Haut PDF A Circuit-based Approach for Routing in Unidirectional Links Networks

A Circuit-based Approach for Routing in Unidirectional Links Networks

A Circuit-based Approach for Routing in Unidirectional Links Networks

101 - 54602 Villers lès Nancy Cedex France Unité de recherche INRIA Rennes : IRISA, Campus universitaire de Beaulieu - 35042 Rennes Cedex France Unité de recherche INRIA Rhône-Alpes : 65[r]

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A cross-layer MAC and routing protocol based on slotted Aloha for Wireless Sensor Networks

A cross-layer MAC and routing protocol based on slotted Aloha for Wireless Sensor Networks

In this paper, we use the cross-layer approach to design a new protocol, PLOSA (Path-loss Ordered Slotted Aloha protocol), for WDCN. PLOSA modies frame aloha to reduce energy consumption. The frame aloha protocol is a widely used access protocol that is characterized by its simplicity, establishing itself as a good candidate for WDCN. However the price of its simplicity is a lack of fairness in media access. Nodes are at various distances from the collector. In free space propagation model, signal attenuation is strictly related to the distance between the transmitter and the receiver. The received signal strength of distant nodes is signicantly lower than those of close nodes. Due to the capture eect, distant nodes have a lower throughput than close nodes. In WSN, the utilization of a multi-hop mechanism avoids the capture eect. PLOSA proposes a multi-hop cross-layer routing protocol where the idea is to order the access of nodes to optimize the energy consumption. The transmission channel is divided into dierent slots and a node has access to a slot related to its distance. The higher the distance between a node and the collector, the earlier this one can access a slot. Once the access of nodes is ordered, the resulting routing protocol is very simple. Indeed it does not require the notion of routing table (the next forwarding hop is always closer to the collector). Our protocol reduces at a minimum the overhead in both the routing protocol and the collision avoidance mechanism. No routing information are required to nd a path between a sensor and the collector. Each time a node sends a packet, a closer one to the collector forwards it until it reaches the collector. In the same way, the number of collisions is limited as the access of nodes is ordered. A collision can only occur in the vicinity of a sender node i.e. two nodes can send a packet into the same time slot if they are at the same distance from the collector. Hence our protocol avoids the hidden node problem without the use of an intrusive collision avoidance mechanism as RTS/CTS handshake. To our knowledge, no other cross-layer routing protocol exists addressing the question of how avoiding routing overhead and hidden node problem. Indeed PLOSA protocol is designed to oer high delivery rate and low end-to-end delay. In most cases PLOSA provides data delivery to the collector within one frame.
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Improving Decision-Making for Fuzzy Logic-based Routing in Wireless Sensor Networks

Improving Decision-Making for Fuzzy Logic-based Routing in Wireless Sensor Networks

Abstract—The task of routing data from a source node to the base station is a critical issue in Wireless Sensor Networks (WSNs). Fuzzy logic is the main proposal of a number of papers in the literature as an effective method for making decisions to transfer data towards the destination. Although fuzzy logic has a very important role in designing routing protocols for WSNs, identifying its fuzzy sets and defining best possible rules is a complex challenge. This paper introduces Improved-fuzzy logic (I-fuzzy), a simple and effective method that helps to address the weakness of fuzzy logic in terms of defining rules. The I- fuzzy method is tested in several scenarios by using GloMosim simulator and compared to a classic fuzzy logic approach and to a traditional minimum hop routing. The results show that the I-Fuzzy method outperforms the other approaches in terms of data delivery, energy conservation and load distribution.
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Broadcast-based Directional Routing in Vehicular Ad-Hoc Networks

Broadcast-based Directional Routing in Vehicular Ad-Hoc Networks

Claudio E. Palazzi and al.[10] also proposed the Fast Broadcast (FB) protocol which uses a distance-based approach with an estimated transmission range in order to reduce the number of redundant transmissions of the alert message as well as the hops to be traversed. This scheme is composed of two phases. The first one, named estimation phase, aims to provide each vehicle with an up-to-date estimation of its backward transmission range. On the other hand, the second one, called broadcast phase, is performed only when a message has to be broadcasted to all cars in the sender’s area-of-interest. In [11], authors propose a zone forwarding scheme for information dissemination in vanets (ZBF). The proposal tackles the problem of retaining the message in the target zone for the duration of the effect time. Thus, the algorithm divides the effect area of the alert message into segments of length the transmission range. A forwarder, a vehicle which is elected in each segment, is assigned the task of broadcasting the information to other neighboring vehicles. When the forwarder is about to leave the zone, a new forwarder will be elected. Simulation results show that ZBF outperforms other information dissemination protocols.
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Monitoring Web Service Networks in a Model-based Approach

Monitoring Web Service Networks in a Model-based Approach

7. Conclusion Web services is the emergent technology for business process integration. Existing formal methods provide rea- soning tools for these applications. As seen before, depend- ing on the kind of problems which are tackled, different modeling techniques are proposed to build formal models for Web services. In this paper, we aim at proposing a mon- itoring and diagnosis tool for Web services. The final goal is to give to these components the ability to detect abnormal situations, to identify the causes of these deficiencies, and lastly to decide recovering actions. We propose to start from existing process descriptions given in BPEL and to trans- late them in order to build a distributed behavioral system model. We examine each activity type and give its transla- tion in term of transition rules. We start with basic activities (definition 3), show how more complex activities with in- ternal states can be translated (definition 4), which enable to consider structure activities. Synchronization links cor- respond to synchronization of DES. In order to allow diag- nosis capabilities, it is shown how alarm propagation can be modeled (definition 6). This modeling task is illustrated on the loan approval example. We argue that, giving the behav- ioral model, off-the-shelf tools can be used to monitor Web services. Moreover, it seems to us that the decentralized and incremental approach that we experimented on telecommu- nication networks is well-suited to this kind of systems.
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Monitoring Web Service Networks in a Model-based Approach

Monitoring Web Service Networks in a Model-based Approach

7. Conclusion Web services is the emergent technology for business process integration. Existing formal methods provide rea- soning tools for these applications. As seen before, depend- ing on the kind of problems which are tackled, different modeling techniques are proposed to build formal models for Web services. In this paper, we aim at proposing a mon- itoring and diagnosis tool for Web services. The final goal is to give to these components the ability to detect abnormal situations, to identify the causes of these deficiencies, and lastly to decide recovering actions. We propose to start from existing process descriptions given in BPEL and to trans- late them in order to build a distributed behavioral system model. We examine each activity type and give its transla- tion in term of transition rules. We start with basic activities (definition 3), show how more complex activities with in- ternal states can be translated (definition 4), which enable to consider structure activities. Synchronization links cor- respond to synchronization of DES. In order to allow diag- nosis capabilities, it is shown how alarm propagation can be modeled (definition 6). This modeling task is illustrated on the loan approval example. We argue that, giving the behav- ioral model, off-the-shelf tools can be used to monitor Web services. Moreover, it seems to us that the decentralized and incremental approach that we experimented on telecommu- nication networks is well-suited to this kind of systems.
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A quality of experience based approach for wireless mesh networks

A quality of experience based approach for wireless mesh networks

{anderson.morais, ana.cavalli}@it-sudparis.eu Abstract. Wireless Mesh Network (WMN) is an emerging technology that is gaining importance among traditional wireless communication scenarios. Wireless Mesh Networks are becoming a popular way of offering end-to-end services, such as Voice over IP (VoIP) and Video on Demand (VOD), in an inexpensive, practical, and fast manner. However, those applications require a minimum network performance level in order to provide an acceptable Quality of Experience (QoE) level to users. In this paper, we present a QoE based approach, which analyzes key QoS parameters like delay, jitter, and packet loss in a mesh network executing the Better Approach To Mobile Ad hoc Network (BATMAN) proactive routing protocol. The proposed mechanism evaluates the actual QoE level from the point of view of each mesh node taking into account the calculated QoS parameters, and then proposes a response in case of QoE degradation as reducing the node broadcasting rate.
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A Belief Approach for Detecting Spammed Links in Social Networks

A Belief Approach for Detecting Spammed Links in Social Networks

Arnaud.Martin, mouloud.kharoune@univ-rennes1.fr, salma.bendhaou@hotmail.fr Keywords: Social Networks, Communities, Theory of belief functions, Probability Abstract: Nowadays, we are interconnected with people whether professionally or personally using different social networks. However, we sometimes receive messages or advertisements that are not correlated to the nature of the relation established between the persons. Therefore, it became important to be able to sort out our relationships. Thus, based on the type of links that connect us, we can decide if this last is spammed and should be deleted. Thereby, we propose in this paper a belief approach in order to detect the spammed links. Our method consists on modelling the belief that a link is perceived as spammed by taking into account the prior information of the nodes, the links and the messages that pass through them. To evaluate our method, we first add some noise to the messages, then to both links and messages in order to distinguish the spammed links in the network. Second, we select randomly spammed links of the network and observe if our model is able to detect them. The results of the proposed approach are compared with those of the baseline and to the k-nn algorithm. The experiments indicate the efficiency of the proposed model.
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Heterogeneous multipath networks: Flow vs Packet based routing in a size-aware context

Heterogeneous multipath networks: Flow vs Packet based routing in a size-aware context

flows does not worth the potential bandwidth savings for short flows. B. Idle Link Opportunistic Aggregation (ILOA) Although aggregation is susceptible to degrade the perfor- mance with concurrent flows, it can still be used positively under low load. Thereby, the Idle Link Opportunistic Aggre- gation (ILOA) mechanism aims to be used together with a flow-based routing scheme, for instance MinFCT, and consists in allowing a path to be used for aggregation only if there are no flows currently assigned to this path (idle link). In this case, the served flow is chosen between the flows assigned to other links accordingly to the Fair Flow scheduler. Here again, the size-aware condition on satellite aggregation is used to avoid the degradation of performance due to the large propagation time. This mechanism should allow a single flow to benefit from multiple paths capacities without degrading the performance of the competing flows.
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Cooperative routing in wireless networks

Cooperative routing in wireless networks

Another possibility arises when the time scale over which the fading states vary is much longer than the time that it takes to transmits a unit of information between two nodes. Assuming that the receiver is able to measure the channel state and there is a feedback mechanism for the receiver to send this information back to the transmitter, the transmitter can leverage this information to adjusted the transmitted power based on the present channel state. This approach, however, requires the channel state information at the transmitter. If we assume that such channel knowledge is not available at the transmitter, there is no way that the transmitter can adjust its power to compensate for very bad channel states. The appropriate model for the wireless link in this scenario is the capacity-versus-outage model, see [15], [16], [14]. In this model, the instantaneous capacity of a wireless link is treated as a random variable. A link is said to be in outage when the instantaneous capacity supported by the link is less than the transmission rate. The reliability of a link, i.e. the probability of correct reception at the receiver, is modeled as a function of the transmission rate, the transmitted power, the distance between the communicating nodes, and the channel fading state. By adjusting the transmission rate or power, the transmitter can control the probability of successful reception at its intended receiver.
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Equal Cost Multiple Path Energy-Aware Routing in Carrier-Ethernet Networks with Bundled Links

Equal Cost Multiple Path Energy-Aware Routing in Carrier-Ethernet Networks with Bundled Links

II. R ELATED W ORKS Related to literature addressing EAR, we found few researches focus on energy saving in Carrier Ethernet net- works [14] [15]. Moreover, none of them cares about saving energy considering SPB protocol. In order to better analyze EAR approach, we choose to study IP approaches which propose EAR protocols compatible with SPB-based Carrier Ethernet context. In this respect, [13] and [16] propose EAR operated with the very popular shortest path protocol, i.e. OSPF, which uses ECMP policy to prevent network congestion. The authors in [13] [17] assume to turn off only the links since turning on/off an entire device may reduce device life cycle. Moreover, the authors in [13] have proposed to use heuristic approach to find a stable OSPF weight setting, along with robust optimization design, for multi-period traffic matrices. As for [17], authors have used genetic algorithms to find the link weights that influence the traffic distribution optimizing both energy-efficiency and load-balancing. Efficient greedy heuristics with different sorting criteria are proposed in [18] and [16], exploiting the possibility to turn off both nodes and links but, in [16], the links weight is optimized so as to reduce both power consumption and network congestion. Fortz et al in [19] have resorted to a local search heuristic by iteratively modifying the OSPF weights setting for load balancing purpose only. Some relevant works have sketched the problem of energy- aware traffic engineering with bundled links by turning off single cables. In [20], which was the first work dealing with energy-aware traffic engineering considering bundled links, the authors formulate the problem as an Integer Linear Program (ILP), and propose to power-off single cables. Moreover, the total load is balanced over all links maxi- mizing the residual capacity of links, which can therefore be powered off. Moreover, this solution does not consider any specific routing rule for traffic demands except the
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Stability Oriented Routing in Mobile Ad Hoc Networks Based on Simple Automatons

Stability Oriented Routing in Mobile Ad Hoc Networks Based on Simple Automatons

2.1 Observations on link stability Several simple propositions aiming with the improvement of the routing decision can be found in the literature. Some works established that choosing routes based on additional information as the position of the nodes, their battery level and the mobility pattern permits to design routing algorithms promising paths with better resilience to topological changes. Most of stability oriented works on routing consider the link stability in the MANETs fundamental. Effectively, the stability of a path depends on the stability of its composing links. Several propositions for stability based routing use a classification of the network links. In (Dube et al., 1997) authors use the strength of the received signal of neighboring nodes to determine whether the associated link is either weakly connected or strongly connected. Routing is then performed through paths maximizing the received signal strength. The signal strength is used as central metric to establish a route with long lifetime in (Agarwal et al., 2000). In their routing method, the authors suggest a routing protocol called Route-Lifetime Assessment Based Routing protocol (RABR) wherein the route selection is done using an intelligent residual-route-lifetime prediction on the basis of affinity appraisal of the candidate routes. Affinity is an estimate of the time after which a neighbor will move out of the threshold signal boundary of a mobile host, and hence is a measure of link availability. A similar, cross-layer information based solution is proposed in (Trivino-Cabrera et al., 2006) to find long-live paths in ad-hoc networks. Since a path is broken if one of the used links is broken, the authors propose the minimal received signal strength along the candidate path as indirect measurement of the path livetime. Targn and al. approach also the link stability by considering the radio propagation effect on signal strength in (Targn et al., 2007). A stochastic radio propagation model is proposed to compute received signal strength between adjacent nodes and to predict path loss. The authors consider that the link stability is equal to the probability of the receiving signal strength exceeding a predefined threshold. So, the estimation of link stability is derived from the prediction of signal strength. Considering the stability of a route, they state that the least stable link within a route would be the bottleneck for the route. The life spans of multi-hop routes decrease by increasing the route length. To model the effect of route length on estimating route stability, the authors consider the route stability as the product of link stabilities (this assumption will also be discussed in Section 3). With awareness of link and route stabilities, then an Ad-hoc On-demand Stability Vector (AOSV) routing protocol is proposed to reactively discover and maintain stable routes adapted to radio channels.
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Route Lifetime based Interactive Routing in Intervehicle Mobile Ad Hoc Networks

Route Lifetime based Interactive Routing in Intervehicle Mobile Ad Hoc Networks

Proactive routing and Reactive routing are two main routing techniques that have been studied for ad hoc networks hitherto. Proactive routing is a table-driven approach in which each node maintains one or more tables that contain routing information to every other node in the network. Changes in network topology result in propagation of route update packets by nodes so that consistent and up-to-date routing information about the whole network is maintained. Reactive routing on the other hand is an on-demand approach in which network routes are not updated with changing topology and instead route discovery is invoked when a source node wants to send data to a destination node. It is then clear that in a rapidly changing topology environment like iv-MANETs, proactive routing is highly intensive (in computation and signaling terms) due to packet overhead caused by frequent update of routing information of the whole network, even if there are no user data packets to be transmitted. Proactive routing is thus only suitable for small networks with limited mobility. Reactive routing was designed to improve on this by invoking route discovery only when it is needed. But even reactive routing may impede the efficient performance of iv-MANETs due to the transient nature of links. In an iv-MANET, due to high relative speeds of successive nodes, a route may cease to exist by the time the first ack of a routing packet reaches back the sender. Reactive routing can also increase packet delay of an ongoing session since in the event of a route path failure, route rediscovery is commenced only when the sender application has the next burst of packets to send and not sufficiently in advance. This might increase the burst transmission delay by the time needed to rediscover a new route in addition to route path failure overheads.
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A routing and resource preservation strategy for traffic engineering in communication networks

A routing and resource preservation strategy for traffic engineering in communication networks

Load balancing has also been a concern during the design of OSPF (version 2) [11], and ECMP (Equal Cost Multi-Paths) consists in using all the paths with equal administrative costs through a network. This mechanism does not rely on any load measurement. Contrasting with WS on the complexity ground, MPLS-OMP [15] is aimed at the dynamic routing and load balancing of flows through a network. MPLS-OMP decreases the load on the most loaded links of the network, by gradually sending traffic on sub- optimal – alternate – paths (roughly determined on the basis of their administrative metrics). Simulations reported in [15] show the good behavior of this approach in realistic conditions, although the complexity of the load adjustment strategy makes it hard to implement. OMP also adapts well to varying traffic patterns, but its gradual moves from one equilibrium to another make it intrinsically less responsive than our proposal.
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An SDN-based approach for QoS and Reliability in Overlay Networks

An SDN-based approach for QoS and Reliability in Overlay Networks

I. I NTRODUCTION Overlay networks have emerged several years ago for different purposes, namely content delivery, privacy, peer- to-peer, on-line gaming, data centers interconnection, among others. Indeed, it is well known that quality-of-service (QoS) is not taken into account by the current Internet de facto routing protocol, BGP, and that following non-BGP routes can provide better QoS and overcome connectivity failures due to BGP outages. Overlay networks can thus bypass these issues, without the need of controlling intermediate nodes nor changing an ossified protocol stack. On the other hand, previous work either doesn’t provide overlay scalable solutions for QoS-aware overlay networks (see e.g. [1]) or rely on decentralized solutions adding overhead (such as relaying on encapsulation techniques).
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Performance Study of an Overlay Approach to Active Routing in Ad Hoc Networks

Performance Study of an Overlay Approach to Active Routing in Ad Hoc Networks

I. M OTIVATION This work is based on the conviction that the active and ad hoc technologies are complementary for building a very flexible network where users do not need a third party to communicate. An ad hoc network is defined as a collection of wireless mobile nodes dynamically forming a temporary network without the use of any existing network infrastructure or centralized administration [1]. In this environment, the only way for a node to reach another one which is not in its range is to use a multi-hop path passing through intermediate nodes. Various multi- hop routing protocols have been developed. They can first be classified in three categories: proactive, reactive and hybrid. Each class has its own assets; one should prefer a proactive protocol if the nodes mobility is low, a reactive one if the mobility is high. Some hybrid protocols are well-suited for large networks while some reactive protocols are not. Even if we only consider the reactive class, there is still a large panel of protocols, each more or less adapted to the network conditions and to the application needs, in terms, for example, of energy
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Explicit Routing in Multicast Overlay Networks

Explicit Routing in Multicast Overlay Networks

Another usage of explicit path selection might be preventing particular nodes of a multicast group to receive a multicast message. This might be useful in secure group communications. In such cases, group keys must be updated whenever a node joins or leaves [1]. For joining nodes, the new key can be distributed along the old multicast delivery tree and by explicitly sending the new key to the joining member. However, in case of a leaving node, the old multicast delivery tree can not be used, because the leaving node would receive the multicast message with the new group key. A naïve approach for key distribution is to distribute the group key via point-to-point connections between the root generating the new key and the individual group members, but this approach is not scalable. Other tree based and hierarchical approaches form sub-groups within the group and distribute the new group key along the sub-group trees. Only a small part of the sub-groups must be re-established for a joining member and most of the established multicast distribution trees for the various sub-groups can be used for efficient key distribution [1][2]. Explicit path selection can be implemented by explicitly specifying the nodes to be traversed, e.g., using the routing header in IPv6 [3] or by describing the multicast group member addresses in explicit multicast [4]. Since specifying all the nodes to be traversed does not scale for large multicast groups, it has been proposed for small groups only. As an alternative, packets can be marked with a unique path identification (ID) such as a label like in multi-protocol label switch- ing (MPLS) [5]. The label must be assigned with a certain path using label distribution proto- cols, which adds significant overhead in terms of signaling bandwidth and delay. MPLS-like approaches add hard states to the involved protocol entities.
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A Routing Architecture for MPLS-TE Networks

A Routing Architecture for MPLS-TE Networks

1) The Off/Cen/Coo MPLS-TE approach: We consider here an Offline mode based approach, where the TE- Trunks paths, potentially including backup paths, are pre-computed periodically without real time computation constraints, in a Coordinated manner. The Fig. 2 shows the distribution of MPLS-TE functions in such approach . The cursor in position P1, separates the blocks which are Centralized on a TE-server (above the cursor) from those which are Distributed on Edge Routers (under the cursor). There is no TE-Trunk adaptation as we are in an Offline mode. The TE-Trunk Path Computation, the TE-Trunk Agent and the TE-Trunk Adaptation blocks are Centralized (actually the TED is maintained on routers and on the server). Other blocks: TE-Trunk Utilization, IGP-TE, RSVP-TE are located in Edge Routers (actually IGP-TE and RSVP-TE are located in all routers). In this approach, the placement of TE-Trunks can be drastically optimized because the TE-Trunk Path Computation function knows all the requests and can perform a Coordinated path computation, with no time limitation. In return, by definition this Offline approach does not allow reacting upon traffic matrix change or network failure and this may lead to packet loss upon congestion, or service disruption upon failure. Also even if this approach allows the pre-establishment of backup paths, such protection may not work upon a multiple failure cases and hence faces some robustness limitations. Thus, the Off/Cen/Coo approach obviously suffers from a lack of survivability and reactivity as it does not allow adaptation to traffic variations and topology changes.
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A Location Routing Protocol Based on Smart Antennas for Wireless Sensor Networks

A Location Routing Protocol Based on Smart Antennas for Wireless Sensor Networks

In the data-centric routing, the sink sends queries to certain regions and waits for data from sensors located in those regions. In this kind of networks each node typically plays the same role and sensor nodes collaborate to perform the sensing task. In the hierarchical routing, nodes play different roles in the network. This approach divides the network into a set of regular linked regions where intra-region packet forwarding is performed by the means of a local coordinate system defined within each region (where is also carried out data aggregation and fusion) and inter-region forwarding is performed to direct data to the sink. In location-based routing, sensor nodes’ positions are exploited to route data in the network. Each node makes a decision to which neighbour to forward the message based solely on the location of itself, its neighbouring nodes, and the destination [5]. Location information is mostly used to calculate the distance between two particular nodes so that routing energy consumption required for communication can be estimated.
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Random Walk Based Routing Protocol for Wireless Sensor Networks

Random Walk Based Routing Protocol for Wireless Sensor Networks

In recent years, design of wireless sensor networks using methodologies and mechanisms from other disciplines has gained popularity for addressing many networking aspects and providing more flexible and robust algorithms. We ad- dress in this paper the problem of random walk to model routing for data gathering in wireless sensor networks. While at first glance, this approach may seem to be overly sim- plistic and highly inefficient, many encouraging results that prove its comparability with other approaches have been ob- tained over the years. In this approach, a packet generated from a given sensor node performs a random motion until reaching a sink node where it is collected. The objective of this paper is to give an analytical model to evaluate the per- formance of the envisioned routing scheme with special at- tention to two metrics: the mean system data gathering de- lay and the induced spatial distribution of energy consump- tion. The main result shows that this approach achieves acceptable performance for applications without too strin- gent QoS requirements provided that the ratio of sink nodes over the total number of sensor nodes is carefully tuned.
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