Should my IoT device have fallback?

In most areas, particularly in more urban settings, network operators have made system upgrades to support 4G LTE or 5G devices. Smaller network operators in more rural areas, however, may have older equipment that isn’t compatible with the latest technology. Unless they make investments into newer generations of networking equipment, your device won’t have coverage in that location unless it’s compatible with that older network technology. This is the concept of “fallback,” or the ability of your cellular device to communicate with older network systems like 3G and even 2G. But how do you know if it is necessary and feasible for your device? Let’s explore the issue further.

Cellular network evolution

1st Generation: When the first generation of cellular networking was introduced, it was for voice phone calls only, and the calls themselves were of low quality. This was basically just analog FM radios. 

2G: With 2G, call quality improved, and basic data and text functionality (SMS and MMS) was introduced.

3G: When 3G was introduced, so was the ability to access data almost anywhere – and with four times the capabilities of 2G. Network speeds also gradually increased over time, as well as an increase in the number of devices or users per section of the radio spectrum.

4G: 4G LTE (long term evolution) brought high-quality streaming at faster speeds. This was a pivotal development, as it brought the ability to support newer technologies, such as IoT devices.

5G: With 5G NR (new radio), we have faster data speeds, greater network bandwidth to support more users in the same area, and lower latency to support time critical applications like autonomous vehicles. More devices can utilize a smaller piece of the spectrum, and the ability to launch mass IoT deployments improved significantly.

The situation for MNOs

Smaller mobile network operators (MNOs) have incentives to upgrade their networks to be 4G or 5G compatible. They normally have contracts with the big national MNOs to support new voice and data network technologies as they are deployed by the big carriers. The problem comes in where technologies diverge between IoT and general consumer use. 4G and 5G include specifications for category M1, NB1, and NB2 cellular radios. These are the lowest cost cellular devices available and they also tend to have the lowest power consumption. They’re designed from the ground up for low cost IoT applications. This is the “millions of devices” part of 5G you may have heard of. These devices use separate spectrum from what’s used by a regular cellular consumer device or higher speed embedded radio modules. 

Smaller MNOs have a direct incentive to support your new iPhone or Samsung tablet because that’s the majority of their customers. When it comes to specialized IoT devices that use M1 or NB however, smaller rural MNOs often lag the big national MNOs simply because they don’t have a pressing economic incentive to create that support.  

In some cases, the expense of doing these network upgrades could bankrupt a small MNO. This is where roaming agreements with larger MNOs come into play. Roaming agreements between national and smaller MNOs may have clauses that require smaller operators to upgrade to the next generation networking technology, but the larger operator will offer financial incentives or other arrangements to help make the transition possible. Many of these agreements are fairly old and have not been updated to include IoT related capabilities.  In rare cases, often in more remote regions, these agreements don’t exist. In either case the smaller MNOs may not choose to upgrade their networks to support M1 or NB IoT technologies.

Should your device have cellular network fallback?

There are a few points to consider including the following:

• Is communicating on 2G or 3G channel sufficient speed for what your device does? If you need a live high bandwidth network feed, streaming video for example, 2G or 3G fundamentally won’t work, so there’s really no point in having fallback.
• What will the data costs entail? Your plan might be optimized for transferring large amounts of data at a low cost, as you can easily do with 4G or 5G. If you are roaming, your data costs can go way up. This can result in fallback being cost prohibitive.
• What percentage of your devices will be used in areas with the latest generation network coverage? If your devices are to be used in North America, for example, it may not be a worthwhile investment. The biggest issue in these geographic areas is dead zones, which will not have 2G or 3G coverage either. But in China or Eastern Europe, it might be a different story. These areas still have massive deployments of 2G and 3G, so fallback becomes more important for maximum coverage capability.
• Do you have a limited power budget? To be the most power efficient, it is best to run IoT devices on 4G networks and up. 2G or 3G could simply be too power hungry to meet your device’s mission requirements.
• Are there newer network features your device requires? 4G and 5G add significant power consumption enhancements, lower network latencies, and other features.
• Are you willing to add additional cost? By adding 2/3G capabilities, you will also drive-up design cost, testing and certification costs and timelines. Adding two 2G bands, for example, could potentially add $2,000 more in cost per band, plus the additional calendar days needed to test your device. Then, you would also have to test it again for the four bands needed for 3G capabilities, which in turn further drive up costs and time.

Industry examples

Here are a few examples of industries that might think to add fallback capabilities:

• Ground transportation – For trucks and railroads operated in North America, you will either have areas of 4G+ coverage, like on most major freeways, 2/3G coverage in rural areas or no coverage at all in very remote areas. 2/3G can help fill in some of those gaps. If you need live immediate information from that vehicle, that’s a situation where fallback might make sense. If you can wait a few minutes for the vehicle to get back into coverage, fallback will cost you more than it’s worth.
• Ships and freighters– For ships, with no cell coverage except very near a coast, it won’t matter if you have fallback. Coverage will only be available at port and the vast majority of port cities will have 4G+ at this point.
• Farm equipment – Rural heavy equipment for agriculture, forestry, and construction can be one of the most difficult applications to deal with. It’s not uncommon to have no coverage at all in these situations but, unlike typical trucking or rail applications, the vehicle in question can spend long periods of time in the same area with no communication. This is where satellite communication can offer a solution.

Conclusion

The decision whether to have fallback coverage for your IoT device really depends on the specifics of your business. At F3, we can help to evaluate your situation to determine if 2/3G fallback is necessary to meet your business needs and customer demands as well as other options available to get the coverage you need.