Packet delay analysis and performance evaluation of dynamic bandwidth allocation algorithms in ethernet passive optical networks | |
| Author | Bharati, Sailesh |
| Call Number | AIT Thesis no.ICT-08-08 |
| Subject(s) | Ethernet (Local area network system) Packet switching (Data transmission) |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Information and Communications Technologies, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. ICT-08-08 |
| Abstract | Due to its high bandwidth capacity, an optical access network is capable of reducing the bandwidth bottleneck between high capacity local area networks and backbone networks. Ethernet Passive Optical Network (EPON), which uses Ethernet as layer-2 protocol and time division multiple access as medium access protocol, has attracted lots of attention as a potential candidate for access networks. EPON is well known for its high capacity, simple architecture, ubiquity, scalability, and use of inexpensive technologies. There are various algorithms for bandwidth allocation in an EPON. Bandwidth allocation algorithms (BAAs) are designed with the objective of being fair and efficient. In addition, there are various BAAs that are capable of supporting differential services. Closed form mathematical expressions of various parameters like packet delay, queue length, jitter, throughput etc., are useful for evaluating the performance of a communication network efficiently while designing. In this thesis, we derive closed form expressions of the mean packet delay in dynamic bandwidth allocation algorithms (DBAAs), viz. gated and limited service BAAs in an EPON. For this, we break the mean packet delay into three components, viz. mean residual time, mean reservation time and mean waiting time, by assuming EPON as a multi-user M/G/l gated system with reservation. As expressions for the mean residual time and the mean waiting time are the same for both kinds of service, by fmding the expression for the mean reservation time for a given BAA, we can derive the expression for the mean packet delay. Our derivation of the mean reservation time can be extended for a variety of polling assumptions like the gating time at the beginning or at the end of each data interval. We compare our analysis with results from simulation experiments. By investigation through simulation experiments, we also propose vanatlOns in existing limited service so as to achieve efficient BAAs in an asymmetric network. For this we demonstrate that limited service can be made more efficient by setting set up different maximum allowable transmission windows (MATW s) for different kinds of optical network units (ONUs). We show that, by allocating different MATWs, the mean packet delay can be improved. We also suggest a mechanism to remove the unused TW portion which results in an increase in channel utilization and a decrease in the mean packet delay |
| Year | 2008 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. ICT-08-08 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Information and Communications Technologies (DICT) |
| Academic Program/FoS | Information and Communication Technology (ICT) |
| Chairperson(s) | Poompat Saengudomlert; |
| Examination Committee(s) | Erke, Tapio J.;Teerapat Sanguankotchakorn; |
| Scholarship Donor(s) | Finland;Asian Institute of Technology Fellowship; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2008 |