Coordinated Sleeping for Beaconless 802.15.4-Based Multihop Networks

Abstract

The last few years have seen a wide adoption of the IEEE 802.15.4 MAC/PHY standard for low-power communication between wireless sensor nodes. Within this work we study some fundamental drawbacks of the 802.15.4 specifications for multihop network deployments, which adversely affect the delivery rate and efficient node energy consumption. These issues are rectified by investigating a timezone-based scheduling, V-Route, that builds on 802.15.4 beaconless mode to enable both a synchronized sleep scheduling and a bidirectional communication between nodes in the sensor network and the PAN coordinator. The contributions of V-Route are threefold: (1) mitigate collisions, (2) enable packet routing and (3) provide energy saving in a multihop context, while maintaining the full compliancy with the 802.15.4 standard. We present a performance evaluation on energy consumption and latency with real experiments on Philips AquisGrain sensor nodes. Enhancing 802.15.4based multi-hop networks with V-Route yields energy reduction ranging from 27.3% to 85.3%, according to the required end-to-end latency.

Ant based Multiple Cluster Tree Routing for 802. 15. 4 Sensor Networks

“…Figure 2 shows that node 10 is chosen as PAN coordinator (P co ). Figure 3 shows the tree (T 0 ) with P co as root node and nodes 5,6,7,8,9 as the leaf nodes. Figure 4 shows the tree (T 1 ) with node 7 as root node and nodes 3, 4, 8 as the leaf nodes.…”

“…As 802.15.4 does not offer any mechanism for a coordinated and energy efficient FFD-to-FFD packet transmission, FFDs should be held in on conditions during the realization of communication through CSMA-CA which minimizes the functioning duration of the node [8].…”