diavox courier 700, digital system telephone for md 110 data

Fig. 7
Signalling system No. 7 in AXE 10, hardware
structure.
The signalling data link consists of a 64 kbit/s timeslot in
the PCM system (speech route). Commands are used to
connect the signalling terminal via a semipermanent
connection through PCD-D and the group swith to an
optional timeslot in the speech route. RP and PCD-D are
duplicated in order to ensure high reliability
Central processor
Regional processor bus
Regional processor
Bus between RP and the devices
Signalling terminal for signalling system No. 7
Multiplexor with 64 kbit s digital inputs
Group switch
Exchange terminal circuit
Signalling message flow
Signalling data link
Fig. 6
Signalling system No. 7 in AXE 10.
Signalling system No. 7 in AXE 10 consists of
subsystem CCS, which corresponds to MTP, and
an addition to TSS, which corresponds to TUP
SSS Subscriber Switching Subsystem
GSS Group Switching Subsystem
TSS Trunk and Signalling Subsystem
CCS Common Channel Signalling Subsystem for
signalling system No. 7
ETC Exchange Terminal Circuit
- .i . Signalling data link
^ ^ ^ — Signalling message flow
Internal control signals in CCS
— — — Speech circuit
signed in accordance with CCITT recommendations
3 .
TSS controls the connection and disconnection
of telephone circuits. In
TSS functions specific for signalling
system No. 7 are the translation of the
signalling information into the format
standardized by CCITT, and the translation
from the internal indication of the
speech circuit in AXE 10 into the message
label standardized by CCITT AXE
10 can contain speech routes with several
different conventional signalling
systems and speech routes with signalling
system No. 7. The functional content
of TUP therefore corresponds to
the R2/MFC signalling diagram recommended
byt CCITT, which in turn covers
most of the existing signal ling schemes.
A standard version of TSS can therefore
be used for many markets. Market adaptation
of TSS is made for markets with
special signalling reguirements.
Subsystem CCS consists of a number of
function blocks divided into four different
groups, namely signalling link
functions, message handling functions,
singalling network management functions,
and operation and maintenance
functions. CCS contains most of the
functions specified for MTP by CCITT.
These functions cover all the applications
for signalling system No. 7 that are
envisaged in AXE 10 within the foreseeable
future. CCS has been designed
to permit the successive incorporation
of new functions and new UPs in the
AXE 10 system.
The design of a signalling network must
economically meet the reguirements on
reliability and capacity set by the user of
the network. The signalling network
should also be designed for ease of
administration. The following description
of signalling system No. 7 in AXE 10
is based on these reguirements.
Economy
In a telecommunications network the
need for communication between the
exchanges is great. When signalling
system No. 7 is introduced the amount
of signalling eguipment will be reduced
because the signalling for a large num-