Comparison of Receive Signal Level Measurement Techniques in GSM Cellular Networks

The received signal level (RSL) is one of the fundamental measurements performed in cellular system operation and maintenance. Network RF optimization, coverage verification, and quality of service estimation rely on RSL measurements collected from the field using one of commercially available drive testing systems. This paper presents a comparative study of a series of RSL measurements in the GSM 1900 MHz frequency band. The measurements were collected with three different drive test systems used in common engineering practice. Data analysis shows significant difference between the measurement systems. The differences were observed both in the size of the area from which the measurements may be collected as well as in the actual measured values. Computer simulation and theoretical analysis were used to verify the result of the measurements and extrapolate their validity to a set of more general cases.