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
 Power
routing protocols
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 routemaintenance 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 802.11b
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
routing protocols  a more
complete evaluation of COMPOW
 Other Ad-hoc
Q&A
Thank you for your attention!