Proxy-based multicast congestion control for ad hoc networks

Mulitcast communication is an effective and promising way for dissemination of the same data to potentially large number of receivers. In multicast congestion control proposed thus far, the receiver with the worst congestion level is selected as the representative and transmission rate of multicast sender is regulated so that it is adjusted to TCP throughput of the representative. However, in wireless networks, receivers even in good wireless quality environment may suffer low throughput because the worst receivers can obtain very low throughput and the representative is changed frequently with fluctuation of wireless channel quality. In this paper, we propose proxy-based multicast congestion control. In our proposed method, the sender uses general multicast congestion control, i.e. above described representative approach and proxy hosts are selected from intermediate nodes in a multicast tree. Our proposed scheme which regulates the number of receivers in sub-tree can improve throughput performance. We evaluate our proposed proxy-based congestion control by computer simulation. Our proposed proxy-based congestion control obtains higher throughput and keeps high throughput even with increase of receivers.