PERFORMANCE EVALUATION OF COMMON POWER ROUTING FOR AD-HOC NETWORK Zhan Liang Supervisor: Prof. Sven-Gustav Häggman Instructor: Researcher Boris Makarevitch Helsinki University of Technology Communications Laboratory 18th, May, 2004

Contents  Background  Objectives  Introduction  Implementation  Evaluation of COMPOW  Conclusion  Future Work

What is Ad-hoc  A local area network, or some small networks, parts are time-limited, and only usable for the duration of a communication session  The routers are free to move randomly, organize themselves arbitrarily  The wireless topology vary rapidly and unpredictably

Background  Many power control methods are designed and implemented over Ad-hoc network’s routing protocols (CLUSTERPOW, COMPOW, MINPOW, etc.)  Few evaluation reports on the power control methods can be found

Why power control methods?  A big effect on improving network capacity  A higher transmit power:  a higher range and a higher signal-to-noise ratio to the receiver  more interference to the adjacent nodes.  Power control  reduce the interfering nodes  improve the capacity  Energy Savings

Objectives  To implement a common power control method (COMPOW) over one Ad-hoc network’s routing protocol, AODV  To evaluate this power control method

Introduction  Ad-hoc routing protocols  Power control methods

Ad-hoc routing protocols(1)  Table-driven: all the nodes know the routing information of the whole network  Source-initiated: routes are established only when the source nodes require them

Ad-hoc routing protocols(2)

Table-driven routing protocols Destination-Sequenced Distance-Vector (DSDV)  To find the shortest paths, the least hops  A routing table where all the routing information is stored

Source-initiated routing protocols(1) Dynamic Source Routing (DSR)  A route cache to cache the known routes to the destinations  Main routing functions:  Route discovery  Route maintenance

Source-initiated routing protocols(2) Ad-hoc On-Demand Distance Vector (AODV) (1)  A combination of both DSR and DSDV protocols  The basic route-discovery and route- maintenance of DSR,  The hop-by-hop routing, sequence numbers and beacons of DSDV

Source-initiated routing protocols(3) Ad-hoc On-Demand Distance Vector (AODV) (2)  Route discovery:

Power control methods(1)  COMPOW (COMmon POWer) control method  CLUSTERPOW (CLUSTERing POWer) control method  MINPOW (MINimum POWer) control method

Power control methods(2) COMPOW  All the nodes use the same power level, the lowest power level at which the network is connected

Power control methods(3) CLUSTERPOW  To separate nodes into several different clusters

Power control methods(3) MINPOW  Each node chooses the transmit power level

Implementation of COMPOW(1) Simulation Assumptions (1)  Simulation Environment: NS2  Network card: CISCO Aironet 350  The channel is bi-directional link  The free space loss with two ray ground reflection model

Implementation of COMPOW(2) Simulation Assumptions (2)  The antennas are omni directional (same gain and attenuation in all horizontal directions)  The MAC layer protocol: IEEE b

Implementation of COMPOW(3) COMPOW over AODV: Route Discovery procedure

Implementation of COMPOW(4) Architecture

Implementation of COMPOW(5) Functions included in Simulation  Route Discovery  Route Maintenance  Route Release  Route Error handle

Evaluation of COMPOW Testing Scenarios  Scenario 1: 10 fixed nodes, 10 pairs of connection, 100 seconds, 250 m^2  Scenario 2: 25 fixed nodes, 25 pairs of connection, 100 seconds, 625 m^2  Scenario 3: 25 mobile nodes, 25 pairs of connection, 1000 seconds, 1000*1000 m^2

Results:Throughput vs. Load for fixed nodes (TCP)

Results:Throughput vs. Load for fixed nodes (UDP)

Results:Energy Consumption vs. Load for fixed nodes (TCP)

Results:Energy Consumption vs. Load for fixed nodes (UDP)

Results:Throughput vs. Load for mobile nodes

Results:Energy Consumption vs. Load for mobile nodes

Conclusions  A network transmitting packets by TCP: COMPOW performs good  A network transmitting packets by UDP: the lifetime of the COMPOW network may be even shorter than that of the network without using power control methods

Future works  More complicated scenarios’ test  acquire a complete evaluation  Non-uniform load generation environment  Other Ad-hoc routing protocols  a more complete evaluation of COMPOW

Q & A Thank you for your attention!