An overview of various propagation model for mobile communication

System's propagation characteristics through a medium is one of the important task to be done before planning and optimization of any network in order to estimate the signal parameter accurately for mobile system. Propagation analysis provides a good initial estimate of the signal characteristics .The ability to accurately predict radio-propagation behaviour for wireless personal communication system, such as cellular mobile radio, is becoming crucial to system design. This paper aim to address various propagation model used in planning and optimization of the network and much emphasize on empirical (statistical) models it address models limitation and its applicability. To validate the models, field measurements were carried out at different locations within Dar es Salaam and its environs. The measurements system consist of live radio base stations transmitting at 900/ 1800/2100 MHz Downlink signal strength level data were collected using drive test exercise. The respective path loss values were estimated and compared with existing model for rural, suburban and urban areas. The result indicated an appreciable inconsistency with the empirical models for all terrain areas.