Relay employment problem for unacknowledged transmissions: Myopic policy and structure

The idea of D2D relay has received much interest recently as an essential ingredient in next generation networks. Future networks with user relay assistance, will have issues regarding relay employment considering the trade offs between throughput gain and cost incurred. In this work, we formulate the relay employment problem, where a source assesses a candidate relay's “employability” by accounting for the channel evolution with time in an unacknowledged transmission mode. We present a myopic policy which takes an initial belief about channel states as input and outputs a recommended sequence of actions. This sequence specifies whether to use a relay or not at each time slot. The myopic policy has different structures that impacts the gain obtained by the source. We present an analysis of this policy structure and provide sufficiency conditions for each of them. The myopic policy is compared with the one step decision policy which does not account for channel evolution. Numerical results show that relative gains up to 30% are obtained by myopic policy over one step decision policy.

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