Surface Areas of Some Interconnection Networks

An interesting property of an interconnected network (G) is the number of nodes at distance i from an arbitrary processor (u), namely the node centered surface area. This is an important property of a network due to its applications in various fields of study. In this research, we investigate on the surface area of two important interconnection networks, (n, k)-arrangement graphs and (n, k)-star graphs. Abundant works have been done to achieve a formula for the surface area of these two classes of graphs, but in general, it is not trivial to find an algorithm to compute the surface area of such graphs in polynomial time or to find an explicit formula with polynomially many terms in regards to the graph's parameters. Among these studies, the most efficient formula in terms of computational complexity is the one that Portier and Vaughan proposed which allows us to compute the surface area of a special case of (n, k)-arrangement and (n, k)-star graphs when k = n-1, in linear time which is a tremendous improvement over the naive solution with complexity order of O(n * n!). The recurrence we propose here has the linear computational complexity as well, but for a much wider family of graphs, namely A(n, k) for any arbitrary n and k in their defined range. Additionally, for (n, k)-star graphs we prove properties that can be used to achieve a simple recurrence for its surface area

Neighbourhood Broadcasting in Hypercubes

International audienceIn the broadcasting problem, one node needs to broadcast a message to all other nodes in a network. If nodes can only communicate with one neighbor at a time, broadcasting takes at least $\lceil \log_2 N \rceil$ rounds in a network of $N$ nodes. In the neighborhood broadcasting problem, the node that is broadcasting needs to inform only its neighbors. In a binary hypercube with $N$ nodes, each node has $\log_2 N$ neighbors, so neighborhood broadcasting takes at least $\lceil \log_2 \log_2 (N+1) \rceil$ rounds. In this paper, we present asymptotically optimal neighborhood broadcast protocols for binary hypercubes

Neighbourhood Broadcasting in Hypercubes

International audienceIn the broadcasting problem, one node needs to broadcast a message to all other nodes in a network. If nodes can only communicate with one neighbor at a time, broadcasting takes at least $\lceil \log_2 N \rceil$ rounds in a network of $N$ nodes. In the neighborhood broadcasting problem, the node that is broadcasting needs to inform only its neighbors. In a binary hypercube with $N$ nodes, each node has $\log_2 N$ neighbors, so neighborhood broadcasting takes at least $\lceil \log_2 \log_2 (N+1) \rceil$ rounds. In this paper, we present asymptotically optimal neighborhood broadcast protocols for binary hypercubes

A general upper bound on broadcast function B(n) using Knodel graph

Broadcasting in a graph is the process of transmitting a message from one vertex, the originator, to all other vertices of the graph. We will consider the classical model in which an informed vertex can only inform one of its uninformed neighbours during each time unit. A broadcast graph on n vertices is a graph in which broadcasting can be completed in ceiling of log n to the base 2 time units from any originator. A minimum broadcast graph on n vertices is a broadcast graph that has the least possible number of edges, B(n), over all broadcast graphs on n vertices. This thesis enhances studies about broadcasting by applying a vertex deletion method to a specific graph topology, namely Knodel graph, in order to construct broadcast graphs on odd number of vertices. This construction provides an improved general upper bound on B(n) for all odd n except when n=2^k−1

k-neighborhood broadcasting

Broadcasting refers to the task whereby a node in a network, knowing piece of information, must transmit it to all the other nodes. In this pap we consider a generalized form of broadcasting, that we call k-neighborho broadcasting. It consists in the following: a node u in the network has send its information to all the nodes which are at distance less than or equ to k from u. We study k-neighborhood broadcasting (or k-NB for short) in paths, tree cycles, 2-dimensional grids and 2-dimensional tori under the store and fo ward, 1-port, unit cost model. For most of these families, we give the optim k-NB time; if not, the optimal k-NB time is given within an additive consta never exceeding 2