Sirén Optical Packet Switching

In this thesis recent research in the area of optical packet switching is reviewed, the main problems in the area are identified and a possible solution to some of the problems, optical burst switching, is studied in more detail. Optical burst switching and the JET protocol are studied by means of a simulation program specially built for this purpose. Optical packet networks are networks, where the switching operations are performed optically, and the data remains in optical domain through the transmission. There have already been several implementations of optical packet switching in laboratory environment, but commercial solutions are not expected within a few next years. This is due to the infancy of optical devices. Although the networks and the components have developed rapidly, there are still many unsolved questions. The main problems at the moment are the lack of optical random access memory and very high switching rates needed. A few solutions that try to overcome these problems, and still offer the benefits of optical packet switching, have been proposed. One interesting alternative is optical burst switching. In the empirical part of the thesis the use of the JET protocol in optical burst switching network was studied. In contrast to earlier research, in this work the performance of JET protocol was studied in networks without wavelength conversion. As a result it was found that with relatively small number of buffers a performance that is comparable to that of a wavelength converted version can be achieved. Avainsanat: optinen pakettikytkentä, optinen purskekytkentä, JET-protokolla iii Preface This work was written in the Networking Laboratory at the Helsinki University of Technology as a part of Optical Access Networks (OAN) project. I would like to thank all the people who have helped me during this work. Especially I would like to express gratitude to the supervisor of the thesis, professor Jorma Virtamo, for his guidance during the work and to my instructor, Esa Hyytiä, Lic.Sc. (Tech), for his valuable help. My parents deserve special thanks for the support and encouragement I have got from them during my studies. Finally , I would also like to thank Klaus, because without him it would have been so much harder to get this thesis into covers.