LPWAN

The technology term “Low Power Wide Area Network” is abbreviated with the letters LPWAN.

The German term ‘Niedrigenergweitverkehrnetz’ sounds rather difficult. For this reason, the English abbreviation LPWAN has become more established. LPWAN stands for network protocols that connect low-energy devices such as battery-powered sensors to a server via a wireless network. The network consists of end devices called nodes, and gateways, which act as base stations. The gateways forward the data collected by the end devices to the network server for evaluation. The end devices are thus monitored by the network server.

The physical connection between end devices and gateways can be established via license-free frequencies or mobile radio frequencies. LPWAN is available on the market both as an unlicensed radio network (LoRaWAN, Sigfox and mioty), and as cell-based narrowband technology (NB-IoT, LTE-M). An LPWAN solution can be implemented proprietarily, or on the basis of LPWAN standards. It can support public or private networks.

LPWAN technologies offer flexible architecture options, which will be explained in some of the following sections. The choice of network architecture depends on the specific requirements of the application, including range, scalability, energy efficiency, and complexity.

Asset tracking of construction machinery is a good example of how LPWAN can demonstrate its capabilities. LPWAN can send data packets over long distances, even in rural or remote areas, and without the need for a continuous connection to a mobile network. As already explained, the spectrum used (radio frequency ranges) can be licensed or unlicensed.

LPWAN devices also score highly when it comes to energy efficiency. They require little energy and therefore have a long battery life. This is particularly important for outdoor applications where it can be difficult to replace or recharge batteries on a regular basis. LPWAN is considered robust and weather resistant, which is crucial for outdoor applications.

The exact positioning of assets with LPWAN does not usually achieve the same accuracy as the mobile network, BLE or UWB. However, RTLS and positioning accuracy can be improved through triangulation or the use of additional sensors. As with all wireless transmission technologies, the data generated via LPWAN must also be secured. Numerous other use cases for LPWAN technologies are described in the following sections. LPWAN is a key technology for the Internet of Things (IoT).

The global LPWAN market is set for strong growth. The British market research institute “The Business Research Company” forecasts an increase in market volume of over 53 percent between 2023 and 2028. This development is being driven by the increasing demand for LPWAN connectivity over long distances. The most important application areas include the digitalization of agriculture, smart city applications such as smart metering and fleet management, the digitalization of the construction industry, and the digitalization of the energy industry.

The choice of the right technology depends on the specific use cases and the requirements in terms of range, energy consumption, data rate, and infrastructure. While LoRaWAN and Sigfox score with their simple implementation and long range, NB-IoT and LTE-M offer advantages by using existing mobile networks and higher data rates. Wi-SUN and Weightless offer flexibility and extended network options, but are less widespread.

In addition to the wireless technologies LoRaWAN, NB-IoT, Sigfox, LTE-M, Weightless, Su-NIN, and mioty that are described in more detail, there are also the two standardized LPWAN technologies Symphony Link and Wi-Fi HaLow. Furthermore, RPMA (Random Phase Multiple Access) and WavIoT NarrowBand Fidelity (WavIoT NB-Fi) are offered by LPWAN providers without a published standard.

LoRaWAN is an open protocol based on LoRa radio technology. Compared to other LPWAN technologies, it is characterized by a long range and low energy consumption. In rural areas, LoRaWAN achieves a range of up to 40 kilometers under optimal conditions. In urban areas, the range is around two kilometers. Further advantages are the good building penetration and the open protocol. In contrast to Sigfox or NB-IoT, a LoRaWAN network can be set up independently of a provider as a proprietary solution. One disadvantage is the limited data rate, which can lead to interference when using license-free frequency bands.

Semtech Corporation started the introduction and commercialization of LoRaWAN in France, in 2012. The LoRa Alliance was founded in 2015. The first tests and pilot projects with LoRaWAN networks also started in 2015.

Sigfox is a proprietary LPWAN protocol based on ultra-low-band radio technology. Ultra-narrow-band radio technology enables the transmission of data in very narrow frequency bands. This increases the range and reduces energy consumption (battery life of several years). In rural areas, the range can be up to 50 km. In cities, the range is between three and 10 kilometers. This simple LPWAN protocol also enables cost-effective devices.

Sigfox is only suitable for transmitting small volumes of data (up to 12 bytes per message and a maximum of 140 messages per day). Due to the limited data rate and message size, Sigfox is not suitable for all IoT applications. Although Sigfox operates a global network, network coverage varies by region. In some areas, coverage may be insufficient.

Sigfox was founded in France, in 2010. Today, Sigfox builds on a global network that is available in numerous countries worldwide. The founders of Sigfox were Ludovic Le Moan and Christophe Fourtet.

NB-IoT is a cellular LPWAN technology that is operated in existing 5G or LTE networks. By using the existing mobile network infrastructure and standards, the costs for setting up the system are extremely low and NB-IoT can benefit from the network security of the respective mobile network operators.

NB-IoT offers wide coverage, low energy consumption (battery life of up to 10 years) and supports small data volumes. As this wireless technology has high building penetration, it is very suitable for urban areas. The range in cities is up to 10 km. In rural areas, the range is around 15 kilometers.

NB-IoT also has a higher energy consumption compared to other LPWAN technologies, depending on mobile network operators and their coverage.

Development work on NB-IoT began in 2014. The 3rd Generation Partnership Project (3GPP) published the first official specifications in 2016. Pilot projects were launched from 2017.

In addition to NB-IoT, LTE-M is another cellular LPWAN technology that can be operated in 5G or LTE networks. Backward compatibility with 5G networks, the possibility of coordinated frequency usage, and integration into the 5G core network enable seamless connectivity and improved performance for LTE-M devices. This also applies to NB-IoT. The cellular functionality ensures lower implementation costs and offers the advantage of security standards.

LTE-M offers moderate data rates of up to 1 Mbit/s downlink and uplink. Compared to NB-IoT, the data rates are also higher, with a higher energy consumption. LTE-M uses narrower bandwidths (1.4 MHz) to improve efficiency and maximize network capacity for IoT devices.

The battery life of LTE-M (LTE Cat-M1) devices can last several years, often up to 10 years, under optimal conditions and with economical use. Battery life can be maximized by using power saving modes such as PSM and eDRX, as well as optimizing the data transmission frequency and signal quality.

The specifications for LTE-M were standardized in 2016 as part of the 3GPP (3rd Generation Partnership Project) Release 13. The first LTE-M networks were introduced by various mobile network operators in 2017.

Weightless is a family of open LPWAN standards, including Weightless-P, Weightless-N and Weightless-W. They differ in terms of network architecture and modulation method. What they have in common is the energy efficiency and long battery life of the end devices. This is achieved through efficient modulation techniques and energy-saving modes. Weightless uses license-free frequency bands to take advantage of cost savings and global availability.

Despite challenges such as interference and limited bandwidth, Weightless also offers benefits for IoT applications that require a cost-effective, long-range, and scalable communications infrastructure. Weightless has good building penetration and supports bi-directional communication. Compared to other LPWAN technologies, Weightless is not as widespread. The introduction of the first Weightless versions began around 2013.

Wi-SUN supports both license-free and licensed frequency bands. Wi-SUN is an open, international standard for wireless mesh networks. The open standard enables interoperability between devices from different manufacturers. This is an advantage for the integration and expansion of the network.

Wi-SUN uses a meshed network architecture in which each device acts as a node and can forward data via neighboring nodes. Wi-SUN networks are therefore highly scalable. This increases the range and reliability of the network. However, implementation and management is complex and not as energy efficient as other LPWAN technologies. Wi-SUN protocols are energy efficient, which enables a long battery life for the devices and reduces operating costs.

Japan is a leading user of Wi-SUN, especially in the field of smart grids. The city of Tokyo has introduced Wi-SUN technologies to improve urban infrastructure and environmental monitoring. In India and China, there are an increasing number of pilot projects that use Wi-SUN for urban applications and utility services. The Wi-SUN Alliance was founded in 2012.

mioty is an LPWAN technology developed by the Fraunhofer-Gesellschaft and promoted by the Mioty Alliance. It is based on an open standard that was published in 2020 by the European Telecommunications Standards Institute (ETSI) as the Technical Specification TS 103 357. It is based on an innovative approach called Telegram Splitting Multiple Access (TSMA), which enables particularly robust and scalable data transmission.

Telegram splitting means that each message is divided into several small telegrams that are sent at different frequencies and time intervals. This increases robustness against interference and improves the reliability of the transmission.

mioty can process millions of messages per day, making it ideal for large-scale IoT deployments. Similar to other LPWAN technologies, the battery life of the end devices is very long, since mioty is energy efficient. The range is up to 15 km in rural areas. In urban environments, mioty can transmit information up to several kilometers.

The ecosystem around mioty is still under development, which means that there are still fewer hardware and software solutions and providers that support mioty, compared to more established LPWAN technologies. Overall, however, the number of projects that support mioty is increasing. Especially in the area of work safety.

LPWAN are network protocols that connect low-energy devices such as battery-powered sensors to a server. For sensor manufacturers, it is important to select an energy-efficient microcontroller. It must be able to process and transmit sensor data. It must also support different sleep modes to minimize energy consumption.

The LPWAN network is made up of end devices called nodes, and gateways, which act as base stations. The LPWAN gateways forward the data collected from the end devices to the network server for evaluation. The end devices are thus controlled by the network server. The physical connection between end devices and gateways can be established via license-free frequencies or mobile radio frequencies. As already mentioned, LPWAN is available on the market both in the unlicensed spectrum (LoRaWAN, Sigfox and mioty), and as cellular-based narrowband technology (NB-IoT, LTE-M).

LPWAN technologies that are actively represented on the market in Europe include NB-IoT (Narrowband-IoT), LoRaWAN (Long Range Wide Area Network), Sigfox, mioty, and LTE-M (Long Term Evolution for Machines). In Germany, the use of LoRaWAN, NB-IoT, and LTE-M is predominant. mioty is relatively new. Sigfox is represented throughout Europe, especially in its country of origin, France.

LPWAN is the key technology for the Internet of Things (IoT). Data transfer is energy-efficient, cost-effective, and takes place over long distances. The operational side (OT) of LPWAN is already well covered and numerous products are available. These are definitely some good reasons for using LPWAN. The following examples show the numerous solutions that have an advantage over mobile radio or 5G (How does 5G work?) via LPWAN.

• Real-time monitoring of parking spaces to show drivers free parking spaces and reduce congestion ► Smart Parking
• Integration of sensors to monitor air quality, temperature, humidity, and noise pollution and transmission of the data to central systems ► Healthcare
• Intelligent control of street lighting and light sources based on presence, or time of day to save energy ►Sustainability

• Sensors monitor soil conditions in real time to optimize irrigation and fertilization ► Crop Protection
• GPS trackers monitor the health of animals. ► Animal Welfare
• Distributed weather stations that provide accurate and local weather data to plan agricultural activities. ► Decision Support
• Monitoring and protection of wildlife through GPS tracking and environmental sensors. ► Wildlife Tracking

• Tracking freight and containers over long distances. ► Asset Tracking, Digitalization of the Supply Chain, and Fleet Management
• Monitoring the temperature and humidity of temperature-sensitive products during transportation ► Temperature Monitoring
• Automated inventory monitoring and reordering in warehouses. ► Warehouse Management

• Remote reading of water, gas, and electricity meters for accurate and timely billing ► Smart Metering
• Integration of sensors for detecting leaks or faults in water and gas pipes. ► Condition Monitoring and Work Safety

• Health monitoring of patients with wearable devices that send vital data to medical staff ►Wearables
• Integration of sensors that continuously collect and transmit data on the condition of patients ► Safety

• Monitoring the condition of machines and systems in order to carry out predictive maintenance. ► Condition Monitoring, Factory Automation and Predictive Maintenance
• Sensors for monitoring environmental conditions in factories and warehouses to ensure optimum operating conditions. ► Industry 4.0 and Safety

• Monitoring of heating, ventilation, air conditioning, and other systems to optimize energy consumption. ► Facility Management, Temperature Monitoring and Condition Monitoring
• Integration of sensors for smoke, fire and burglary for central monitoring ► Security

• Monitoring and control of solar and wind power plants to optimize energy production ► IoT Asset Management and Condition Monitoring

• Monitoring and control of household appliances, lighting, and security systems. ► Smart Home

• Sensors for monitoring natural disasters such as floods, earthquakes, and forest fires that send early warnings. ► Safety

• Low energy consumption of end devices
• Wide range of communication
• License-free use
• Efficient bandwidth utilization
• Simplified network topology
• Network scalability and capacity expansion
• Low acquisition, installation, and operating costs
• Robustness for M2M communication

In addition to the star-shaped network architecture, various other network architectures can be used in LPWANs. These include mesh network architectures, tree network architectures, hybrid network architectures, point-to-point and point-to-multipoint, or star-of-stars architectures.

These architectures are suitable for different use cases and requirements. The following list shows the most important architectures.

In a mesh network, the devices communicate not only with a central base station, but also with each other. Each device can receive data from other devices.

Advantages

• The range is high as data can be forwarded across multiple devices. This increases the overall range of the network
• The mesh network is reliable as the data is forwarded via alternative paths if one path fails
• Scalability is almost unlimited, as new devices are simply supplemented by additional relay nodes

Disadvantages

• Managing and configuring a mesh network is more complex than with a star-shaped architecture
• Devices that act as relay nodes have a higher energy consumption

Examples

• Zigbee, Thread, Wi-SUN, and some solutions with LoRaWAN

This architecture is a variant of the mesh network in which the devices are arranged hierarchically. There are one or more central nodes (root nodes) that communicate with subordinate nodes (child nodes), which in turn, are connected to other subordinate nodes.

Advantages

• Communication is structured
• Clear hierarchy and communication paths enable simple administration
• New devices can be added to the existing hierarchy

Disadvantages

• The failure of a node can interrupt access to subordinate nodes
• Larger networks can be more difficult to manage and configure

Examples

• Special industrial IoT networks use this architecture

A hybrid architecture utilizes the advantages of various other architectures (e.g. star and mesh) by combining them.

Advantages

• The hybrid network architecture can be flexibly adapted to specific requirements
• Network power and performance are optimized as the advantages of different architectures are combined

Disadvantages

• The system is complex and therefore requires very careful planning and management for the hybrid architecture to function effectively

Examples

• Networks that use both central gateways (star-shaped) and peer-to-peer communication (meshed)

This architecture is based on direct communication between two devices. Integration into specific applications is simple and efficient. However, this solution is not scalable and offers no redundancy. The area of application is often simple, bidirectional communication scenarios such as traditional WLANs (point-to-multipoint) or certain NB-IoT configurations (point-to-point).

With this architecture, a central device communicates with several end devices. One advantage is the simplicity and efficiency. A disadvantage is the high level of dependency, as the failure of the central device can paralyze the entire network. Areas of application are traditional Wi-Fi networks (point-to-multipoint) or certain NB-IoT configurations (point-to-point).

This architecture is based on a hierarchical star-shaped network in which several star networks are often connected to each other via central gateways.

• The range, coverage, and scalability are high, as several star networks are combined
• If a gateway fails, the devices may be able to access other gateways

Disadvantages

• Managing multiple interconnected star networks can be complex

Examples

• Some large-scale IoT implementations that use a mixture of local star networks and overarching communication networks

According to a report by “IoT Analytics”, around 1.3 billion LPWAN IoT connections were recorded worldwide by the end of 2023. It is expected that three billion LPWAN connections will be reached by the end of 2027. That would represent an annual growth rate of 26 percent. 10 percent of all global IoT connections would then be based on LPWAN technologies.

NB-IoT is the most important LPWAN technology with a market share of around 54 percent. In 2023, more licensed LPWAN connections, such as NB-IoT and LTE-M, were registered than unlicensed LPWAN connections, such as LoRa and Sigfox. The market for LoRa is expected to grow by 17 percent by 2027. Without the inclusion of usage figures from China, LoRa would have the largest share of LPWAN connections worldwide at 41 percent.

Why is this the case? China is a growth market for LPWAN technologies. In 2023, China accounted for around 81 percent of all global LPWAN connections and 84 percent of all NB-IoT connections worldwide.
The surge in LPWAN usage is due to demand for use cases such as remote monitoring. Applications such as smart water and gas meters, agricultural resource management, asset monitoring, and asset tracking are the main drivers of global growth.