February 21, 2014

MultiPort APR

MultiPort was a project aimed to modify the frequency for GSM repeaters, remotely, at a certain date and time without human intervention.
The project was made for RCA Group, a major company in the communications. 

Some GSM operators has to change the repeaters from P-GSM to E-GSM at a certain date. The main problem is that the change will affect more than 7.000 GSM repeaters placed in low-coverage areas.

The device has to be field programmable but tamper proof.
The client has some specific requests about compliance to specific industry regulations.
Also, has to be able to make the GSM repeater reprogramming manually as a fail-safe feature.

Therefore, we proposed a solution based on a Microchip controller (PIC24 family) and a ENC28J60 as Ethernet Controller.
To reduce the risk, we decided to a battery operated device but this requests a very low consumption to have the device in stand-by for a long period of time. We take into account for about 6 months in stand-by.

One part of the project was the evaluation of various batteries on the market; we decided for VARTA Alkaline, AA format.

Here are the main features of MultiPort:

-Can change frequency range for  RF Window RFR-G0917  and  Andrew MRx18 MiniRepeater at a programmable date and time ("Trigger")-Battery operated, not connected to Main, more than 6 months of stand-by.
-Field programmable via Hyperterminal.
-"Execute" and "Check" procedure.
-Manual "Execute" possible AFTER the Trigger.
-Password protected access.
-Tamper proof protection.
-Simple installation.
Programming MultiPORT APR:

ComPort setup:


Main Menu (Select GSM Repeater Model):

 Read GSM Repeater Status:

 Real Time Clock Menu:

Battery Status:

MultiPORT APR was ready in about two months from the start at prototype level with all the documentation for mass production.

This article was published with the approval of RCA Grup.