Method for determining when a communication device should rate shift or roam in a wireless environment

DETAILED DESCRIPTION The invention is useful in a method of improving communication performance in a wireless communication system having at least one mobile wireless communication device and a plurality of transmitter/receiver sites that communicate with communication signals, each of which has a geographic area, defined as a cell, within which the at least one mobile wireless communication device can communicate with at least one of the transmitter/receiver sites.
In such an environment, according to a first method embodiment of the invention, communication performance is improved by receiving at one of the transmitter/receiver sites the communication signals transmitted by the communication device, and evaluating over time intervals the quality of the communication signals received from the mobile wireless communication device to obtain measurement values of the quality of the evaluated communication signals.
A functional relationship value based on the measurement values and a configurable parameter associated with the measurement values are created.
The functional relationship value is stored in a memory.
An extrapolated functional relationship value based on a stored functional relationship value is calculated, and an optimal one of the plurality of transmitter/receiver sites for communication with the wireless communication device based on the extrapolated functional relationship value is determined.
According to a second method embodiment of the invention, communication performance is improved by receiving at one of the transmitter/receiver sites the communication signals transmitted by the communication device, and evaluating over time intervals the quality of the communication signals received from the mobile wireless communication device to obtain measurement values of the quality of the evaluated communication signals.
One of a transmission failure and reception failure of the communication signals is detected.
The last measurement value evaluated before the detected one of a transmission failure and a reception failure is stored