As more and more complex automation and control systems can comprehensively save costs, provide comfort and convenience, intelligent buildings are becoming the "new normal". From personal residences and multi-purpose buildings to education and healthcare facilities to workplaces and corporate headquarters, enhanced building automation solutions provide more value-added services by combining it based systems and even artificial intelligence.

This possibility depends on transferring more or less data around the building and its interior space. Easily collect and wirelessly transmit the required data: however, which wireless technologies and standards are most appropriate? And how do we determine the best solution? Professor Michael krodel from the Institute of building technology in ottobrun, Germany, gives some valuable insights.

It depends on the actual application

In krodel's white paper, "trends in intelligent buildings - Comparison of wireless standards for automation and control," he said the first step is to identify processes or systems that need to be automated. The starting point is to list the requirements of room automation and facility automation on the one hand, and then list the requirements of "intelligent building". The most appropriate wireless technology can only be determined on a case by case basis based on the relevant application and its "use case".

Typical room / building automation applications include adjusting the temperature of the room according to the presence of people and the state of the window; adjusting the room ventilation, temperature, and lighting conditions based on air temperature, air quality (such as CO2 or VOC load), and humidity, and lighting levels may darken when the area is not in use. The switch can control a single lamp or group of lamps as required.

The artificial light intensity can also be adjusted according to the weather and time of day according to the natural light intensity. In addition, sun blinds and blinds can be deployed automatically to darken a room when it is warm, or to allow sunlight to enter when the space is cool. With the help of battery free technology, switches and turntables for lighting and external shading can be placed at any position on the partition or wall according to the user's requirements and convenience. Of course, you can also use a handheld remote control.

Housing applications are complemented by a wide range of automation solutions covering heating and cooling requirements, energy system operation, management and fault reporting.

Smart office extends the possibilities to more applications: from smartphone based conference room booking and dynamic booking / publishing of conference room facilities and workplaces in open offices to optimal facility management via occupancy sensors. It can identify the meeting completed ahead of time and unattended working place and adjust accordingly to achieve the best facility management.

Further analysis of the usage pattern can flexibly allocate the working space of employees. Under utilized areas can be set as energy-saving mode, thus reducing the cost and workload of heating, cooling and power plants. The graphical display of building occupancy (usually presented as a "thermal map" or "moving track") is used for regional planning. This can be used to optimize the size and location of workspaces; you can even optimize individual workspaces based on user preferences.

In addition to the inspectors, sensors in the building automation network also monitor pumps, cleaners, HVAC systems, elevators, and so on, and then report any faults in real time to better find faults and take more effective preventive measures.

Classification of wireless standards and their applicability to automation and control

Prof. krodel compares the characteristics of the main candidates for application and RF data transmission. Wireless network standards are characterized by the frequency band they work in, the power of radio signals, and the protocols and modulation schemes they use.

The relevant standards are as follows:

Applicability of frequency band: the use cases considered are mainly characterized by small packets (10-100 bytes), with a delay time of 0.1 to 1 second and a range of 10 to 100 m. The applicability of frequency bands is of decisive importance - described as "Ko criteria" or knock-out factors. Any functional restrictions, even partial ones, will disqualify wireless standards for such applications.

Manufacturer dependence: in the best interests of users, wireless standards should be obtained from as many suppliers as possible. In addition, wireless technology should allow maximum interoperability between technologies and devices produced by different suppliers.

Infrastructure: ideally, equipment does not require additional infrastructure. This is especially true when signals can be transmitted over a larger distance; it is very important when the density of sensor networks is low. The infrastructure of cable connected antennas and gateways allows mesh communication, so scores are higher.

Integrability: wireless standards should be widely supported by many manufacturers of controllers and gateways on the market, and should have reliable reference project information. Wide availability of required hardware components: all required sensors must be freely available on the open market.

Measurement and testing: appropriate fault finding equipment and user documentation shall be provided.

Power supply: one of the main advantages of wireless technology is the free positioning of sensor equipment. The cable power supply represents an obstacle to the required flexibility. Ideally, the sensor should be self powered. Battery powered equipment is in the middle of these choices due to the cost of maintenance and replacement and disposal, including environmental costs. Low power consumption and long life are key considerations.

Data encryption: data security and integrity must be guaranteed by encryption technology.

Which is better or worse?

The analysis based on the broad matrix of application and technology applicability clearly shows that Wan is not suitable for current and future intelligent building applications. The white paper concludes that Wan "is better suited to integrate wireless devices into public areas, where you cannot build your own infrastructure. However, in modern architecture, building your own infrastructure or building a mesh network does not pose any problems and is of great significance in considering the density of sensor networks. "

Compared with Wan, LAN Wireless technology has been proved to be suitable for intelligent building automation in varying degrees. The choice of integrating wireless devices (especially sensors) into building automation systems may be particularly relevant, for example, where controllers and digital control systems are used directly together.

According to the application analysis, the conclusion is that it plays an important role in supporting the specific wireless technology provided by the controller manufacturer. The huge advantage of being able to get compatible components in the open market. Wireless devices that don't need batteries or mains power provide a greater advantage.

As krodel concluded: "it's Enocean and Z-Wave wireless standards seem to be ideal choices for "smart buildings," and two wireless technologies are leading the way. The average score of enocean's applicability index was 1.9, followed by Z-Wave of 1.5. "

But the difference between these leaders is their focus on the market. In business, Z-Wave is more suitable for "DIY" smart home consumer level modification applications. In contrast, enocean has a higher level of interoperability and can meet the needs of professionally installed integrated systems, most commonly in the field of smart home and non residential buildings.

Nevertheless, the enocean alliance is expanding its focus and will become more attractive with the popularity of consumer grade home automation technology.

Source: Qianjia smart home network