Analog Gateway

The DVI-100 (TETRA Voice-Bridge) can now also be connected to analog (Narrow Band) radios. This significantly helps when migrating from an Analog Radio Network to a TETRA network, or in cases where and existing TETRA Network does not (yet) cover the complete customer's area. The physical set-up of the TAG-100 is quite simple - it only requires a 12-24 Volt DC Power Supply, an IP-Connection to the DVI-100 and an analog radio with an M & E (Microphone, Loudspeaker, PTT, Squelch) interface. Since the DVI-100 uses the TETRA Air Interface, no additional setup is required on the TETRA SwMi.

One of the challenges when interfacing analog radios to TETRA is, that the users do not consider the TETRA call setup time and will start speaking immediately after pressing the PTT on the analog radio. The TAM-100 Gateway handles this situation by using a small FiFo-memory where the digitized audio stream is buffered until the TETRA infrastructure is in call. If a call attempt is made when all TETRA traffi c channels are busy, the TAM-100 will indicate this to the analog network by announcing, in speech “Channel Busy, please try again”, once the PTT has been released.

One DVI-100 Server Device can operate with up to ten Clients (these can be other DVI-100, TAG-100 or iPhones), which permits a large diversity of applications. For example PTT audio from an iPhone could be delivered to an analog radio or to TETRA handheld/mobile.