User's Manual

Doc. No.
Rev.
Date
DRAFT
1.01
2012-01-27
Damm Cellular Systems A/S, Denmark
TetraFlex
®
7.5 Manual - Voice Gateway
TetraFlex® 7.5 Manual 2-108
Let us assume two organizations, one with the prefix 101 and the other with
prefix 102, both have fixed phones with local numbers 301 and 302 and TETRA
mobiles with local numbers 401 and 402. The user numbers in the subscriber
register for the mobiles will for organization 1 be set to 101401 and 101402 and
for the second organization 102401 and 102402. When making any call from
101401 the base station will add the prefix 101 from the profile to the called
number. When dialing 402 the complete number will then be 101402. This is
positively checked for existence in the subscriber register after which the base
station will initiate a call to the SSI for that particular mobile.
When making a call from mobile 101401 to the number 301 the base station will
add the prefix and get the number 101301. This does not exist in the subscriber
register so instead the base station will make a call to the voice gateway
indicated in the profile. When the system PABX receives the number 101301 it
recognizes the prefix 101 as belonging to organization 1 and will route the call
from the PABX with the prefix removed, effectively calling organizations 1’s
phone 301.
When a fixed phone in organization 1 calls the number 401 their PABX will
recognize the number as a TETRA mobile and route it to the TETRA system
PABX. The TETRA system PABX will add their prefix 101 to get the full number
101401 and call the TETRA gateway. The TETRA gateway will find the user
number in the subscriber register and then create a call to the associated SSI.
2.11 VOICE GATEWAY
Voice gateways can be activated on any node using the SIP protocol with Voice-over-IP
(VoIP). The gateway is able to handle up to 31 simultaneous speech connections including
conversion of speech from TETRA to A-law and vice versa, when running on the standard
BSC412 platform and up to 15 simultaneous speech connections when running on a
standard BSC421 platform. Up to 32 simultaneous speech connections are possible when a
voice gateway is installed on a PC node.
The gateway does not provide any PABX features but has the capability to connect via the
SIP protocol to an external PABX/gateway where routing, number modification, and protocol
conversion (to e.g. ISDN or H.323) are handled. The gateway is tested to support the
recommended Innovaphone V6 software, running on an IP400 (No PABX feature), IP800 or
IP2000. Products from other manufacturers can easily be applied as well.
Each voice gateway is
related to a node number.
The SSI provided from the
mobile station when making a
call is not used in the system.
Instead the system will
always look in the calling
mobiles profile and forward
the call to the specified
primary or alternate gateway
node. This ensures predicted
functionality independent of
mobile programming.
The TetraFlex
®
System
supports the unique feature
of adding a fixed prefix to all
PSTN calls made of mobiles
with a specific profile. This prefix can be used in the interconnected PABX for routing
analyses, allowing a single TetraFlex
®
gateway to route calls to different organizations.
The TetraFlex
®
voice gateway supports incoming and outgoing duplex calls. It also provides
full support to allow any PSTN phone (fixed, IP, GSM, etc.) to establish call in connection to
group calls. The caller will initially be prompted for ID and pin code before the group
attachment. All group communication can then be monitored in the phone. PTT activation can
be done by a combination of key pressure and VOX (Voice Operated Transmit).
The voice gateway automatically makes SIP registration to the PABX. In case the redundant
BSC takes over it will automatically re-register with the same name and its new IP Address
giving full gateway hardware redundancy. In addition an alternate voice gateway can be
established and defined in the subscriber register.