This article, written by Urban Control Solutions Manager, Mark Cooper, originally appeared in the May 2022 issue of the Institution of Lighting Professionals' Lighting Journal, which can be found at https://issuu.com/theilp/docs/lighting_journal_-_may/18
The use of cellular technology in smart cities and intelligent street lighting is still relatively new, but its combination of flexibility and interoperability is increasingly making it the go-to choice for a more sustainable connected lighting solution
The initial hype around smart cities has passed, with applications now moving beyond early pilots and proof-of-concepts into commercially deployed systems.
There is a wide range of options when it comes to which wireless IoT (Internet of Things) technology to deploy but not all are suitable to overcome the challenges imposed by the requirements of a smart city.
Each has different capabilities and strengths, making them better suited for certain deployment scenarios and applications. However, the most important of these is longevity and support for the technology.
The danger of not thinking about longevity and support is that, ultimately, the choice of an unsuitable technology can lead to the failure of a smart city vision. But how can you pick the winners and avoid deploying a technology that is at risk of unplanned obsolescence?
There is one major factor present in all wireless IoT technologies that have successfully made the transition from pilot to the mainstream – this is that they are based on standards-based technologies rather than closed proprietary ones.
In fact, it’s been clear for some time that the vendors that have promoted proprietary technologies are those that have struggled to gain traction, with the past few years having seen the fall of, for example, Harvard Technology and Sigfox both entering administration and the much-hyped LoRaWAN now facing its own public network challenges [1].
There are significant benefits for all players involved in connected technologies in developing standards-based technologies.
The most obvious from a city’s perspective is being able to avoid ‘lock-in’ from using a proprietary solution from a single vendor. The risk here is that this then forces you to buy equipment from that vendor alone.
In contrast to this, standards-based technologies are developed after gathering a huge amount of knowledge and input from across the ecosystem, and so are likely to be technically better.
But they also introduce competition between vendors, allowing customers to buy from multiple suppliers knowing that interoperable technologies will work together seamlessly, with better prices, and avoiding the potential pitfalls of single-vendor sourcing.
WHY CELLULAR DOESN’T JUST MEAN MOBILE
In the smart city world, the most important and successful standards we have seen to date (and are now using) are the 3GPP family of cellular IoT technologies – ‘Long-Term Evolution for Machines’ (LTE-M) and ‘Narrowband-Internet of Things’ (NB-IoT).
Cellular IoT refers to the 3GPP standardised family of secure operator-managed IoT networks deployed in licensed spectrum.
These have been designed to support IoT applications that are low cost, use low data rates, require long battery lives, can operate in remote and hard to reach locations, and which are based on existing cellular networks that have evolved to deliver service to billions of new devices providing complete IoT connectivity.
Due to the diversity of IoT application requirements, a single technology is not capable of addressing all the LPWA (low-power wide-area) use cases.
It is for this reason that the mobile industry has focused on LTE-M and NB-IoT as two complementary licensed 3GPP standards.
Cellular technology in smart cities and intelligent street lighting is still relatively new but its technical specifications (as described below) make it the analyst’s choice as the leading technology for IoT applications in smart cities.
In fact, according to recent reports from the specialist IoT analyst firm Transforma Insights, cellular IoT will account for over two-thirds of all IoT connections by 2030, which is estimated to be more than 633 million end points in smart city applications alone [2].
There are several critical factors that must be considered when making an evaluation of suitable IoT network solutions: bandwidth and data throughput, cost, coverage, power consumption, security, and standards. These are outlined in more detail in the figures below.
Let’s now take a look at why this technology is having such a disruptive impact on IoT and connected street lighting.
Traditionally low-power wide-area networks (LPWANs) have required extensive network planning and additional hardware (base stations/gateways/access points) to be meticulously deployed and installed in pre-selected locations before street lighting controllers and IoT devices can be installed.
This pre-install work adds increased complexity and costs in terms of stocking, project management, installation and ongoing operation and maintenance of the privately managed networks. These traditional networks also operate in the unlicensed spectrum frequencies, where devices and applications as diverse as Wi Fi networks, taxicab firm radios and radio-controlled cars can also exist.
This inevitably brings problems with clashes, bandwidth, and signal disruption, which can mean lost data and disruption in service. It means there is a need to find ways to protect against this happening and prevent loss of signal, all of which adds further costs to the network hardware and loss of reputation when this interference occurs, along with the cost of trying to resolve these issues.
Cellular IoT, however, exists in licensed spectrum along with your mobile phone signal and so has no such problems, as this licensed spectrum is protected and enforced by the UK government via the regulator Ofcom.
Legislation gives Ofcom and the courts considerable scope to punish offenders and to deter others, including imprisonment for some offences. Unlimited fines may be imposed by higher courts. The courts can also order offenders to forfeit expensive equipment and to pay Ofcom's prosecution costs.
Cellular IoT devices are also as close to ‘plug and play’ as we can get to in the street lighting controller sector, with automatic location, LED lantern and driver information upload and commissioning all carried out within minutes of powering up the unit.
No more stickers on a plan or spreadsheet, no scanning of barcodes to locate a device and manually checking or adjusting asset information – these devices do it all for you!
So, what are some of the more technical aspects to be considered in designing a cellular node with these features as compared to that of previous generation technology? The key, to my mind, is interoperability.
INTEROPERABILITY’S THE THING…
Interoperability is critical, allowing nodes or networks to work with equipment from different manufacturers, allowing data exchange using open standards.
However, we also need to bear in mind that, when one product or system must adapt its solution to a proprietary system, we will be speaking about compatibility and not about interoperability.
Interoperability is a key topic for today’s smart cities. Proprietary IoT solutions frequently lead to vendor lock-in, difficult and expensive integration with others, poor or non-existent updates and, eventually, its obsolescence.
The increasing standardisation at all levels of the solution means that, beyond the wireless network for connectivity, we are seeing widespread adoption of other standards such as uCIFI, LwM2M, and TALQ.
These complement the increased security features and wider network coverage that cellular networks provide. Ultimately, with the proper device management and scalable deployments, these future-proof solutions are now a sustainable reality for smart cities and connected lighting.
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