The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part Bl. Beijing 2008 
Topology-based routing protocols, which can be further divided 
into proactive, reactive, and hybrid approaches, use the 
information about the links that exist in the network to perform 
packet forwarding. Proactive routing protocols employ classical 
routing strategies such as distance-vector routing (e.g., DSDV 
(Perkins and Bhagwat, 1994)) or link-state routing (e.g., OLSR 
(Clausen et al., 2003) and TBRPF (Ogier et al., 2000)). They 
maintain routing information about the available paths in the 
network even if these paths are not currently used. The main 
drawback of these approaches is that the maintenance of unused 
paths may occupy a significant part of the available bandwidth 
if the topology of the network changes frequently (Das et al., 
2000b). Reactive routing protocols, such as AODV (Perkins and 
Royer, 1999), DSR (Johnson and Maltz, 1996), and TORA 
(Park and Corson, 1997), maintain only the routes that are 
currently in use, thereby reducing the burden on the network 
when only a small subset of all available routes is in use at any 
time. Hybrid routing protocols, such as ZRP (Haas and 
Pearlman, 2001), combine local proactive routing and global 
reactive routing strategy in order to achieve a higher level of 
efficiency and scalability. 
Position-based routing protocols require additional information 
about geographical position of participating nodes. Commonly, 
each node determines its own position through the use of GPS, 
and then made available to the adjacent neighbors in the form 
of periodically transmitted beacons. A sort of location service is 
used by the sender of a packet to determine the position of the 
destination and to include it in the packet’s destination address. 
The routing decision at each node is based on the destination’s 
position contained in the packet head and the position of the 
forwarding node’s one-hop neighbors. Position-based routing 
algorithms thus does not require establishment or maintenance 
of routes, which means that nodes have neither to store routing 
tables nor to transmit messages to keep routing tables up to date. 
Examples for position-based routing protocols are DREAM 
(Basagni et al., 1998), face-2 (Bose et al., 2001), GPSR (Karp 
and Kung, 2000), and terminode routing (Blazevic et al., 2000). 
The objective of this paper is to evaluate routing performance 
of those two classes. We will mainly study and compare the 
following algorithms knows as AODV, DSDV, and DSR, using 
extensive simulation experiments. The remainder of this paper 
is organized as follows: Section 2 outlines the related work, 
Section 3 presents the simulation models, including highway 
mobility and network evaluation models, Section 4 discusses 
the simulation results, and Section 5 concludes the paper. 
2. RELATED WORK 
Several recent efforts are the most related to our work, as they 
also use simulation-based methodology (e.g., NS-2 or QualNet). 
(Broch et al., 1998) is the first to provide a realistic, quantitative 
analysis comparing the relative performance of the four mobile 
ad hoc network routing protocols (AODV (Perkins and Royer, 
1999), DSDV (Perkins and Bhagwat, 1994), DSR (Johnson and 
Maltz, 1996), and TORA (Park and Corson, 1997)). They 
simulated 50 wireless nodes, moving according to the random 
waypoint (RWP) model over a rectangular (1500m X 300m) flat 
space for 900 seconds. The mobility patterns were generated 
with 7 different pause time (0, 30, 60, 120, 300, 600, and 900 
seconds) and with 2 different maximum node speed (1 and 20 
mps). The type of communication patterns was chosen to be 
constant bit rate (CBR), and the parameters experimented with 
3 different communication pairs (10, 20, 30 traffic sources), 
each sending 1, 4, and 8 packets per second (packet sizes of 64 
and 1024 bytes). Packet delivery fraction, number of routing 
packets transmitted, and distribution of path lengths were 
chosen as the performance metrics. Simulation results 
demonstrated that DSR and AODV performed significantly 
better than DSDV, and TORA acted the worst in terms of 
routing packet overhead. (Boukerche, 2002; Das et al., 2000a; 
Johansson et al., 1999; Perkins et al., 2001) did similar 
performance analysis of topology-based routing algorithms. 
(Hsu et al., 2003) presented a comprehensive study on the 
performance of topology-based routing protocols under realistic 
network scenarios. The routing protocols used include AODV 
(Perkins and Royer, 1999), DSR (Johnson and Maltz, 1996), 
OLSR (Clausen et al., 2003), OSPF version 2 (which represents 
a traditional wired link-state routing protocol), and ZRP (Haas 
and Pearlman, 2001). The simulated mobility scenario, based on 
a 4-hour field test, involved 1 static node (e.g., base station) and 
19 mobile nodes, which follow a dual counter rotating ring 
mobility pattern comprising of an inner loop and an outer loop. 
The 14 outer loop nodes rotate clockwise whereas the 5 inner 
loop nodes rotate counter-clockwise. Mobility of the nodes was 
simulated using GPS logs and traffic patterns generated fell into 
five categories, ranging from high rate traffic (120 or 200 kbps 
of 1 KB packets) to low rate traffic (800 bps of 100 B packets). 
The network throughput, packet delivery ratio, and end-to-end 
delay were chosen as performance metrics. Simulation results 
show that AODV performed to be vastly superior to the other 
compared routing protocols in this type of scenario. 
(Boukerche, 2004) presented an extensive simulation studies to 
compare the performance of five routing protocols: AODV 
(Perkins and Royer, 1999), PAODV (Pre-emptive AODV) 
(Boukerche and Zhang, 2004), CBRP, DSR (Johnson and Maltz, 
1996), and DSDV (Perkins and Bhagwat, 1994), using a variety 
of workload and scenarios, such as mobility, load, and size of 
the ad hoc networks. Simulation results indicated that despite 
the improvement in reducing route request packets, CBRP has a 
higher overhead than DSR because of its periodic hello 
messages while AODV’s end-to-end packet delay is the shortest 
when compared to DSR and CBRP. PAODV has shown little 
improvements over AODV. 
(Choudhury and Vaidya, 2005) evaluated the impact of direc 
tional antennas on the performance of ad hoc routing (e.g., DSR, 
which is originally designed for omnidirectional antennas). Per 
formance evaluation suggested that using directional antennas 
may not be suitable when the network is dense or linear; 
however, the improvement in performance is encouraging for 
networks with sparse and random topologies. 
More recent work on performance evaluation and comparisons 
of routing protocols in mobile ad hoc networks include (Lahde, 
2007; Peiyan and Layuan, 2006; Trung et al., 2007). While 
communication between vehicles is frequently mentioned as a 
target for ad hoc routing protocols, there have previously been 
few studies on how the specific mobility patterns of vehicles 
may influence the protocols performance and applicability. 
Typically, the behavior of routing protocols for mobile ad hoc 
networks is analyzed based on the assumption that nodes in the 
networks follow the random waypoint model (Bettstetter et al., 
2004; Bettstetter et al., 2003). Since this movement pattern of 
nodes has no similarity to the behavior of vehicles, the random 
waypoint model seems to be inappropriate to investigate the 
characteristics of vehicular ad hoc networks or to determine 
1016