Testing LPWAN IoT technology: An essential step to a connected future
The transformative properties of the IoT are undeniable and inevitable, yet the diversity of applications and their requirements also throws up significant challenges.
How can we connect this connected environment, ensuring billions of sensors spread remotely across the globe are able to send and receive data, at low latency, in a cost-effective manner, whilst – in many cases – relying on power from a single-cell battery? How can operators prepare their networks, testing their reliability in the face of this huge volume of connected ‘things’ set to flood the market?
LPWAN: the future of IoT connectivity
Low-power wide area network (LPWAN) technology has been developed as a solution to cost-effectively and efficiently connect the IoT. It is designed with end-user devices in mind, connecting low-cost chip-sets and making devices and systems more affordable.
The technology allows long-range communications at a lower bitrate than tradition cellular technology, thus ensuring network capacity is not unnecessarily wasted.
A number of different LPWAN technologies have been offered as solutions to support the IoT, however those that are getting the most market traction today are Sigfox, LoRa, and NB-IoT.
Sigfox and Lora
Sigfox and LoRa both take advantage of unlicensed spectrum. These technologies require a new network infrastructure to operate, distinct from current cellular technology.
Technology provider Sigfox operates its own network which is geared up to support the IoT. The lightweight protocol has backing from the likes of Texas Instruments, Silicon Labs, and Axom, and after establishing a presence in the European market, has looked to the US to grow its business. Since making this announcement in 2017, Sigfox USA has achieved over a 50% increase in coverage, and a 45% increase in its partner ecosystem
Sigfox uses different radio frequencies to send short bursts of data across significant distances yet consumes little power. Its urban range is 3-10km, extending to up to 50km in rural areas. This means it’s well-suited to applications like water meters, location monitoring and parking sensors – all of which are basic, one-way systems.
However, Sigfox is not an open standard, and there’s potential for higher RF interference. As such, other LPWAN technologies will also be required to support the diversity of IoT applications.
LoRa offers long battery life of at least 10 years and in some cases up to 20, and works well in dense urban areas. It is therefore viewed by many in the industry as a strong contender for supporting smart city infrastructure. It also boasts widespread support; the LoRa Alliance has hundreds of members across the globe, including telecoms companies, OEMs, system integrators, and sensor and semiconductor manufacturers. Furthermore, it uses 868-MHz/915-MHz ISM bands, available worldwide.
Like Sigfox, LoRa can be used for uplink-only applications with multiple end-points and is not suitable for real-time applications requiring low-latency. It is also limited to locations where an operator has already rolled out the network, so its coverage is still limited at present.
Narrow Band IoT (NB-IoT) is suitable for deployment in licensed spectrum and directly compatible with existing LTE and future 5G NR networks. Many operators’ existing base stations can support NB-IoT with a software upgrade, removing the need to replace or add new hardware. It’s no surprise then that many operators including Vodafone, Deutsche Telekom as well as China Mobile, China Telecom and China Unicom (all with strong government backing), consider NB-IoT to be a game changer for IoT.
The channel bandwidth of NB-IoT is only 200KHz (180KHz, plus guard bands). This makes it suitable for channel reforming; it can be deployed ‘in-band’ alongside spectrum guarded by an operator for LTE. This makes it possible for operators’ NB-IoT/LTE networks to accommodate a huge number of IoT devices – such as smart electricity meters, parking lots, tracking and logistics, security alarms and weather warning systems – without compromising the performance of regular mobile devices connected to the network.
The standard boasts low-power consumption and deep in-building penetration and supports high numbers of simultaneously operating units. Smart meters, for instance, can be connected to the internet via NB-IoT, with units placed anywhere within a building without the problem of infrastructure blocking signal. Data from thousands of meters can be sent quickly and accurately to the energy company, and timely, precise billing information then sent to the customer.
For the IoT to be viable in the long-term and on a global scale, energy efficiency is crucial. It’s been claimed that the NB-IoT will enable ten-year life from a single-cell battery – which the majority of end-points will likely be powered by. This, in addition to the simplicity of the technology, will ensure operating and device costs remain low.
Regardless of which LPWAN technology an operator chooses, all must ensure their networks can support millions of active connections and generate revenue from the IoT. Testing this future scenario and building the required a real-life environment is possible using RAN-to-core validation equipment. Operators are breaking down the traditional vertical telecoms silos, disaggregating the network core and converging RAN and core network functions at the edge of the network.
At MWC 2018 VIAVI demonstrated the impact of NB-IoT smart meters in real-time working mobile network environment. The company was able to emulate smart meter devices to validate the capability and performance of the mobile network when flooded with massive amounts of connections and data.
Testing LPWAN technology against real world uses cases is crucial before commercialisation of the networks. It can help operators ensure their networks will be able to perform to high levels, whilst remaining secure.
As the IoT expands, testing too can be scaled up, without the cost and complexity of having to add additional hardware or physical end-points. Assuring service quality – as well as ensuring that networks are robust enough to handle the IoT – is an essential first step on the route to a connected future.