Performance analysis of connection status table based wavelength assignment algorithm under session traffic | |
| Author | Rajapakse, R. G. D. Harsha |
| Call Number | AIT Thesis no.TC-02-11 |
| Subject(s) | Telecommunication--Traffic Wavelength division multiplexing |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. TC-02-11 |
| Abstract | With the emerging of new types of services with shorter data transfer periods on optical transport networks, some links have become underutilized and costly comparing to the required bandwidth. The cost of bandwidth of such lines can be reduced by dynamically allocating bandwidth according to user demand. This situation has brought up various new issues. Routing and wavelength assignment is one such widely discussed topic. The shortening of connection holding times has made it important to reduce lightpath setup time. "Connection Status Table" based wavelength assignment algorithm is an effort taken to solve this problem. While reducing lightpath setup time, the disordered wavelength assignment of this algorithm maintains a high blocking probability. This work is an improvement of the above algorithm by introducing wavelength conversion to it and thus reducing blocking probability. The performance of the network was analyzed in terms of gain in number of switching configurations, connectivity of the network, wavelength conversion degree, placement of converters, Fixed Routing and Fixed Alternate Routing, wavelength conversion factor, converter utilization and number of wavelengths in a fiber. Wavelength conversion allows mixing of wavelengths within the same connection and supports more connections utilizing same amount of wavelength resources used with wavelength continuity constraint. Therefore, connection blocking could be reduced from 13.49% to 6.86% under certain conditions. In this work, a superposition of many ON/OFF sources was used as the input traffic to the network which is an ideal representation of a finite number of users in an optical transport network. Long range dependent traffic resulted in performance degradation compared to Poisson traffic. The performance of full wavelength conversion could almost be achieved by limited wavelength conversion with 53% of the conversion capacity and 10% of the number of converters. Through the results it can be clearly stated that, to benefit from wavelength converters, they must be properly located in a network and used in optimal numbers and capacity. |
| Year | 2002 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. TC-02-11 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Information and Communications Technologies (DICT) |
| Academic Program/FoS | Telecommunications (TC) |
| Chairperson(s) | Erke, Tapio; |
| Examination Committee(s) | Ahmed, Kazi M. ;Sharma, A. B.; |
| Scholarship Donor(s) | Government of Finland; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2002 |