By the end of this comprehensive explainer, you’re going to understand not just the ins and outs of connectivity but the ups, downs and sideways too.
Are You Ready to Be an IoT Connectivity Expert?
There is an unreasonable number of acronyms, abbreviations and initialisms swimming around in the IoT world. It can often feel like they’ve been named to confuse rather than to clarify. We want to demystify IoT. We’re an agnostic connectivity provider, meaning that we never push our customers to one option over another. We’ve got no stake in pushing one type of connectivity. As we’re impartial, we’re the ideal people to explain just what all those terms mean and what their key properties are.
The intention of language should be to communicate and clarify, not to confuse.
Here, We Explain Connectivity Types in Simple English
We’re going to explain what terms such as LPWAN, LoRa, NB-IoT, Cat M1 mean, what their specifications are and list some potential ideal use cases for each one. Hold on to your hats, by the end of this article you’ll be a complete connectivity expert. You’ll know your Cat M1 from your Cat 1 and you’ll be able to explain to your boss the advantages of licensed vs unlicensed cellular networks.
Let’s start with the basics…
IoT connectivity is broadly either cellular (licensed spectrum) or LPWAN (unlicensed spectrum).
Key features: larger data rates, shorter battery life, greater standardization.
Cellular networks tend to be standardized and run by telcos or other large operators.
Cellular covers services such as 2G, 3G, 4G LTE, etc, but the two main flavors of low powered cellular services are NB-IoT and Cat-M1. One of the main differences between them is how data is transmitted when the device is in motion.
They both use cellular towers to transmit information. Cat-M1 operates in the same way as a cellphone, connecting from tower to tower as it moves. NB-IoT devices do not transfer the connection and have to re‑establish a new connection to each new cellular tower.
This means that Cat-M1 is more suitable for IoT applications which are mobile. NB-IoT could be used for IoT devices that move, as long as it was within a defined area, for example in an elevator, where the device would move but not out of the range of a cellular tower.
1G – The G Stands for Generation
This analog technology was the first generation of wireless cellular connectivity.
Maximum speed: 2.4 Kbps
Use case: Voice calls.
2G – The Second Generation, Cellular Goes Digital
The second generation of mobile networks is digital. Calls could be encrypted and the sound quality was much clearer. Currently, many operators are sunsetting their 2G services, meaning that anyone still using 2G needs a plan in place in order to keep their devices connected.
Speed: 9.6 Kbps when the technology was first introduced, 50 Kbps by the end of the era.
Use case: Live transport time updates.
2.5G – A half step forward
When GPRS (General Packet Radio Services) was introduced it offered packet-switched data services, which enabled (in theory) maximum speeds of up to 50 Kbps.
This was considered to be 2.5G, not enough of a step forward to call it the next generation of cellular communication but a significant improvement on prior 2G speeds.
EDGE (Enhanced Data Rates for GSM Evolution) was an enhancement to GPRS in order to offer higher data speeds. Many networks introduced EDGE alongside network upgrades on their radio when deploying 4G services.
With EDGE, there is a theoretical maximum transfer speed of 384 kbit/s.
3G – Third Generation Cellular Technology Enabled Video and Mobile Internet
The third generation of cellular connectivity was a big jump in speed, enabling people to surf the web or watch videos on their phones for the first time. IoT applications that required a video display were now possible.
Maximum speed: 384 Kbps –
Initially, the maximum speed of 3G was 384 Kbps. Then came HSDPA (High-Speed Downlink Packet Access) and HSPA (High-Speed Packet Access) services, which offered speed improvements.
The current maximum 3G speed is 3 Mbps.
Use case: Digital signage, ATMs, kiosks.
3G offers much the same service as Cat-1 and it is likely that Cat-1 will replace 3G once it is sunsetted.
4G – Higher speeds open up a range of new possibilities
Maximum speeds: 4G LTE 150 Mbps and 4G LTE+ up to 300 Mbps.
Use cases: Vending machines, digital signage, CCTV, and HVAC.
5G – The future …
Although 5G does currently have some limited availability we’re going to keep filing this under future technology for now.
Maximum (promised) speeds: 1 Gbps.
Theoretical use cases: Telesurgery, augmented reality, autonomous vehicles.
Pros: Super fast, low-latency, high-bandwidth.
Cons: Costs, practicality, coverage.
NB-IoT (narrowband IoT)
Maximum speed: 250 kbps.
Range: 1 km (urban), 10 km (rural).
Use case: Smart metering.
Pros: Low energy use means battery life is extended. It is cheaper than Cat-M1.
Cons: Although it supports non-static IoT applications, there is no cellular handover between cells. So data communications would be disrupted.
Maximum speed: 1 Mbps.
Use cases: Connected health such as outpatient monitoring, personal/asset trackers.
Pros: High data rates, better suited to IoT applications which move, voice data transfer is possible.
Cons: More expensive.
Maximum speed: 10 Mb/s downlink and 5 Mb/s uplink.
Use cases: Digital signage, ATMs, kiosks.
Pros: Cat-1 is already standardized.
We should note here that, despite its confusing name, Cat-0 is an upgrade from Cat-1.
Maximum speed: 1Mbs peak downlink and uplink rate.
Use case: Live transport time updates.
Pros: Lower cost and lower power requirements.
Cons: Lower-power requirements are due to reduced functions and lower data rates.
Unlicensed LPWAN (low power wide area networks)
Pros: Long battery life, covers a wide area, can be more cost-effective to deploy.
Cons: Transmits a very low amount of information. Requires network coverage.
There are two principal types of unlicensed LPWAN, LoRa (Long Range) and Sigfox.
Maximum speed: Between 250bit/s and 11kbit/s in Europe uplink (downlink is lower).
Range: Several kilometers.
Use case: Remote monitoring of energy infrastructure.
Pros: Long range, long battery life, low cost.
Cons: Low bandwidth, you may have to set up your own network.
Range: 10 km (urban), 40 km (rural).
Use case: Asset tracking, predictive maintenance, smart metering.
Pros: Long battery life, wide coverage area, lower costs.
Cons: It requires a Sigfox licensed network, which is not available everywhere. However, Sigfox has launched its Access Station Micro, which will enable people to add coverage where there is no existing Sigfox network.
So, there you have it, our guide to IoT connectivity technologies. We tried to make it as complete as possible (with the sad knowledge that a new type of connectivity will probably come along five minutes after we publish it).
The most important thing to remember about IoT connectivity is that there is no ‘one size fits all’ answer. Which is the right type of connectivity for me? Well, it depends on your IoT application. Does it rely on batteries? Will it need to transfer large amounts of data? Where is it located? Does it move?
All IoT connectivity standards have pros and cons. When selecting the type of IoT connectivity you want it is important to carefully consider which of the pros and cons are relevant to your application.
At Pod Group, we’re proud to be agnostic IoT connectivity providers. That means that we’ll provide you with the best connectivity for your device. We don’t play favorites. Our in-house IoT connectivity experts will give you real advice you can trust.