4 Timing of transmitted signals

05.103GPPRadio subsystem synchronizationTS

The timing of signals transmitted by the MS, BTS and CTS-FP are defined in 3GPP TS 05.02.

The MS can use the timing of receipt of the synchronization burst to set up its timebase counters as follows:

QN is set by the timing of the training sequence;

TN = 0 when the synch burst is received;

FN = 51 ((T3‑T2) mod (26)) + T3 + 51 x 26 x T1 when the synch burst is received,(where T3 = (10 x T3′) + 1, T1, T2 and T3′ being contained in information fields in synchronization burst).

For Compact, the MS can use the timing of receipt of the synchronization burst to set up its timebase counters as follows:

QN is set by the timing of the training sequence;

FN = (R1 x 51 + R2) x 52 + 51 when the synch burst is received (where R1 and R2 are contained in information fields in synchronization burst);

TN is determined from TG as described in 3GPP TS 05.02, where TG is contained in information fields in synchronization burst.

For CTS, the timebase counters are set as follows:

QN is set by the timing of the training sequence;

TN is set according to the CTSBCH-SB position (see Annex C);

T4 = 51 when the CTSBCH-SB is received (prior to attachment);

FN = (51 ((T3‑T2) mod (26)) + T3 + 51 x 26 x T1) mod (2715648) when the CTS-MS receives the last CTSAGCH burst of the non-hopping access procedure, where T2 = T4 mod (26), and T1 and T3 being contained in this CTS immediate assignment message.

Thereafter, the timebase counters are incremented as in subclause 3.2.

(When adjacent BTS’s are being monitored for handover purposes, or for cell reselection purposes in group receive mode, the MS may choose to store the values of QN, TN and FN for all the BTS’s whose synchronization bursts have been detected relative to QN, TN and FN for its current serving BTS).