Using asymmetric links to improve SSR's routing performance

• Published in: 2010 The 9th IFIP Annual Mediterranean Ad Hoc Networking Workshop (Med-Hoc-Net) pp. 1 - 6
• Main Authors: Birnstill, Pascal, Pengfei Di, Fuhrmann, Thomas
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01-06-2010
• Subjects: Ad hoc networks; Network topology; Proposals; Routing; Routing protocols; Topology
• ISBN: 1424484367; 9781424484362
• DOI: 10.1109/MEDHOCNET.2010.5546852

Empirical evidence shows that asymmetric links occur frequently in wireless networks. Still, most routing protocols assume symmetric links. Thus, they cannot exploit the additional connectivity and bandwidth that asymmetric links provide. In this paper, we propose an extension of the scalable source routing protocol (SSR) that enables SSR to use asymmetric links. It enhances SSR's hello messages with a limited amount of local topology information, which allows the nodes to discover directed cycles in the network. Such cycles provide a return path in cases where the forward path contains asymmetric links. With our proposed extension, SSR can thus use asymmetric links and still guarantee bidirectional connectivity. We evaluate our proposals with extensive simulations. A practical test in a 150 node test bed is ongoing work.