Optical-router-based dynamically reconfigurable photonic access network

The Broadband photonics (BBP) project under the Freeband consortium of projects investigated the design of a dynamically reconfigurable photonic access network. Access networks form a key link in ensuring optimal bandwidth to the end user without which any improvements deeper in the network in the aggregation or core segments are mitigated. Optical fiber deployment in the access are a natural choice as the bandwidth demands increase and Passive Optical Networks (PONs) form a preferred way of implementing fiber deployments. PONs have a logical Point to Multi-Point (P2MP) topology where in the downstream, the Optical Line Termination (OLT) broadcasts to all Optical Network Units (ONUs) while in the upstream, it is a many-toone transmission and is contention based. Time Division Multiplexing (TDM) access is one way of arbitration and in this thesis a qualitative analysis and comparison of the leading TDM based PON standards- EPON and GPON is presented. In traditional PONs, the average bandwidth available per user depends on the number of ONUs supported by a single OLT. Typically the OLT-ONU association is fixed. The BBP network concept extends the view of a fiber plant deployment to a stack of logical PONs where multiple wavelength pairs are used to support a number of "logical" PONs. In this network, a headend based OLT transmits the downstream data by modulating a C-Band, Dense Wavelength Division Multiplexed (DWDM) laser. In addition it transmits the light of a Continuous Wave (CW) DWDM laser, also in the C-Band, which is modulated with data by a Reflective Semiconductor Optical Amplifier (RSOA) in an ONU and used for upstream communication. The ONUs are thus wavelength agnostic. The OLT-ONU association is thus dynamic and depends on the wavelength pair added/dropped towards the ONU. The bandwidth availability to an end user can be optimised on an inter-PON basis. The research work focuses on the techniques to realise the bandwidth optimisation using Linear Programming techniques and describes the service delivery architecture that can be realised to ensure an optical service delivery to the end user using conventional protocols of operation. The perspective views of the network from a data to control plane operation are also presented.