3 Timebase counters

05.103GPPRadio subsystem synchronizationTS

3.1 Timing state of the signals

The timing state of the signals transmitted by a BTS, a MS, a CTS-FP, or an Compact BTS and MS is defined by the following counters:

‑ Quarter symbol number QN (0 ‑ 624)‑ Symbol number BN (0 ‑ 156);

‑ Timeslot number TN (0 ‑ 7);

‑ TDMA frame number FN (0 to (26 x 51 x 2048) ‑ 1 = 2715647); or

– for a non attached CTS-MS, TDMA frame number modulo 52 T4 (0 – 51); or

– for Compact, TDMA frame number FN (0 to (52 x 51 x 1024) -1 = 2715647).

In CTS, the CTS-MS shall manage different sets of counters for CTS operation and GSM operation.

3.2 Relationship between counters

The relationship between these counters is as follows:

‑ QN increments every 12/13 µs;

‑ BN = Integer part of QN/4;

‑ TN increments whenever QN changes from count 624 to 0;

‑ FN increments whenever TN changes from count 7 to 0; or

– for a CTS-MS, T4 increments whenever TN changes from count 7 to 0.