All-optical networks are of interest because they are suppossed to use large available bandwidth in fiber to provide large capcities. The all-optical networks in subscriber access has been studied and experimented widely. They are of interest because services requiring very high bandwidth can only be provided to subscribers using fiber. Their had been many fiber-optic subscriber access network proposals e.g. FTTH (fiber to the home), FTTC (fiber to the curb), TTOSS (totally transparent optical subscriber system) [1], TPON (Telephony Passive Optical Network) [2], and PPL (Passive Photonic Loop) [3].
Any subscriber loop architecture for wideband applications should have certain desirable properties. The access equipments in subscriber premises should be low cost and easy to maintain. The high cost equipments should be in central office. This reduces the cost per subscriber for the network. The network should provide large bandwidth to the subscribers. Further, as all the subscribers will not initially subscribe to high bandwidth services, the architecture should be able to provide low bandwidth services at much cheaper price. Later when the subscriber would like to upgrade to a high bandwidth service, the service provider should be able to do so at a small additional cost. The protocol used must be simple and scalable. This is very important, as the number of active subscribers will change and protocol should efficeintly accomodate all the changes while keeping the network usage as high as possible. Further, the protocol overhead should be low. As the bandwidth demand will increase in future, the carrier company should be able to provide more capacity on the same fiber. This can be done using WDM technology.
In this paper a new scheme which will be useful as subscriber access network has been proposed. Any such network will suffer from split losses which reduces the number of subscribers that can be attached to the sytem. In view of this, the use of optical amplifiers in the proposed architecture has also been investigated in this paper.