Design and Analytical Analysis of a Novel DBA Algorithm with Dual-Polling Tables in EPON

Abstract

Ethernet passive optical network is a point-to-multipoint structure, and an effective media access protocol should be designed for collision avoidance and bandwidth allocation. Most previous researches have aimed to solve the problem using dynamic bandwidth allocation (DBA) algorithms with polling-based schemes. Unfortunately, idle channel time among the polling cycles cannot be overcome efficiently. In this paper, a dual-polling DBA (DP-DBA) algorithm which consists of an interpolling mechanism and an intrapolling mechanism is proposed. The interpolling mechanism helps eliminate the idle time problem while the intrapolling part aggregates the unused bandwidth of the light-loaded users and those due to nondefragmentation of the Ethernet frames of the general users. We also evaluate the performance of the DP-DBA algorithm by a comparison with the interleaved polling with adaptive cycle time (IPACT), the dynamic bandwidth allocation with a modified grant table generation algorithm (DBA2), the Double-Phase Polling (DPP), and the adaptive DBA algorithm with sorting report messages (Sort-DBA) schemes with simulation results. For greater realism with regard to general applications, we also simulate the asymmetric traffic loads at the optical network units (ONUs).The results show that DP-DBA outperforms the other DBA schemes under asymmetric load conditions.

Comprehensive bandwidth utilization and polling mechanism for XGPON

“…reports. 24 The study in quality of service DBA in Chadi et al 27 presents an offline framework for IPACT and shows that light load punishment is eliminated by allowing ONUs to allocate the bandwidth to lower priority class frames instead of the newly arriving frames after the REPORT message has been sent by the ONU. The offline framework for IPACT 23 has also been explored in many studies.…”

“…If the traffic load of the ONUs is nonuniform, then such schemes may lead to monopolization of channel by overloaded ONUs. 24,28,29 The studies in Lai et al, 24 McGarry et al, 30 and Usmani et al 31 may be referred for a detailed review of DBA schemes presented for EPON. [24][25][26][27] A scheme following this framework requires an OLT to wait for all the queue reports from all the ONUs before it executes the DBA algorithm.…”

“…The offline framework for IPACT 23 has also been explored in many studies. [24][25][26][27] A scheme following this framework requires an OLT to wait for all the queue reports from all the ONUs before it executes the DBA algorithm. Thus, the OLT can fairly allocate bandwidth to all the ONUs.…”

“…The bandwidth requests are normally served in a round robin manner but may also be served in order of processing time of the reports 26 or size of the reports. 24 The study in quality of service DBA in Chadi et al 27 presents an offline framework for IPACT and shows that light load punishment is eliminated by allowing ONUs to allocate the bandwidth to lower priority class frames instead of the newly arriving frames after the REPORT message has been sent by the ONU. Overall, the drawback of the offline approach is additional idle time due to OLT waiting time for all the queue reports.…”

“…Many studies have tried to improve this weakness of offline approach by integrating online and offline approaches. 24,28,29 The studies in Lai et al, 24 McGarry et al, 30 and Usmani et al 31 may be referred for a detailed review of DBA schemes presented for EPON.…”