Valuable Detours: Least-Cost Any Path Routing

Valuable Detours: Least-Cost any path Routing

ABSTRACT:

In many networks, it is less costly to transmit apacket to any node in a set of neighbors than to one specificneighbor. This observation was previously exploited by opportunisticrouting protocols, by using single-path routing metricsto assign to each node a group of candidate relays for a particulardestination.

This project addresses the least-cost any path routing (LCAR)problem: how to assign a set of candidate relays at each nodefor a given destination such that the expected cost of forwardinga packet to the destination is minimized. The key is the followingtradeoff: on one hand, increasing the number of candidate relaysdecreases the forwarding cost, but on the other, it increases thelikelihood of “veering” away from the shortest-path route. Priorproposals based on single-path routing metrics or geographiccoordinates do not explicitly consider this tradeoff, and as aresult do not always make optimal choices.

The LCAR algorithm and its framework are general andcan be applied to a variety of networks and cost models. Weshow how LCAR can incorporate different aspects of underlyingcoordination protocols, for example a link-layer protocol thatrandomly selects which receiving node will forward a packet, orthe possibility that multiple nodes mistakenly forward a packet.In either case, the LCAR algorithm finds the optimal choice ofcandidate relays that takes into account these properties of thelink layer.

Finally, we apply LCAR to low-power, low-rate wirelesscommunication and introduce a new wireless link-layer techniqueto decrease energy transmission costs in conjunction with any pathrouting. Simulations show significant reductions in transmissioncost to opportunistic routing using single-path metrics. FurthermoreLCAR routes are more robust and stable than those basedon single-path distances, due to the integrative nature of theLCAR’s route cost metric.

ARCHITECTURE:

C Documents and Settings user Desktop Eg anypath gif

EXISTING SYSTEM:

Link-layer any casting has been previously proposed andmotivated in various forms. These works focus onmechanisms to implement any cast forwarding at the link layer,and assume that the network layer maintains a list of possiblerelay candidates that isprovided to the link layer. These works do not propose specificStrategies for the selection of these candidates by the routingprotocol, and the LCAR algorithm could be used to feed theselink layers with relay candidates.Jain and Das go a step further by integrating any castextension of the link layer with the multi-path AODVrouting protocol. They observe the same tradeoff as between number of candidates and path length.Motivated by an empirical evaluation, they modify AOMDVto allow the use of paths up to one hop longer than the shortestpath.

Disadvantage

Thesingle-path metric effectively disqualifies nodes.

PROPOSED SYSTEM:

Weshow how LCAR can incorporate different aspects of underlyingcoordination protocols, for example a link-layer protocol thatrandomly selects which receiving node will forward a packet, orthe possibility that multiple nodes mistakenly forward a packet.In either case, the LCAR algorithm finds the optimal choice ofcandidate relays that takes into account these properties of thelink layer.

Advantage:

Increases the likelihood of veering away from the shortest-path route.

Wirelesscommunication and introduce a new wireless link-layer technique

To decrease energy transmission costs in conjunction with any path routing.

MODULES:

Any cast link cost

We must first generalize the notion of link cost to account for any cast rather than unicast forwarding. We define the any cast link cost (ALC) as the cost to send a packet from any node in the. Similarlyto standard unicast link costs, choosing any cast link costis a modeling decision that depends on the cost criterion ofour network. Note that for any path routing to be worthwhile,it must be used with any cast link costs that decrease whenthe candidate set is enlarged; otherwise there is no advantageto having more than one candidate relay, and any path routingwill end up computing least-cost single-path routes.Any ALC must have two simple properties. This protocol must ensure that the nodes receiving apacket all agree and select the correct relay in a distributedway. While an ideal protocol does this with complete reliability,it is in practice possible that the outcome of executingthe coordination protocol is incorrect. One such error wouldbe that more than one receiver forwards a packet.

Transmission-count:

We can generalize the expected transmission count metric for unicast transmission. This metric countsthe expected number of transmissions to successfully deliver apacket across an unreliable unicast link. With link-layer any cast,the expected number of transmissionsuntil any node in J receives the packet. Its expression isOf course, the above definition assumes spatial independence, such that transmission is received independently by nodes. Our aim here is not to derive a complex metricthat captures spatial loss correlations in general conditions; butwe note that the LCAR framework can accommodate suchmetrics and others.

System Requirements:

Hardware Requirements:

System : Pentium IV 2.4 GHz.

Hard Disk : 40 GB.

Floppy Drive: 1.44 Mb.

Monitor: 15 VGA Colour.

Mouse: Logitech.

Ram: 512 Mb.

Software Requirements:

Operating system : Windows XP.

Coding Language: ASP.Net with C#

Data Base : SQL Server 2005

SYSTEM DESIGN

Data Flow Diagram / Use Case Diagram / Flow Diagram

The DFD is also called as bubble chart. It is a simple graphical formalism that can be used to represent a system in terms of the input data to the system, various processing carried out on these data, and the output data is generated by the system.

Dataflow Diagram:

Class Diagram:

Activity Diagram:

Sequence Diagram:

Use Case Diagram: