Gossiping with interference in radio chain networks (upper bound algorithms)

International audienceIn this paper, we study the problem of gossiping with interference constraint in radio chain networks. Gossiping (or total exchange information) is a protocol where each node in the network has a message and wants to distribute its own message to every other node in the network. The gossiping problem consists in finding the minimum running time (makespan) of a gossiping protocol and efficient algorithms that attain this makespan

Gossiping with Interference Constraints in Radio Chain Networks

International audienc

Gossiping with interference in radio chain networks

International audienceIn this paper, we study the problem of gossiping with interference constraint in radio chain networks. Gossiping (or total exchange information) is a protocol where each node in the network has a message and wants to distribute its own message to every other node in the network. The gossiping problem consists in finding the minimum running time (makespan) of a gossiping protocol and efficient algorithms that attain this makespan

Gossiping with interference in radio ring networks

In this paper, we study the problem of gossiping with interference constraint in radio networks. Gossiping (or total exchange information) is a protocol where each node in the network has a message and is expected to distribute its own message to every other node in the network. We focus on the case where the transmission network is a ring network that is a node has 2 neighbors and can only transmit to its neighbors (such an action is named a call). We consider synchronous protocols where it takes one unit of time (step) to transmit a unit-length message. During one step we suppose that a node cannot send and receive (half duplex model). Moreover communication is subject to interference constraints. We model them by a fixed integer dI ≥ 1, which implies that nodes within distance dI from a sender in the network cannot receive messages from another node. Here we focus on the case dI = 1, which implies that if a node receives a message from one of its neighbors, its other neighbor cannot send at the same time. A round consists of a set of non-interfering (or compatible) calls and uses one step. We solve completely the problem for ring networks, with unit length messages and dI = 1 by giving the minimum running time (makespan) of a gossiping protocol that is the minimum number of rounds needed to complete the gossiping. We first show lower bounds and then give gossiping algorithms which meet these lower bounds and so are optimal

Gossiping with interference in radio chain networks

IIn this paper, we study the problem of gossiping with neighboring interference con- straint in radio chain networks. Gossiping (or total exchange information) is a protocol where each node in the network has a message and is expected to distribute its own mes- sage to every other node in the network. The gossiping problem consists in finding the minimum running time (makespan) of a gossiping protocol and efficient algorithms that attain this makespan.We focus on the case where the transmission network is a chain (directed path or line) network. We consider synchronous protocols where it takes one unit of time (step) to transmit a unit-length message. During one step, a node receives at most one message only through one of its two neighbors. We suppose that during one step, a node cannot be both a sender and a receiver (half duplex model). Moreover we have neighboring interference constraints with which a node cannot receive a message if one of its neighbors is sending. A round consists of a set of non-interfering (or compatible) calls and uses one step. We solve completely the gossiping problem for Pn, the chain network on n nodes, and give an algorithm that completes the gossiping in 3n − 5 rounds (for n > 3), which is exactly the makespan

Gossiping with interference in radio ring networks

In this paper, we study the problem of gossiping with interference constraint in radio ring networks. Gossiping (or total exchange information) is a protocol where each node in the network has a message and is expected to distribute its own message to every other node in the network. The gossiping problem consists in finding the minimum running time (makespan) of a gossiping protocol and algorithms that attain this makespan. We focus on the case where the transmission network is a ring network. We consider synchronous protocols where it takes one unit of time (step) to transmit a unit-length message. During one step, a node receives at most one message only through one of its two neighbors. We also suppose that, during one step, a node cannot be both a sender and a receiver (half duplex model). Moreover communication is subject to interference constraints. We use a primary node interference model where, if a node receives a message from one of its neighbors, its other neighbor cannot send at the same time. With these assumptions we completely solve the problem for ring networks. We first show lower bounds and then give gossiping algorithms which meet these lower bounds and so are optimal. The number of rounds depends on the congruences of n modulo 12

Broadcasting in Hypercubes under Circuit Switched Model

International audienceIn this paper, we propose a method which enables to construct almost optimal broadcast schemes on an n-dimensional hypercube in the circuit switched,-port model. In this model, an initiator must inform all the nodes of the network in a sequence of rounds. During a round, vertices communicate along arc-disjoint dipaths. Our construction is based on particular sequences of nested binary codes having the property that each code can inform the next one in a single round. This last property is insured by a ow technique and results about symmetric ow networks. We apply the method to design optimal schemes improving and generalizing the previous results

Symmetric flows and broadcasting in hypercubes

International audienceIn this paper, we propose a method which enables to construct almost optimal broadcast schemes on an n-dimensional hypercube in the circuit switched,-port model. In this model, an initiator must inform all the nodes of the network in a sequence of rounds. During a round, vertices communicate along arc-disjoint dipaths. Our construction is based on particular sequences of nested binary codes having the property that each code can inform the next one in a single round. This last property is insured by a ow technique and results about symmetric ow networks. We apply the method to design optimal schemes improving and generalizing the previous results

Gossiping with interference in radio chain networks (upper bound algorithms)

International audiencethis paper, we study the problem of gossiping with interference constraint in radio chainnetworks. Gossiping (or total exchange information) is a protocol where each node in the networkhas a message and wants to distribute its own message to every other node in the network. Thegossiping problem consists in finding the minimum running time (makespan) of a gossiping protocoland efficient algorithms that attain this makespan

Gossiping with interference in radio ring networks

International audienceIn this paper, we study the problem of gossiping with interference constraint in radio ring networks. Gossiping (or total exchange information) is a protocol where each node in the network has a message and wants to distribute its own message to every other node in the network. The gossiping problem consists in finding the minimum running time (makespan) of a gossiping protocol and efficient algorithms that attain this makespan.Transmission model A radio network consists of communication devices equipped with an half duplex interface. The network is assumed to be synchronous and the time is slotted into rounds. The half-duplex hypothesis implies that a node can transmit or receive at most one message during a round. The network is modeled as a digraph, where the vertices represent the nodes and the arcs represent the possible communications. The messages are transmitted through the communication over the arcs and we will denote a call such a transmission.Interference model We use a binary asymmetric model of interference based on the distance in the communication digraph like the ones used in [1, 2, 5]. Let d(u,v) denote the distance, that is the length of a shortest directed path, from u to v in G and dI be a non negative integer. We assume that when a node u transmits, all nodes v such that d(u,v) ≤ dI are subject to the interference from u’s transmission. So two calls (u, v) and (u′, v′) do not interfere if d(u, v′) > dI and d(u′,v) > dI.This problem has been studied in [4] where approximation results are given (see also the survey [3]). Here we focus on the case where the transmisson network is a ring network Cn on n nodes with the interference distance dI = 1. We presented some partial results at JCDCG^G 2013, and we have now solved completely the gossiping problem by giving the minimum running time (makespan). We show lower bounds and then give gossiping algorithms which meet these lower bounds and so are optimal