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We consider path-based survivable service provisioning in transparent optical networks with the constraints of wavelength continuity and a limited number of add/drop ports at each OXC node in the presence of limited tunability of transmitters. We develop simple but valid analytical models to estimate the effects of number of add/drop ports and transmitter tunability on survivable service provisioning performance. We propose effective algorithms for the assignments of wavelength resources and add/drop ports for each survivable connection service and conduct simulations to evaluate the impacts of number of add/drop ports and transmitter tunability on path-based survivable service provisioning and further to examine the validity of the analytical models. It is found that a certain system add/drop ratio is required at each node so as to eliminate the blocking due to the lack of free add/drop ports. A network with a higher density requires a larger relative number of add/drop ports (i.e.. add/drop ratio) for a given overall blocking objective. A network with a higher density benefits more in blocking from transmitter tunability. Finally, the analytical models are verified to be able to qualitatively predict the trends and effects of all the related constraints on the performance of survivable service provisioning. [ABSTRACT FROM AUTHOR]

Abstract: -cycles offer an approach to protection of optical transport networks which is fully pre-connected and as fast as a ring-based protection but with mesh-like capacity efficiency. As a result, -cycles are receiving much study and attention. One open question is, however, whether -cycle network design exhibits a “threshold hop-limit” effect corresponding to that aspect of span-restorable mesh networks. To study this question we extend the existing -cycle network design theory to include the capability of direct restriction of protection path lengths, rather than indirect restriction through cycle circumference limits. A second practical question is how well simple limitation of cycle circumferences serves as a surrogate for a more involved design method of directly asserting a hop (or distance) limit on the maximum length of protection paths. The answers to these questions, and the methods developed to address them, both enhance our ability to design -cycle networks in which limitations to optically transparent reach (or other hop or distance limitations) can be directly taken into account. The main findings are that -cycles do exhibit threshold hop-limiting effects at about three or four hops above those in corresponding mesh networks and that cycle limiting is a simple and effective surrogate for direct limitation on path lengths in -cycle design problems. [Copyright &y& Elsevier]

Dense wavelength division multiplexing (DWDM)-based optical networks that are assumed to employ exactly two working fibers uniformly on every span are matter of recent interest in the field of telecommunication. An interesting and highly efficient strategy for protection of such networks is to use, if possible, a single dark-Fiber p-cycle formed on a Hamiltonian cycle. It has been showed that in a homogeneous Hamiltonian network, a Hamiltonian p-cycle is the most efficient overall solution, although interestingly it does not always correspond to the individually most efficient p-cycle that can be formed. The article also considers p-cycle planning in non-Hamiltonian but homogeneous networks and introduce the concept of a semi-homogenous network, specifically linked to the p-cycle concept. The proposed semi-homogeneous class of network actually realizes the theoretical lower bound on span-restorable networks in terms of network redundancy. Such networks also provide a strategy to accommodate certain patterns of capacity growth beyond a homogenous network without any increase in protection capacity. The work also demonstrates and explains why a single Hamiltonian p-cycle is not as efficient as a specifically optimized set of individual p-cycles in a "capacitated" network where the working capacity on each span varies in a general way.

Presents a study which examined span-restorable mesh networks under dual-failure events. Aim of ring and mesh-based restoration technique; Literature on the analysis of service path availability in ring-based networks; Theory and method for mesh network availability analysis; Experimental result for the dual failure restorability.

Proposes a design-refinement approach to increase the capacity efficiency of span-restorable mesh networks on sparse facility graphs. Information on the meta-mesh graph; Advantages of wavelength-division-multiplexing networking elements; Practical aim in the design of survivable transport networks; Description of several forms of network protection; Conventional design of span-restorable mesh networks.