得伯乐科技有限公司
DBL Technology Limited
RoIP-302 User Manual
Web:
www.dbltek.com
Tel: +86 755 8829 0211
VIII. Initiating a Cellular Call
The model RoIPx02G and RoIPx02GM have built-in GSM module to enable voice
communication with the radio channels that belong to the same group. This means that a telephone
user can dial in to the RoIP to conduct a voice call with the radio channels. A radio terminal
equipped with DTMF capability can also dial out to the telephone network to conduct a voice call.
The ability to communicate with other voice networks makes the RoIP302 a truly “Cross-platform
Gateway”. Below are the procedures to initiate a voice call.
i. Initiate a call from the telephone network to the radio
Use a PSTN or Cellular phone to call the phone number of the SIM card that is installed on the
RoIP302. Once the RoIP302 answers the call, it generates a voice prompt to ask the caller to enter
the
GSM IN Password
(described in Section 7.7) and then press the “#” key. The default password
is “123”. Once the correct password is entered, RoIP302 generates double beeps as confirmation.
The caller can then hear the voice communications of the group that the GSM Channel is assigned
to. Please note that only one way voice communication is allowed. The caller should wait for a
silent period before enabling the voice channel to talk. To enable the voice transmission, the caller
needs to press the “*” key to enable the PPT control before talking. Once the caller completes the
conversation, he/she should press the “#” key to disable the PTT control in order to deactivate the
voice transmission. Therefore, the Radio party can talk back. This mechanism simulates the PTT
method used in Radio Communication.
Please note that when the “*” or “#” key is pressed, the caller should hear a confirmation tone
(double beeps). If the caller does not hear this tone, he/she should dial the digit again. The caller
can just hang up the phone to end the call.
ii. Initiate a call from the radio to the telephone network
To initiate a call via the GSM channel, the radio user should press and hold the PTT button to
activate the transmission and the dial the following sequence.
<password> + “#” + <phone number> + “#”
where the password is the GSM OUT Password as described in Section 7.7. Please make sure
that
the PTT button is pressed while dialing the sequence. Once the RoIP accepts the dialed sequence, it will
then play the voice prompt of “Dialing in Progress”. Once the call is answered, the RoIP will
then broadcast
a voice prompt of “Call connected” to the radio caller.
Since the called party may not know the call is coming from a Radio party, the mechanism used in 1
cannot be used. Instead, the voice activated detection (VAD) mechanism is adopted. When there
is no voice
activities on the radio side, voice signal at the telephone side will be transmitted. Therefore, both
sides will have to adapt to this talking method in order to conduct a normal conversation.
