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

 SPIN  LEACH

Outline   Introduction – –Conventional Protocols   Flooding, Gossiping, Ideal – –Deficiencies   SPIN – –Features – –Protocols   SPIN-PP, SPIN-EC, SPIN-BC, SPIN-RL – –Examples – –Results   LEACH

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

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

Deficiencies  Implosion A B C D (a) A B C (r,s) (q,r) qs r  Data Overlap  Resource blindness

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

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

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

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

Meta-Data   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 Data about data Eg: Geographically disjoint sensors, may use their unique ID, say all data by sensor x Target tracking – signal energy + geographical location

SPIN Messages   ADV – advertise data   REQ – request specific data   DATA – requested data A B A B A B ADV REQ DATA

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

SPIN Family of Protocols  Point-to-Point Networks –SPIN - PP –SPIN - EC  Broadcast Networks –SPIN - BC –SPIN - RL

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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