Research On Time-slots Allocation And Reconfiguration Algorithm In OBTN Networks

Recently, solutions based on broadband IP metro optical transport network, such asIP over ATM, IP over DWDM, RPR, etc., in terms of scalability, resource utilization ornetworking cost there are some defects. In order to better meet the needs of thedevelopment of broadband optical metropolitan, and further enhance resource utilizationand network performance, OBTN (Optical Burst Transport Network) ring networkprogram came into being.At first, this paper proposes an improvement slots allocation scheme. Now theresearch on OBTN ring network commenced mainly for single-ring topology, adjustingthe slots allocation scheme to realize the rational allocation of bandwidth resources. Theexisting slots allocation scheme can be divided into static configuration and dynamicconfiguration. The former will cause a lot of delay and cache, while the latter is difficultto ensure the high response rate of business needs. To solve this problem, this paper, onthe basis of the analysis and appraisal of the two schemes, proposes an improvementscheme: make the two configurations integrated. The scheme improves the utilization ofnetwork resources without increasing additional network consideration or networkdelay.Then, the second part of this paper is to design a time slots allocation scheme forpredictable/forecast demand scenarios. Take into account the future business needs incurrent network resource allocation decisions, can effectively improve the utilization ofthe resources of the global network. This paper sets up a slots allocation model based oninteger linear programming (ILP), minimizing the network cost in premise of businessneeds are all able to get a response. Through solving the model by CPLEX as well asdoing some network simulation experiments, we evaluate the performance of the slotsallocation scheme based on the model. The experiment found that the scheme allows thenetwork has a good performance.To further enhance the network capacity, this paper also extended OBTN singlering network to multi-ring network. The design for multi-ring scheme is divided into two cases: hybrid optoelectronic switching and all-optical switching.In hybrid optoelectronic switching, span-ring businesses need OEO (optical-electrical-optical) conversions at boundary nodes, while the rest businesses istransmitted only in the optical layer. In such scenario, just convert the span-ringbusinesses to the boundary nodes, then each individual ring can use the slots allocationscheme for OBTN single ring to allocate time slots for each node. This paper designsthe control processes for this scenario. As for all-optical switching, all networkbusinesses are transmitted in the optical layer and no business needs to take anoptical-electrical conversion including the span-ring business. In such scenario, the keyparts of the network design are the control processes and slots allocation algorithm. Thispaper designs the entire network control processes based on centralized control mode,and designs slots allocation algorithm for all-optical switching network as well. Finally,we simulate the two schemes and the result shows their feasibilities, in additional theperformance of the two schemes were compared and analyzed.