Some technicians are using the "CDMA US Cellular" or "CDMA US PCS" channel table selection, and the associated CD1 measurements, when measuring signals on CDMA2000 base stations. This will work as long as the base station is only responding to CDMAOne (IS-95, IS-95B) calls. But as soon as a faster CDMA2000 call or data session comes up, the YBT250 (NetTek) may be unable sync, or once sync is lost, unable to regain sync, as shown by the "Cannot Sync" error message. This is particularly likely to happen at times of high loading. The fix is to use the "CDMA2k US Cellular" or "CDMA2k US PCS" channel tables, and the option CD2 measurements, when measuring a CDMA2000 BTS.
CDMAOne, IS-95, and IS-95B all refer to the same older standard. CDMA2000, CDMA2k, 1xRTT, RC3, RC4, and RC5 refer to the same newer standard. RC1 and RC2 refer to the CDMA2000 backwards compatibility mode, which allows CDMAOne phones to use a CDMA2000 base station.
A CDMA2000 base station can accept CDMAOne calls. When only CDMAOne calls are in process, (RC1 and RC2) the NetTek can demodulate the CDMA2000 signals using the older standards of "CDMA US Cellular" or "CDMA US PCS." But as soon as a RC3, 4, or 5 call comes up, the NetTek may loose sync. If the RC3, 4, or 5 call is up when the NetTek is initially hooked up, the NetTek will not sync at all. If the RC3, 4, or 5 call then goes away, sync will be regained. While the NetTek is doing exactly what it was designed to do, this behavior can appear random.
The solution, in every case, is to use the right standard for the BTS under test. CD1 is the option in the YBT250 for CDMAOne demodulation measurements and option CD2 for the YBT250 works for both CDMAOne and CDMA2000 demodulation measurements.
FAQ ID : 55801View all FAQs »