Performance evaluation of group forming service in push to talk over cellular for GSM/GPRS network | |
| Author | Tran Tuan Anh |
| Call Number | AIT Thesis no.TC-05-10 |
| Subject(s) | General Packet Radio Service Cellular telephone systems Radio--Packet transmission |
| 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 |
| Abstract | The General Packet Radio Services (GPRS) is a radio service that supports packet data transmission in GSM network. The characteristic of GPRS opens a significant way in IP-based applications such as Voice over IP (VoIP) in wireless networks. Recently, one of the proposed services is Push-To-Talk over cellular (PoC) which is based on half duplex VoIP technology over GSM/GPRS network. In this thesis work, traffic modeling and group behavior modeling for PoC traffic are proposed. The behavior of users in group forming service and the traffic of PoC service are investigated. It is assumed that the arrival process of PoC calls is Poisson, while the offered PoC service time and floor holding time are exponentially distributed. The proposed group generation follows Binomial model. The floor traffic is modeled as a limited source ONOFF traffic. Based on proposed traffic models, PoC environment and PoC calls are simulated. Two invitation methods in PoC service are considered: one by one invitation, and batch invitation. The influence of stop talking actions, floor request habits, and maximum group size in PoC traffic are studied. The simulation result shows that the number of users in group call is affected by type of invitation and stop taking actions. The floor blocking is influenced mainly by maximum group size, type of invitation. PoC traffic consists a combination of calls terminated by inactivity time, and normal completed calls. That is why there are two peaks in PoC traffic distribution in some cases when the number of calls released by inactivity time is high. The number of PoC calls failing to form a group in one by one method is higher than that in batch method, but the floor blocking probability is lower in one by one invitation method. Mean ON time is also shorter than in batch nmethod. Stop talking action helps to decrease the floor blocking probability, increase the number of success floor requests, and different talking users in group call, and also reduces floor utilization. Maximum group size contributes significantly in the floor utilization in PoC call. |
| Year | 2005 |
| 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 J. |
| Examination Committee(s) | Ahmed, Ahmed M.;Teerapat Sanguankotchakorn |
| Scholarship Donor(s) | Government of Japan |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2005 |