CPC H04W 74/0833 (2013.01) [H04W 72/0446 (2013.01)] | 12 Claims |
1. An apparatus, comprising:
at least one processor; and
at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the apparatus to perform:
selecting a resource indicator which indicates a channel resource to be used by a terminal device for non-scheduled access to a network;
transmitting the selected resource indicator to an access device of the network;
maintaining the selected resource indicator and setting a time offset for a retransmission with the selected resource indicator based on an access response received from the access device responsive to the non-scheduled access;
monitoring access responses received from the network to detect at least one used resource indicator of a channel resource that has been allocated to another terminal device for non-scheduled channel access or at least one non-allowed resource indicator;
deleting a detected used or non-allowed resource indicator from a list of resource indicators of available channel resources maintained at the terminal device;
transmitting a first scheduled transmission to the access device;
adjusting the time offset based on a feedback received from the access device;
checking if the feedback comprises at least one of the following indications:
an indicator of a layer 2 error caused by a random access channel resource collision of two or more terminal devices;
an indication of an acknowledgement or an indication that new data can be sent; and
an indication of a non-acknowledgement or the lack of a new data indication or an indication that no new data shall be sent;
using a parameter to adjust the time offset;
incrementing the parameter if the feedback indicates a non-acknowledgement for layer 2;
decrementing the parameter if the feedback indicates an acknowledgement; and
maintaining the parameter if the feedback indicates a non-acknowledgement for layer 1.
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