To date the use of optical fibre in the access network has typically only proved cost effective for supplying the high bandwidth demands of large corporate customers. For new and established network operators, however, the increasing demand for bandwidth to deliver bearer, interactive and bundled services to business and residential customers is requiring them to seriously consider the high volume rollout of optical fibre based systems. Network operators therefore face some major decisions, not only in terms of the type of fibre transmission systems to deploy, but also how to install a cost effective network of fibre cables, ducting and joints to connect to the customers they wish to serve. Installing fibre in the ground represents a major commitment and a long term investment. Network operators can typically expect the fibre infrastructure to equate to at least 60% of the cost of the overall access transmission system. Planning and building such networks is a major upfront investment, and in today's highly competitive markets operators are faced with the added complications of uncertain take up of services by customers and the likelihood of high customer churn.

This chapter focuses on fibre to the home (FTTH) and the deployment options and challenges for the physical fibre infrastructure. The key difference associated with connecting optical fibre to residential properties instead of business properties is not technical but commercial. There is typically a much smaller potential revenue from a residential property than from a business property. This leads to a need for cost optimisation of both the transmission system and the fibre infrastructure. The chapter also examines the fibre infrastructure issues that need to be considered for a FTTH deployment and describes the fibre access network modelling activities carried out by BTExact's Broadband Network Engineering Unit. The aim of this modelling is to automatically plan and cost optimise the deployment of access networks based on real geographical and demographic data.

BT's telecommunications network in the UK consists of two main segments. First, a core network of approximately 5500 exchanges (switching sites) connected by high speed, mostly optical fibre, links. Second, an access network connecting customers to the switching sites. For large, and increasingly for medium sized customers, this access network is also based on optical fibre. The fibre access network is currently carrying traffic at anything from 2 Mbit/s to hundreds of Mbit/s. For residential customers the access network consists of twisted copper pairs contained within a tree and branch cable network. This network design has not changed appreciably for 50 years or more. Indeed some cables have been in service for that long.