A semi-analytical approach for performance evaluation of TCP-IP based mobile radio links

A semi-analytical approach is proposed to evaluate the performance of TCP-IP based applications on wireless channels. The physical, data link and IP layers are analytically treated; the TCP is simulated. Additive Gaussian noise, slow and fast impairments due to the mobile radio channel are taken into account, with particular attention focused on a careful description of the different time scales to be used for the different processes introduced by the wireless link. It is shown that the fast fading and the spatial correlation due to shadowing can be analytically studied by means of a suitable combination of the link-level bit error rate (BER) vs. signal-to-noise ratio (SNR) curves and the Gilbert-Elliott model. Results are first given for wireless TCP-IP based on generic physical and data link layers; then, the application to IP over GPRS is considered. A validation of the approach is carried out by comparisons with pure simulation at the logical link control (LLC) level