this device have RJ 11 line to PSTN land line ,and a SIM card to the box with GSM network.
you can dial in to GSM number,the base will pick up PSTN line,you can dial again though PSTN land network to any people you want to talk.or the base will auto-dial special number to call one people.
anther,a call though PSTN land line will change GSM network by SIM card number to call special number .

Sell 2 line telephone(GSM <-->PSTN) transfer for difference region to save fee
2 line telephone can be auto-transfered, when you(A place) dial one line phone number to the base(B place), the base test and pick up anther line, you will hear anther dialling tone, you can dial the phone(C place) number again.
Used in borderline of country or difference region to save fee!

FOB prices (for minimum order quantity)---------98usd
Minimum order quantity--------------------------100set
Sample availability/cost------------------------200usd

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Mannal 

 

OW TO PROGRAM THE PHONE NUMBER IN THE BASE?
The GSM system need SIM card to dial. So, you can use your own mob-phone to program it, you can set 1 phone number in SIM card, be sure in first (1) position in the SIM card, which 1 number is to be dialed out  with GSM network when you phone in in PSTN .

HOW TO USE THE BASE?
1). Power on
When you set the SIM card (be sure it has set phone number) into the GSM base, connect power on, which need 9V—12V DC, must be over 1000mA current. The lamp on panel will bright on red in 20 second, then, it will flash yellow in 10 second, after that, it will flash green, this show the base work well. You can test the system.if it is still green, this show the base has not phone number inside.

2). Dial in from PSTN to GSM
When you dial in from Phone B use PSTN to phone A or GSM Base, as the phone A  ring 1 time, the GSM base will work up and start to dial out from GSM network ,dial out number is you will hear return back ring voice two or more times untill Phone C answer B call. If you do not program any phone number, the base will not dial out to C or anyone from GSM network.

3). Dial in from GSM to PSTN ( normal )
When you (Phone C)dial in from GSM network to the base,after you hear 3 voice come back from GSM net (also phone A will ring 3 time),the base will pick up PSTN line (Phone A), and you will hear dial voice come from PSTN  ,you can use your keybod to dial out any number you want, this is called the second time calling(dial).
In this way ,GSM base exchenger pay call from PSTN and phone C pay call from GSM NET.

4). Dial in from GSM to PSTN ( call back)
When you (Phone C)dial in from GSM network to the base,when phone C hear one voice come back from GSM net (also phone A will ring 1 time),then, phone C take off (close),the base will answer phone C and dial into phone C ,when phone C hear the ring, phone C can answer the base..when the base get in touch with phone C , the base will pick up PSTN line (Phone A), and phone C will hear dial voice come from PSTN  , phone C can use his keybod to dial out any number you want, this is called the second time calling(dial). In this way ,GSM base exchenger pay both call from PSTN and GSM NET.

About (SIGNAL) lamp
(SIGNAL) lamp show red in 20 second when the base is power on. (SIGNAL) lamp flash yellow show it start to get in touch GSM network .If (SIGNAL) lamp still flash yellow, show SIM card is set un-correctly or GSM network is not good. If (SIGNAL) lamp still on yellow, show not name or phone number in SIM card .if every thing is ok, (SIGNAL) lamp show flash green (in normal situation)or still green (not programed the phone number in the situation).if base in exchange situation , (SIGNAL) lamp show flash red .