Rosina Kreutzer, Head of System-to-Market and Stephan Schoenfeldt, System Architect, Infineon Technologies
The world we live in is advancing at an ever increasing pace. More and more people are moving into metro areas and this increased urbanization brings with a rising expectation of convenience and services. It is rapidly becoming apparent to city administrators that smart infrastructure is going to play an increasingly important role in defining the world we are living in.
The expectations we have come with some interesting challenges that must be solved. The implementation of these new technologies must be carefully planned and take into account often competing requirements such as cost, public acceptance, privacy, and security. Designers are rethinking common everyday objects, and either adding functionality or completely redesigning them. Part of this redesign must include ways to minimize energy consumption while meeting the increasing energy demands we place on this infrastructure.
Smart street lights are a key part of this energy efficient world of the future that we are building. Street lights are no longer just a mundane light on the street corner – they are evolving into a highly functional connected energy-efficient portal that is forming the backbone of the smart city infrastructure. This sophisticated outdoor lighting evolution has some essential requirements for connectivity, passive and active sensing technologies, and security solutions.
Illuminating smart cities
Infineon is working in collaboration with the Munich-based startup company eluminocity, and Intel. The combination of talent in these three companies is developing a core component of tomorrow’s smart cities, an advanced and highly efficient LED street lighting solution that acts as a hub for smart applications. At the heart of it all are Infineon’s 24GHz radar sensors, energy efficient semiconductors, XMC™ microcontrollers, and a highly advanced security solution from the OPTIGA™ family.
Intel provides the connectivity with a cellular modem that supports low power, high coverage through LTE Cat.1 / LTE Cat.M1 / Cat.NM1 / LTE-NB / 5G-IoT modules. By integrating the security provided by the Infineon OPTIGA™ technology, sensitive data is protected and security risks are reduced by requiring lamps and servers to uniquely identify each other through mutual authentication. They also prevent confidential information from being compromised by transmitting data over secure channels.
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Figure 1: Block diagram of the LED street lighting solution
The lights themselves use Infineon’s power management and switching devices, making them very efficient, but even more can be done to increase the efficiency. Infineon’s 24 GHz radar technology is used to detect when an object is approaching, triggering the control system to increase the light intensity when it is required, and then dim the light after a defined period. This provides a far more energy efficient solution than the best always-on lighting solutions by lighting the area only when the light is required.
The eluminocity smart street lights are much more than just highly efficient lighting solutions that can dim the lights when no one is around. The built-in proximity detection allows them to detect other things such as empty parking spaces. This information can be communicated directly to drivers in the vicinity, providing valuable information for intelligent traffic management and autonomous driving systems. By monitoring the local traffic conditions, drivers can also be guided around traffic congestion, via traffic signal controls, or connected in-car navigation systems.
Electric vehicle use is on the rise but the lack of a large scale charging station network is limiting its uptake. Smart street lights equipped with vehicle charging stations can easily provide this key part of the infrastructure. Street lights with this feature are already in place in various cities around the world such as Munich, Chicago, Oxford, and Eindhoven, with more charging stations to follow.
The technology behind smart street lighting
24 GHz radar: Object detection is becoming increasingly important to the ever increasing array of smart systems and devices. 24 GHz radar technology is found in multiple applications including UAV/multicopters, service robotics, industrial robotics, security systems, smart street lighting, and many other IoT-based applications.
The proximity detection used in smart lighting hubs is based upon Infineon’s BGT24LTR11, the market's smallest 24 GHz industrial radar chip solution. The BGT24LTR11 is a silicon germanium radar Monolithic Microwave Integrated Circuit (MMIC) transceiver. It operates in the 24.0GHz to 24.25GHz ISM band and it provides a very high level of measurement precision. With Infineon’s 24GHz radar portfolio, one can measure various parameters including Doppler-based object speed and velocity, and electromagnetic wave based distances. Additional receiving channels allow it to detect angle and direction based upon phase detection at the antennas.
This 24 GHz technology can be operated in a wide range of atmospheric conditions, including places where there are significant temperature changes, and high levels of humidity and dust. This robust design makes it an excellent choice for outdoor use, even in cities impacted by harsh weather conditions.
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Figure 2: Block diagram and package size of the BGT24LTR11
OPTIGA™ security: Smart street lights require connectivity as a core part of their advanced capabilities. The connectivity that provides this functionality comes with some potential security vulnerabilities. To address this issue and secure the networks, the smart street light uses technology from Infineon's OPTIGA™ family of reliable security solutions. These standardized security controllers provide a broad range of security functions for embedded platforms. All OPTIGA™ products are based on Infineon's advanced hardware security technology that gives you as a designer or end user, confidence that your data is secure and protected. Embedded security functions include system and data integrity, authentication, secured communication, secured data storage, and secure updates. Each of these functions is essential to protecting the data integrity in our evolving smart cities.
The OPTIGA™ family, built around a 16-bit state-of-the-art security controller, is easy to integrate into a wide range of IoT systems. Support for both Microsoft Windows and Linux (and its derivatives), and integration support for proprietary systems make OPTIGA™ and ideal choice. The OPTIGA™ family also contains TPM devices that are the first to support the latest TPM 2.0 standard from the TCG, making it easy to implement the very latest security protocols.
Lighting controller: The digital core in the XDPL8220 allows a variety of systems to be based on the same device. Its advanced control algorithms allow the use of constant current or constant voltage mode within the same circuit. The comprehensive parameter set can be adjusted to adapt the device to various target applications.
The XDPL8220 is well suited for the high expectations of modern power systems. It has an input voltage range of 90-305 V AC, efficiency greater than 90 percent, and THD less than 15 percent which is compliant with IEC 61000-3-2 class C. The device selects the optimum mode for operation, and can dim lights via current amplitude reduction. Its low standby power of less than 70 mW ensures that the smart street light is as power efficient as possible.
Sensors: Smart street lights can use almost any sensor. Audio sensors can be used to measure noise levels, detect automobile accidents, or other events. Gas sensors can be used to measure air quality. Even simple light sensors can be used and adapted to add functionality to the smart street light. By measuring light levels, they can be used to detect low light conditions and other times when the light levels need to be adjusted to make sure that the correct light levels are always available. The light level detection can also be used to monitor the wear of the lamp. This data can be used to plan maintenance and even notify of a premature light failure or other problems.
Smart, secure, efficient – a bright future
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Figure 3: The eluminocity LED street lamp
Infineon, Intel, and eluminocity have transformed the humble street light into a versatile secure hub that forms the heart of the smart city infrastructure. The intelligent street light provides urban areas with a wide range of features, such as flexible energy-efficient street lighting, a network of charging stations for electric cars, and a range of sensor functionality to monitor lighting conditions, air quality, and a host of other functionalities. The intelligent street light does not only provide tangible benefits to the inhabitants of the evolving smart cities, it also offers a platform for adding new features and developments. The range of possible functions has not yet reached its limits – the future of our evolving smart cities is very bright indeed.