Opportunistic Networks: Present Scenario- A Mirror Review

Opportunistic Network is form of Delay Tolerant Network (DTN) and regarded as extension to Mobile Ad Hoc Network. OPPNETS are designed to operate especially in those environments which are surrounded by various issues like- High Error Rate, Intermittent Connectivity, High Delay and no defined route between source to destination node. OPPNETS works on the principle of “Store-and-Forward” mechanism as intermediate nodes perform the task of routing from node to node. The intermediate nodes store the messages in their memory until the suitable node is not located in communication range to transfer the message to the destination. OPPNETs suffer from various issues like High Delay, Energy Efficiency of Nodes, Security, High Error Rate and High Latency. The aim of this research paper is to overview various routing protocols available till date for OPPNETs and classify the protocols in terms of their performance. The paper also gives quick review of various Mobility Models and Simulation tools available for OPPNETs simulation

Pervasive intelligent routing in content centric delay tolerant networks

This paper introduces a Swarm-Intelligence based Routing protocol (SIR) that aims to efficiently route information in content centric Delay Tolerant Networks (CCDTN) also dubbed pocket switched networks. First, this paper formalizes the notion of optimal path in CCDTN and introduces an original and efficient algorithm to process these paths in dynamic graphs. The properties and some invariant features of these optimal paths are analyzed and derived from several real traces. Then, this paper shows how optimal path in CCDTN can be found and used from a fully distributed swarm-intelligence based approach of which the global intelligent behavior (i.e. shortest path discovery and use) emerges from simple peer to peer interactions applied during opportunistic contacts. This leads to the definition of the SIR routing protocol of which the consistency, efficiency and performances are demonstrated from intensive representative simulations

Swarm-based Intelligent Routing (SIR) - a new approach for efficient routing in content centric delay tolerant networks

This paper introduces Swarm-based Intelligent Routing (SIR), a swarm intelligence based approach used for routing content in content centric Pocket Switched Networks. We first formalize the notion of optimal path in DTN, then introduce a swarm intelligence based routing protocol adapted to content centric DTN that use a publish/subscribe communication paradigm. The protocol works in a fully decentralized way in which nodes do not have any knowledge about the global topology. Nodes, via opportunistic contacts, update utility functions which synthesizes their spatio-temporal proximity from the content subscribers. This individual behavior applied by each node leads to the collective formation of gradient fields between content subscribers and content providers. Therefore, content routing simply sums up to follow the steepest slope along these gradient fields to reach subscribers who are located at the minima of the field. Via real traces analysis and simulation, we demonstrate the existence and relevance of such gradient field and show routing performance improvements when compared to classical routing protocols previously defined for information routing in DTN

Opportunistic mobile social networks: architecture, privacy, security issues and future directions

Mobile Social Networks and its related applications have made a very great impact in the society. Many new technologies related to mobile social networking are booming rapidly now-a-days and yet to boom. One such upcoming technology is Opportunistic Mobile Social Networking. This technology allows mobile users to communicate and exchange data with each other without the use of Internet. This paper is about Opportunistic Mobile Social Networks, its architecture, issues and some future research directions. The architecture and issues of Opportunistic Mobile Social Networks are compared with that of traditional Mobile Social Networks. The main contribution of this paper is regarding privacy and security issues in Opportunistic Mobile Social Networks. Finally, some future research directions in Opportunistic Mobile Social Networks have been elaborated regarding the data's privacy and security

A critical review of the routing protocols in opportunistic networks.

The goal of Opportunistic Networks (OppNets) is to enable message transmission in an infrastructure less environment where a reliable end-to-end connection between the hosts in not possible at all times. The role of OppNets is very crucial in today’s communication as it is still not possible to build a communication infrastructure in some geographical areas including mountains, oceans and other remote areas. Nodes participating in the message forwarding process in OppNets experience frequent disconnections. The employment of an appropriate routing protocol to achieve successful message delivery is one of the desirable requirements of OppNets. Routing challenges are very complex and evident in OppNets due to the dynamic nature and the topology of the intermittent networks. This adds more complexity in the choice of the suitable protocol to be employed in opportunistic scenarios, to enable message forwarding. With this in mind, the aim of this paper is to analyze a number of algorithms under each class of routing techniques that support message forwarding in OppNets and to compare those studied algorithms in terms of their performances, forwarding techniques, outcomes and success rates. An important outcome of this paper is the identifying of the optimum routing protocol under each class of routing

A Survey on the Application of Evolutionary Algorithms for Mobile Multihop Ad Hoc Network Optimization Problems

Evolutionary algorithms are metaheuristic algorithms that provide quasioptimal solutions in a reasonable time. They have been applied to many optimization problems in a high number of scientific areas. In this survey paper, we focus on the application of evolutionary algorithms to solve optimization problems related to a type of complex network likemobilemultihop ad hoc networks. Since its origin, mobile multihop ad hoc network has evolved causing new types of multihop networks to appear such as vehicular ad hoc networks and delay tolerant networks, leading to the solution of new issues and optimization problems. In this survey, we review the main work presented for each type of mobile multihop ad hoc network and we also present some innovative ideas and open challenges to guide further research in this topic

Towards social-aware opportunistic network datasets

Dissertação de mestrado em Engenharia InformáticaDelay-tolerant networks are wireless networks designed to be used in cases where network infrastructure is nonexistent or not available to be used. Because of this, there are several problems that need to be addressed in this environment, such as lack of continuous end-toend connectivity and increased delay and error rates in data transfer. As such, conventional routing schemes aren't feasible in providing e cient solutions for these cases. Since the nodes present in these kinds of networks usually possess very limited resources, opportunistic routing protocols should not only try to achieve a good message delivery probability, but also reduce the number of message replicas present in the network. This is done so as to avoid an unnecessary waste of storage and energy that comes from storing and transmitting messages to other nodes. Some of the recent Delay-tolerant network routing proposals involve using social information to determine which node has a higher probability of successfully delivering a message to its intended destination. This seems to be a popular strategy, that achieves a good delivery probability while reducing the message overhead, when compared to simpler schemes. One way to analyze the performance of a routing protocol is to use real opportunistic contact datasets to simulate a real life environment. This work focuses on providing a research on opportunistic network traces as a way to determine the contact patterns of Delay-Tolerant network nodes and their impact on routing algorithm performance, as well as proposing an architecture for a future data collection experiment

TAO: A Time-Aware Opportunistic Routing Protocol for Service Invocation in Intermittently Connected Networks

International audienceHandheld devices owned by nomadic people can form intermittently connected mobile ad hoc networks spontaneously. Such networks appear as an attractive solution for service providers, such as local authorities, in order to extend a pre-existing infrastructure-based network composed of several infostations so as to provide nomadic people with application services in a large scale area (e.g., a city). In such hybrid networks, intermittent connections are prevalent, and end-toend paths between clients and providers cannot be maintained all the time. Service provisioning thus remains a challenging problem today in these networks. In this paper, we propose a new time-aware opportunistic routing protocol called TAO. TAO is designed for service invocation in intermittently connected hybrid networks. This protocol makes it possible to select the best next message forwarder(s) among a set of neighbor nodes based on the dates of contacts of these nodes with infostations, and tends to implicitly estimate the distance separating these mobile nodes and the infostations. This paper gives a detailed description of this protocol supported with some simulation results