32 bits – synchronization code (S-field): constant bit string AAAAE98AH for FP transmission, 55551675H for PP transmission 388 bits – data (D-field), including 64 bits – header (A-field): control traffic in logical channels C, M, N, P, and Q 320 bits – user data (B-field): DECT payload, i.e. voice data 4 bits – error-checking (X-field): CRC of the B-field 4 bits – collision detection/channel quality (Z-field): optional, contains a copy of the X-field