Internet of things (IoT) is a very hot topic but to understand it, one needs to understand also the IoT cellular connectivity terms and standards.
According to the World Economy Forum (WEF), IoT is likely to be the next major value opportunity across industries. The number of connected devices, which enable and drive business models in the IoT, could reach 30 billion till 2025, or according to other estimations could even reach 50 billion. This means that connectivity is a major enabler with high value.
Although part of this connectivity will be served by short-range radio technologies like Wi-Fi and Bluetooth, a significant proportion will be enabled by Wide Area Networks (WANs) that are facilitated mostly by cellular networks. Operators are in an excellent position to capture a share of the IoT market value, as they are largely responsible for wireless connectivity in global scale.
Thus, to be able to understand and follow-up IoT, one should understand the terms and standards used to describe the IoT cellular connectivity.
IoT Cellular Connectivity Terms & Standards
3GPP – The 3rd Generation Partnership Project (3GPP) is a collaboration between groups of telecommunications associations, known as the Organizational Partners. The scope of 3GPP is the development and maintenance of cellular technologies, including GSM, WCDMA, LTE and the future 5G
Cellular Technologies – are the 3GPP technologies like GSM, WCDMA, LTE and the future 5G. All these operate on licensed spectrum and historically have targeted high-quality mobile voice and data services. They are now being rapidly evolved to form an attractive solution to the emerging low power wide area (PLWA) applications.
LPWA – Low Power Wide Area is considered the dominant technology for IoT applications and covers / enables the following four IoT requirements: low device cost (less than 5 USD), 10+ years battery life, better coverage (indoor), scalability to handle millions of devices from a single cell. Two types of LPWA exist: the licensed LPWA (NB-IoT) by 3GPP and the unlicensed LPWA (SIGFOX, LoRa), which is proprietary.
MTC – Machine-Type Communications is the term used in 3GPP to refer to Machine-to-Machine (M2M) communications, that is, “machine” devices talking to each other through mobile networks or locally.
EC-GSM – Extended Coverage GSM is an extension of GSM for the IoT applications that can be implemented with only software updates to the cellular base stations. It provides coverage improvements of up to 20dB with respect to GPRS on the 900MHz band, and can handle up to 50.000 devices per cell on a single transceiver. EC-GSM can be used to provide IoT application e.g. in smart cities where only 2G networks (GSM) are deployed. As GSM is the current dominant cellular technology around the world, it’s significance for IoT is big.
eDRX – Extended Discontinuous Reception is a functionality that enables longer (10+ yeras) battery life for IoT modules. Initially part of EC-GSM is now a separate 3GPP item that improves the idle time behavior.
LTE-M – LTE for Machine to machine communications, is an extension of the LTE cellular technology developed for IoT applications. It consists of Cat 1, Cat 0 and Cat M. LTE-M supports Power Saving and eDRX to extend battery life of IoT modules to 10 years or more.
NB-IoT – Narrow Band IoT is being developed in parallel with LTE-M and is specifically tailored for ultra-low-end IoT applications as it uses only 200kHz bandwidth. NB-IoT can be deployed with a software update to LTE base stations. Due to it’s specifications it rivals the module costs of unlicensed LPWA technologies.
Cat-1 – Category 1 – was included in the LTE specifications early on for M2M applications. With Cat-1, it is possible to achieve 10 Mbps downlink and 5 Mbps uplink channel data rates. It has become an attractive, early alternative for IoT applications over LTE, because it is already standardized. Cat-1 can also meet requirements of a wider range of MTC applications (not just ultra-low-end) thus being a complementary solution to Cat-M1 and also to NB-IoT.
Cat-0 – Category 0 – is a newer standardized category in LTE for IoT use cases, and provides 1 Mbps data rates for both up- and downlink. Cat-0 modules have reduced complexity by up to 50% compared to Cat-1 thus lower cost.
Cat-M1 – Category M1 – is to the current work of LTE, where up to 75-80%complexity reduction techniques on top of the ones for Cat-0 are standardized. The most important additional feature is the possibility to operate with 20 MHz bandwidth with a maximum channel bandwidth limited to 1.4 MHz. A further helpful feature for many IoT use cases is coverage enhancements of more than 15 dB, which can, for example, be enabled to reach the UEs behind the thickest walls in the cell.