, the retransmission format being received from the network node in the message.   
     
     
         3 . The method of  claim 2 , wherein:
 the adaptive uplink retransmission comprises asynchronous uplink retransmission; and   the message includes downlink control information indicating a process number for the adaptive uplink retransmission.   
     
     
         4 . The method of  claim 2 , wherein the retransmission format defines, for the adaptive uplink transmission:
 a modulation and coding rate; and/or   a frequency resource; and/or   a second number of repetitions.   
     
     
         5 . The method of  claim 1 , wherein:
 the result of the monitoring comprises failing to detect or decode the message or determining that the message lacks a request for retransmission; and   performing the uplink retransmission according to the retransmission format received from the network node comprises performing non-adaptive uplink retransmission, the retransmission format being received from the network node before the first number of subframes after the transmitting on the uplink shared channel.   
     
     
         6 . The method of  claim 1 , wherein receiving the grant for uplink transmission comprises receiving downlink control information indicating a grant for random access channel Msg3 transmission. 
     
     
         7 . A wireless terminal comprising:
 a receiver configured to receive a grant for uplink transmission from a network node of a wireless communication network, the grant indicating a first number of repetitions;   a transmitter configured to transmit on an uplink shared channel according to the first number of repetitions; and   processing circuitry configured to:   monitor a downlink channel for a message, using the receiver, a first number of subframes after the transmitter transmits on the uplink shared channel according to the first number of repetitions; and   perform, based on a result of the monitoring, uplink retransmission via the transmitter according to a retransmission format received from the network node.   
     
     
         8 . The wireless terminal of  claim 7 , wherein:
 the result of the monitoring comprises the processing circuitry detecting the message, correctly decoding the message, and determining that the message requests retransmission;   to perform the uplink retransmission according to the retransmission format received from the network node, the processing circuitry is configured to perform adaptive uplink retransmission, the retransmission format being received from the network node in the message.   
     
     
         9 . The wireless terminal of  claim 8 , wherein:
 the adaptive uplink retransmission comprises asynchronous uplink retransmission; and   the message includes downlink control information indicating a process number for the adaptive uplink retransmission.   
     
     
         10 . The wireless terminal of  claim 8 , wherein the retransmission format defines, for the adaptive uplink retransmission:
 a modulation and coding rate; and/or   a frequency resource; and/or   a second number of repetitions.   
     
     
         11 . The wireless terminal of  claim 7 , wherein:
 the result of the monitoring comprises the processing circuitry failing to detect or decode the message or determining that the message lacks a request for retransmission;   to perform the uplink retransmission according to the retransmission format received from the network node, the processing circuitry is configured to perform non-adaptive uplink retransmission, the retransmission format being received from the network node before the first number of subframes after the transmitting on the uplink shared channel.   
     
     
         12 . The wireless terminal of  claim 7 , wherein to receive the grant for uplink transmission, the receiver is configured to receive downlink control information indicating a grant for random access channel Msg3 transmission. 
     
     
         13 . A method performed by a network node in wireless communication network, the method comprising:
 transmitting a grant for uplink transmission to a wireless terminal in the wireless communication network, the grant indicating a first number of repetitions; and   transmitting, to the wireless terminal via a downlink control channel a first number of subframes after the wireless terminal transmits on an uplink shared channel according to the first number of uplink repetitions, an adaptive retransmission format for a subsequent uplink retransmission from the wireless terminal.   
     
     
         14 . The method of  claim 13 , wherein the adaptive retransmission format defines, for the adaptive uplink retransmission:
 a modulation and coding rate; and/or   a frequency resource; and/or   a second number of repetitions.   
     
     
         15 . The method of  claim 13 , wherein transmitting the grant for uplink transmission comprises transmitting downlink control information indicating a grant for random access channel Msg3 transmission. 
     
     
         16 . The method of  claim 13 , wherein the adaptive uplink retransmission comprises asynchronous uplink retransmission, and wherein the message includes downlink control information indicating a process number for the subsequent uplink retransmission from the wireless terminal. 
     
     
         17 . A network node comprising:
 a transmitter and processing circuitry communicatively coupled to the transmitter, the
 processing circuitry configured to:
 transmit, via the transmitter, a grant for uplink transmission to a wireless terminal in a wireless communication network, the grant indicating a first number of repetitions; and 
 transmit, via the transmitter to the wireless terminal and over a downlink control channel a first number of subframes after the wireless terminal transmits on an uplink shared channel according to the first number of repetitions, a message indicating an adaptive retransmission format for a subsequent uplink retransmission from the wireless terminal. 
 
   
     
     
         18 . The network node of  claim 17 , wherein the adaptive retransmission format defines, for the adaptive uplink retransmission:
 a modulation and coding rate; and/or   a frequency resource; and/or   a second number of repetitions.   
     
     
         19 . The network node of  claim 17 , wherein the grant for uplink transmission comprises downlink control information indicating a grant for random access channel Msg3 transmission. 
     
     
         20 . The network node of  claim 17 , wherein:
 the adaptive uplink retransmission comprises asynchronous uplink retransmission; and   the message includes downlink control information indicating a process number for the subsequent uplink retransmission.