Low-Power Wide-Area Network
Low-Power Wide-Area Network (LPWAN) is a type of wireless telecommunication wide area network designed to allow long range communications at a low bit rate among connected objects, such as sensors operated on battery.
On one end of the spectrum are cellular standards (3G, 4G) that offer good range and good data rates but also consume lot of power. On the other end are short-range technologies such as Wi-Fi and Bluetooth that consume less power but are limited by range. LPWAN fills the gap in between where a longer range is desired at lower power for sending small amounts of data.
What's the big picture of LPWAN in IoT?
LPWAN is a key driver for Internet-of-Things (IoT) innovation. LPWAN helps connect far-flung sensors and other devices. LPWAN technologies optimize battery life by decreasing power consumption, while networking standards ensure reliable connections at low speeds to support low levels of data use. Thus, LPWAN enables energy-efficient transmission of small data volumes over long distances.
Where does LPWAN fit?
The low power, low bit rate and intended use distinguish LPWAN from a wide area network that is designed to carry more data using more power. LPWAN data rate ranges from 0.3 kbit/s to 50 kbit/s per channel. Cellular networks based on GPRS used to offer this connectivity for carrying M2M data back since the late 1990s. However, operators across the world are shutting down their legacy 2G networks. For example, AT&T announced that its 2G network will be completely shutdown by end of 2016. It's in this context that new LPWAN technologies were invented and sometimes standardized.
- Cellular (e.g. NB-IoT and LTE Category M1) WANs using licensed spectrum.
- Wireless WANs operating in unlicensed frequency bands(e.g. LoRaWan and Sigfox).
What are the different types of LPWAN and how do they compare?
The comparison between any of the LPWANs available is based primarily on coverage, bandwidth, data rate, and number of messages per day. Selecting the right LPWAN is application dependant but typically the goal is to obtain decent rates at minimum power consumption.
- LoRa: Unlicensed sub-GHz spectrum. Chirp Spread Spectrum (CSS) modulation. Can define packet size. Transceiver chip is available only from Semtech Corporation. LoRaWAN the Medium Access Control (MAC) layer for managing communication between LPWAN devices and gateways.
- Sigfox: Proprietary. Unlicensed 868 MHz or 902 MHz bands with only a single operator per country. Coverage of 30-50 km (rural), 3-10 km (urban) and up to 1,000 km (line-of-site). Uplink 150 messages of 12 bytes per day. Downlink 4 messages of 8 bytes per day.
- NB-IoT: Licensed bands including unused 200 kHz bands previously used for GSM or CDMA. Based on LTE resource blocks.
What are the application areas or use cases of LPWAN?
LPWANs are deployed globally in many countries, some even nationwide, to enable services in the Smart metering, Facilities and Logistics management, Wearables, Smart dustbins, Smart street lighting, Industries with connected appliances, Environmental monitoring, and more.
Deployments noted above include both kind of licensed LPWANs (NB-IoT) and unlicensed LPWANs (LoRaWAN, Sigfox). The choice is based on requirement and availability.
How do I select a suitable LPWAN for my application?
Selecting a LPWAN involves understanding and refining the key characteristics and requirements of the IoT application and a particular use case. The following parameters can be considered: Battery life, Capacity, Range, Cost, Licensed/Unlicensed spectrum, Quality of Service, Reliability, and Security.
What LPWAN products are available for prototyping or deployment?
Microchip Technology Inc. have developed its RN2483 LoRa® module, the world’s first to pass the LoRa Alliance’s LoRaWAN™ Certification Program. Some of the operations performed on RN2483 transceiver include:
- radio get bt - reads back current data
- radio get mod - current mode of modulation - LoRa, FSK
- radio get fr - reads back current frequency of transceiver
- radio get power - reads back the current transmit output power
For Cellular LPWANs there are various chip-set vendors available such as Alter Semiconductors, Huawei, Mediatek, etc.
What's that status of LPWAN standardization and interoperability?
3GPP governs and provides specification for the cellular IoT alternates as NB-IoT and LTE-M.
IEEE 802.15.4 is a technical standard which defines the operation of low-power wireless personal area networks (LP-WPANs). It specifies the physical layer and media access control for LP-WPANs, and is maintained by the IEEE 802.15 working group, which defined the standard in 2003. It is the basis for the ZigBee, ISA100.11a, WirelessHART, MiWi, SNAP, and Thread specifications, each of which further extends the standard by developing the upper layers that are not defined in IEEE 802.15.4. Alternatively, it can be used with 6LoWPAN, the technology used to deliver the IPv6 version of the Internet Protocol (IP) over WPANs, to define the upper layers.
Is there anything in place to test and certify LPWAN products?
A new study item titled "Cellular System Support for Ultra Low Complexity and Low Throughput Internet of Things" is proposed in 3GPP. This kick-starts the work on NB-IoT. The document states that 3GPP M2M devices use legacy GPRS but there are competing technologies that provide better coverage and efficiency at lower cost. Document proposes looking into evolving GERAN plus designing a new access system.
- 3GPP. 2016. "Standardization of NB-IOT completed." June 22. Accessed 2018-06-18.
- 3GPP TSG GERAN. 2014. "New Study Item on Cellular System Support for Ultra Low Complexity and Low Throughput Internet of Things (GP-140421)." 3GPP TSG-GERAN Meeting #62, Valencia, Spain, May 26-30. Accessed 2018-06-18.
- Adelantado, Ferran, Xavier Vilajosana, Pere Tuset-Peiro, Borja Martinez, Joan Melià-Seguí, and Thomas Watteyne. 2017. "Understanding the Limits of LoRaWAN." IEEE Comms Magazine, vol. 55, no. 9, pp. 34-40, September 8. Accessed 2018-06-18.
- BehrTech. 2019. "Where Do My IoT Sensors Live? An Overview of the Sub-GHz ISM Bands." Blog, BehrTech, December 10. Updated 2020-07-29. Accessed 2020-07-31.
- Beser, Nurettin Burcak. 2008. "Operating cable modems in a low power mode." U.S. Patent No. 7,389,528, June 17. Accessed 2018-06-18.
- Deutsche Telekom. 2016. "Deutsche Telekom and Huawei implement first standardized Narrowband IoT network worldwide." October 20. Accessed 2018-06-18.
- Gluhak, Alex. 2016. "Low Power Wide Area Networks: The new backbone for the Internet of Things." The Institution of Engineering and Technology, December 15. Accessed 2018-06-18.
- Grantec. 2018. "LTE-M & Narrow Band IoT (NBIoT)." Blog, Grantec, March 8. Accessed 2020-07-31.
- Hernandez, Maria. 2018. "Connectivity Now and Beyond; exploring Cat-M1, NB-IoT, and LPWAN Connections." Blog, Ubidots, July 05. Accessed 2019-01-12.
- Honeywell. 2007. "The History of the Radio Line Card." Honeywell Tech Note, October 04. Accessed 2018-06-18.
- i-SCOOP. 2018. "LPWA network technologies and standards: LPWAN wireless IoT guide." Accessed 2018-06-18.
- LoRa Alliance. 2018a. "LoRaWAN certifications." Accessed 2018-06-18.
- LoRa Alliance. 2018b. "LoRa Alliance™ Authorized Test Houses." Accessed 2018-06-18.
- LoRa Alliance. 2018c. "What is the LoRaWAN™ Specification?" Accessed 2018-06-18.
- LoRa Alliance. 2018d. "About the LoRaWAN™ Specification." Accessed 2018-06-18.
- Lux Research. 2017. "NB-IoT Standard Poised to Take 90% Share of Low-Power Wide-Area Networks for IoT." Lux Research, April 27. Accessed 2020-07-31.
- Mekki, Kais, Eddy Bajic, Frederic Chaxel, and Fernand Meyer. 2018. "A comparative study of LPWAN technologies for large-scale IoT deployment." ICT Express, January 4. Accessed 2018-06-18.
- Melo, Michael. 2014. "What is GPRS and Why Does it Matter for Business?" The Sine-Wave Blog, January 08. Accessed 2018-06-18.
- Microchip. 2015a. "Microchip’s LoRa® Wireless Module is World’s First to Pass LoRa Alliance Certification." Press release, December 17. Accessed 2018-06-18.
- Microchip. 2015b. "RN2483 LoRa Technology Module Command Reference User's Guide." January 27. Accessed 2018-06-18.
- Microchip. 2018. "RN2483: Low-Power Long Range LoRa® Technology Transceiver Module." August 15. Accessed 2019-09-23.
- Prajzler, Vit. 2015. "LoRa, LoRaWAN and LORIOT.io." August 01. Accessed 2018-06-18.
- Ray, Brian. 2017. "The Past, Present, & Future of LPWAN." LinkLabs Blog, March 27. Accessed 2018-06-18.
- Riaz, Saleha. 2016. "DT to demo world’s “first” NB-IoT system." Mobile World Live, October 12. Accessed 2018-06-18.
- Romeo, Saverio. 2019. "5 Key Insights from 350 Smart City IoT Projects." IoT Analytics, March 5. Accessed 2020-07-31.
- Schatz, Glenn. 2018. "An Overview of Narrowband IoT (NB-IoT)." LinkLabs Blog, June 5. Accessed 2018-06-18.
- Schwartzman, Alejandro, and Chrisanto Leano. 2009. "Methods and apparatus for enabling and disabling cable modem receiver circuitry." U.S. Patent No. 7,587,746, September 8. Accessed 2018-06-18.
- Sigfox Build. 2018. "Certifications." Accessed 2018-06-18.
- Song, Yonghua, Jin Lin, Ming Tang, and Shufeng Dong. 2017. "An Internet of Energy Things Based on Wireless LPWAN." Engineering, vol. 3, no. 4, August, pp. 460-466. Accessed 2018-06-18.
- Sornin, N. (ed). 2017. "LoRaWAN™ 1.1 Specification." LoRa Alliance, October 11. Accessed 2020-07-31.
- Sornin, N., M. Luis, T. Eirich, T. Kramp, and O. Hersent. 2015. "LoRaWAN™ Specification." LoRa Alliance, January. Accessed 2020-07-31.
- Weissberger, Alan. 2017. "LoRaWAN and Sigfox lead LPWANs; Interoperability via Compression." IEEE ComSoc Technology Blog, October 25. Accessed 2018-06-18.
- Wikipedia. 2020. "IEEE 802.15.4." Wikipedia, July 2. Accessed 2020-07-31.