Wireless connectivity and lighting solutions for devices within smart buildings

　　The smart building revolution is underway, providing better comfort and convenience for residences, reducing operating costs, and boosting employee productivity in commercial sectors. By 2022, the global market was valued at nearly $78 billion.

　　Wireless control lighting is a key factor in this revolution, allowing for a variety of operating modes that help avoid wasted energy and prevent disruptions and costs associated with large-scale rewiring projects. Installing wireless controllers can save up to 70% of the cost of rewiring existing homes, or 15% of the cabling cost for new projects.

　　While some new homes, such as luxury properties, may be cleverly designed from the start, existing homes may be upgraded in phases. Owners can prioritize heating or lighting systems as the first step toward smart technology, then expand the system with other smart features such as device controllers, shutters, or door locks. All types of smart building devices seem to have a bright future, ranging from simple light switches, wall plugs, or radiator covers to complex central controllers. This provides new brands with opportunities to gain market share by offering technologically advanced or more fashionable products than those offered by more mature competitors.

　　Interoperability and coexistence will become key issues for developers seeking success, as customers tend to gradually introduce smart features into their buildings.

　　Candidate connection standards

　　Various connection standards for controlling devices (such as lights, radiator valves, windows) have been proposed for openers and appliances in smart buildings. Currently, popular standards for certified products on the market include EnOcean, KNX, ZigBee, and Z-Wave Commercial.

　　EnOcean and Z-Wave operate in the sub-GHz radio band. In Europe, this is 868 MHz. Z-Wave is based on mesh network topology and supports up to 232 nodes. This protocol provides application-level interoperability and supports many Z-Wave system-on-chip devices, such as Sigma Designs ZM5202. The Z-Wave stack resides on the chip and is accessed via APIs also provided, allowing developers to simply load applications into the device's integrated program memory, as shown in Figure 1. The SoC supports a single-chip solution with all hardware features such as sensor ADC, 128-bit secure encryption, and a three-terminal bidirectional thyristor dimmer controller integrated into the device.

　　Figure 1: Access the Z-Wave protocol via the provided API.

　　EnOcean technology is based on ultra-light radio protocols and enables battery-free modules running from solar cells or other energy sources—such as power converters or Peltier elements—harvesting systems used to transmit short telegrams containing sensor data. This is a strong proposition for items like light switches, which can be placed anywhere in the room to communicate with line-powered lighting actuators built using system modules like EnOcean TCM300U (Figure 2). EnOcean switches can also be easily integrated into larger home automation networks. For example, German KNX developer Weinzierl (www.weinzierl.de) built an EnOcean-KNX gateway that receives EnOcean wireless telegrams and generates appropriate signals on the KNX bus.

　　Figure 2: Wireless sensors communicate with line-driven actuators.

　　KNX claims to be the only standard worldwide approved under standards such as ISO/IEC14543-3, EN-50090 (CENELEC), EN13321-1/2 (CEN), China's home automation standard GB/T20965, and the US ANSI/ASHRAE 135. Unlike wireless-based standards like EnOcean, ZigBee, and Z-Wave, KNX buses can operate on various media, including twisted pair (KNX). TP), AC power lines (KNX PL), Ethernet/Wi-Fi (KNXnet/IP), and wireless (KNX RF) operating in the 868 MHz band. The KNX Association also provides equipment developers and system installers with tools independent of the manufacturer.

　　ZigBee Home Automation is a special profile based on the renowned ZigBee standard for 2.4 GHz radio. It is optimized for controlling home devices and uses the ZigBee PRO mesh network stack. ZigBee Pro can be implemented on various microcontrollers. Silicon Labs owns many ZigBee modules, such as ETRX357, which include single-chip ZigBee transceivers and the EmberZNet mesh stack compliant with ZigBee PRO standards. These modules allow developers without RF experience to add wireless network functionality to their products.

　　Use the criteria for selection

　　Each standard is supported by its own alliance or association, which is responsible for managing technical specifications as well as legal aspects such as licensing and product certification. The certification process ensures interoperability between products from different manufacturers. OEMs hoping to penetrate markets currently using any of these standards must provide their new product designs for certification.

　　Typically, the path to developing certified, interoperable devices (such as luminaires, switches, or dimmers) begins by purchasing developer kits from Sigma Designs, such as the RBK-ZW500DEV-CON Z-Wave kit. Sigma also offers many low-cost regional packages that can serve different subbands in Europe, North America, Japan, and other regions. For Z-Wave, purchasing the developer kit also grants access to Sigma's Z-Wave software development kit SDK. The SDK allows online access to resources such as protocol libraries, application examples, and documentation. Using the available tools, developers can make necessary decisions, such as hardware selection, protocol selection, as well as devices and command classes. After completing hardware and software development, products can be submitted to the Z-Wave Alliance for certification.

　　Centralized control

　　In smart buildings, activation lighting may be needed in several areas, not limited to traditional manual switching or dimming controlled by wall-mounted systems. The central controller can be programmed to turn lights on or off at certain times, or respond to occupancy sensors that are also part of the home security system, or receive signals from ambient light sensors that can adjust dimming for optimal lighting. Additionally, as consumers increasingly adopt networked mobile devices, smart building users will be attracted to a variety of applications that can control various aspects of smart buildings, such as lighting and heating. Appliances and security settings for tablets or smartphones. Gateway devices connecting smart building networks to internet routers provide key functionality, as shown in Figure 3. Any smart building technology requires such an IP domain-based gateway, whether it communicates with tablets connected to the building via Wi-Fi networks or connects to the internet via mobile devices via cellular or Wi-Fi hotspots anywhere in the world. Many manufacturers offer gateways designed for connecting smart home networks (such as EnOcean, KNX, ZigBee, or Z-Wave environments) to building internet routers.

　　Figure 3: Connecting the smart home network to an IP domain allows various devices to control settings.

　　Application developers can leverage the features supported by selected technologies to provide convenient features for end users. These include configuring device groups to allow single-click controls, or creating custom "scenes" to automatically apply required settings for lighting, heating, and other equipment. Users can create a "home theater" scene while dimming the lights, closing blinds, adjusting the temperature, turning on the flat-screen TV, or in the "Sleep Mode" scenario locking the door, closing windows, turning off heating, and turning off all lights except the bedroom.

　　Conclusion

　　The standards defining connections between devices within smart buildings each provide product developers with the structure needed to address quantifiable markets. Ensure interoperability with other products already available on the market. The association vigorously promotes its own standards, but developers must choose based on the resources they provide and accurate opportunities and competitive assessments.