Self Healing Wireless Sensor Network Routing based on Biological Inspiration

1. S Sensor Temp., light, humidity,chemicals, acoustics, vibration R Basestation Radio 2.4 GHz IEEE 802.15.4,<100m TX range C Computer 4 MHz Atmel ATmega 128L(equiv. to original ’82 IBM PC) Practical applications • Enemy intrusion detection • Habitat monitoring • Structural monitoring • Home automation and safety • Traffic control • Supply chain management (RFID) 4 or 6 1 3 2 S D 5 1 4 2 3 How to get information across a wireless sensor network as quickly and with as little power expenditure as possible. X X 6 6 1 2 S D 5 1 4 2 3 SHR quickly adapts to changing conditions of the network. Delay Reduction: Reliability: Traditional routing protocols mimic point-to-point connectivity of wired networks, decreasing over-listening but limiting adaptability of route selections. Route repair often requires repeated flooding of the neighborhood of the failed node or link resulting in high packet count in case of failures. Congestion avoidance needs to be added as a separate feature to the traditional protocols increasing their complexity. • MAIN RESULT:Self-Healing Routing (SHR) with Path Preference • Routes packets to the destination selecting the shortest path at any given instance of routing • Repairs broken routes using small number of packets • Enables routing using nodes according to specific criteria (most energy remaining, least busy with routing for other paths, etc.) • Learns the most reliable nodes on the path and promotes their use by “fixing” elections, to ensure that they win, and are used as often as possible HOW IT WORKS:Self-Healing Routing (SHR) uses a broadcast in each hop of multi-hop routing in three roles: (i) to pass a packet towards the destination, (ii) to synchronize its recipients, and (iii) to signal to previous sender that their transmission was successful. One of the recipients self-selects itself for forwarding through an election based on a random delay timer. Repeated winners are allowed to cut their delay by an increasing factor at each successive win, ensuring winning nodes continue to win and paths are stabilized. While ensuring paths are repeated, this also serves to speed packets through the network, as delays are minimized. Through their normal routing process, nodes also discover when neighbors are no longer functional, and have the ability to re-route their traffic along the next shortest possible path to the destination. INSPIRATION: The inspiration for the Path Preference algorithm came both from the idea of the benefit a political incumbent enjoys in an election, and from the idea of ants and their use of pheromones to lead other ants from their colony along discovered paths to food sources. • LIMITATIONS: • Sensor nodes use broadcast for communication • Sensors are energy limited • Sensors can be inhibited by random link connectivity. • SHR is ideal for networks of stationary nodes. • FUTURE WORK: • Energy Conservation • Node Mobility Self Healing Wireless Sensor Network Routing based on Biological Inspiration STATUS QUO • The research addresses the following unique aspects of military sensor networks: • Dealing with additional vulnerabilities such as physical damage, intentional interference with their operation, etc. • Ad-hoc, massive deployment with limited capabilities of learning or maintaining topology or routing information over the network lifetime. • Usage defined by the mission for which they provide information with greatly varying activity level from passive monitoring to active tracking. RELEVANCE In sensor networks: • Broadcast is the basic communication primitive • Links are transient and nodes unreliable • Over-provisioning results in interference • Autonomous operations including learning, self-selection and healing are crucial NEW INSIGHTS Self-Healing Routing with Path Preference (SHR-PP) for Wireless Sensor Networks provides a high level of self-adaptability with low overhead for route repair and the ability to accelerate the delivery rate of data in stable networks, making it well suited for networks composed of stationary nodes that require high speed end to end communication.