From smart lighting to smart cities: the role of communication networks
As previously mentioned, one thing that smart cities and smart lighting have in common is the information and communication technology. Considered „the nervous system”, the communication technology is the one that integrates all elements of a smart system into a single platform. It ensures the transmission of information between hardware and software, it acts as a binder among devices and software. In this way, smart cities integrate all services via digital infrastructures, without having to manage them individually.
But as there are a number of communication technologies available at the moment, how do you decide which one facilitates the integration of smart street lighting with other smart city devices?
The goal is to link together more technological innovations in a meaningful way. But different suppliers use technologies with different connectivity and data models and not all communication technologies offer the same flexibility when it comes to integration. While some manufacturers are using open source communications, others have adhered to globally accepted standards, while others are using proprietary API integration.
Open standards vs proprietary protocols – avoid a locked-in city
A city shaped by a long term vision will want to encourage an interaction between all the smart city systems. In this case, an open communication is the one that will empower the city with limitless future smart applications. That’s because open standards networks are freely available and can be implemented within any business model. As they are more flexible, they allow the ability to link to existing smart control applications without the need to buy a separate system to manage each additional device or system, which makes it a good foundation for IoT devices.
Let’s assume that the city wants to link an air monitoring system to a previously smart lighting installation. That would be possible only if these systems use a common language, an open communication standard. Cities that deploy open standard systems will be able to use smart city solutions from multiple suppliers that “talk” to each other.
What if you decide to change the supplier of the smart lighting network? Probably the city will be required to reinstall a large number of information systems and sensors, which means losing all the historical data that cannot be transferred from the old provider. Again, this situation can be avoided by using open standards that enable large amounts of data to be stored and then used by other systems.
This information exchange needed for smart applications created the need for establishing standards that are globally accepted. One of them is TALQ Certification, which ensures the interoperability between software and networks from different vendors. For example, because the inteliLIGHT smart lighting solution uses open standards systems with vendor interoperability and is TALQ certified, it can be integrated with other smart city software applications and can coexist with other compatible controllers or entirely different lighting solutions.
On the other hand, there are the proprietary protocols that might hinder the adoption of other smart services and innovations, as they come with the risk of vendor lock-in. Once an initial investment is made in a proprietary system, that system will be compatible only with the provider’s patented communication technology. It will be required an investment continuity over time with the same producer, which may lead to being vendor-locked. And shifting to another technology or standard might prove costly and difficult.
Another option that is worth to be taken into account is an API connection. The existing proprietary standards, which limit interoperability between vendors, has led to the use of APIs (Application Programming Interface). In this way, suppliers and partners can share and leverage each other’s data and services.
Public and private networks
When it comes to communication, it is important to analyse whether a public or private network allows an easier deployment of specific smart solutions together. They require different costs and have different levels of security and reliability. However, it all comes to the specific needs of the city and the other existing smart systems.
Public networks (e.g. NB-IoT, LTE-M, GSM) are installed and maintained by telecom operators. Being under the responsibility of network operators, they take steps to ensure that the network is secured and functional at all times. Therefore, this type of communication comes with increased security and reliability.
The private networks (e.g. LoRaWAN, Wi-SUN etc.) are operated directly by the municipality or the street lighting provider. These networks require several skills and responsibilities: network planning, installation, maintenance and security – that must be performed by the lighting provider. Furthermore, the installation costs are higher and users have to ensure the network maintenance themselves, but the cost of having to pay for a subscription is completely eliminated.
Smart city services are designed at different scales, which require various communication networks that can cover various ranges. For this reason, there exists the possibility to choose from three different networks, each of them having different limits and benefits: cellular networks, long-range networks and short-range networks.
Cellular networks (NB-IoT, LTE-M) can include an unlimited number of devices and are more suitable for real-time communication. If the applications deployed require commands to be executed as soon as they are sent out, cellular networks can guarantee instantaneous communication. However, it comes with a tax on the energy consumption and a price for the connectivity.
Long-range networks (LoRaWAN, Sigfox) typically function on long range and low power and can connect as many as 5000 devices to a single gateway, being preferred by solutions providers when designing IoT or smart city systems. That’s because they are suitable for the specific needs of machine-to-machine communication and can allow IoT devices to operate reliably for up to 10 years on a single battery. Short-range networks such as RF mesh or Wi-Fi have a maximum node-to-node distance of 200-300 meters and can comprise around 200 devices. The network reliability increases the more nodes there are installed.
As cities need solutions that accommodate their infrastructural needs, finding the best communication match may prove challenging. Fortunately, different communications technologies can be used both separately or combined. And indeed, there are cities that go for a mix of technologies to ensure full coverage in any area. For instance, Grottaglie, a small city from Italy, has decided to combine LoRaWAN and GSM communications into a hybrid installation that provides both lamp-level and segment-level control and awareness.
Anyway, each network has pros and cons, which should be assessed by taking into account the area’s geography, urban density, the needs and future development plans of the city. It is important to know that proprietary connectivity will restrict the options for future system development; the communication itself should have a reliable future (high adoption rate), so you will have replacement parts and support for the foreseeable future; interoperability is a big plus, adding future-proof and flexibility.