Research On Some Key Technologies Of Wireless Optical Communication For Networking

With development of the world, multimedia services are becoming more and moreimportant. The demands of bandwidth for transinformation are increasing sharply. Nowthat Wavelength Division Multiplex (WDM) can offer resourceful bandwidth, it makesoptical network have capacity for carrying and switching mass data. The characteristicof the future communication network must be all optical networking. For satisfyingrequirements for politics, economy, military affairs, education, optical network has beenthe cornerstone of national information infrastructure of a great power. Currently, thespeed of optical network development is accelerating. Based on wireless lasercommunication, this paper engages in study of optical network.In fiber network, all elements can only be fixed in an supporting body, the positionof each element is changeless. Usually, a fiber network is of ground network system. Ittakes a long time to set up. The setting of nodes are independent of cabling, and areimprisoned by fibers as well. A fiber link is vulnerable. Furthermore, in manycircumstances, e.g. in intersatellite optical communication, to lay a fiber link is hard,even is impossible. Moreover, there is conflict between Quality of Service (QoS) andefficiency of using fiber network resources. Wireless optical communication cansupport all protocols of fiber communication. The rate of information transmission inwireless optical communication can be similar to that in fiber communication, butwireless optical communication extricates itself from the shackle of fiber. A wirelesslaser link can be established as long as there is a clear line of sight between two wirelessoptical nodes. So a wireless optical link can be integrated into the wireless optical nodes,the attribute of the wireless optical link is robust. Elements of a wireless optical networkcan be fixed in different supporting bodies. The distance between a supporting bodymay be different from other one's, so does the regularity of the supporting body. Thuswireless optical communication has unique merits, for example, the maneuverabilitywith confidentiality is so excellent, in fact, wireless optical communication is in a classby itself. It can support high-speed communication as supporting bodies are in moving.In addition, the sightless laser beam is narrower than microwave beam too much. This makes privacy and the security of information that carried by it be better, This is alsohighly beneficial to antijam. Sure enough, the volume is less, the weight is lighter. Toset up a wireless optical network is simple and easy, corresponding configuration andmaintenance are facile.At present wireless optical communication is applied as substitution of high-speedlink for fiber, but the advantage can not be taken sufficiently. For improving utilizationratio of resources to the upmost, guaranteeing QoS, achieving bestReliability---Availability---Serviceability (RAS), it is absolutely necessary that toresearch and develop wireless optical network based on the characteristics of wirelessoptical communication specially. Then the technology for optimally building wirelessoptical node, the technology for optimally setting up wireless optical network, and thetechnology for wireless optical network behaving optimally can be obtained. In the lightof the above consideration, in chapter 2, the architecture of wireless optical network ispresented. The multi-section multi-class three-dimensional wireless optical networkmodel is constructed. The technologies of building the wireless optical sectionsubnetwork and its section domain, the transregional three-dimensional subnetwork andits transregional domain, and the domains group are provided. The optimum structuralframe of wireless optical network is discussed in detail. With wireless optical nodevirtual ring connection graph, the algorithm for building the robust wireless opticalnetwork with high cost performance, the algorithm for allocating resources, and thealgorithm for steering virtual ring are proposed. With the numeric emulation, theeffectiveness of the technologies are demonstrated.None but is connected by laser beam, information can be transfered from onewireless optical network node to the other, so in chapter 3, the functional configurationsof wireless optical nodes are presented. After technique details about high power laserdiode arrays with Talbot cavity, especially the stability of the laser diode arrays working,are studied, technology for compensating the excursion in the external cavity isprovided. By the help of special simulation software and experiment, the influence ofenvironment on wireless optical communication is analyzed. And then the predistortiontechnology for guaranteeing high quality of the optical connection in poor workingconditions is provided. The effectiveness of the technologies are demonstrated by theexperiment. Only after all wireless optical network nodes well know the network state, routeplanning and allocation of resources can be done properly. Now that wireless opticallink establishment and neighbour discovery in wireless optical network becomeintegrated, so chapter 4 provides wireless optical open shortest path technology,wireless optical multi-cast technology, wireless optical monolayer routing technology,wireless optical hierarchical multi-layers routing technology, hybrid optical network andcorresponding routing technology. And presents the wireless optical hierarchical logicalstructure. Corresponding numeric emulation demonstrated the effectiveness of thetechnologies.Generalized Multi-Protocol Label Switching technology (GMPLS) is themainstream of control technique for setting up dynamical connection in optical networktimely. After GMPLS is extended into Wireless Laser Generalized Multi-Protocol LabelSwitching (WLGMPLS) in chapter 5, seven types of interfaces are defined. Andresource reservation protocol is modified to involve the self-adaption field. Thenformats and structures of wireless laser generalized label switching objects arepresented. Finally, wireless optical nesting technology is proposed. Subsequently, withWLGMPLS, the linchpin that Optical Burst Switching (OBS) technology uses wirelessoptics is exposed. The architecture, the general rules of constructing, the key detailedrules, decision-making technique are discussed. From the mother cone to the effectivecover, then to the shortest sight vector, the techniques for constructing the one-wayresource reservation domain in wireless optics are provided. Whereafter correspondingworking pattern and algorithms are proposed. With numeric emulation, wireless opticalcommunication who integrates with fiber network improves performance of opticalnetwork is demonstrated. Wireless optics and fiber optics are complementary. Aswireless optical network technology progresses, the prospect of optical network is beingbetter and better cheerful. To my knowledge, no proces-verbal to the above-mentionedtechnical details, except our lab's papers and patents, has been vended.