Data Placement and Transmission Scheduling for coded multicast in mobile edge networks

Edge caching is a promising strategy to reduce the traffic load in mobile core networks, by caching popular contents at the edge of mobile networks, e.g., base stations (BSs). For the BSs to transmit data to user equipment (UEs), coded multicast can be used to improve the transmission efficiency. Moreover, in future densely deployed networks, the coverage areas of adjacent BSs are overlapped. Therefore, these cache-aided BSs can collaboratively carry out coded multicast to improve the performance of data transmission. In this paper, we consider the Data Placement and Transmission Scheduling (DPTS) problem for cached-aided coded multicast in mobile edge networks. Our objective is to minimize the total cost of data download from the data source to BSs and data transmission from the BSs to UEs. The DPTS problem is proved to be NP-hard and we first propose an Iterative Relaxation Linear Programming (IRLP) algorithm to solve it. Since the complexity of IRLP algorithm is high, we also propose another two low-complexity algorithms to solve the DPTS problem. Performance evaluation by simulation shows that the proposed algorithms can achieve a substantial reduction in total cost of data download and transmission, compared with the existing methods. © 2023 Elsevier B.V.