Epidemic Routing Protocol Research Articles

Analysis and improvement of TCP performance in opportunistic networks

Opportunistic networks have attracted attention due to their inherent characteristics, such as long latency, low data rate, and intermittent connectivity. Extensive research has been conducted on opportunistic networks, including the architecture, and routing. However, few in the literature report the performance of TCP in opportunistic networks, especially in the case of Epidemic Routing. In this paper, we first evaluate the performance of TCP in opportunistic networks with Epidemic Routing. Our results show that the Epidemic Routing in opportunistic networks degrades the performance of TCP because multicopy data packets cause duplicate ACKs, and in turn reduce the transmission rate of TCP. Then an enhanced algorithm for TCP, named A-TCP/Reno is proposed to solve the above problem. A-TCP/Reno avoids the duplicate ACK problem caused by Epidemic Routing. The simulation results show that A-TCP/Reno outperforms the TCP/Reno in opportunistic networks with Epidemic Routing protocol.

Adaptive message size routing strategy for delay tolerant network

Delay tolerant network (DTN) is a kind of computer network that suffer from the frequent disconnections, network partitioned and unstable network connectivity, therefore maintaining an uninterrupted route from source to destination is not possible. Therefore, the transmission of message is achieved via intermediate nodes by adopting a novel transmission mechanism called store-carry and forward where node stores the incoming message in its buffer, carries it while moving and forward it when it comes in the transmission range of other nodes. DTN routing protocols can be either single copy or multi copy. In single copy protocols, the node forwards the unique copy of message along a single path. These protocols suffer the long delivery delay. In multi copy protocols, the node diffuses multiple copies of same message along dissimilar paths. Thus, message can reach destination via more than one path. However, the replication process consumes high volume of network resources such as buffer space, bandwidth and node energy. The probabilistic routing strategies for instance PRoPHET Protocol minimizes the consumption of resources and forwards a message to a custodian by using a metric of delivery probability. The probability describes the suitability of a node to meet the destination of message. However, when node mobility pattern is not symmetric the probabilistic computations cannot predict the accurate forwarding decision. In this paper, we have proposed a novel message forwarding strategy called Adaptive Message-Size Routing strategy (AMRS) by which a node handovers the copy of message to its neighboring nodes by using a metric named as mean threshold (MTH). We have compared the performance of AMRS with Epidemic and PRoPHET routing protocols. The proposed routing strategy has performed better in terms of maximizing delivery probability while minimizes message drops and number of transmissions.

Application of Computational Intelligence Paradigm in the Probabilistic Routing for intermittently connected network

In this project an approach is being made to use Fuzzy Logic(a computational intelligence paradigm) in the Probabilistic routing protocol for Intermittently connected network: Delay Tolerant Network. Communication between two mobile nodes in an infrastructure less network is possible if they are within the wireless communication range. Delay Tolerant Network (or DTN) is not only an infrastructure less network but it also suffers from intermittent connection i.e. there is not always a connected path from the source to the destination. As a result traditional routing protocols cannot serve the purpose of this type of network. A passive routing protocol for DTN's named PROPHET routing works on the principle of history of encounters and transitivity (3). It is called Probabilistic routing protocol since it uses a parameter 'Delivery of Predictability'. Using Fuzzy Logic some rules will be defined and another parameter 'Energy value' will be considered to calculate the probability of delivery. With the aim of consuming fewer resources by the network and minimizing the delay in message delivery this new Fuzzy based probabilistic routing protocol has been introduced. Keywords: Delay tolerant network, Fuzzy logic, Delivery Predictability, Prophet routing protocol, Epidemic routing protocol.

IMPROVING QoS IN DELAY TOLERANT MOBILE AD HOC NETWORK USING MULTIPLE MESSAGE FERRIES

Most ad hoc network routing algorithms are designed primarily for networks that are always connected. While it is certainly desirable to maintain a connected network, various conditions may cause a mobile ad hoc network to become partitioned. If the partitions last for a long duration of time, then it is not possible to deliver a packet from source to destination. To deliver messages in a partitioned network, new routing approaches were proposed for delivering data using message ferries and/or gateways. This paper analyzes various parameters of the routing scheme called Routing with Multiple Message Ferries and Gateways (MMFGW) which eliminates online collaboration between all the communication entities in the network. This paper also investigates the results of simulations, by comparing the performance of our protocols which uses message ferries proposed previously with epidemic routing protocol. The simulation analysis shows that, delivery ratio of MMFGW improves from 35% to 50% with optimal latency and overhead ratio.

IMPROVING QoS IN DELAY TOLERANT MOBILE AD HOC NETWORK USING MULTIPLE MESSAGE FERRIES

Most ad hoc network routing algorithms are designed primarily for networks that are always connected. While it is certainly desirable to maintain a connected network, various conditions may cause a mobile ad hoc network to become partitioned. If the partitions last for a long duration of time, then it is not possible to deliver a packet from source to destination. To deliver messages in a partitioned network, new routing approaches were proposed for delivering data using message ferries and/or gateways. This paper analyzes various parameters of the routing scheme called Routing with Multiple Message Ferries and Gateways (MMFGW) which eliminates online collaboration between all the communication entities in the network. This paper also investigates the results of simulations, by comparing the performance of our protocols which uses message ferries proposed previously with epidemic routing protocol. The simulation analysis shows that, delivery ratio of MMFGW improves from 35% to 50% with optimal latency and overhead ratio.

MACRE: a Novel Distributed Congestion Control Algorithm in DTN

Congestion control is a very important problem which can affect network performance directly. However, owing to the lack of steady end-to-end connection and high latency, the traditional congestion control mechanism based on end-to-end feedback is not feasible in DTN. Because obtaining the global information of network is difficult, the congestion control decisions should be made autonomously with local information only. We propose a novel distributed congestion control algorithm based on epidemic routing protocols----MACRE (Message Admission Control based on Rate Estimation). Preliminary experimental results show that this congestion control mechanism can improve the network performance efficiently.

Impact of Mobility Models on DLA (Drop Largest) Optimized DTN Epidemic Routing Protocol

mobile nodes depend on their mobility to carry the message to destination. Therefore it is important to understand the effect of buffer management policies on the performance of DTN routing protocols under different mobility models. In our previous work of DLA we examine that epidemic router was not showing good delivery probability in case of SPMBM. This paper is the performance of DLA (drop largest) and DOA (Drop oldest) buffer management policy with impact of varying mobility models under epidemic routing protocol. We show that how combination of mobility models and queuing mechanism can optimize the performance of epidemic routing protocol in term of delivery probability, message dropped, buffer time average, overhead ratio and hop count averages.

TMHF: Transmit Max Hop First forwarding Strategy to Optimize the Performance of Epidemic Routing Protocol

Tolerant Networks vary from conventional networks in that they have reserve constraints, unbalanced mixture traffic, data redundancy, network dynamics, and energy balance. Moreover due to node mobility DTN suffers from unpredictable connectivity and limited transmission duration. A mobile node in DTN routing may not be able to transmit all messages from its forwarding queue; therefore the order in which messages are transmitted becomes very important. In this paper, we propose forwarding queuing mechanisms named Transmit Max Hop Count first (TMHF) in which when the connection opportunity arises, the node will transmit the message with max hop count.

A geometric routing protocol in disruption tolerant network

We describe a novel geometric localised routing protocol in disruption (delay) tolerant network (DTN). Although DTNs do not guarantee the connectivity of the network all the time, geometric location information could still be used to make routing decisions in a store-and-forward way. Geometric planar spanners, especially local Delaunay triangulation (LDT) can also be used in DTNs to provide a good routing graph with constant stretch factor and shorter paths during communications. In this work, we design local distributed solutions to extract spanning trees from LDT graphs from source to destination. Our protocol resorts to flooding packets along trees with high probability of being delivered without significant delays. Through experimentation, we have shown that the proposed routing protocol achieves higher delivery ratios with lower delays and limited storage requirements than the benchmark epidemic routing protocol.

A Border Node Based Routing Protocol for Partially Connected Vehicular Ad Hoc Networks

Research on vehicular ad hoc networks (VANETs) has focused primarily on efficient routing protocol design under conditions where there are relatively large numbers of closely spaced vehicles, typical of major highways and urban areas. These routing protocols are designed principally for fully connected networks and are not suitable for packet delivery in a sparse, partially connected VANET. In rural areas, vehicle densities are low and roadway communication infrastructure is scarce, leading to long periods where vehicle-to-vehicle or vehicleto- roadside communications is infrequent, interrupted, or simply not possible. These attributes characterize a sparse VANET, and are characteristic of delay tolerant networks (DTNs). In this paper, we examine the challenges of VANETs in sparse network conditions, review alternatives including epidemic routing and propose a Border node Based Routing (BBR) protocol for partially connected VANETs. Unlike many VANET protocols that assume location awareness or mobility patterns to aid in routing decisions, BBR is designed to function in domains where location and mobility information is not available, as is typical in rugged terrain conditions. The BBR protocol can tolerate network partition due to low node density and high node mobility. The performance of this protocol is evaluated in OPNET TM with a Random Waypoint mobility model and a Geographic and Traffic Information (GTI) based mobility model that captures typical highway conditions. The simulation results are compared with those obtained using the Dynamic Source Routing (DSR) protocol and with an epidemic routing protocol. The simulation results show that BBR performs well for partially connected VANETs where other protocols fail and provides the advantage of not relying on a location service required by other protocols proposed for VANETs.

A Priority Routing Protocol Based on Location and Moving Direction in Delay Tolerant Networks

Delay Tolerant Networks (DTNs) are a class of emerging networks that experience frequent and long-duration partitions. Delay is inevitable in DTNs, so ensuring the validity and reliability of the message transmission and making better use of buffer space are more important than concentrating on how to decrease the delay. In this paper, we present a novel routing protocol named Location and Direction Aware Priority Routing (LDPR) for DTNs, which utilizes the location and moving direction of nodes to deliver a message from source to destination. A node can get its location and moving direction information by receiving beacon packets periodically from anchor nodes and referring to received signal strength indicator (RSSI) for the beacon. LDPR contains two schemes named transmission scheme and drop scheme, which take advantage of the nodes' information of the location and moving direction to transmit the message and store the message into buffer space, respectively. Each message, in addition, is branded a certain priority according to the message's attributes (e.g. importance, validity, security and so on). The message priority decides the transmission order when delivering the message and the dropping sequence when the buffer is full. Simulation results show that the proposed LDPR protocol outperforms epidemic routing (EPI) protocol, prioritized epidemic routing (PREP) protocol, and DTN hierarchical routing (DHR) protocol in terms of packet delivery ratio, normalized routing overhead and average end-to-end delay. It is worth noting that LDPR doesn't need infinite buffer size to ensure the packet delivery ratio as in EPI. In particular, even though the buffer size is only 50, the packet delivery ratio of LDPR can still reach 93.9%, which can satisfy general communication demand. We expect LDPR to be of greater value than other existing solutions in highly disconnected and mobile networks.

Performance of ad hoc networks with two-hop relay routing and limited packet lifetime (extended version)

We consider a mobile ad hoc network consisting of three types of nodes (source, destination and relay nodes) and using the two-hop relay routing. This type of routing takes advantage of the mobility and the storage capacity of the nodes, called the relay nodes, in order to route packets between a source and a destination. Packets at relay nodes are assumed to have a limited lifetime in the network. Nodes are moving inside a bounded region according to some random mobility model. Closed-form expressions and asymptotic results when the number of nodes is large are provided for the packet delivery delay and for the energy needed to transmit a packet from the source to its destination. We also introduce and evaluate a variant of the two-hop relay protocol that limits the number of generated copies in the network. Our model is validated through simulations for two mobility models (random waypoint and random direction mobility models), and the performance of the two-hop routing and of the epidemic routing protocols are compared.

Performance Evaluation of SUVnet With Real-Time Traffic Data

In this paper, we present the characteristics of a vehicular ad hoc network (VANET), which is the Shanghai urban vehicular network (SUVnet). We construct a mobility model using the GPS data collected from more than 4000 taxis in Shanghai. The model is both realistic and large scale. Based on this model, network topology and connectivity of SUVnet are studied. Because of the sparse distribution and dynamic topology of SUVnet, simply utilizing the conventional mobile ad hoc network routing protocols in SUVnet may not achieve a satisfactory performance. Therefore, we apply the delay-tolerant network model to SUVnet and evaluate the epidemic routing protocols. We propose a new protocol, which is the distance aware epidemic routing (DAER), to improve the bundle delivery ratio. Results show that DAER performs well for a VANET. This paper provides a basis in studying a realistic urban VANET.

Delay and resource analysis in MANETs in presence of throwboxes

This paper addresses the delay analysis and resource consumption in mobile ad hoc networks (MANETs) equipped with throwboxes. Throwboxes are stationary, wireless devices that act as relays, and that are deployed to increase the connectivity between mobile nodes. Our objective is to quantify the impact of adding throwboxes on the performance of two routing protocols, namely the Multicopy Two-hop Routing protocol and the Epidemic Routing protocol, in the cases where the throwboxes are fully disconnected or mesh connected. To this end, we use a Markovian model where the successive meeting times between any pair of mobile nodes (resp. any mobile node and any throwbox) are represented by a Poisson process with intensity λ (resp. μ ). We derive closed-form expressions for the distribution of the delivery delay of a packet and for the distribution of the total number of copies of a packet that are generated, the latter metric reflecting the overhead induced by the routing protocol. These results are then compared to simulation results. Through a mean-field approach we also provide asymptotic results when the number of nodes (mobile nodes and/or throwboxes) is large.