Vierling ECOTEL GSM3-110A Gateway teardown - Page 1
Forum section: electronics / general

author: hgg
author_rank: Frequent Contributor
timestamp: April 27, 2016, 09:51:11 am
content: Hi,Recently I was searching for a GSM Gateway to use in my house in order to make and receive GSM callsfrom my landline. First think I did is to look at ebay for one and I found some Chinese custom jobs for30 euros shipped. When I searched further I found out that these are made from some stripped Nokiamobiles phones interfaced with a micro in a custom case. I said ok, now I need to search more... :-)It seems that there are not many of them out there. One thing I did not know is that they are called Premicells.Luckily I found a great deal for the Vierling ECOTEL GSM3-110A for a silly price... These were sold for quitea steep price and they are still sold for about 250 euros and more. The main reason I bought it is to beable to use my mobile line around the house and more importantly to be able to talk without worrying forthe now proven harmful radiation.Never heard of the company, but it looks like they are specialized in communication equipment.Maybe its well known in Germany.So, here is a brief look for those interested.(you can click on the images for full resolution)What came in the package:First thing you notice is how lightweight the whole thing is. It feels very cheap and the plastics are indeedcheap. The case is held together with some clips on the sides which are very easy to open.But when you open it you will see that it is basically empty space. Its a single board mounted on the bottom.The whole thing could have been 3 times thinner...Some input protection. Fuse for the DC In and some MOVs for the phone lines.I thought that it was better to use GDTs for telecom applications (?)The GSM external antenna jack:and the RF on board module:..no idea what this is. Its another little board on top of the mainboard which is soldered directly.Some SMD Siemens relays. You can hear them clicking when the units boot up.A XILINX CPLD gate maze:The usual suspect:and some flash memory:The power adaptor, again made with cheap plastics (slightly better) :The interesting thing is that the modular AC jack clips on the actual PCB of the poweradapter. Not sure if this is a good idea though. I could not open it to see whats inside.It looks like its ultrasonically sealed and I don't want to destroy it since it already seemsfragile enough.Finally these are the front panel LED indicators:and the rear panel connector terminals:Not sure what the FXS I/O port is yet. In the manual its printed as the FXS Fax port. Maybe its the same.The SIM card slot is thicker than needed and you can easily drop the SIM card inside the case...It comes with a software that you need to install in order to set it up via its serial interface.No problems with the software. Works fine and has a ton of options.Very versatile hook up options as well:Despite the fact that it is enclosed in very cheap plastic cases which does not instill any confidence at all,it is a very well engineered unit that works fine. At least better than the hacked Nokia phone...Recommended.

author: SeanB
author_rank: Super Contributor
timestamp: April 27, 2016, 11:54:27 am
content: Hybrid module is a SLIC Subscriber Line Interface Card, basically all the stuff you need to make a phone line interface, all in one. Has isolation, off hook detection and separates the audio coming in and out, and handles the ring generation for the connected phone. Just needs a few rails on the equipment side and a single -48V supply to drive the line side. You can see it bridges the boundary between the GSM side and the line side, though here it looks like the whole phone side ( they seem to be expecting that you can plug a standard 56k modem in on one port, a fax on another and a regular phone, with the interface directing as required and using the first to be off hook to capture for the GSM use) is isolated.Have had a few over the years, from Siemens ones ( which used an actual cellular Siemens phone inside without the case and keyboard and custom firmware) to Ericsson ones which integrate pretty much all in one board, though the current ones in use only a small GSM module on the board. Some Nokia ones have an internal battery to keep them running when power is off, which made them pretty popular as a street item as it enabled street vendors to have a phone on the table for selling phone calls.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: April 27, 2016, 12:00:51 pm
content: And that is related to Test Equipment in what way?@mods - please move to "Other Equipment & Products"

author: hgg
author_rank: Frequent Contributor
timestamp: April 27, 2016, 12:06:07 pm
content: >> And that is related to Test Equipment in what way?>> @mods - please move to "Other Equipment & Products"Indeed. Sorry, wrong category...>> Hybrid module is a SLIC Subscriber Line Interface Card, basically all the stuff you need to make a phone line interface, all in one.Interesting!>> Some Nokia ones have an internal battery to keep them running when power is offI was also considering ones with internal battery because they would be a saferalternative for alarm systems notification in case of a power failure. It consumes 3 watts idle.I might connect it with a small UPS.