The proliferation and popularity of IoT devices has led to the rise of low-power, wide-area network (LP-WAN) options such as SigFox, LoRa, and Weightless.
Traditional cellular options, such as 4G and LTE networks, consume too much power. Furthermore, they are not suitable for applications where small amounts of data are rarely transmitted, such as meters for reading water levels, gas consumption or electricity consumption.
Cellular IoT attempts to respond to the ongoing search for better low-power, long-range applications.
Cat-1
Cat-1 represents an early push to use existing LTE networks to connect IoT devices. While the performance isn’t as good as 3G networks, it’s an excellent choice for IoT applications that require a browser interface or voice. The main attraction is that it is already standardized and, more importantly, it is easy to transition to Cat-1 networks. Experts predict that as 3G technology, and eventually 4G technology, becomes obsolete, Cat-1 (and Cat-M1) networks will replace it.
Cat-0
For LTE-based IoT networks to be successful, they need to have the following characteristics:
1) Long battery life;
2) Low cost;
3) Support a large number of devices;
4) Enhanced coverage (eg, better signal penetration through walls)
5) Long range/broad spectrum.
Cat-0 optimizes cost by eliminating features that support Cat-1’s high data rate requirements (dual receiver chains, duplex filters). While Cat-1 replaced 3G, Cat-0 was the protocol that laid the foundation for Cat-M to replace 2G as the cheaper option.
Cat-M1/Cat-M/LTE-M
Cat-M (officially known as LTE Cat-M1) is generally considered a second-generation LTE chip built for IoT applications. It completes the cost and power reductions that Cat-0 initially laid the foundation for. By limiting the maximum system bandwidth to 1.4 MHz (as opposed to Cat-0’s 20 MHz), Cat-M has specific use cases in LPWAN applications, such as smart metering, where only small amounts of data transmission are required.
But the real advantage of Cat-M over other options is this: Cat-M is compatible with existing LTE networks. That’s good news for carriers like Verizon and AT&T, because while connecting Cat-M to LTE networks requires software patches, they don’ t have to spend money building new antennas. Verizon and AT&T’s existing customer base will likely conclude that Cat-M is by far the best choice. Finally, 5G and LTE technologies will almost certainly coexist in the 2020s, so Cat-M’s backwards compatibility is a big plus.
NB-IoT/Cat-M2
NB-IoT (also known as Cat-M2) aims to be similar to Cat-M. However, it uses DSSS modulation instead of LTE radio. As a result, NB-IoT cannot operate in LTE bands, which means providers need to incur higher upfront costs to deploy NB-IoT.
Still, NB-IoT is touted as a potentially cheaper option because it eliminates the need for a gateway. Other infrastructure typically has gateways that aggregate sensor data and then communicate with primary servers. (Here is a more in-depth explanation of gateways). However, with NB-IoT, sensor data is sent directly to the main server. Therefore, Huawei, Ericsson, Qualcomm and Vodafone are actively investing in commercial applications of NB-IoT. Sierra Wireless predicts that NB-IoT and LTE-M will be available in many regions around the world by the end of 2018.
EC-GSM (formerly EC-EGPRS)
EC stands for Extended Range. EC-GSM is an IoT-optimized GSM network, and 80% of the world’s smartphones use the wireless protocol. As the name suggests, EC-GSM can be deployed in existing GSM networks – a huge advantage in terms of practicality and modularity, as a simple software can enable EC-GSM connectivity in 2G, 3G and 4G networks. EC-GSM also has specific use cases in non-Western regions such as Malaysia, African and Middle Eastern countries, where 2G remains the popular standard. Ericsson, Intel and Orange are said to have completed field testing of EC-GSM earlier this year. However, EC-GSM doesn’t generate the same buzz as Cat-M or NB-IoT.
Keywords: serial port control module