A Novel Proportional Window based Dyamic Bandwidth Allocation Algorithm in Optical Network

Abstract

Dynamic bandwidth allocation (DBA) algorithm for the passive optical networks (PON) is a key issue for network planner. There are always various constraints during the bandwidth allocation process, so that it can be regarded as a multi-object mathematic problem. In this paper, we have proposed a novel proportional window based bandwidth allocation algorithm that considering service QoS requirement. We mainly arrange more bandwidth for higher level service. Finally, we establish a simulation platform to verify the proposed approach, and the result show that it outperforms traditional static bandwidth allocation approach and the mostly used interleaved polling with adaptive cycle time approach especially for the higher grade service. responsible for the bandwidth requirement collection and the overall bandwidth assignment for each ONU. As each ONU is separated, there will not be any overlapped bandwidth 0 . The primary node is a common node with specific function, while it is the controlling algorithm manager. The bandwidth allocation and release shall be management by the primary node, so that the released bandwidth can be used by extra service flow. G. Kramer has proposed a bandwidth allocation algorithm named Interleaved Polling with Adaptive Cycle Time (IPACT), and it is now widely used in the centralized managed network 0 . The bandwidth usage information is transmitted through a polling approach to solve the fixed time slot shortage. The OLT works in round-robin mode and send polling command to each ONU separately. The ONU receive data in the authorized window. The buffer length in ONU is controlled by OLT, and it takes direct effect on the next round bandwidth allocation. The global round-robin time is maintained by the central OLT, during the allocating process, the consecutive frame is separated with a guaranteed time period. The data frame is not constraint whether in a sequential manner or a synchronized transfer scheme. The GPON network supports a mix of services with different bandwidth requirement, DBA algorithm is used to improve the resource utilization. In this paper, we have proposed a novel proportional window based dynamic bandwidth allocation algorithm (PWDBA) to solve the fairness of each service flow, and keep the priority at a reasonable range at the same time. Also a simulation platform is constructed to verify the performance of proposed approach.