Maintenance Guide Part 4

NeTIS MAINTENANCE GUIDE – Version 1.1 127/139
This gateway is used to interconnect a phone link to any location of an ETELM IP TETRA
network having the TETRA UDP phone and signalling from the different TETRA
SWITCHES.
This IP / PABX Gateway, in the case of a "full IP" TETRA network with several switches
each having phone access, makes it possible to route phone calls from anywhere on the
network to the TETRA SWITCH managing the network at time t, without using external inter
PABX links.
And on the opposite, for a radio call to a phone, the TETRA SWITCH routes the call to the IP
Gateway corresponding to the phone call.
Communications from phone sets connected to the PABX are sampled, converted to binary
data using MIC decoding (modulation by impulse coding), then encapsulated in IP packets by
the TETRA IP Gateway for PABX.
On the other hand, radio calls are sent to the TETRA IP Gateway for PABX which routes
them to the PABX and, when the connection is made transforms the TETRA UDP IP phone
blocks onto the MIC blocks needed for the phone link.
SWITCH
A
B
B
IP
SWITCH
B
B
B
IP
IP
GATEWAY IP TETRA
Link T2, T0, S0,