Specifications

Interface Protocols
Operating Characteristics
3-14 68P81095E55-E August 08, 2000
Signaling Scheme
Different protocols are used to complete a call. The process to complete an
Interconnect call is more complex than a Dispatch call. The protocols used to
complete an Interconnect call are the same as those used for Circuit Switched data
networking. Dispatch and Packet Data processing use different paths and protocols.
Figure 3-12 shows the various signaling schemes and protocols encountered when a
user places a call or networks from the MS.
Multi-frequency (MF) Inband signaling is used to connect the MSC with other
networks. This process requires the MSC seize the PSTN circuits, send dialed
information and supervise the call. This process uses ANSI SS7-ISUP if it is
supported and available on the other networks (PSTN).
Figure 3-12 Signal Paths and Protocols
Facilities
T1, E1, DSx,
Fiber,
µ wave,
ATM, FDDI,...
EBTS
Mobile Station
Modem
DACS
Speaker
Microphone
Computer
Display
4.2kbs
VSELP
Data
(SMS - Packet Data)
Data
(Circuit Switched)
Vocoder
A to D
&
VSELP
RS-232
RF
Modulator/
Demodulator
RF
Modulator/
Demodulator
ModemACG
Coaxial
M16QAM TDMA
MOBIS
(1-6) timeslots
Ethernet LAN
CMSA/CD
audio and data
Frame Relay
T1
DS0's
1/radio
RLP
MOBIS
Dispatch/Packet Data
Frame Relay
MPS
DAP
PD -
APD
MDG
Packet Data
Frame Relay
V.35
T1
T1
T1
BSC
XCDR
MSC
IWF
RF
M16QAM TDMA
7.2 kbs/channel
(1-6) timeslots
MOBIS/RLP
CP
4.2kbs
VSELP
PCM
64kbs
SS7
ML
DS1
Modem tones
DACS
PSTN
SS7 ML
PCM
DACS
Facilities
T1, E1, DSx,
Fiber
microwave,
ATM, FDDI ..
T.
French