BAHG:
Back-Bone-Assisted Hop Greedy Routing for VANET’s City Environments
ABSTRACT:
Using advanced wireless local area network
technologies, vehicular ad hoc networks (VANETs) have become viable and
valuable for their wide variety of novel applications, such as road safety,
multimedia content sharing, commerce on wheels, etc. Multihop information
dissemination in VANETs is constrained by the high mobility of vehicles and the
frequent disconnections. Currently, geographic routing protocols are widely
adopted for VANETs as they do not require route construction and route maintenance
phases. Again, with connectivity awareness, they perform well in terms of
reliable delivery. To obtain destination position, some protocols use flooding,
which can be detrimental in city environments? Further, in the case of sparse
and void regions, frequent use of the recovery strategy elevates hop count. Some
geographic routing protocols adopt the minimum weighted algorithm based on
distance or connectivity to select intermediate intersections. However, the
shortest path or the path with higher connectivity may include numerous
intermediate intersections. As a result, these protocols yield routing paths
with higher hop count. In this paper, we propose a hop greedy routing scheme
that yields a routing path with the minimum number of intermediate intersection
nodes while taking connectivity into consideration. Moreover, we introduce
back-bone nodes that play a key role in providing connectivity status around an
intersection. Apart from this, by tracking the movement of source as well as
destination, the back-bone nodes enable a packet to be forwarded in the changed
direction. Simulation results signify the benefits of the proposed routing
strategy in terms of high packet delivery ratio and shorter end-to-end delay.
EXISTING SYSTEM:
In a city network, intersections place a unique
challenge to routing protocols. A routing protocol has to key on some parameters
to decide the routing path. When the routing path is the shortest distance
path, it may involve a very high number of change of directions, resulting in
higher hop counts. If the connectivity is chosen as the parameter, the most
connected road segment would be overcrowded by frequently routing data packets
through the same path.
DISADVANTAGES
OF EXISTING SYSTEM:
Apparently,
the multi constrained optimal path finding problems are known to be NP-hard
problems. The
issues in a city network would not be exactly the same as in a highway or in a
delay torrent network. The outskirts may have sparse vehicular density, whereas
downtown has to deal with vehicular congestion.
PROPOSED SYSTEM:
In this paper, we introduce a back-bone mechanism in
which some specialized nodes perform functions such as tracking the movement of
end nodes, detecting void regions on road segments, storing packets on
unavailability of forwarding nodes, and selecting the most suitable
intersection node as the forwarding node. Since the routing algorithm selects a
path using destination position, we employ a unicast request-reply-based
destination probing mechanism. To implement this approach, we divide the city
into many zones that are outlined by the multilane road structures. Some dense
intersections (identified as the meeting point of multiple road segments) on
the boundary of the zones are chosen as the boundary intersections. As the position
of each boundary intersection is known, the unicast request messages initiated
by the source can be easily sent to each boundary intersection. The back-bone
nodes stationed at boundary intersections then take the responsibility to
spread the request messages within the respective zones. The fact that unicast
packets do not provide burst traffic and is shielded by request to send/clear
to send (RTS/CTS) handshake is the basic motivation to adopt unicast to carry
out all control packet transmissions. Once the destination receives the request
message, it finds a suitable path to the source and sends the reply. On
receiving the reply message, the source forwards data on a routing path
computed by the hop greedy routing algorithm. Finally, the routing protocol
includes an update mechanism that takes care of inter-zone movement of end nodes.
ADVANTAGES
OF PROPOSED SYSTEM:
ü We
have explored crucial problems such as unreliable location service,
intersection node probing problem, etc., experienced by VANET routing
protocols.
ü We
then propose a hop greedy routing protocol that aims to reduce the end-to-end
delay by yielding a routing path that includes the minimum number of
intermediate intersections.
ü To
address connectivity issues such as void regions and unavailability of
forwarders, the concept of back-bone node is introduced.
ü We
also propose an update procedure that is very effective to deal with destination
movements.
SYSTEM
REQUIREMENTS:
HARDWARE REQUIREMENTS:-
ü Processor - Pentium –III
ü Speed - 1.1 Ghz
ü RAM - 256
MB(min)
ü Hard
Disk - 20
GB
ü Key
Board - Standard
Windows Keyboard
ü Mouse - Two
or Three Button Mouse
ü Monitor - SVGA
SOFTWARE REQUIREMENTS:-
v Operating System : LINUX
v Tool : Network Simulator-2
v Front End : OTCL (Object Oriented Tool Command Language)
REFERENCE:
Pratap Kumar Sahu, Eric Hsiao-Kuang Wu,Member, IEEE,
Jagruti Sahoo, and Mario Gerla “BAHG: Back-Bone-Assisted Hop Greedy Routing for
VANET’s City Environments”- IEEE
TRANSACTIONS ON INTELLIGENT TRANSPORTATION SYSTEMS, VOL. 14, NO. 1, MARCH2013.
