Broadband Networks In Key Technology Research,

With the increasing development of digital services based on Internet,the bandwidth of traditional telecommunication network designed for telephone service is adverse to deliver IP service.Hence,for next generation network,the broadband of network has becoming one of the hot topics.Broadband of network is a kind of system engineerings, which includes not only broadband of core network,but also broadband of access network. If any of them is delayed,network charcterestics will be influenced,and thus subscribers will not be able to enjoy broadband services.Sponsored by the Education & Research Fund of the Scholars returned from oversea provided by National Education our innovative research in this dissertation is listed as follow:1.A two-level network is firstly proposed in the future network.It is considered to provide one kind of high rate and digital schemes among stateless core nodes. The congestion control scheme is completed by edge nodes.A scheduling algorithm on cost in stateless core nodes is proposed in this paper,and the simulation analysis is given according to this algorithm.It is resulted that the cost would be nearly linear with the service performance provided in the network..2.A routing algorithm on cost in the stateless core network is proposed to make the Internet highly scalable and robust in this paper.According to this algorithm,the link cost of a mesh core network model can be calculated and the optimized route is selected.3.Based on the coordinated distribution nework model,a new proportional-based distributed wireless-network cross-layer scheduling algorithm is proposed in this paper.The core of this algorithm is the introduction of cross-layer design and adaptive madulation,meaning that in order to distribute the wireless resources efficiently and improve in fairness of the network.The simulation results show that the thuoughout and fireness network are improved.4.A proactive multipath optimized link state routing protocol(MOLSR) based on optimized link state routing protocol(OLSR),which introduces the cross-layer concept as well as the node discovery algorithm employed to discover every node on the route to build disjoint paths.The simulation results show that MOLSR achieves lower delay and packet dropping ratio with little more overhead than the classic OLSR algorithm.5.The amplication on an OFDM-ROF optical wireless transmission system for the future broadband network is finally researched through the system simulation. We present a OFDM-ROF system model based on chanal estimation and adaptive modulation technology to mitigate its nonlinear integrated influence in the fiber and wireless chanal.