Joint Minimization of Wired and Wireless Traffic for Content Delivery by Multicast Pushing

Abstract

As more mobile users become subscribers of content services, their subscribed content can be directly pushed from the content provider into the user equipment after the content is generated. In current and future network paradigms, a joint wired and wireless transmission design for this pushing is needed to guarantee the user experience without the extra deployment of communication infrastructures or consumption of resources. In this paper, we investigate a joint wired and wireless content delivery system that incorporates wired and wireless multicast. The users in the same group are served by wireless multicast from a base station (BS), while the BSs of the same content form a multicast tree in a backbone wired network. The sum of wired and wireless traffic is minimized by a joint design of user grouping, subchannel allocation, wired routing, and wired link usage. Exploiting the monotonicity of wired and wireless traffic with regard to the wired hop count, the original problem is converted for searching the optimal hop count vector that achieves the minimum sum of both types of traffic, which is solved by a monotonic optimization (MO)-based iterative algorithm. Compared with existing schemes and according to the numerical results, a reduction in total traffic of 43% can be achieved by our approach.