CONDITIONAL SHORTEST PATH ROUTING IN DELAY TOLERANT NETWORKS


Conditional Shortest Path Routing in
Delay Tolerant Networks

ABSTRACt:
                       Delay tolerant networks are characterized by the sporadic connectivity between their nodes and therefore the lack of stable end-to-end paths from source to destination. Since the future node connections are mostly unknown in these networks, opportunistic forwarding is used to deliver messages. However, making effective forwarding decisions using only the network characteristics (i.e. average intermeeting time between nodes) extracted from contact history is a challenging problem. Based on the observations about human mobility traces and the findings of previous work, we introduce a new metric called conditional intermeeting time, which computes the average intermeeting time between two nodes relative to a meeting with a third node using only the local knowledge of the past contacts. We then look at the effects of the proposed metric on the shortest path based routing designed for delay tolerant networks. We propose Conditional Shortest Path Routing (CSPR) protocol that routes the messages over conditional shortest paths in which the cost of links between nodes is defined by conditional intermeeting times rather than the conventional intermeeting times. Through trace-driven simulations, we demonstrate that CSPR achieves higher delivery rate and lower end-to-end delay compared to the shortest path based routing protocols that use the conventional intermeeting time as the link metric.

Existing System:
                         Routing in delay tolerant networks (DTN) is a challenging problem because at any given time instance, the probability that there is an end-to-end path from a source to a destination is low. Since the routing algorithms for conventional networks assume that the links between nodes are stable most of the time and do not fail frequently, they do not generally work
in DTN’s. Therefore, the routing problem is still an active research area in DTN’s .Routing algorithms in DTN’s utilize a paradigm called store-carry-and-forward. When a node receives a message from one of its contacts, it stores the message in its buffer and carries the message until it encounters another node which is at least as useful (in terms of the delivery) as itself. Then the
message is forwarded to it.
.Proposed System:
                     To show the benefits of the proposed metric, we adopted it for the shortest path based routing algorithms designed for DTN’s. We propose conditional shortest path routing (CSPR) protocol in which average conditional intermeeting times are used as link costs rather than standard2 intermeeting times and the messages are routed over conditional shortest paths (CSP). We compare CSPR protocol with the existing shortest path (SP) based routing protocol through real trace driven simulations. The results demonstrate that CSPR achieves higher delivery rate and lower end-to-end delay compared to the shortest path based routing protocols. This shows how well the conditional intermeeting time represents inter-node link costs (in the context of routing) and helps making effective forwarding decisions while routing a message.

Advantages:
  1. New metric called conditional intermeeting time that measures the intermeeting time between two nodes relative to a meeting with a third node using only the local knowledge of the past contacts.
  2. Such measure is particularly beneficial if the nodes move in a cyclic so-called Mobi-Space in which if two nodes contact frequently at particular time in previous cycles.
  3. we updated the shortest path based routing algorithms using conditional intermeeting times and proposed to route the messages over conditional shortest paths.








Architecture:

Software Requirements Specification:

Software Requirements:
Front End                         :     java swings
Back End                          :     No Database
IDE                                    :     my eclipse 8.0
Language                          :     java (jdk1.6.0)
Operating System             :    windows XP

Hardware Requirements:
System                                             :   Pentium IV 2.4 GHz.
Hard Disk                            :   80 GB.
Floppy Drive                        :   1.44 Mb.
Monitor                                :   14’ Colour Monitor.
Mouse                                   :   Optical Mouse.
Ram                                       :   512 Mb.
Keyboard                              :   101 Keyboards.


Modules Description:
  1. Network Model Construction
  2. Neighbour node connection
  3. Intermeeting calculation time (delay tolerant time specification)
  4. Conditional Shortest path routing identification
Network Model Construction:
                  We model a DTN as a graph G = (V , E) where the vertices (V ) are mobile nodes and the edges (E) represent the connections between these nodes. However, different from previous DTN network models, we assume that there may be multiple unidirectional (Eu) and bidirectional (Eb) edges between the nodes.
Neighbour node Connection:
                 These edges differ from each other in terms of their weights and the corresponding third node. This third node indicates the previous meeting and is used as a reference point while defining the conditional intermeeting time (weight of the edge). In, we illustrate a sample DTN graph with four nodes and nine edges. Of these nine edges, three are bidirectional with weights of standard intermeeting times between nodes, and six are unidirectional edges with weights of conditional intermeeting times.
Intermeeting calculation time (delay tolerant time specification):
               Each node first adds up times expired between repeating meetings of one neighbor and the meeting of another neighbor. Then it divides this total by the number of times it has met the first neighbor prior to meeting the second one. For example, if node A has two neighbors (B and C), to find the conditional intermeeting time of τA(B|C),each time node A meets node C, it starts a different timer. When it meets node B, it sums up the values of these timers and divides the results by the number of active timers before deleting them.
Conditional Shortest path routing identification:
               Each node forms the aforementioned network model and collects the standard and conditional intermeeting times of other nodes between each other through epidemic link state protocol as in. However, once the weights are known, it is not as easy to find CSP’s as it is to find SP’s. Consider where the CSP(A, E) follows path 2 and CSP(A, D) follows (A, B, D).
Algorithms:
Conditional Shortest Path Routing

3 comments:

  1. Hello sir plZ send this project on my mail id: jsgaira.cs@gmail.com

    ReplyDelete
  2. this is our major project plz send it

    ReplyDelete
  3. Hello mister, can you send the project on ghazwanherisa@gmail.com
    Thanks

    ReplyDelete