Low Usage Data Only SIM

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k14

629 posts

Ultimate Geek

#171216 10-Apr-2015 08:10

I have tried searching for this but haven't been able to work out any information.

For work I am installing a communication network using a GPRS modem to transmit data (flow from a river) back to a central point. I have investigated various options including stand alone 2.4Ghz network but seeing as direct line of site is not available I would have to install two repeaters on private land (quite costly). So using a GPRS modem is potentially the best solution. However, one of the main aims of the project is to setup a low (or zero) cost solution. Do Vodafone/2 Degrees/Spark offer a low cost sim option? There needs to be two sim cards, one that receives and one that sends and the data use will be very minimal but very frequent. Something along the lines of 10-50mb per month but data sent every 5 minutes.

Does anyone have any info or advice on this?

shk292

2858 posts

Uber Geek

Lifetime subscriber

#1280211 10-Apr-2015 09:14

Why 2 SIMs? Surely you're going to send the data to the internet, from where you can retrieve it on any machine? I think you'd struggle trying to set up a point to point connection using mobile devices, because you won't be able to control the IP addressing.

scheduler

264 posts

Ultimate Geek

#1280229 10-Apr-2015 09:28

Spark $3 for 30MB of $6 for 60MB

k14

629 posts

Ultimate Geek

#1280240 10-Apr-2015 09:33

shk292: Why 2 SIMs? Surely you're going to send the data to the internet, from where you can retrieve it on any machine? I think you'd struggle trying to set up a point to point connection using mobile devices, because you won't be able to control the IP addressing.

It is a closed loop point to point link with both ends on GPRS. No computers involved only PLC's to do control of a related equipment. According to the supplier only Vodafone's network supports the equipment and I would prefer no pre pay option. That way someone has to remember to top up the account every year or however long it takes for the money to expire. Ideally a monthly billed plan would be the best option.

This is the hardware I am planning on using https://www.phoenixcontact.com/online/portal/ca?urile=pxc-oc-itemdetail:pid=2313106

Yabanize

2350 posts

Uber Geek

#1280256 10-Apr-2015 09:46

According to the specs it supports GSM 900mhz which means it will work on 2degrees too. This device is 2g only, so it won't work on Spark or Skinny (3g only)

Aredwood

3885 posts

Uber Geek

#1287225 19-Apr-2015 14:46

You would want to talk to Vodafone and confirm that you can send data directly between 2 numbers. As there will be a CGNAT router between the cell towers and the internet. So the data may have to go through 2 NAT routers to get between both modems. Is mobile data the only internet connection available at the central point? As you may need to ask Vodafone to create a private APN for you. So you can get a point to point connection across the cell network.

Does the data need to be sent / received in real time? If not then sending via SMS would probably be far better.

Otherwise consider setting up a VPN server on a non mobile data internet connection. Stick a VPN client at the remote site. And have it connect to the server. Restrict the IP address ranges that the server listens on to the Vodafone ranges. And if the central point only has mobile data available. Stick a VPN client there as well. And have both clients connect to the server in a 3rd location.

Whatever you do - Don't use the "direct" APN. As that will bypass the CGNAT router and place your devices directly on the internet. Meaning they will get fingered by the port scanners. And script kiddies will try to hack or brute force your passwords. Meaning your equipment will get taken over. And / or you will get a very large data bill. (Imagine if someone tries DDOSing your IP, how quickly that will run up the mobile data bill).

Talkiet

4793 posts

Uber Geek

Trusted

#1287265 19-Apr-2015 16:01

You need to VERY carefully examine the billing mechanisms of the ISPs. I _DON'T_ know the specifics of any of the SPark/VF/2D plans, BUT I have looked into this in the past and a couple of years ago at least there was a significant amount of overhead data charged on all telcos for tiny packet flows. Due to the way the networks and billing systems work, minimum traffic accounting increments are NOT bytes, they are kilobytes at least. This means that if you send a thousand tiny (100byte?) packets that each kick off new sessions (that's a point I'm vague on) you will see traffic accounting saying you sent a lot more than 100 Kilobytes.

I wanted this for an IP based car GPS tracker but at the time the frequency of heartbeats and accounting of VF (specifically although I think Spark is similar) made it a silly idea.

I think there are some telemetry plans available from VF (or used to be) but you're not going to get to zero or near zero cost.

Cheers - N

Please note all comments are from my own brain and don't necessarily represent the position or opinions of my employer, previous employers, colleagues, friends or pets.

scottr

262 posts

Ultimate Geek

Trusted

#1288815 21-Apr-2015 21:46

You'll want to look up M2M, it's starting to become all the rage.

http://www.telecomwholesalelabs.co.nz/site/page/view/main
https://www.vodafone.co.nz/m2m/

Or look into 2 degrees prepay with rollover data.