Smart Street Lighting as a Smart City Platform

Smart street lighting offers cities the chance to deploy smart city solutions that improve citizens quality of life, operations efficiency saving money, improving sustainability, and attracting talent and business to the city.

LEDs can reduce energy consumption for street lighting by up to 50% and as price and quality of LED lighting continues to improve the reasons to make an upgrade to LED only increase. New York City, for example, expects $6 million annually in energy savings from replacing its 250,000 street lights with LEDs and a further $8 million in maintenance cost savings.

These energy savings alone are a good reason for a smart street lighting deployment. When new LED deployments are made together with networking and monitoring controls installations they reduce costs, increase efficiency and functionality of street lighting and provide a smart city platform for many solutions.

Just by having Basic LED lighting connected through the electric wire with PLC or RFMesh has great results, with performance and energy monitoring performed which can have huge impact in energy savings and maintenance, with elementary features such as remote on-off control, dimming, and scheduling functions.

Connecting the street lamps with cellular technology can be achieved at relatively low price providing Advanced Lighting features, provide intelligent controls which require faster response and greater security, and which provide color controls, adaptive lighting and emergency response.

Once you enter cellular networks smart street lighting has the potential to support a number of IoT applications which makes them perfect for a Smart City Platform, opening new opportunities for urban innovation. 

Connected street lighting poles can also become an asset providing a source of new revenue for cities by incorporating small cell communications to extend cellular access, EV charging equipment, or digital signage for advertisers.

The study made by Navigant Research for Echelon, shows that Mediumband is the best choice for a balance of cost and functionality, with several advantages stemming from using power line carrier PLC and radio frequency RF mesh technologies. However there are limits to the security, latency and bandwidth of the network, so they are not so well suited for many applications.

For basic lighting controls, there are several narrowband connectivity options such as the unlicensed Sigfox and LoRaWAN, and the new licensed NB-IoT, that will work at very low cost but limited in the number of applications that can be layered on top. They can be used for many IoT monitoring applications, such as air quality, noise monitoring, traffic or pedestrian activity. Together with other sensors, they can support operational systems such as smart parking and waste collection.

In contrast, massive broadband options such as point-to-multipoint RF solutions, public 3G or 4G LTE networks, Wi-Fi, are the most expensive, but costs are falling. These networks provide the security, low latency and higher bandwidth necessary for video and critical applications. Data rates can be of 50 Mbps-100 Mbps. 5G is coming up promising up to 1 Gbps. Some applications which need these features are HD video surveillance, traffic light controls and digital signage which deliver real-time information to pedestrians. Wi-Fi can provide connectivity to business and citizens in wide areas, growing the economy and lessening the digital divide.

So what network technology to use? There is no simple answer to the question of which is the best street lighting network for a city. The choice will depend on current requirements and existing investments, medium-term priorities, and the longterm vision that is shaping the needs of the city. It's probably going to be an hybrid of these technologies that will change through time.

But technology is just an enabler. Cities must understand their own needs and which applications are suitable at each stage of their smart city development and adapt to each situation.