Do I need special M2M Sim cards?
No, any SIM card will work as long as it can get a data connection on the network.
Do The SIM Cards Need To Support Voice and SMS?
The SIM card does not need to support voice calls and technically does not need to support SMS either.
We recommend that the SIM supports SMS in case you need to send a text message to the device to get it on air, but it is not required.
Do I need a Dedicated APN?
No, the SIM cards can use a public APN, or a private APN.
Do i need a SIM card with a static IP address?
No, the SIM card can use a dynamic IP address.
How do I see which SIM card is being used by which device?
A SIM card is uniquely identified by its ICCID (serial number). SIM management systems (eg Jasper) will allow you to search for a SIM using this. Wikipedia link
There are two places that this information is shown in our systems:
Click on the 'Details' link for the device:
On the details page the SIM ICCID is shown:
You can find the SIM ICCID on the 'Advanced' tab of the Asset.
This column is now also available on the "Asset List" report.
- How much data do the devices use per month?
This question comes up often, and depends on a few factors:
- Device Type: the type of device affects how much data is sent and how often
- Device Setup: what is the device setup to do?
- Network: what is the minimum connection charge?
- Network quality: how often is the device forced to reconnect?
Rules of thumb:
- Remora, Oyster and other battery powered devices use about 5MB per month
- Dart, G60, G100 and other powered device use 10-15MB per month:
- Roughly 0.25 MB per month for aiding data
- About 30 kB per hour in-trip, on default settings
- About 2 kB per upload in connection overhead, plus any minimum connection charge
Keep in mind:
- The minimum connection charge has a massive effect on the data usage. Consider Vodacom in South Africa. Each new data connection is charged a minimum of 10KB. The device may send less than 1KB on a heartbeat, but it is still charged for 10KB. With hourly heartbeats, this adds up fast. 10KB per heartbeat x 24 hourly heartbeats x 30 days = 7.2MB. That's just on heartbeats. MTN in South Africa charges 25KB minimum per connection. That's 18MB.
- Dropped connections have an effect: each reconnection could be charged the minimum connection charge.
How Does the Cellular Modem Select a Network?
Digital Matter Cellular products (G52S, G60, G100, Dart, Remora, Oyster, Flexi1) allow the modem to automatically select the network to register on.
The Automatic Network Selection Mode Procedure works in this way:
The Mobile Station (MS) selects and attempts registration on other Public Land Mobile Networks (PLMNs), if available and allowable, in all of its bands of operation in the following order:
- Home Public Land Mobile Network (HPLMN) (if not previously selected);
- Each PLMN in the "PLMN Selector" data field in the SIM (in priority order);
- Other PLMNs with received signal level above -85 dBm in random order;
- All other PLMNs in order of decreasing signal strength.
If successful registration is achieved, the MS indicates the selected PLMN. If registration cannot be achieved because no PLMNs are available and allowable, the MS indicates "no service" to the user, waits until a new PLMN is available and allowable and then repeats the procedure. If there were one or more PLMNs which were available and allowable, but a Location Register (LR) failure made registration on those PLMNs unsuccessful or an entry in a forbidden Location Area Identity (LAI) list prevented a registration attempt, the MS selects the first such PLMN again and enters a limited service state.