Control and Management of Optical Infrastructures

Abstract

This thesis addresses selected controlling aspects of optical infrastructures.For all the topics, solutions are presented, which can be used to support the realisation of future optical networks. Packet-to-packet power equalisation in combination with optical regenerations is a prerequisite for developing flexible optical packet switched networks. It is discussed, where, in an optical packet switch, such equalisation should take place, and it is argued that controlling the gain of a cross gain modulator before a regenerator provides the best results. In combination with digital control electronics, the equaliser equalises packet-to-packet power variations up to 9 dB with an insignificant power penalty. A novel scheme for header processing in optical packet switched networks without header modification is proposed and thoroughly analysed. The scheme obsoletes complex header erasure and resynchronisation at the expense of a slightly larger packet header. The scalability of the scheme is analysed, and it is argued that it can be implemented in even very large networks up to 200 optical nodes without significant scalability problems. In the thesis, the use of directly modulated lasers of 10 Gbit/s in fibre access networks is evaluated. A 1310 and a 1550 nm laser are evaluated and both are found viable for future integration into cost-efficient and highly integrated fibre to the home equipment. Finally, the integration of telecommunications and research optical infrastructures is discussed, and the concepts for providing application driven bandwidth allocation in these integrated infrastructures are proposed. This also offers a couple of parameters as “handles” for the network operator to control the level of dynamics in his network. Most of the covered topics are related to the two European IST projects: DAVID and MUPBED. These are detailed in the thesis