Directed Diffusion: A Scalable and Robust Communication Paradigm for Sensor Networks

This paper describes the directed diffusion approach for coordinated sensing and data dissemination in wireless sensor networks. The design of this new paradigm is driven by robustness, scalability and energy efficiency requirements. Data-centric communication in this scheme involves a request for "interests" followed by data propagation and local aggregation. The authors stress that energy efficiency requirements dictate the need for short-range hop-by-hop communication and local computation. Directed diffusion has a few features reminiscent of the TAG service discussed in the previous paper, such as in-network data aggregation and caching.

The evaluation suggests that novel features such as reinforcement-based best path adaptation do indeed provide substantial energy savings, especially given the task-specific nature of modern sensor networks. One interesting point of discussion would be the potential feasibility of the local approach adopted here for a general IP-based network. I found this paper interesting but it is perhaps not as essential in the syllabus as the TAG paper.