A Study Of Switching Technique In The Quantum Multi-user Communication Network

Quantum communication is a new interdisciplinary produced by the combination of basic quantum mechanical theory and information science. It has a theoretical unconditional security. With the successes of the point-to-point quantum communication experiments, deeper quantum network development has increasingly become a matter of concern that researchers have. However, Due to the quantum unique properties of quantum, there are many difficulties in implementation quantum repeater and quantum router so that problems exist in the switching technique of quantum multi-user communication network, and these problems have to be solved with technical solutions differ from the classical communication networks. Quantum switching, an important technology in the quantum multi-user communication network, will be discussed and researched in this paper.This research first of all introduces the basic concepts and the present situation of the development of quantum communication, and describes the current situation and development prospects of quantum communication networks. Next, the theoretical basis of quantum communication are elaborated, including the basic assumptions of quantum mechanics, the basic properties of quantum mechanics, the basic concepts of quantum information and quantum key distribution. Five basic assumptions which support the foundation of quantum mechanics is the theory of quantum mechanics; The basic characteristic of quantum mechanics includes Heisenberg uncertainty principle and single quantum no-cloning theorem, which support the unconditional security of the quantum communication; Quantum information is a combination of quantum mechanics and classical communication, which presents the quantum bit and the quantum logic gates; quantum key distribution is the longest current study, the closest practical quantum communication, the communication protocols including BB84 protocol and B92 protocol.Then the quantum communication network switching technology has been studied. Firstly the architecture of quantum communication network, including quantum communication network structure and the multiple access technology is introduced in this part; Secondly, this paper introduces the space division switching technology which is most commonly used in the current quantum communication networks, as well as wavelength division switching and the switching based on quantum swap gate, which are suit for the small-scale users; Finally, on the basis of the optical burst switching, this research puts forward the optical quantum burst switching technology, gives its structure diagram and elaborates the function of the input/output edge node and the core node. The classical-quantum channel multiplexing technology is introduced briefly at last. After that, this paper introduces the structure and improvement of the quantum switching. Firstly, a quantum communication network model with three layers, whose control module and transmission module are separated is set up. Based on this model, the structure and implementation diagram of quantum switching is given. Then the control part of this quantum switching is introduced, and its program design is given. Adding the function of identity authentication in the call connection module, this research improves the security of quantum switching and analyzes its performance. Finally, the last part makes a summary of this paper, and prospects about the further research work of optical quantum burst switching technique and quantum switching.