2.1 General

2 FORMATS AND CODES

2.1 General

All mobile telephone signal messages contain a transaction number and a heading consisting of two parts, heading code HO and heading code H1. Code H0 identifies a specific message group while H1 either contains a signal code or in case of more complex messages, identifies the format of these messages.

The general structure of mobile telephony signal messages is illustrated by figure 2.1.a

F	CK	SIF		SIO				LI	F I B		FSN	B I B	BSN	F
8	16			8		2		6	1		7	1	7	8
														1st bit to transfer.-->

MUP INFORMATION			H1		H0		TRANSACTION NUMBER			SCCP HEADER
n*8			4		4		32

Figure 2.1.a General format of Mobile Telephony Signal Messages.

The general structure of MUP- information messages is illustrated in figure 2.1.b.

First bit to transfer is Bit A in field «a». The following fields are transmitted in alphabetic order.

e	d	c	b	a
L............BA	H..........BA	D.....BA	D.....BA	fe.........BA
MTXV IDENTITY Id₁Id₂Id₃	MTXV RESTRICTIONS	HEADING CODE H1	HEADING CODE H0	TRANSACTION NUMBER
12	8	4	4	32
g	f
H............BA	D..........BA
MOBILE STATION IDENTITY ZX1..X6(K1K2K3)	NUMBER OF DIGITS
n * 8 4<n<5	4

Figure 2.1.b General structure of MUP- information messages