The edge fault-tolerant spanning laceability of the enhanced hypercube networks

Abstract

In the design of an interconnection network, one of the most fundamental considerations is the reliability of the network, which can be usually characterized by the fault tolerance of the network. Embedding paths into a network topology is crucial for the network simulation. This paper investigates the problem of embedding spanning disjoint paths in the enhanced hypercube networks with edge fault tolerance. A k-container C(u, v) of a graph G is a set of k-disjoint paths joining u to v. A k-container of G is a $k^{*}$-container if it contains all the vertices of G. A bipartite graph H with bipartition $V_{0}$ and $V_{1}$ is $k^{*}$-laceable if for any $u\in V_{0}$ and $v\in V_{1}$ there is a $k^{*}$-container between u and v. A bipartite graph H is f-edge fault-tolerant $k^{*}$-laceable if $H-F$ is $k^{*}$-laceable for any edge set F of H with $|F|\le f$. It is shown that the n-dimensional bipartite enhanced hypercube network $Q_{n,m}$ is f-edge fault-tolerant $k^{*}$-laceable for every $f\le n-1$ and $f+k\le n+1$. Moreover, the result is optimal with respect to the degree of $Q_{n,m}$, and some experimental examples are provided to verify the theoretical result.