Disruption-Tolerant Networking Essay

At first, I would like to talk about DSN which is a basic telecommunication systems in the world. According to the NASA DSN official website, the full name of DSN is Deep Space Network, which is famous as the system used to do the two-way communication between the Earth and the spacecraft or satellite in the space. (NASA Jet Propulsion Laboratory)Two-way communication, contains the uplink and downlink, means it can send information to the space and collect information from

AODV are utilized, instead of broadcasting data packets, S start off a route discovery protocol that requires broadcasting smaller Route Request

Furthermore, different business considerations are taken into account. The system supportspartially closed protocols and it does not affect existing and future manufacturer’sproducts.

The Two-Tier Data Dissemination (TTDD) assumes that the sensor nodes are stationary and location aware and sinks are allowed to change their location dynamically [9]. When any change is sensed by sensors the source node will generate the reports. Then the source node chooses itself as a start crossing point and sends data to its adjacent crossing points. This is also used in which nodes are stationery for multiple mobile sinks.

This protocol use Dijkstra algorithm. It maintains a complex data base, also called as link state database, which contains full information about the remote routers and the exact network topology. The goal from this protocol is to provide similar information about network connection to each router, so each router can calculate the best route to each network this is happen when each router generates information about itself and pass these information to other routers in the network so each router make a copy of this information without changing it.

DSDV is a proactive, hop-by-hop distance vector routing protocol where the routing table is maintained by each and every network node. The routing table consists of all the nodes required to reach destination also including the nodes to which packets are not sent. The routing table is kept updated at every time after each entry. In order to avoid the routing loops, DSDV uses the concept of sequence numbers to maintain the originality of route at all times. For the network in figure. 1 below, the routing table for node A can be seen in table. 1 which contains information about all possible paths reachable by node A, along with the next hop, number of hops and sequence number.

In order to evaluate the performance of the proposed DCHS algorithm, we compare MILP with the energy consumption and delay constrained routing protocol.

A group of wireless sensor nodes (devices) dynamically constructs a temporary network without the exercise of any pre-existing network infrastructure or centralized administration. The main goal of ad-hoc networking is multihop broadcasting in which packets are transferred from source node to destination node through the intermediate nodes (hops). The main function of multi hop WSN is to enable communication between two terminal devices through a bit of middle nodes, which are transferring information from one level to another level. On the foundation of network connectivity, it dynamically gets to determine that which nodes should get included in routing, each node involved in routing transmit the data to further

routing. In this chapter, we introduce some popular routing protocols in each of the three

All the computers, in the logically and physically networks have to follow the same rules known as Protocols such as TCP/IP, IPX/SPX and NETBEUI etc. Today, there are many computer networking technologies such as LAN, MAN, WAN, WLAN, ISDN, ATM, Frame Relay, X.25, Bluetooth,

Several energy-aware routing protocols have been proposed in literature for heterogeneous WSNs. In \cite{Georgios2004}, the authors proposed SEP, a Stable Election Protocol, that improves homogenous LEACH protocol \cite{Heinzelman2000} by considering two levels of heterogeneity: normal nodes and advanced nodes, where the later are equipped with an extra amount of energy. The cluster head is selected based on a weighted probability according to the node initial energy in such a way that the nodes having a higher initial energy become cluster heads more times than the other nodes. The election probabilities for the normal and advanced nodes are given as follows:

The root initially broadcasts a DIO message (DODAG Information Object) as depicted in Figure 1. This message contains the information required by RPL nodes to discover a RPL instance, get its configuration parameters, select a parent set, and maintain the DODAG graph. Upon receiving a DIO message, a node adds the sender of the message to its parents list and determines its own rank value by taking into account the objective function referred in the DIO message. The rank value of a node corresponds to its position in the graph with respect to the root and must always be greater than its parents rank in order to guarantee the acyclic nature of the graph. It then forwards updated DIO messages to its neighbors. Based on its parents list, the node selects a preferred parent which becomes the default gateway to be used when data has to be sent toward the DODAG root. At the end of this process, all the nodes participating in the DODAG graph have an upward default route to the DODAG root. This route is composed of all the preferred parents. The DIO messages are periodically sent according to a timer set with the trickle algorithm [16] which optimizes the transmission frequency of control messages depending on the network state. A new node may join an existing network by broadcasting a DIS message (DODAG Information Solicitation) in order to solicit DIO messages from its neighbors. The DAO messages (Destination Advertisement Object)

The cross layer based reliable routing algorithm, is designed using the metric from the physical layer, data link layer and transferring it to the network layer to make the routing decisions. This algorithm involves the mobile node cooperatively to establish the route and introduces the radio link stability with extensive cross layer cooperation to establish reliable and stable routes. We have developed this algorithm by modifying the underlying principle of dynamic source routing protocol. Dynamic source routing is known for its benefits of routing in multiple paths avoiding the overhead of new route discovery whenever the route in use breaks [10. Hang Shen et.al, 2008]. The route discovery and route maintenance easily

Abstract: Because of high speed of vehicles, short contact durations and rapid changes in topology occurs in Vehicular Delay Tolerant Network (VDTN). This will generates few transmission opportunities and high and unpredictable delay. This problem can be solved by different routing protocol of VDTN. The VDTN protocol can be divided as single copy and multi copy. In single copy protocol the node is allowed to generate the unique copy of message and forward it on a unique path. The multi copy protocols generate and transmit the multiple copies of each message and forward it along various paths. If more number of copies spread in network there are more chances for successful transmission. The objective of paper is to improve performance of VDTN by modifying existing Spray and Wait protocol. In this paper we provide proposed algorithm for modify spray and wait protocol for improving delivery probability with different number of message copy. The modifications based on stored number of message copies at source/rely nodes and encountered nodes ratio.

The DSR (Dynamic Source Routing) routing protocol dependent on the cache memory for every node to store the routing path from source to destination. It is a new algorithm using DSR routing cache technique to improve the routing between mobile nodes to reduction the effect of mobility in link transmitting that can solve link broken problem.