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Message broadcasting in networks can be efficiently carried over spanning trees. A set of spanning trees in the same network is node independent if two conditions are satisfied. First, all trees are rooted at the same node r . Second, for every node u in the network, all trees’ paths from r to u are node-disjoint, excluding the end nodes r and u . Independent spanning trees have applications in fault-tolerant communications and secure message distributions. Gaussian networks and two-dimensional toroidal networks share similar topological characteristics. They are regular of degree four, symmetric, and node-transitive. Gaussian networks, however, have relatively lesser network diameter that could result in a better performance. This promotes Gaussian networks to be a potential alternative for two-dimensional toroidal networks. In this paper, we present constructions for node independent spanning trees in dense Gaussian networks. Based on these constructions, we design routing algorithms that can be used in fault-tolerant routing and secure message distribution. We also design fault-tolerant algorithms to construct these trees in parallel.

Network survivability is a key design issue for optical transport mesh networks. Various survivability schemes have been introduced among which p-cycle has (and continues) attracted quite a lot of attention because of its fast and efficient protection capabilities. The concept of p-cycle has been generalized to pre-cross-connected trails, or p-trails, by exploiting the fact that providing pre-cross-connected protection paths and obtaining fast restoration do not necessarily require a cyclic structure as in p-cycles. In this paper, we investigate the benefits and sharing capabilities of p-trails and observe that non-simple p-trails and p-cycles can be built from merging simple trails. We derive two ILP models for survivable network design using p-trails. Our first design model is a simple ILP whose optimal solution relies on the exhaustive enumeration of all simple trails in the network. We observe that the size of our ILP model, and therefore the computation time, become prohibitively large making the model unpractical for larger network instances. Therefore, to overcome this scalability issue, we develop an enhanced model for this complex optimization problem using the column generation (CG) decomposition technique. Our developed design approach is shown to be very scalable, as opposed to other prior p-trail design methods; further, we show that p-trails are more efficient than p-cycles in terms of protection resource redundancy in the network.