Deploying Digital Media Libraries in Multi-Service Access Networks

A current important trend is the introduction of new services in the access and aggregation network, close to the end user. A major opportunity for such service enabled access networks is providing users with fast and reliable storage, allowing them to transparently access and share their digital media library anytime, anywhere, while guaranteeing data retention. An important issue in deploying such a service is where to put the storage servers, in order to minimize deployment cost without sacrificing performance. This paper presents and evaluates two algorithms for solving the storage server placement problem, minimizing the deployment cost while guaranteeing a low delay for accessing the digital media libraries from any access node. The base algorithm, referred to as SSPA (storage server placement algorithm), assumes the access and aggregation network has unlimited bandwidth. SSPA provides a lower bound on the required number of servers, respecting a maximum delay constraint. The extended algorithm, SSPA, solves the storage server placement problem, respecting both a maximum delay constraint and bandwidth constraints of the network links. It will be shown that the algorithms produce close to optimal results relatively fast