Study On The Key Technologies Of Passive Optical Networks Based On ATM

Having built the national backbone communication network, how to provide the services including broadband service to users through it at anytime and anywhere is the subsequent important thing In all kinds of alternatives, ATM based passive optical network (APON) has the most promising prospect, which supports broadband service and service transparency In addition, it combines the advantages of multi-service and multi-bit rate capabilities of ATM and the advantages of wide bandwidth and low cost of PONWe study the ATM based PON and discuss its networkarchitecture, layered model and their components. An optical distribution network (ODN) used in APON is also designed In addition, we bring forward a wavelength division based time division access technology Recently Passive Optiacal Networks gained a lot of attention as a possible solution to the broadband local access network PON may be deployed as a bus ,ring, or tree topology While it is a very cost-effcetive solution, it has some unique problems, not found in backbone or metroplolitan networks One of such problems is upstream traffic synchronization In the upstream direction PON is a multipoint-to-point network Because distance from central office to Every network unit is different, if every unit will tranmit in its own time slot, due to differences in propagation delays, data will collide in the point where fibers from different network units join together In this paper we present an operation called ranging -a process of finding a specific delay for every network unit, such that all upstream transmissions will arrive to the central office withoutcollisions o There are several ways to perform ranging 0 The presented solution is very cost-effective,as it doen't require addition optical transmitters and receivers to be installedoAPON is a tree-like medium-shared network, which has its own characteristics that employs a particular medium access control (MAC) protocol to avoid collision between cells from different terminals? Hence, We analysis a kind of MAC, and make a conclusion of its verity and fault, and how to promote its quality ? â– ...