Techniques for the planning of multi-service telecommunications networks over a multi-period scenario are proposed, based on routing optimisation to reduce network cost by removing DWDM transmission systems. A model of a medium-size national network is optimised using the various techniques, and the results presented in terms of the total number of DWDM systems required and the amount of wavelength-hops (giving an indication toward the number of optical transponders required). Traffic is taken as a mix between unprotected and 1+1 SNCP optical path protected demands. Traffic growth is applied over the 5 year planning horizon to give a tenfold increase in total traffic volume for the final year. A greenfield situation is assumed, yet since deployment occurs over several years, a present value calculation is used to estimate total cost, assuming that transponders and systems are only installed when they are due to be 'lit'.

With the development of rings employing subnetwork connection protection (SNCP-rings) numerous complex solutions can be realised in the design of survivable synchronous digital hierarchy (SDH) networks. Three algorithms for optimising the planning of equipment cost-effective SDH networks using SNCP-ring solutions have been implemented. Results indicating the efficiency of the algorithms and the factors affecting this efficiency, supported by simulation work, are presented and discussed.

The increased demand for distribution of telecommunication services over survivable network architectures led to the identification of resilient ring architectures as a very desirable network option. With the recent development of rings employing subnetwork connection protection (SNCP-rings) numerous complex solutions can be achieved in the design of survivable SDH subnetworks. In this paper, the methodology for the strategic planning of survivable SDH SNCP-ring subnetworks is presented and analysed. The various subnetwork solutions are classified. The trade-offs of the different solution types for subnetwork planning are introduced and the factors affecting them are discussed. Three algorithms for optimising the planning of equipment cost-effective SDH subnetworks using SNCP-ring solutions have been implemented. Results, indicating the efficiency of the algorithms and the factors affecting it, supported by simulation work, are presented and discussed.

Fibre optic transport systems are being installed at a rapid pace in national networks to meet the large demands for capacity. However, the consequences of service disruption are becoming more severe essentially due to the advent of these high capacity fibre optic systems. In an increasingly competitive world, network reliability is becoming the key characteristic which differentiates between competitive network solutions. A challenging task for service providers is to ensure service continuity at affordable costs. We present a novel framework to assess the network availability and we examine its applicability in a model network.