AMPS Testing

A primary feature of IS-136 TDMA/DAMPS was its coexistence with Advanced Mobile Phone System (AMPS). IS-136 TDMA handsets could access digital IS-136 TDMA networks, or the legacy IS-553 AMPS.

TDMA cells tended to be smaller and in more densly populated areas while AMPS cells could be quite large and dominated rural regions.

In rural areas, towers tended to be farther apart creating greater risk of fade outs (low received signal strength) and dead areas. Multipath could be a problem with AMPS in rural areas but not to the extent encountered in built up urban areas where TDMA/DAMPS dominated.

When executing scripts for say reselection, a script might be run once with strong signals simulating the phone being near a tower and again with weak, heavily attenuated signals simulating distant signals.

As part of regression test automation and intelligent roaming, I had to verify a number of different AMPS requirements including cell selection, reselection, handoffs, basic call control and error handling.

These tests were written as scripts and could be run individually, or as fully automatic batches. AMPS test scripts were functionally similar to those I wrote for automated regression testing and intelligent roaming.