Improving mobile terrestrial TV playback quality with cooperative streaming in MANET

In this paper, we propose a method for improving the playback quality of one segment terrestrial television broadcasting (called 1seg, hereafter) at mobile terminals staying in a weak 1seg radio reception area (called WRA terminals) by wireless multi-hop video streaming from terminals in strong 1seg radio area (called SRA terminals). First, we formulate the problem to derive the set of video forwarding paths that maximize the number of WRA terminals to be “relieved” by receiving the forwarded video, under the constraints on the wireless bandwidth and the maximum number of hops. Since this problem is NP-hard and deriving the optimal solution in real-time is infeasible, we propose a greedy algorithm that each WRA terminal find a video forwarding path from a SRA terminal receiving the required 1seg channel based on the information periodically exchanged among neighboring terminals. In order to increase the number of relieved terminals, we introduce a technique to let a SRA terminal change its watching 1seg channel, forward the video to a WRA terminal, and ask for the relief for itself. Through computer simulations, we confirme that the proposed algorithm with 2-hop relief paths improved the video playback quality in more than 60% of the total WRA staying time.