Synchronization Channel (SCH) and Synchronization Burst Encrypted Bits

Specifically the synchronization channel (SCH) shall contain two encoded parameters:

  1. Base transceiver station identity code (BSIC): 6 bits (before channel coding) consists of 3 bits of Public Land Mobile Network (PLMN) color code with range 0 to 7 and 3 bits of base station (BS) color code with range 0 to 7 as defined in 3GPP TS 23.003.

  2. Reduced TDMA frame number (RFN):

    19 bits (before channel coding) =

    T1 (11 bits) range 0 to 2047 = FN div (26 x 51)

    T2 (5 bits) range 0 to 25 = FN mod 26

    T3 (3 bits) range 0 to 4 = (T3 - 1) div 10

    where

    T3 (6 bits) range 0 to 50 = FN mod 51

Multiframe Structure of BCH

SACCH Blocks (Downlink)