Joint optimal transceiver placement and resource allocation schemes for redirected cooperative hybrid FSO/mmW 5G fronthaul networks

To meet the requirements of the 5G mobile network, a new innovative approach called centralized radio access network (C-RAN) architecture is introduced. In CRAN architecture, the fronthaul network must provide high capacity, high availability, and low latency to be able to transmit massive traffic between remote radio heads (RRHs) and baseband processing units. In this paper, two joint transceiver placement and resource allocation schemes are proposed for redirected cooperative hybrid free-space optics (FSO)/millimeter-wave (mmW) fronthaul networks. The schemes aim to obtain the optimal FSO/ mmW transceiver placement that optimizes reliability, average transmitted power, average bit error rate (BER), and number of disrupted links of redirected cooperative hybrid FSO/mmW fronthaul networks in various weather conditions. The schemes are formulated as multiobjective and bilevel integer linear programming problems and solved by using an exhaustive search method to obtain optimal solutions. The numerical results reveal that improvements are obtained in the network reliability, average transmitted power, and average BER by implementing the optimal placement, especially at low visibility and/or high rainfall rate conditions.