Board Versions
An important thing to know when buying the LTE CAT-M/NB-IoT shield is which one to choose! The first thing to note is that the shield doesn't operate on traditional LTE but uses LTE CAT-M which is based on the existing LTE networks but the networks must support LTE CAT-M1 in order for the shield to work with that mode. However, SIM7000C and SIM7000E versions can also "fall back" to 2G or 2.5G as appropriate. The shield comes in three version to cater to different parts of the world using the following SIM7000 module variations:
Generally speaking the suffix denotes the region. For example, "A" for "American", "C" for "Chinese", "E" for "European". These regions are called ITU regions and correspond to the highlighted geographical areas shown in the map below:
Photo credit: Map above is from en.wikipedia.org
So generally speaking, if you live in Australia you would pick the SIM7000C; if you live in Greenland you would choose the SIM7000A; and if you live in Norway or Russia you would select the SIM7000E. However, you should also make sure that you have LTE CAT-M1 coverage in your area by checking with the operators in your area. The following map shows some major operators that support CAT-M1 or NB-IoT or both, as of June 2017:
Photo credit: Map above is from www.qualcomm.com
Moreover, these modules are catered to their respective regions in terms of the LTE cellular frequency "bands" that are used in those countries and different cell carriers may use different bands so it's important to know which ones they use in your country because you will want to match up the bands supported by the SIM7000 module and the bands used by certain carriers in your country. The following list shows the bands that each SIM7000 module supports:
- SIM7000A: Quad-Band FDD-LTE B2/B4/B12/B13
- SIM7000C: FDD-LTE B1/B3/B5/B8
- SIM7000E: Tri-Band FDD-LTE B3/B8/B20
It should be noted that the SIM7000A version only supports LTE CAT-M1 and NB-IoT, whereas SIM7000C and SIM7000E are backward-compatible with 2.5G (EDGE) and 2G (GSM/GPRS), although this mode is still being tested by users in Europe and Asia.
Now to find which bands are widely used in your country you can use this online tool by selecting (or searching for) your country. Next, what we are interested in is the "LTE" section of the page. For example, the following image shows the LTE table that appears for the United States:
This table lists the major bands that are used and clicking on each one brings up more info on which regions and which carriers use that band. For example, AT&T uses B2.
Now in order to choose the correct module variant you should check which carrier you will plan on using and see what band they use in your country. From there, see which SIM7000 variant supports those bands. For example, in the United States AT&T uses band B2 so the SIM7000A should work just fine! However, Malaysia uses B3 and B7 so the SIM7000C would be more appropriate (supports B3), whereas in Russia the SIM7000E would be more suitable because they use B3/B7/B20.
Note that this is just traditional LTE though, so you have to further investigate if LTE CAT-M is supported in your area to be sure it will work!
Not all countries support NB-IoT so you should investigate whether your country has it or not since I'm not aware of any "magic map" that shows exact coverage since many carriers are in the process of implementing it and it's rapidly changing. For example, in the United States NB-IoT is expected to be fully deployed sometime in 2018 so for now we have to stick to LTE CAT-M1 alone.
There are inherent differences between the two types. I am not going to write an essay about what those differences are and I don't claim to be an expert on them but here is what I understand:
LTE CAT-M1:
- Uses the existing LTE infrastructure so it's easier for carriers to implement
- Uses less bandwidth and therefore less power than traditional LTE CAT-1, 3, 4, 6, etc.
- Has transfer speeds of about 3x that of NB-IoT
- Has great mobility and can switch from cell site to site easily so is suitable for asset tracking, fleet management, etc.
NB-IoT:
- Uses less power than CAT-M1 while sleeping, great for transmitting once in a while
- Also uses less bandwidth for very minimal data transmission
- Great building wall penetration
- Great for stationary equipment but not good for things like long-distance GPS tracking, etc.
- Has latency time that can vary up to 10s
Based on your needs you may want to choose one or the other!
You can order any of the above versions on my website.
NOTE: This tutorial is meant to be supplementary information only and I leave it up to you to make the final decision on which version to order. I am not liable for any operation failure resulting in selecting an incorrect module and you are fully responsible for researching if this module will work for you! That being said, I do offer prompt technical support and try my best to resolve any issues!