Cooperative caching for dynamic shared spectrum networks

This paper considers cooperation between primary and secondary users in shared spectrum radio networks via caching. A network consisting of a single macro (primary) base-station and multiple small (secondary) base-stations is considered. Secondary base-stations can cache some primary files and thereby satisfy content-requests generated from nearby primary users. For this cooperative scenario, we develop two caching and scheduling policies under which the set of primary and secondary request generation rates that can be supported is expanded from the case without cooperation. The first of these algorithms provide maximum gain in the set of supportable primary and secondary request generation rates. However under this algorithm primary packet transmissions from secondary base-stations do not have higher priority of access than that of secondary packets. As a result, we propose another suboptimal algorithm wherein primary file transmissions from secondary base-stations have high priority of access than that of secondary files. Extensive simulations are conducted to compare the performance of both algorithms with that of a non-cooperative algorithm that is optimal, with respect to set of supportable request generation rates, among all non-cooperative policies.