The cellular Internet of Things – technologies, standards and performance
With each new generation, cellular systems have evolved to provide support for new services and applications. Currently the fifth generation (5G) radio access network is under development and an important pillar in this project is support for the Internet of Things (IoT). Ericsson has since 3GPP Release 13 contributed to this development with the design of three new technologies for support of massive Machine-Type Communications (mMTC). mMTC provides wireless connectivity for large number of network-enabled devices. This work is covered in detail in the recently published book ‘Cellular Internet of Things – Technologies, Standards and Performance’ authored by me and my colleagues Mårten Sundberg, Y.-P. Eric Wang, Johan Bergman and Joachim Sachs.
- Extended Coverage GSM Internet of Things (EC-GSM-IoT) is in a backwards compatible manner designed based on GPRS/EGPRS. Already GPRS/EGPRS is competitive in the MTC market through its low device cost and global footprint. To these qualities, EC-GSM-IoT adds support for operation in extended coverage, LTE-grade security, power efficient operation and reduced device complexity compared to what EGPRS supports.
- LTE for Machine-Type Communications (LTE-M) is based on a series of low-cost device categories and two coverage enhancement modes. LTE-M was originally designed to make LTE competitive with EGPRS in the MTC market. To do so it supports reduced device complexity compared to LTE, and in addition improved coverage. Its inherent ability to operate as a full-duplex system also gives it an additional dimension in terms of high data rates and low latency compared to the EC-GSM-IoT and NB-IoT half-duplex operation. Read more about LTE-M in a previous blog post, Enhanced 4G LTE coverage for Machine-Type Communications and Internet of Things.
- Narrowband Internet of Things (NB-IoT) is to a large extent a new radio access technology reusing components from LTE. It can operate in a system bandwidth as narrow as 200 kHz and supports deployment both in spectrum originally intended for GSM or LTE. It also supports a minimum device bandwidth of only 3.75 kHz. This design gives NB-IoT a high deployment flexibility and high system capacity. Just as EC-GSM-IoT and LTE-M the technology also supports energy efficient operation, ultra-low device complexity and ubiquities coverage. Read more about NB-IoT in previous blog posts, Narrowband IoT in The Cloud and Narrowband IoT Standardization soon finalized.
In its 10 chapters, our book sets out to go beyond this brief introduction to in detail describe these three new technologies that can be said to define the Cellular Internet of Things. Our ambition is to make these technologies accessible for an audience outside of 3GPP and to make the technical details of EC-GSM-IoT, LTE-M and NB-IoT easily understandable. While the 3GPP standards provide the detailed description of how to implement these technologies our book aims at explaining why certain design choices have been made. This deeper understanding will hopefully ease the task to approach the Cellular IoT technologies in different contexts.
Besides the technical description of the 3GPP design and functionality a significant portion of the book is dedicated to present a unique performance comparison of EC-GSM-IoT, LTE-M and NB-IoT. An overview of the competitive IoT market including a set of proprietary systems is also presented. Common for these systems is the operation in unlicensed frequency bands, and one chapter introduces the most important unlicensed band regulations and explains the differences between licensed and unlicensed bands for IoT connectivity. Finally, our book, elaborates on which technology to choose for deployment under different circumstances.