Buffer analysis of lossless handover for mpeg ii video source in wireless ATM networks | |
| Author | Sittichoke Thongjuapet |
| Call Number | AIT Thesis no.TC-00-12 |
| Subject(s) | Wireless communication systems Asynchronous transfer mode |
| 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-00-12 |
| Abstract | Wireless Asynchronous Transfer Mode (W ATM) enhances to meet the demand for delivery of multimedia service to mobile users. In wireless environment, the continuity of a call while a mobile terminal (MT) is moving between cells is processed by the handover function. The handover control sequence has to protect cell disordering and cell loss in which impact the quality of services (QoS) requirement. An approach providing lossless handover is cell buffering. To avoid changes of ATM switch configuration, buffering at base station (BS) should be utilized. However, buffering induces cell delay variation (CDV) or jitter. The jitter has no significance for computer based application but deteriorates constant bit rate (CBR) type video service. However, the jitter can be absorbed by initial filling cells the perstream buffer at MT up to a threshold value before delivering them to the higher layer of application. The amount of buffer at both BS and MT can control cell loss and jitter respectively. Therefore, the analysis of buffer requirement based on CBR-type video service becomes an enchanting topic to study. The thesis proposes the behavior model of downstream buffer at both BS and MT. This model makes us to understand the behavior of the downstream during execution of a handover. It shows that the amount of BS buffer is affected by the accumulative time. During this time interval, all of arrival cells are temporary stored in the BS buffer. While MT buffer requirement depends on the MT input interruption time. Both the accumulative time and the MT input interruption time are derived in this thesis. To dimension both BS and MT buffer for fulfillment of CLR and CDV, the analytical model achieves the relationship both BS buffer size versus cell loss ratio (CLR) and MT buffer size versus maximum cell delay variation (Max-CDV). We can conclude that the characteristic of occupancy size distribution of BS buffer depends on handover-cross-load termed as ratio between a number of executed and maximum handover calls. When handover-cross-load becomes high, the distribution is approaching the distribution of accumulative time. In addition, we can observe that the CLR, which is lower than 10-3 gives a benefit to dimension the BS buffer economically. For dimensioning MT buffer, more buffer size can reduce the jitter at the output of MT buffer. Increasing MT buffer size for the low downstream transmission rate can absorb the jitter significantly more than the high downstream transmission rate. The simulation is also set up to ensure the validity of the analytical model. The result shows a good consistency between analysis and simulation. |
| Year | 2000 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. TC-00-12 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Information and Communications Technologies (DICT) |
| Academic Program/FoS | Telecommunications (TC) |
| Chairperson(s) | Teerapat Sa-nguankotchakom; |
| Examination Committee(s) | Ahmed, Kazi M.;Erke, Tapio ; |
| Scholarship Donor(s) | Siemens Limited; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2000 |