Method for indicating the allocated resources for a HARQ message in a random access procedure for a low-complexity, narrowband terminal

A method of operating a terminal for receiving an acknowledgment message in a random access procedure in a mobile telecommunications system, the method comprising:

• transmitting an uplink random access request;
• receiving a downlink allocation message in response to the uplink random access request and indicating downlink resources for sending a downlink message;
• receiving the downlink message using the resources indicated in the downlink allocation message;
• responsive to receiving the downlink message, transmitting an uplink message via the transmitter;
• and
• receiving, via the receiver, an acknowledgment message in respect of the uplink message and using one or more acknowledgment resources, wherein the one or more acknowledgment resources are identified based on at least one of the downlink allocation message and the downlink message, wherein the one or more acknowledgment resources are first implicitly identified to reduce the possible acknowledgment resources that can be used and subsequently a reduced explicit signaling indicates a precise acknowledgment resource from the implicitly identified acknowledgment resources.

A terminal for receiving an acknowledgment message in a random access procedure in a mobile telecommunications system, the terminal comprising a transmitter, a receiver and a controller, the controller being configured to:

• transmit, via the transmitter, an uplink random access request;
• receive, via the receiver, a downlink allocation message in response to the uplink random access request and indicating downlink resources for sending a downlink message;
• receive, via the receiver, the downlink message using the resources indicated in the downlink allocation message;
• responsive to receiving the downlink message, transmit an uplink message via the transmitter;
• and
• receive, via the receiver, an acknowledgment message in respect of the uplink message and using one or more acknowledgment resources, wherein the one or more acknowledgment resources are identified based on at least one of the downlink allocation message and the downlink message, wherein the one or more acknowledgment resources are first implicitly identified to reduce the possible acknowledgment resources that can be used and subsequently a reduced explicit signaling indicates a precise acknowledgment resource from the implicitly identified acknowledgment resources.