Cost over Progress Based Energy Efficient Routing over Virtual Coordinates in Wireless Sensor Networks

International audienceWe propose an energy efficient routing protocol, VCost, for sensor networks. We assume that nodes are unaware of their geographic location thus, VCost assigns virtual coordinates to nodes as follows. Based on the node hop count distances from a set of landmarks, our method computes a distance metric to obtain the node's virtual coordinates. VCost, then uses these coordinates to route packets from node u to node v, in its neighborhood, such that the ratio of the cost to send a message to v to the progress in the routing task towards the destination is minimized. Compared to existing algorithms that use virtual locations, our simulation shows that VCost improves significantly energy consumption and preserves the small percentage of successful routings

End-to-End Energy Efficient Geographic Path Discovery With Guaranteed Delivery in Ad Hoc and Sensor Networks

International audienceWe propose a novel localized routing protocol for wireless sensor networks (WSN) that is energy-efficient and guarantees delivery. We prove that it is constant factor of the optimum for dense networks. To forward a packet, a node $s$ in graph $G$ computes the cost of the energy weighted shortest path (SP) between $s$ and each of its neighbors which are closer to the destination than itself. It then selects node $x$ which minimizes the ratio of the cost of the SP to the progress towards the destination. It then sends the message to the first node on the SP from $s$ to $x$: say node $x'$. Node $x'$ restarts the same greedy routing process until the destination is reached or the routing fails. To recover from failure, our algorithm invokes Face routing that guarantees delivery. This work is the first to optimize energy consumption of Face routing. First, we build a connected dominating set from graph $G$, second we compute its Gabriel graph to obtain the planar graph $G'$. Face routing is applied on $G'$ only to decide which edges to follow in the recovery process. On each edge, greedy routing is used. This two-phase (greedy-Face) End-to-End routing process (EtE) reiterates until the final destination is reached. Simulation results show that EtE outperforms several existing geographical routing on energy consumption metric

Vers un protocole de routage géographique économe en énergie de bout en bout avec garantie de livraison.

International audienceNous introduisons EtE, le premier protocole de routage géographique qui soit à la fois économe en énergie et garantissant la livraison. EtE combine les points forts de techniques existantes que sont le coût sur progrès et le routage Greedy-Face-Greedy. Les résultats de simulation montrent que EtE présente une consommation énergétique non seulement plus faible que ses concurrents mais également supérieure de seulement 5% de la consommation optimale centralisée

Energy-aware Georouting with Guaranteed Delivery in Wireless Sensor Networks with Obstacles

International audienceWe propose, EtE, a novel end-to-end localized routing protocol for wireless sensor networks that is energy-efficient and guarantees delivery. To forward a packet, a node s in graph G computes the cost of the energy weighted shortest path between s and each of its neighbors in the forward direction towards the destination which minimizes the ratio of the cost of the shortest path to the progress (reduction in distance towards the destination). It then sends the message to the first node on the shortest path from s to x: say node x′. Node x′ restarts the same greedy rout- ing process until the destination is reached or an obstacle is encountered and the routing fails. To recover from the latter scenario, local minima trap, our algorithm invokes an energy-aware Face routing that guarantees delivery. Our work is the first to optimize energy consumption of Face routing. It works as follows. First, it builds a connected dominating set from graph G, second it computes its Gabriel graph to obtain the planar graph G′. Face routing is invoked and applied to G′ only to determine which edges to follow in the recovery process. On each edge, greedy rout- ing is applied. This two-phase (greedy-Face) End-to-End routing process (EtE) reiterates until the final destination is reached. Simulation results show that EtE outperforms several existing geographical routing on en- ergy consumption metric and delivery rate. Moreover, we prove that the computed path length and the total energy of the path are constant factors of the optimal for dense networks

Energy Efficient Multi-Flow Routing in Mobile Sensor Networks.

International audienceControlled mobility is one of the most complex challenges in Wireless Sensor Networks (WSN). Only a few routing protocols consider controlled mobility in order to extend the network lifetime. They are all designed to optimize the physical route topology from a source to a destination. However, there is often more than one sensor which reports an event to the sink in WSN. In existing solutions, this leads to oscillation of nodes which belong to different routes and their premature death. Experiments show that the need of a routing path merge solution is high. As a response we propose the first routing protocol which locates and uses paths crossing to adapt the topology to the network traffic in a fully localized way while still optimizing energy efficiency. Furthermore the protocol makes the intersection to move away from the destination, getting closer to the sources, allowing higher data aggregation and energy saving. Our approach outperforms existing solutions and extends network lifetime up to 37%

Energy-aware Georouting with Guaranteed Delivery in Wireless Sensor Networks with Obstacles

International audienceWe propose, EtE, a novel end-to-end localized routing protocol for wireless sensor networks that is energy-efficient and guarantees delivery. To forward a packet, a node s in graph G computes the cost of the energy weighted shortest path between s and each of its neighbors in the forward direction towards the destination which minimizes the ratio of the cost of the shortest path to the progress (reduction in distance towards the destination). It then sends the message to the first node on the shortest path from s to x: say node x′. Node x′ restarts the same greedy rout- ing process until the destination is reached or an obstacle is encountered and the routing fails. To recover from the latter scenario, local minima trap, our algorithm invokes an energy-aware Face routing that guarantees delivery. Our work is the first to optimize energy consumption of Face routing. It works as follows. First, it builds a connected dominating set from graph G, second it computes its Gabriel graph to obtain the planar graph G′. Face routing is invoked and applied to G′ only to determine which edges to follow in the recovery process. On each edge, greedy rout- ing is applied. This two-phase (greedy-Face) End-to-End routing process (EtE) reiterates until the final destination is reached. Simulation results show that EtE outperforms several existing geographical routing on en- ergy consumption metric and delivery rate. Moreover, we prove that the computed path length and the total energy of the path are constant factors of the optimal for dense networks

Optimal production and inventory control of multi-class mixed backorder and lost sales demand class models

10.1016/j.ejor.2020.09.009European Journal of Operational Research2911147-16

A Novel Decomposition-Based Method for Solving General-Product Structure Assemble-to-Order Systems

10.1016/j.ejor.2020.03.01

An Optimal Scheduling Policy for a Multi-flow Priority Queue with Multiple Paths

International audienc

1 Reader Anti-Collision in Dense RFID Networks With Mobile Tags

Abstract—In a Radio-Frequency IDentification network, while several readers are placed close together toimprove coverage and consequently read rate, reader-reader collision problems happen frequently and inevitably. High probability of collision not only impairs the benefit of multi-reader deployment, but also results in misreadings in moving RFID tags. In order to eliminate or reduce reader collisions, we propose an Adaptive Color based Reader Anti-collision Scheduling algorithm (ACoRAS) for 13.56 MHz RFID technology where every reader is assigned a set of colors that allows it to read tags during a specific time slot within a time frame. Only the reader holding a color (token) can read at a time. Due to application constraints, the number of available colors should be limited, a perfect coloring scheme is not always feasible. ACoRAS tries to assign colors in such a way that overlapping areas at a given time are reduced. To the best of our knowledge ACoRAS is the first reader anti-collision algorithm which considers, within its design, both application and hardware requirements in reading tags. We show, through extensive simulations, that ACoRAS outperforms several anticollision methods and detects more than 99 % of mobile tags while fitting application requirements. I