Methods for improving communication performance in a wireless communication system where the wireless communication system has at least one mobile wireless communication device and a plurality of transmitter/receiver sites. The transmitter/receiver sites have a geographic area, defined as a cell, within which the mobile wireless communication devices can communicate with at least one of the transmitter/receiver sites. The methods determine when the mobile wireless communication device should rate shift or roam based on connection quality measurement data or position information such as GPS. In one method, the measurement data is subjected to configurable parameters to create a functional relationship value that is recorded. The recorded functional relationship values are trended and extrapolated to determine whether a rate shift or roam should be performed. In a second method, the measurement data taken prior to a communication connection failure is stored in at least one data vector with there being at least one data vector for each rate shift and one for roam. A functional relationship utilizing current measurements, last data rate, and the respective data vectors determines whether a rate shift or roam should be performed. In a third method, the position information for the wireless communication device is compared to at least one transmitter/receiver site and a determination is made as to the optimal transmitter/receiver site for communication.