NB-IoT, Sigfox, LoRaWAN: a trio with many capabilities

Drinking water is one of the most intensively tested commodities in Germany. On that point the Federal Environment Agency and municipal utilities are fully agreed. With around 60 percent of the country’s drinking water extracted from groundwater, it too must be continuously monitored. That is a state responsibility, in North Rhine-Westphalia, for example, of the State Agency for Nature, Environment and Consumer Protection. Together with water utilities and other companies the state agencies operate thousands of measuring points all over the country, monitoring not only the water quality, including thresholds for salt, dissolved solids, or toxins like nitrates and pesticides, but also for water level and pressure when the groundwater level is lowered for civil engineering, sewage and pipeline construction work.

Once all the sensors, water level gauge cables and measuring probes are connected via the wireless network and the cloud, forming a part of the Internet of Things (IoT), measurements can be read and evaluated remotely. That makes regular on-site checks unnecessary and real-time alerts possible when measurements fall short of or exceed critical levels. The technician in charge is then notified automatically on his PC or mobile device and can undertake countermeasures.

If IoT data from measuring points - or in other industries, for example, from gas meters, pallets, waste bins, containers and wind turbines - are transmitted wirelessly, one question arises: Which wireless technology best serves this IoT use case? Simply an LTE module with SIM card is not the most efficient solution in many cases. This is because the IoT end devices installed here, such as sensors or trackers, have a completely different requirement profile than smartphones and laptops. For example, they do not have a battery or power cable and are therefore dependent on batteries when installed away from any power source.

Energy efficiency is therefore an important criterion to ensure that the devices function for as long as possible without the need to replace batteries. Appropriate wireless modules must also be developed for a mass roll-out in the factory, smart city or agriculture to be cost-effective. At the same time, a long range is required, as well as good building penetration - because they often work in environments with poor reception conditions such as basements or cellars.

Radio modules with conventional LTE mobile communications consume too much energy, and other widely used standards from NFC to Bluetooth and WLAN to RFID lack range. This is why LPWAN (Low Power Wide Area Networks) technologies for transmitting data from IoT devices came onto the scene a few years ago.

As the acronym indicates, LPWA low energy consumption and wide range standards fulfill the requirements of many IoT applications. But which solutions are available, what distinguishes them from one another, and what should a company go for? In view of these questions, finding the right technology for an IoT project is a challenge. Three of the most widespread standards are LoRaWAN, Sigfox and NarrowBand IoT. Each can be used wherever relatively small data packets such as fill level, position or carbon dioxide count are to be relayed to the cloud at regular intervals – hourly, daily or weekly – and wherever wireless must bridge long distances or penetrate cellar walls and sewage pipes. The standards are also designed for energy efficiency to enable batteries to power modules for months or years without maintenance.

But there are differences: LoRaWAN, Sigfox and NB-IoT differ in terms of distribution and availability, standardisation and security, efficiency and effectiveness as well as costs. Previous publications on the performance of the standards are mostly based on theoretical specifications from the standardisation process or measured values from laboratory situations. Deutsche Telekom therefore subjected the three technologies to an actual measurement comparison under real-life conditions in 2020. NB-IoT, Sigfox and LoRaWAN were tested for the following criteria in this fact check:

• Transmission quality
  How likely are successful connection establishment and data transmission?
  How much data can be sent in a certain time frame?
  How quickly can data be sent?
  How far does the signal reach under certain conditions?
• Coverage
  What about availability and roaming?
• Energy efficiency
  How high is the power consumption under certain conditions?
• Security
  How are security mechanisms integrated, where are vulnerabilities?
• Costs
  How high are the user fees and costs for infrastructure and maintenance?
• Future viability
  Are the technologies usable in the long term?