Mobile network - 3G, 4G
Mobile network modem installation in DFNEXT camera system type
The DFNEXT / DFNSMALL observatories usually ship without modems as many of them are deployed with WiFi or Ethernet connectivity and different areas of the world require different modems.
If you wish to network your DFNEXT observatory via mobile broadband instead of WiFi or Ethernet you need to source a modem and request a modem installation care package from DFN Camera Help. You will also need to organize a 2FF ("standard") sized SIM with an active data plan.
Recommended modem module types
The recommended embedded modem modules are the 3G/4G capable Sierra Wireless AirPrime MC Series MC7455 (for the Americas, Europe, the Middle East and Africa) and the MC7430 (for Asia Pacific including Australia). In most cases, 3G speeds are more than sufficient. A lot of countries use 800-900MHz 3G for coverage of the country anyway because the lower frequency reaches further, while the higher speeds are demanded and hence 4G/5G technology deployed mostly in metropolitan areas to handle data traffic from all the city dwellers. MC8705 is a very good 3G modem module and nowadays (2018+) very cheap and nearly global option. Good for Europe, Asia, Australia, Africa, possibly South America, unfortunately not really in North America.
Mobile network modem module installation
To install modem module into the DFNEXT camera system you will need a modem converter card - which provides mPCIe to USB conversion, including USB and HF patch coaxial cable/pigtail. Some of the DFNSMALL camera systems have Commel PC , which has a free mPCIe card slot and SIM card slot as well. In such a case you will need only the modem module and HF patch coaxial cable.
DFNEXT Modem Installation - Blue PCB modem converter card
DFN Modem Installation - Green card - Green PCB modem converter card
Mobile network modem configuration
Mobile network configuration in the observatory PC operating system
Checking the quality of reception - signal strength
Mobile signal strength check in the observatory PC operating system
Alternative: Rugged mobile network router
The configuration of the modem card in the embedded linux system can become complicated, especially on remote sites with marginal signal coverage.
The other option for 3G/4G mobile network connection is to use an external router with Ethernet port, ideally some rugged industrial type (wide temperature range and designed for 24x7 operation). In that case, no special configuration of the camera system is required, just connect the router with the camera system using Ethernet cable. The router comes at high initial cost than the modem module, but it is more straightforward to set up as well as more robust for operation.
Easiest solution might be to use a router recommended and supported by local operator for the local climatic conditions. Staying with the same brand we use for modem modules, Sierra Airlink router (for example RC50X or similar https://www.sierrawireless.com/products-and-solutions/routers-gateways/rv50/ ) is a good option.
Important is to make sure it is appropriate region version and supports all the bands/frequencies of the local mobile operator. Since the introduction of 4G/LTE, there is really high number of bands with different frequencies and encodings, and very few truly global devices exist that would support all of them. Typically there are 2-3 sibling versions, for the 3 main regions: EMEA (Europe/Middle East, Africa), Americas, and Asia/Pacific (including Australia). Regarding temperature range, RC50X is rated up to 70C, that should be enough everywhere.