Haut PDF Efficient routing protocols in nameless networks

Efficient routing protocols in nameless networks

Efficient routing protocols in nameless networks

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An Efficient Energy aware Link Stable Multipath Routing Protocol for Mobile Ad hoc Networks in Urban Areas

An Efficient Energy aware Link Stable Multipath Routing Protocol for Mobile Ad hoc Networks in Urban Areas

Several multipath protocols [8-10], that conserve the networks energy, have been proposed in order to extend network lifetime by minimizing link breaks. All of these works solve the energy conservation problem, but the majority of the uses techniques used are based on the remaining energy only; they are not designed to discover the best path between source and destination nodes. On one hand, when a node accepts routing requests because it has enough residual battery capacity, routing traffic is routed through this node. On the other hand, many energy saving mechanisms/algorithms neglect the power consumption induced by each node own message sending, which may cause network partitioning due to node battery depletion. Indeed, it decreases reduces network performance. Hence, balanced energy consumption is a remedy for these natures of problems. Finally, another problem of these routing protocols schemes is that they do not consider the paths stability in their path establishment process. The nodes mobility makes the network topology very unstable and causes path-breaking. Several protocols [11-13] have been proposed to contribute to solving this problem. In the most of these routing schemes, a new path-discovery process is launched once a path rupture is detected. This increases delay and causes node resources wastage which may reduce network lifetime. The multipath routing is an effective concept in mobile ad hoc networks to adjust the problem of frequent topology changes in the network caused mainly by link failures. Many existing multi-path routing protocols [14-16], are primarily related to link instability issues.
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Modeling Uncertainties in Proactive Routing Protocols for AdHoc Networks

Modeling Uncertainties in Proactive Routing Protocols for AdHoc Networks

Abstract—In this paper we introduce a new model for ad hoc networks. Our model aims at reproducing the states alternation of links and nodes led by dynamic and random topology of ad hoc networks as well as random delays of packets delivery. Furthermore, we study the phenomenon of uncertainties in routing operation due to the unpredictable topological changes. Unlike mobility models which reflect only the impact of mobility on routing protocols, our proposal can demonstrates the impact of several identified hazards on the performances of proactive routing protocols. We show through various simulations the performances of our model within the framework of a proactive routing.
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Energy efficient cluster-based routing in wireless sensor networks

Energy efficient cluster-based routing in wireless sensor networks

Abstract—Because of the lack of a global naming scheme, routing protocols in sensor networks usually use flooding to select paths and deliver data. This process although simple and effective, is very costly in terms of energy consumption, an important design issue in sensor networks routing protocols. Cluster-based routing is one solution to save energy. In this paper, we propose a combination of an improved clustering algorithm and directed diffusion, a well-known data-centric routing paradigm in sensor networks. Our aim is to prolong the network lifetime by modifying passive clustering rules for building/maintaining the topology so an energy load balancing is achieved among the network nodes. We performed extensive computer simulations and showed that our solution outperforms original directed diffusion as well as when it is combined to passive clustering without energy considerations.
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Efficient data aggregation and routing in wireless sensor networks

Efficient data aggregation and routing in wireless sensor networks

Figure 1.2: Energy consumption level [ Est02 ] slowly over time, whereas for spatial aggregation, the data gathered by neigh- bouring sensors is similar. As all sensors gather and route the data either to other sensors or to an ex- ternal entity called sink, self-configuration is mandated to give all sensors the possibility of efficiently forwarding data towards the sink. In the most applica- tions, sensors are assumed to be static, allowing the reporting of gathered data in a reactive manner. However, [ WT09 ] show that the static deployment of sen- sors has many limitations as limited connectivity, battery, storage capacity, etc. Considering the limited connectivity, the deployment of static sensors may not guarantee the whole coverage of the sensing area [ KPQT05 ]. So, the network may be partitioned into several non-connected subnetworks. As sensors are battery- powered, some sensors may die due to the exhaustion of their batteries and may break the network connectivity. The introduction of some mobile elements in the WSN to enhance its limitations could be an interesting solution. Instead of having a central sink responsible for aggregating all the data, introducing multiple mo- bile data collectors, which are responsible to maintain a fully-connected network topology, aggregate the data and forward it towards the sink. Thus, reducing the congestion appearance and relaxing the requirement on network connectivity.
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Multicast Routing In Optical Access Networks

Multicast Routing In Optical Access Networks

Centralized-Splitting Algorithm This algorithm aims to build a Steiner-based tree that achieves an efficient utilization of network resources while producing low power loss in or- der that the transmitted light signal is maintained above the signal sensitivity threshold. Initially, a multicast diffusion tree is constructed by ap- plying the Member-Only algorithm without any consideration of the power-level impairment. Then some adjustments are made in the tree produced according to the following guidelines. Firstly, if there are more than two successive MC nodes in a subtree, they will produce a cascade effect on power loss (as indicated in Figure 9(a)). Hence, it is better to replace the successive MC nodes by a single MC node. Secondly, although a power splitter located near to the source can balance the power loss on each subtree, the effect of the power loss will be propagated to all children nodes located within its subtree. In order to reduce power loss, the algorithm assigns the splitting capability to the node furthest from the source node whenever possible. For instance in Figure 9(b), the light splitting happens in the last level of the tree; hence the power loss decreases to 2e 0 /3 compared to the cascade splitter situation with 3e 0 /4 in Figure 9(a). Thirdly, when the number of splittings at a node increases, the incremental power loss caused by each additional splitting decreases. As a result,
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Fast loop-free transition of routing protocols

Fast loop-free transition of routing protocols

3) Cost of the transition: Figure 6 shows the cost of the transition, computed as the average number of control messages required to perform the transition for all destinations. For all heuristics, the number of control messages increases with the network size, as more nodes have to be configured overall. For large networks, RTH-p and SCH-p achieve similar results, which comes from the fact that these two heuristics are unable to merge destinations. The number of control messages is equal to n.d for SCH-p. For ACH, the small control overhead comes from the fact that all steps are merged: when a node appears several times in the same step for different destinations, it is counted only once as a single
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Energy-efficient reliable transport protocols for IP-based low power wireless networks

Energy-efficient reliable transport protocols for IP-based low power wireless networks

One of the first TCP/IP header compression methods was Compressed TCP (CTCP), which has been proposed by Jacobson [Jac90]. Jacobson’s header compression algorithm distinguishes dynamic fields from static fields. The static fields (i.e., fields that are expected to be constant throughout the lifetime of the packet stream such as source address and source port) are sent in two situations: when initiating a connection, and when refreshing the context (i.e., the state used by the compressor to compress a header, and by the decompressor to decompress a header) after a loss of synchronization. CTCP proposes to send the difference between the current and the previous value of dynamic fields (e.g., sequence number, acknowledgment number). When the synchronization is lost between the compressor and the decompressor (i.e., the destination does not success to decompress the compressed segments), the TCP sender sends a segment with a regular header to refresh the context. Experimental studies [PM97, SFRF01, Wan04] have shown that the performance of Jacobson’s algorithm may degrade significantly in noisy/lossy network environments. An important disadvantage of CTCP is that it does not support TCP options, some of which are ubiquitous nowadays (e.g., SACK).
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Security issues in link state routing protocols for MANETs

Security issues in link state routing protocols for MANETs

This section presents an overview of the OLSR protocol and its vulnerabilities. OLSR is a proactive routing protocol designed for MANETs. The core of the pro- tocol is the selection, by every node, of MPRs among their one-hop neighbors. The MPR set is selected such that all two-hop neighbors are reachable through at least one MPR. Fig. 1 compares the MPR mechanism and classical flooding. In Fig. 1(a), control traffic information is retransmitted by all the one-hop neighbors. In Fig. 1(b), control traffic information is retransmitted exclusively by the MPRs. This optimiza- tion improves the network performance by reducing the size and number of control traffic messages in the network. OLSR is defined in RFC3626 [12]. A second ver- sion of the protocol, i.e., OLSRv2, is presented by Clausen et al. in an Internet- Draft [13]. OLSRv2 uses and extends: the MANET Neighbor Discovery Proto- col (NHDP) [16], RFC5444 - Generalized MANET Packet/Message Format [17], RFC5497 - Representing Multi-Value Time in MANETs [14] and RFC5148 - Jitter Considerations in MANETs [15] (optional). These protocols were all originally cre- ated as parts of OLSRv2, but have been specified separately for wider use. OLSRv2 retains the same basic mechanisms and algorithms for distributing control traffic (i.e., MPR-based flooding) but provides a more efficient signaling framework and implements some message simplifications.
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Distributed fast loop-free transition of routing protocols

Distributed fast loop-free transition of routing protocols

I. I NTRODUCTION In computer networks that have a long lifetime, the routing protocol may have to be changed without service interruption. This is the case when a security update of a routing protocol appears [1], when significant modifications of the topology or link metrics have to be taken into account [2], [3], [4], or to handle the apparition of urgent traffic in a wireless sensor network designed for energy efficiency [5]. Another example is when a change of router is planned: link metrics around the router can be increased until no route traverses these links anymore; then, the router can be safely removed [6].
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Explicit Routing in Multicast Overlay Networks

Explicit Routing in Multicast Overlay Networks

Mechanisms for explicit path selection are not included in most multicast distribution concepts. With explicit path selection, the sender of a multicast packet can explicitly select the distribution path (usually a tree) of a single multicast packet. This allows a sender selecting individual multi- cast trees for each single packet in order to react on events such as link breaks, node failures, congested links, and group member leaves. We propose that a sender of a multicast packet can select a backup multicast tree instead of the default multicast tree by inserting a fixed size iden- tifier to the multicast packet. A multicast delivery tree is typically established by multicast rout- ing protocols in case of IP multicast and by peer-to-peer protocols in case of application level multicast. Such a multicast delivery tree is then used for the distribution of multicast data. The selected backup multicast tree can then be used to immediately react on link failures without any delay caused by reestablishing a new multicast delivery tree for the new topology. Load balanc- ing can be achieved by using different trees simultaneously and can be applied when a particular link of the default multicast tree becomes congested or for increasing throughput.
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Routing and Broadcasting in Hybrid Ad Hoc Networks

Routing and Broadcasting in Hybrid Ad Hoc Networks

6 Conclusion In this paper, we have considered hybrid networks, which are composed of mobiles ad hoc network and access points, in which the ad hoc communicating mode is available to increase the flexibility and mobility of users. A terminology was introduced that allows one to easily describe such a network. We also presented several algorithms for basic data communication tasks in a network, such as broadcasting and routing. These algorithms are adapted from ad hoc networks to hybrid networks, to take advantage of access point as much as possible. In our future work, we want to further improve some of these protocols and to design some experiments to obtain their respective performances, which could allow a fair comparison between them. We want to study broadcast protocols involving topology management with radius adjustment in hybrid networks. Finally, some assumptions can also be removed and
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Vertex labeling and routing in expanded Apollonian networks

Vertex labeling and routing in expanded Apollonian networks

We have proposed an expanded deterministic Apollonian network model, which represents a transition for degree distribution between exponential and power law distributions. Our model successfully reproduces some remarkable characteristics in many natural and man-made networks. We have also introduced a vertex labeling for these networks. The length of the label is optimal. Using the vertex labels, it is possible to find in an efficient way a shortest path between any pair of vertices. Nowadays, efficient handling and delivery in communication networks (e.g. the Internet) has become one important practical issue, and it is directly related to the problem of finding shortest paths between any two vertices. Our results, therefore, can be useful when describing new communication protocols for complex communication systems.
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Routing and mobility in large heterogeneous packet networks.

Routing and mobility in large heterogeneous packet networks.

In order to function correctly, however, routing protocols require that each node in the network is uniquely identified. In the Internet, as we have already seen, this unique name is an IP address. Therefore, there is a need for a mechanism dynamically assigning unique addresses to nodes in a MANET. Contrary to traditional networks, the roles of hosts (i.e. nodes that use the network) and routers (i.e. nodes that form and maintain the network) are not clearly separate in a mobile ad hoc environment. Indeed, each node may act in both capacities simultaneously. Another particularity of MANETs is that no assumption can be made regarding preexisting infrastructures. However, classical autoconfiguration mechanisms, such as DHCP [44], ZeroConf [45] or similar mechanisms, assume the presence of a server, which can coordinate and assign addresses to hosts in the local network. Other traditional mechanisms, such as IPv6 Stateless Autoconfiguration [49], assume that direct communication is available between each interface in the local network. However, the multi-hop nature of MANETs does not allow the assumption that direct communica- tion between an arbitrary pair of nodes is always possible.
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Adaptation of Topology-Based Routing Protocols for Data Gathering Applications in VANETs

Adaptation of Topology-Based Routing Protocols for Data Gathering Applications in VANETs

Abstract—The use of VANETs for data gathering applications imply that vehicles are not only able to generate data but also to forward it from others towards an access point (AP). Given the mobility characteristics of vehicles and the difficult propagation conditions of urban scenarios, it is commonly stated that topology-based routing solutions are less efficient than geographic-based routing solutions. However, these statements refer to generic vehicular communications, ignoring specific characteristics of data gathering scenarios. In this work, two existing routing protocols that prior to forwarding data, set a path from each vehicle towards the AP are adapted for data gathering applications. While the existence of a path reduces the number of ineffective retransmissions and the delay, it also increases the overhead, and therefore the presented protocols were adapted to improve the overall performance. Aiming to correctly evaluate the routing protocols, simulations are launched using a realistic trace from the city of Cologne. The results obtained show that it is possible to limit the overhead associated to topology updates, outperforming geographic-based solutions.
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Efficient Agreement Protocols for Asynchronous Distributed Systems

Efficient Agreement Protocols for Asynchronous Distributed Systems

The agent technology aims at moving the code where the data are produced [50]. Consequently, this technology seems appropriate. A mobile agent is a computer program that can migrate autonomously from node to node, in order to perform some computation on behalf of the codes’s owner. In our context, the code’s owner is the customer who issues a transaction and expects a firm commitment of n traders about its n requests. The agent is in charge of exploring a geographical area (i.e. the mall). In order to move within this area, it relies on both fixed and ad-hoc networks. Indeed, an agent is a proven solution to cope with the dynamic changes that continually modify the topology (connections and discon- nections, node’s movings). For example, in such contexts, this technology was adopted to solve routing [6, 35] and service discovery [41, 22]. Herein, for each of the n stages of the transaction, the agent must identify a node (called a place) able to satisfy the corresponding request. A node is defined as either a static or a mobile device owned by a trader. By defi- nition, a node is a computing unit that provides an appropriate infrastructure to support a mobile agent migrating to and from that location. For a given request, a node is able, first, to test if it may satisfy the request and, second, to execute the corresponding work if needed. During both the test and the request’s execution, a node may interact with its surrounding environment and in particular with available devices located nearby. As sensor-generated data fluctuate both with time and with the location of a device, the values taken into account are those available at the time of the visit of the agent. Regarding its communication capa- bilities, during the visit of an agent, a node can provide an IP address which can be used later to contact this node directly. The concept of transactional mobile agent [51] has been introduced as a mix between the agent technology and the transactional model. During its move, the agent discovers and visits n places that satisfy the n requests. During the agent’s visit, a node records enough information so that it can subsequently either commit or abort the transaction.
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Comparing QoS of DSDV and AODV routing protocols in vehicular network

Comparing QoS of DSDV and AODV routing protocols in vehicular network

Ad-Hoc On demand Distance Vector (AODV) is one of the renowned reactive routing protocols in wireless ad-hoc networks; it is used as a reference when a new protocol is being tested [11]. In AODV [12] [13], before a sender send a packet to destination, the source sends a RREQ packet to its neighbors and they maintained the sender address and broadcast the RREQ till it reaches either to destination or an intermediate node that has a valid route to destination, then a RREP packet is unicasted to the source through the routing table that has been stored route back to the originator. The nodes add the next hop address to their routing table for destination during transferring the RREP. In AODV, when a link breakage occurs, a broken node would send a RERR packet - that includes all the nodes which are not accessible anymore to the sender and all intermediate nodes therefore they would be informed about the broken link and sender will generate a new RREQ to find a new route.
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New Routing Protocol in Ad Hoc Networks

New Routing Protocol in Ad Hoc Networks

Many routing protocols have been proposed to keep the connectivity between nodes, including the AODV protocol (Ad Hoc On-Demand Distance Vector), which is maintained a[r]

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Diverse Routing in Networks with Star SRLGs

Diverse Routing in Networks with Star SRLGs

Diverse routing, SRLG Motivations. To ensure reliable communications, many protection schemes have been proposed. One of the most used, called dedicated path protection, consists in computing for each demand both a working and a protection path. A general requirement is that these paths have to be diversely routed, so that at least one path can survive a single fail- ure in the network. This method works well in a single link failure scenario, as it consists in finding two edge-disjoint paths between a pair of nodes. This is a well-known prob- lem in graph theory for which there exist efficient polyno- mial algorithms. However, the problem of finding two di- versely routed paths between a pair of nodes becomes much more difficult in case of multiple correlated link failures that can be captured by the notion of SRLG (Shared Risk Link
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Proximity aware routing in ad hoc networks

Proximity aware routing in ad hoc networks

Abstract: Most of the existing routing protocols for ad hoc networks are designed to scale in networks of a few hundred nodes. They rely on state concerning all links of the network or links on the route between a source and a destination. This may result in poor scaling properties in larger mobile networks or when node mobility is high. Using location information to guide the routing process is one of the most often proposed means to achieve scalability in large mobile networks. However, location- based routing is difficult when there are holes in the network topology. We propose a novel position- based routing protocol called Proximity Aware Routing for Ad-hoc networks (PARA) to address these issues. PARA selects the next hop of a packet based on 2-hops neighborhood information. We introduce the concept of “proximity discovery”. The knowledge of a node’s 2-hops neighborhood enables the protocol to anticipate concave nodes and helps reduce the risks that the routing protocol will reach a concave node in the network. Our simulation results show that PARA’s performance is better in sparse networks with little congestion. Moreover, PARA significantly outperforms GPSR for delivery ratio, transmission delay and path length. Our results also indicate that PARA delivers more packets than AODV under the same conditions.
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