Common pool survivability for meshed SDH-based ATM networks

In order to improve the overall availability of SDH-based ATM transport networks in a cost-effective way, a survivability strategy coordinating the recovery schemes at both ATM and SDH layers has to be devised. This paper proposes a new survivability concept, common pool survivability, for multi- layer ATM over SDH transport networks. The basic idea is to share a common pool of spare resources amongst the ATM and SDH recovery schemes. This can be accomplished by supporting the ATM spare link capacity through unprotected preemptible connections in the SDH network. It is shown on a set of sample networks that common pool survivability yields considerable cost savings when compared to traditional multilayer survivability designs.