SHARP: A Hybrid Adaptive
Routing Protocol for
Mobile Ad Hoc Networks
Venugopalan Ramasubramanian, Zygmunt J. Haas, and
Emin Gun sirer
ACM MobiHoc 2003
Speaker ： ChiChih Wu
Outline
• Introduction
• Overview of SHARP
• SHARP Routing Protocols
• Simulations
• Conclusions
Introduction
• Ad hoc routing protocols
– Proactive protocols
• DSDV
– Reactive protocols
• AODV
• TORA
– Hybrid protocols
Introduction
• Proactive protocols
– Advantage
• good reliability
• Low latency through frequent dissemination
of routing information
– Disadvantage
• high overhead
Introduction
• Reactive protocols
– Advantage
• Low routing overhead
– Disadvantage
• Increase latency due to on-demand route
discovery and route maintenance
Overview of SHARP
• SHARP Routing Protocol
– Proactive Zone
– All nodes not in the proactive zone use reactive
routing protocols to establish routes to that
node
– Making some nodes more popular than others
Overview of SHARP
Proactive Zone
Reactive Routing
Protocol
Overview of SHARP
• Proactive Zone
– By increasing the radius, SHARP can decrease
the loss rate and variance in delay, but will pay
more in packet overhead to maintain routes in
a large zone
– By decreasing the radius, SHARP can reduce
routing overhead, as fewer nodes need to be
proactively updated; however, it may pay more
in delay jitter and experience higher loss rates
SHARP Routing Protocols
• Proactive Routing Component
– Destination Sequenced Distance Vector
(DSDV)
– Temporally Ordered Routing Algorithm
(TORA)
• Reactive Routing Component
– Ad-hoc On-demand Distance Vector
(AODV)
SHARP Routing Protocols
• DSDV
– Table driven
A
B
dest
next
metric
A
A
B
C
C
dest
next
metric
0
A
A
B
1
B
B
2
C
…
dest
next
metric
1
A
B
2
B
0
B
B
1
B
1
C
C
0
…
…
SHARP Routing Protocols
• TORA
3
2
height
s
1
3
2
0
2
1
s
d
d
SHARP Routing Protocols
SHARP Routing Protocols
• TORA
s
d
SHARP Routing Protocols
• Proactive Routing Component
– Building and maintaining a directed acyclic
graph (DAG ) rooted at the destination
SHARP Routing Protocols
• Reactive Routing Protocols
d
s
d
s
d
s
s
d
Source
Destination
Simulations
• 600 nodes
– 3000m X 3000m
– 8 packets per second
– 256 bytes per packet
• 200 nodes
– 1700m X 1700m
– 2 packets per second
– 256 bytes per packet
• Velocities ranged between 0 m/s and 20
m/s
Simulations
Mobility fraction
Simulations
Simulations
Simulations
Conclusions
• SHARP could be used to minimize
packet overhead, to bound loss rate,
and to control delay jitter
• SHARP achieves performance that is
better than each one of its
concomitant purely reactive and
purely proactive protocols across a
wide range of network conditions
THANK YOU