“双网结构“的光分组交换网关键技术的研究

Optical packet switching network has many prominent merits such as high bandwidth, transparency to data rate and data format, excellent compatibility with ATM and IP. It is recognized by people working in telecommunication industry that optical packet switching network represents the developing direction of optical.network in future. Sponsored by China Natural Science National Fund, we have.achieved the following results, mainly as follows:1. We have analyzed and compared the present developments of the optical packet switching network technologies at home and abroad, especially the developments in developed countries. Then, we put forward a dynamic report about these developments.2. Using N-ISDN and Internet as signaling network, we have studied optical network with “Double Net” structure through some experiments. It has been found that N-ISDN and Internet as signaling networks are not suitable for optical packet switching because it is difficult to realize synchronization between header and payload and it is also difficult to control the delay of signaling with N-ISDN and Internet as signaling network. However, it is suitable to use N-ISDN and Internet as signaling network for channel switching such as wavelength switching, wavelength.group switching, wavelength band switching, even fiber switching..3. Based on the analyses of many structures of optical packet switching nodes proposed by foreign scholars, we have put forward two structures of optical packet switching nodes, i.e. wavelength routing optical packet switching node and broadcast and select optical packet switching node. They can realize the function of wavelength routing and the function of broadcast and select respectively. Their structures are.simple and they can realize very good network performances.4.Optical packet buffering is the key technique for the application of optical packet switching network. Up to now, the optical buffering is realized with optical delay lines and other optical devices at home and abroad. They have some shortcomings like large bulk, large loss of optical power, low reliability, and at the same time, optical signals can be easily affected by many factors such as temperature,dispersion, and so on. Therefore, we firstly brought forward the method of optical random access based on EIT, and the node structure of optical packet switching based on this memory principle.5. The future network will be of ulti-granularity of optical switching, including fiber switching, wavelength band switching, wavelength group switching, wavelength.switching and optical packet switching. Based on our study of optical packet.switching, we have deeply investigated the switching with three different granularities,i.e. fiber switching, wavelength group switching and wavelength switching. We have put forward one structure of switching node with multi-granularity and built an.experimental platform of it. We have developed two kinds of software for.communication and control on Internet as signaling network and the primary.functions of multi-granularity automation switching have been verified. It is a pity.that we could not further extend our experiment to optical packet because of lack of outlay.6. We have presented the model of integrated controlling plane (ICP) and service model, and given the elementary protocol realized by label forward, routing and label switching routing. These are important for IP enabled optical network.

研究空间微分动力系统倍周期分支的理论,重点在于给出一个经严格论证确实存在倍周期分支的例子,从而填补国内外同行学者极为关心的这一空白状态,研究耦合系统Poincare分支的存在性,类型及稳定性,探索理论研究的途径,作出若干创新工作.