Sensor Protocols for Information via Negotiation (SPIN)
- 1. Sensor Protocols for Infor mation via Ne gotiation (SPIN) Rajiv Agarwal B.Sc.(cs)Hons. 115090
- 2. Outline WSN Components of Sensor node SPIN Conclusions
- 3. Wireless Sensor Network Wireless sensor networks consist of large number of nodes that have sensing, computing and communication capabilities. It is basically an interconnection between large number of nodes that are deployed for system monitoring by measuring its parameters. Wireless Networks of sensors are likely to be widely deployed in the future
- 5. Limitations of a Sensor node Several obstacles need to overcome Energy - limited supply of energy simply performing computations and transmitting information in a wireless environment, energyconserving forms of communication and computation are essential . Computation - limited computing power so may be unable to run some network protocols. Communication - The bandwidth of the wireless links connecting sensor nodes is often limited, on the order of a few hundred Kbps.
- 6. Classic flooding A source node sends its data to all of its neighbors. Upon receiving a piece of data, each node then stores and sends a copy of the data to all of its neighbors. limitations – Implosion – Overlap – Resource blindness
- 7. Implosion (A) A B (A) C (A) (A) D The implosion problem. In this graph, node A starts by flooding its data to all of its neighbors. Two copies of the data eventually arrive at node D. The system energy waste energy and bandwidth in one unnecessary send and receive.
- 8. Overlap q r s A B (q,r) (r,s) C The overlap problem. Two sensors cover an overlapping geographic region. When these sensors flood their data to node C, C receives two copies of the data marked r. 8
- 9. Resource blindness In classic flooding, nodes do not modify their activities based on the amount of energy available to them at a given time. A network of embedded sensors can be “resource-aware” and adapt its communication and computation to the state of its energy resource. The SPIN (Sensor Protocols for Information via Negotiation) family of protocols incorporates two key innovations that overcome these deficiencies : negotiation resource-adaptation 9
- 10. SPIN: A Data Centric Protocol For Wireless Sensor Networks Data-centric protocols differ from traditional address-centric protocols in the manner that the data is sent from source sensors to the sink. In address-centric protocols, each source sensor that has the appropriate data responds by sending its data to the sink independently of all other sensors. In datacentricprotocols, when the source sensors send theirdata to the sink, intermediate sensors can performsome form of aggregation on the data originating from multiple source sensors and send the aggregated data toward the sink.
- 11. SPIN SPIN-1 SPIN-2 The SPIN family of protocols rests upon two basic ideas: ◦ To operate efficiently and to conserve energy ◦ Nodes in a network must monitor and adapt to changes in their own energy resources to extend the operating lifetime of the system. 11
- 12. Meta-Data SPIN does not specify a format for meta-data Meta-data format is application specific SPIN Messages ADV-When a node has new data to share; it can advertise this using ADV message containing Metadata. REQ- Node sends an REQ when it needs to receive actual data. DATA – Contains actual data message
- 13. SPIN-1 : 3-Stage Handshake Protocol (SPIN-PP) Simple handshake protocol for disseminating data through a lossless network Work in three stages (ADV-REQ-DATA) Node A starts by advertising its data to node B (a). Node B responds by sending a request to node A (b). After receiving the requested data (c), node B then sends out advertisement to its neighbors (d), who in turn send requests back to B (e, f). 13
- 14. SPIN-1 : 3-Stage Handshake Protocol SPIN-1 can be run in a completely unconfigured network with a small, startup cost to determine nearest neighbors If the topology of the network changes frequently, these change only have to travel one hop before the nodes can continue running the algorithm SPIN-2 : SPIN-1 with a Low-Energy Threshold (SPIN-EC) Adds a simple energy-conservation heuristic to the SPIN-1 protocol When energy is plentiful, SPIN-2 nodes communicate using the same 3-stage protocol as SPIN-1 node 14 When its energy is approaching a low-energy threshold, it adapts by reducing its participation in the protocol
- 15. Conclusions SPIN solves the implosion and overlap problems. SPIN-1 and SPIN-2 are simple protocols for wireless sensor networks. SPIN-1 consumes only 25% energy w.r.t flooding SPIN-2 distributes 60% more data per unit energy w.r.t flooding.
- 16. Thank you!