Introduction: The Challenges of cdmaOne BTS Testing
A communications network is only as good as the quality of its user access - customer satisfaction and operating efficiency begin and end with the link between the system and its subscribers. In wireless telecommunication systems, the Base Transceiver Station (BTS) provides the user access with its RF air interfaces to mobile devices. Since these interfaces are also the elements of the system that are most susceptible to faults and outside interference, they present a formidable challenge to those who install and maintain them.
Leading edge troubleshooting tools and techniques are essential to the maintenance of systems at peak performance. These modern testers provide clear insight into the complex transmitter systems by capturing and displaying information in formats that are easy to interpret. Testers must also be compact, dependable and rugged to withstand the rigors of field use. Most of all, portable troubleshooting tools must get the job done quickly and efficiently - zeroing in on problems and minimizing service disruptions and time spent off-line.
Introduction: The Challenges of cdmaOne BTS Testing
Table of Contents
The stakes are high. Network systems must perform reliably in the face of fierce competition - success or failure will be the direct result of customer satisfaction. Sophisticated new technology must coexist in a complicated landscape of previous generations and new mobile systems - most of which must be supported for many years to come. Exponential growth in other wireless and RF devices is introducing new sources of noise and interference that threaten to degrade performance.
This application note addresses the most common measurement challenges faced by RF technicians and engineers who maintain cdmaOne base station equipment. It explains the fundamental concepts of key transmitter signals, examines typical faults and their consequences and offers guidelines for tests to verify performance and troubleshoot problems in the field. Reference information is also provided on the differences between cdmaOne and previous analog and 2G digital standards and the evolution to new 3G systems.
We'll begin with a brief overview of analog and digital multiplexing methods and a review of key CDMA signal parameters. We will then examine the various types of testing tools used to characterize those parameters. In this document there is a Test Notebook that provides summaries and guidelines for making key transmitter measurements at an operating cdmaOne base station. For a brief history of wireless telephony please see Appendix (page 11).