On the push-based converged network with limited storage

By pushing popular contents directly to users through broadcast networks while serving individual requests using the cellular networks, a “converged” wireless network provides a highly effective means to cope with the wireless traffic bottleneck. In this paper, we contribute to analyze the network capacity of the push-based converged network with limited user storage and then develop the corresponding optimal pushing schemes. Specifically, we first establish two operational regions for the converged network, namely, the push-limited region and the cache-limited region, to reveal the fundamental tradeoff between the broadcast pushing ability and the user caching capacity. The network capacity is then derived under the traditional popularity-based pushing scheme. Moreover, we investigate the optimal pushing scheme under two different criteria, i.e., to maximize either the offloading probability or the offloading data percent. The pushing optimization problem is modeled as the 0–1 knapsack problem, and can be easily solved by the greedy algorithm. Interestingly, the optimal scheme depends on not only the optimization objective, but also the region where the system operates. Finally, numerical results are provided to confirm the accuracy of the developed analytical results.