Sleep assistive dynamic bandwidth assignment scheme for passive optical network (PON)

2018 ◽  
Vol 36 (3) ◽  
pp. 289-300
Author(s):  
Rizwan Aslam Butt ◽  
M. Faheem ◽  
M. Waqar Ashraf ◽  
Sevia M. Idrus
2020 ◽  
Vol 41 (3) ◽  
pp. 279-293 ◽  
Author(s):  
Rizwan Aslam Butt ◽  
M. Waqar Ashraf ◽  
M Faheem ◽  
Sevia M Idrus

AbstractIn time division, multiple access (TDMA)-based passive optical network (PONs), a dynamic bandwidth assignment (DBA) is necessary for efficient utilization of the available bandwidth of the upstream link. An efficient DBA scheme can improve the upstream performance of a traffic class of an ONU in two ways. First, it can increase the bandwidth assignment to it by efficiently utilizing the available bandwidth. Secondly, it can reduce the channel and frame idle time by increasing the polling frequency and by assigning extra surplus bandwidth not used by the other ONUs. Many DBA schemes have been reported for both ITU PONs (GPON and XGPON) and IEEE PONs (EPON and 10 G EPON). In this study, we explain the impact of DBA scheme on the upstream performance of PON and then do a thorough survey of both PON standards, categorize the DBA schemes and review them critically. Based on the literature review we also give our opinion on the most suitable DBA scheme for both type PONs on the basis of upstream delays, frame loss and bandwidth utilization efficiency.


2019 ◽  
Vol 40 (1) ◽  
pp. 55-66 ◽  
Author(s):  
Rizwan A. Butt ◽  
Sevia M. Idrus ◽  
Shahid-Ur Rehman ◽  
Pir Meher Ali Shah ◽  
Nadiatulhuda Zulkifli

Abstract Dynamic bandwidth assignment (DBA) schemes for long reach PONs face a suffer from higher upstream channel idle time due to long round trip time (RTT). In ITU PONs, the DBA schemes; Immediate allocation with colorless grant (IACG), Efficient bandwidth utilization (EBU) and GPON redundancy eraser algorithm (GREAL) minimize idle time by sending bandwidth grants to the optical network units (ONUs) every downstream frame (DF). EBU further improves IACG by utilizing unused bandwidth (UBW) of other traffic classes. Sending the grant results every DF requires optical line terminal (OLT) to remember all previous grants sent to ONU during RTT and subtract them from the received queue reports. Since, both IACG and EBU assign the excess bandwidth equally to ONUs. Therefore, the OLT is actually not aware of the complete grant to each traffic class and thus do not subtract these completely from receiving reports. This leads to wastage of bandwidth and higher US delays due to over granting. GREAL resolves this problem by not utilizing the excess bandwidth which also leads to increased US delays. The proposed scheme in this study eliminates this shortcoming by allocating excess bandwidth to each traffic class completely at the OLT. Moreover, the UBW assignment mechanism of EBU is also improved. Simulation results show a 50–85 % reduction in delays of type-2 (T2) and type-3 (T3) traffic classes versus GREAL and IACG and up to 40 % reduction in delays for type-4 (T4) versus EBU.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
N. A. M. Radzi ◽  
N. M. Din ◽  
M. H. Al-Mansoori ◽  
H. Zainol Abidin

The advantages of Ethernet passive optical network (EPON) are setting it to be a natural ubiquitous solution for the access network. In the upstream direction of EPON, the directional property of the splitter requires that the traffic flow be mitigated to avoid collision. A dynamic bandwidth allocation (DBA) scheme is desirable in optimizing the bandwidth usage further. In this paper, a global priority DBA mechanism is discussed. The mechanism aims to reduce the overall delay while enhancing the throughput and fairness. This study was conducted using MATLAB where it was compared to two other algorithms in the literature. The results show that the delay is reduced up to 59% and the throughput and fairness index are improved up to 10% and 6%, respectively.


2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Jiunn-Ru Lai ◽  
Hsin-Yi Huang ◽  
Wen-Ping Chen ◽  
Luke K. Wang ◽  
Ming-Yuan Cho

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.


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