Geographical Routing With Location Service in
Intermittently Connected MANETs
ABSTRACT:
Combining mobile platforms such as manned or unmanned vehicles and peer-assisted wireless communication is an enabler for a vast number of applications. A key enabler for the applications is the routing protocol that directs the packets in the network. Routing packets in fully connected mobile ad hoc networks (MANETs) has been studied to a great extent, but the assumption on full connectivity is generally not valid in a real system. This case means that a practical routing protocol must handle intermittent connectivity and the absence of end-to-end connections. In this paper, we propose a geographical routing algorithm called location-aware routing for delay-tolerant networks (LAROD), enhanced with a location service, location dissemination service (LoDiS), which together are shown to suit an intermittently connected MANET (IC-MANET). Because location dissemination takes time in IC-MANETs, LAROD is designed to route packets with only partial knowledge of geographic position. To achieve low overhead, LAROD uses a beaconless strategy combined with a position-based resolution of bids when forwarding packets. LoDiS maintains a local database of node locations, which is updated using broadcast gossip combined with routing overhearing. The algorithms are evaluated under a realistic application, i.e., unmanned aerial vehicles deployed in a reconnaissance scenario, using the low-level packet simulator ns-2. The novelty of this paper is the illustration of sound design choices in a realistic application, with holistic choices in routing, location management, and the mobility model. This holistic approach justifies that the choice of maintaining a local database of node locations is both essential and feasible. The LAROD–LoDiS scheme is compared with a leading delay-tolerant routing algorithm (spray and wait) and is shown to have a competitive edge, both in terms of delivery ratio and overhead. For spray and wait, this case involved a new packet-level implementation in ns-2 as opposed to the original connection-level custom simulator.
EXISTING SYSTEM
- Existing routing algorithms can be broadly classified into topology-based and position-based routing protocols. Topology-based routing determines a route based on complete network topology as state information
- In order to recover from a local minimum, most existing protocols switch to a less efficient mode known as face routing. Face routing runs on a planar graph (a graph without crossing edges), in which the message is routed around the perimeter of the face (an area surrounded by the edges in the planar graph) which intersects the line between the source and the destination.
PROPOSED SYSTEM
In this project, we are going to remove the local minimum problem (face routing) by using two new methods.
1. Construct a virtual small-world network: Specifically, each node in the network constructs some remote contacts connected by virtual long links (VLLs). Each VLL consists of multiple consecutive physical links. By using these VLLs is to reduce the number of local minima for each destination and increase the success rate of the greedy routing.
2. Virtual force (VF)-based greedy routing: It can recover from local minima without resorting to face routing. In this method, a message is forwarded along the increasing gradient of the composition of the VFs. Each VF has a source. The destination is the only source of an attractive (positive) VF. Whenever the greedy method fails in a local minimum under the composition of the VFs, a new source of a repulsive (negative) VF is added to the local minimum to expel the message from it. Thus, the local minimum is removed, and greedy routing is recovered. This method is an iteration of greedy forwarding and local minimum removal.
HARDWARE REQUIREMENTS
• SYSTEM : Pentium IV 2.4 GHz
• HARD DISK : 40 GB
• MONITOR : 15 VGA colour
• MOUSE : Logitech.
• RAM : 256 MB
• KEYBOARD : 110 keys enhanced.
SOFTWARE REQUIREMENTS
• Operating system : Windows XP Professional
• Front End : JAVA
• Tool : NetBeans IDE
MODULES
1. Network Formation
2. Greedy Routing
3. SWING+ protocol
Module Description:
1. Network Formation
A VLL can be considered as a virtual path between an arbitrary pair of nodes in the network, rather than as a path for a specific pair of source and destination as in traditional routing such as DSR and AODV. Considering scalability, the length of each VLL is under the power-law distribution. In our algorithm, each node periodically sends out VLL discovery messages which go away and then come back to report a VLL. The first problem here is the determination of the maximum hop and direction of a message.
2. Greedy Routing
Extending the traditional greedy protocol to our small world greedy routing, which uses VLLs and VF, is straightforward. First, we define a general set of links of a node to be the set of links of the node containing both the physical links to its neighbors and its VLLs. Thereafter, we use links to refer to the links in this general set of links without causing confusion. We define the force of a VLL as the maximum force of the nodes in the VLL. Letting l be a VLL
3. SWING+ protocol
It is inherited from the family of greedy algorithms that Algorithm 1maygo to a local minimum and fail. The best part of SWING+ is the iterative method that allows the message to continue to travel to the other parts of the network after greedy failures in local minima. In order to recover from local minima, a list VR is maintained in each message which contains the positions of the encountered local minima that will exert repulsive (negative) VFs to the message.
REFERENCE
Erik Kuiper and Simin Nadjm, “Geographical Routing With Location Service in Intermittently Connected MANETs”, IEEE Transactions on Vehicular Technology, Vol. 60, No.2, February 2011.
