Routing Protocols for Sensor Networks

1. Routing Protocols for Sensor Networks Negotiation-based protocols for Disseminating Information in Wireless Sensor Networks by Joanna Kulik, Wendi Rabiner Heinzelman, and Hari Balakrishnan Presented by Siva Desaraju Computer Science WMU

2. SPIN • LEACH

3. Outline • Introduction • Conventional Protocols • Flooding, Gossiping, Ideal • Deficiencies • SPIN • Features • Protocols • SPIN-PP, SPIN-EC, SPIN-BC, SPIN-RL • Examples • Results • LEACH

4. Introduction Sensor Network Challenges • Energy-limited nodes • Sense/Transmit/Route data • Computation • Network protocols • Communication • Bandwidth-limited Goal: Minimize energy dissipation

5. B D G C A E F Conventional Protocols • Classic Flooding (Send to all neighbors)

6. (a) (a) A • Implosion • Data Overlap B A C B (a) (a) D C r q s (r,s) (q,r) Deficiencies • Resource blindness

7. Gossiping A B D C • Forward data to a random neighbor • Avoids implosion • Disseminates information at a slower rate • Fastest rate = 1 node/round

8. B D G C A E F What is the ideal protocol? • “Ideal” • Shortest path routes • Avoids overlap • Minimum energy • Need global topology information

9. SPIN: Sensor Protocols for Information via Negotiation • Basic Idea • Negotiation (meta-data) • Resource-adaptation (resource manager) • Features • Application-level Control • Meta-data • Messages • Resource Management

10. Application Level Control • Design motivated by Application Level Framing (ALF) • network protocols must choose transmission units that are meaningful to application • i.e. packetization is best done in terms of application data units • Next step: routing decisions are also best made in application-controlled and application-specific ways • using knowledge of not just network topology but also application data layout and the state of resources at each node

11. Meta-Data Data about data Eg: Geographically disjoint sensors, may use their unique ID, say all data by sensor x Target tracking – signal energy + geographical location • Sensors use meta-data to describe the sensor data briefly • Consider data X and data Y • If x is the meta-data descriptor for data X sizeOf (x) < sizeOf (X) • If x<>y sensor-data-of (x) <> sensor-data-of (y), i.e X<>Y • If X<>Y meta-data-of (X) <> meta-data-of (Y) • Meta-data format is application specific

12. SPIN Messages • ADV – advertise data • REQ – request specific data • DATA – requested data ADV A B REQ A B DATA A B

13. Resource Management • Sensors poll their system resources to find available energy • They can also calculate cost of performing computations

14. SPIN Family of Protocols • Point-to-Point Networks • SPIN - PP • SPIN - EC • Broadcast Networks • SPIN - BC • SPIN - RL

15. SPIN on Point-to-Point Networks • Linear cost with number of neighbors • SPIN-PP • 3-stage handshake protocol • Advantages • Simple • Minimal start-up cost • SPIN-EC • SPIN-PP + low-energy threshold • Modifies behavior based on current energy resources

16. REQ DATA DATA DATA DATA REQ ADV REQ ADV ADV ADV DATA REQ ADV DATA ADV ADV REQ REQ SPIN-PP:Example A B I already have the data, I don’t need it / I’m tired, I will sleep…zzz

17. Test Network 25 Nodes 59 Edges Average degree = 4.7 neighbors 500 bytes 16 bytes Network diameter = 8 hops Antenna reach = 10 meters Data Meta-Data

18. Point-to-Point Network Simulations • Enhanced ns simulator • Lossless links • Unlimited energy • Data distributed • Energy dissipated • Limited energy • Data distributed • Effect of resource-adaptation

19. Unlimited Energy Simulations • Flooding converges first • No queuing delays • SPIN-PP • Reduces Energy by 70% • No redundant data messages -- SPIN-PP -- Ideal -- Flooding -- Gossiping

20. Limited Energy Simulations -- SPIN-PP -- SPIN-EC -- Ideal -- Flooding -- Gossiping • SPIN-EC distributes 20% additional data

21. Data Distributed per unit energy -- SPIN-PP -- SPIN-EC -- Ideal -- Flooding -- Gossiping • SPIN-EC distributes • 10% more data per unit energy than SPIN-PP • 60% more data per unit energy than flooding

22. SPIN on Broadcast Networks • One transmission reaches all neighbors • SPIN-BC • Same 3-stage handshake protocol as SPIN-BC • Uses only broadcast communication • Same transmission cost as unicast • Coordination among nodes • Broadcast message suppression sensor-data-of (x) = sensor-data-of (y) • SPIN-RL • SPIN-BC + Reliability • Periodically re-broadcast ADVs and REQs

23. E E E ADV DATA D D D C ADV REQ SPIN-BC: Example E B A D C Nodes with data Nodes without data Nodes waiting to transmit REQ

24. Broadcast Network Simulations • Extended CMU monarch extensions to ns • 802.11 MAC protocol • No packet losses • Data distributed • Energy dissipated • Packet losses • Due to • Transmission errors • Collisions • Measure • Effect of reliability enhancement

25. Simulations with no packet loss -- SPIN-BC -- Ideal -- Flooding • SPIN-BC • Converges quicker than flooding • Reduces energy by 50% compared with flooding • Meta-data negotiations successful in broadcast

26. Simulations with packet loss -- SPIN-BC -- SPIN-RL -- Ideal -- Flooding • Ideal run on lossless networks • SPIN-RL • Expends more energy • Reliability protocol effective

27. Data Distributed per unit energy -- SPIN-PP -- SPIN-EC -- Ideal -- Flooding • SPIN-RL acquires 100% more data per unit energy than flooding

28. Conclusions • Advantages • Seems better than flooding (solves data implosion and overlap) • Resource-adaptive enhancements • Outperforms gossiping • Disadvantages • Implosion problem still exists in REQ stage • The paper does not consider collisions in the REQ stage

29. References • Negotiation based protocols for Disseminating Information in Wireless Sensor Networks, Joanna Kulik, Wendi Heinzelman, and Hari Balakrishnan • http://www-mtl.mit.edu/~wendi/slides/mobicom99/index.html • Architectural Consideration for a New Generation of Protocols, Clark, D and Tennenhouse, D.

30. Questions/Comments? Thanks