6781097079

viii GSM Networks: Protocols, Terminology, and Implementation

7.3.1	Mapping of Logical Channels Onto Physical Channels	95
7.3.2	Possible Combinations	97
7.4	Interleaving	100
7.5	Signaling on the Air Interface	101
7.5.1	Layer 2 LAPDm Signaling	101
7.5.2	Layer 3	107
8	Signaling System Number 7	125
8.1	The SS7 NetWork	125
8.2	Message Transfer Part	126
8.3	Message Types in SS7	127
8.3.1	Fill-In Signal Unit	127
8.3.2	Link Status Signal Unit	128
8.3.3	Message Signal Unit	128
8.4	Addressing and Routing of Messages	130
8.4.1	Example: Determination of DPC, OPC, and SLS in a Hexadecimal Tracę	131
8.4.2	Example: Commissioning of an SS7 Connection	132
8.5	Error Detection and Error Correction	133
8.5.1	Send Sequence Numbers and Receive Seąuence Numbers (FSN, BSN, BIB, FIB)	135
8.5.2	BSN/BIB and FSN/FIB for Message Transfer	135
8.6	SS7 NetWork Management and NetWork Test	138
8.6.1	SS7 Network Test	139
8.6.2	Possible Error Cases	140
8.6.3	Format of SS7 Management Messages and Test Messages	142
8.6.4	Messages in SS7 Network Management and Network Test	142
9	Signaling Connection Control Part	153
9.1	Tasks of the SCCP	153