advertisement feature
Building bridges for smart TETRA solutions
At the recent International TETRA Awards in London, a network interface design by Funk-Electronic Piciorgros was highly commended by the judges for its innovation
W
ith the DVI-100 (Digital Voice Interface) unit from Piciorgros GmbH, different TETRA
infrastructures can be interconnected easily and effectively, regardless of manufacturer, frequency band and geographical location. Te device can be connected to a TETRA
infrastructure without any loss of the excellent TETRA voice quality, since the voice is never turned into an analogue signal. It remains digital throughout the whole process. A number of different options are available for
connecting the DVI-100 to an infrastructure: back-to-back, directly through a TETRA base station or switch, through a computer or iPhone via IP/Wi-Fi or using GSM 3G/IP communications, as a backup solution, and as a MicroSPOT. Te DVI-100 is attached to a TETRA
network in the same way as a normal TETRA handportable, and it can be a member of up to 25 talkgroups. When it receives a voice call, instead of decoding the digitally coded ACELP data stream into audio and feeding it to the loudspeaker, it sends the voice as a digital (UDP) data stream to its IP port.
Plan 1 Te first option is to connect two DVI-100s back-to-back with each device connected to a different TETRA network. Te two
networks could be from different infrastructure manufacturers, on different frequency bands or even geographically separated. In this way the networks can be interconnected for group calls, status messages, and short data messages (SDS). Since the voice data stream is not converted to
analogue at any time, the voice signal retains the same brilliant quality as if received directly on a TETRA hand portable. A typical use of this option might be
in a nationwide ‘blue light’ network that – in the event of a disaster – must be able to communicate with a privately-owned infrastructure. One example could be a tram accident in a tunnel where public transport staff have to co- operate with ambulance, fire brigade and police. Although the public transport operator
may use a privately-owned TETRA network for communicating with its fleet, it cannot communicate via the public safety TETRA infrastructure, because the systems are provided by different manufacturers or because the public safety system uses encryption while the private network does not. Te DVI-100 can overcome that problem by interconnecting the two networks back-to-back, making it possible for radio users on the public safety system to talk to a group in the private infrastructure. Additionally, the DVI-100 is able to
communicate with groups from an encrypted
infrastructure to a non- encrypted infrastructure or vice versa. Voice data is always decrypted before being sent between DVI-100 devices. By connecting two DVI-100s via back-to-back using an IP link, Funk-Electronic Piciorgros has invented an easy Inter System Interface (ISI) for voice, status and SDS transmission.
Plan 2 Te second option the DVI-100 provides is to connect the device directly to a TETRA base station in order to expand an existing TETRA infrastructure. Tis is useful if a TETRA infrastructure operator wants to cover a white spot or a TETRA island or even if he wants to provide in-house coverage somewhere, where the existing TETRA infrastructure cannot be reached. Tis is also an interesting option if a new
infrastructure should be connected to an existing one. Te DVI-100 is registered on a base station anywhere in the existing network and is connected to the new base station using IP. Te DVI-100 acts as a gateway between the two infrastructures, enabling members of a TETRA network to make group calls to radios in a white spot within (or outside) the TETRA network.
Plan 3 To communicate via a PC from outside the network into an existing TETRA infrastructure,
26
TE TRA TODAY Issue 7 2012
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36