Radio Systems

The term “radio” refers to a method of transmitting information using radio waves. The wireless data transmission of signals or information takes place by means of electromagnetic waves. The information is transmitted by an antenna and received by a transmitter or receiver. In order to transmit a signal, it must be modulated. Modulation is the process by which the signal or information is converted into an electronic or optical carrier signal. The information, also known as the carrier signal, becomes a radio wave with a constant waveform, constant amplitude, and constant frequency.

A large number of frequencies are available, so that numerous different contactless radio technologies are also offered. The variety of frequencies is a major advantage. Another advantage is the wireless transmission of information.

It is important to secure the radio systems to prevent unauthorized interception. In the following, we will focus on wireless technologies that are important in the manufacturing, logistics, healthcare, smart city, transportation, traffic, sports, construction, and retail sectors.

Contactless wireless technology is optimally tailored to the respective industries in terms of IoT platforms, middleware, hardware, and software.

A rough classification of radio technologies is easy to make: Radio technologies with short, medium, or long range. These three transmission methods have different advantages and disadvantages. Here are the most important ones.

Short-range communication technologies consume little energy, offer fast data transmission, are reliable, and often cost-effective, as short-range systems require less technical infrastructure. Near Field Communication (NFC technology) is one such example, with a range of only a few centimeters. This category mainly includes access control, payment transactions, or authentication solutions with smartphones, tokens, or RFID and NFC cards.

Medium-range radio technologies have a range of up to 100 meters. This group includes the wireless technologies Bluetooth Low Energy (BLE), Wireless Local Area Network (WLAN), Ultra Wide Band (UWB), and Radio-Frequency Identification (RFID). The maximum range is a few hundred meters.

If many wireless systems are to be operated in parallel, radio technologies with a short or medium range are prone to errors and interference.

Ideal application scenarios for medium-range radio technologies include building automation, asset management in hospitals, inventory in retail, container management in logistics, or industrial identification, for example, to name just a few.

In combination with UWB technology, radio technology scores with real-time localization. They send information about the status of an object (in conjunction with sensors), and provide information about the location of an object. These are just a few examples. In reality, hundreds of use cases with short-distance communication technology are conceivable.

The third method of radio transmission offers a long range. This radio technology can transmit information over several kilometers. The advantage: It is not restricted by buildings or walls. When it comes to transmitting large data packets over an equally long distance, this technology is ideal. However, it consumes more energy than short-distance technologies. Data transmission can be slower, as longer distances also have to be covered, and interference can occur in heavily frequented areas. Long-range radio technologies include all Low Power Wide Area Networks (LPWAN) technologies, for example.

The application scenarios for long-range radio technologies go beyond spatially limited scenarios. LPWAN technology makes it possible, for example, to monitor the condition and position of construction vehicles over hundreds of kilometers, to record sensor data for an entire city, or to monitor entire industrial parks.

LPWAN networks currently dominate, either operating in license-free frequency bands, such as Long Range Wide Area Network (LoRaWAN), mioty and Sigfox, or based on existing mobile communications infrastructures, such as NB-IoT and LTE-M. An important future competitor is likely to be the next-generation mobile communications standard (5G), which should be available throughout Germany by 2025. On the one hand, this standard offers functions that ensure low energy consumption at low data rates, and on the other, functions that enable reliable connections with low latency. This is crucial for autonomous vehicles and industrial plants, for example.

In terms of short-range wireless technologies, the global market for NFC technologies and applications is growing. According to a report by the market research platform “Gitnux”, 67 percent of all Point of Sales (POS) terminals in Europe were NFC-enabled by the end of 2020. By 2027, NFC in the consumer electronics segment is expected to hold a global market share of 39 percent. In 2020, 85 percent of all transactions in Australia were contactless. This includes the use of NFC-based payment methods.

The global markets for medium-ranged wireless technologies are also expected to grow. For example, according to a report by the technology intelligence firm “ABI Research”, there were 109 million UWB-enabled devices that were shipped globally in 2019. This number is expected to grow to over 1 billion devices by 2025. According to a market update report by “Bluetooth SIG”, Bluetooth LE will be included in 90 percent of all Bluetooth devices by 2027. The report also predicts 338 thousand Bluetooth RTLS implementations by 2027.

For long-range wireless technologies, according to a report by the data and business intelligence platform “Statista”, the number of LPWAN IoT connections will surpass that of other IoT connectivity technologies by 2030.

NFC technology is based on Radio-Frequency Identification (RFID). NFC has a transmission range of just a few centimeters. This is a key aspect for security. The maximum data rate is 424 kBit/s.

Power consumption is significantly low:

• NFC chips consume only 5 mA
• Bluetooth low-energy chips consume 15 mA
• Bluetooth chips consume 30 mA

The short range limits access to the transmitted data to people in the immediate vicinity, and makes it difficult for third parties to intercept data from a distance. In addition, RFID chips that support encrypted data transmission are now available on the market.

NFC is used in various areas such as cashless payment and two-factor authentication. Today, an NFC chip is integrated in almost every smartphone or tablet PC.

Two Frequency Bands

A local WLAN network is installed in almost every household. This is why WLAN is probably the most frequently used radio technology in rooms. In industry, WLAN routers, access points, and WLAN tags are used to transmit status data, location data, or movement data to central systems. The primary purpose is to monitor processes. Compared to technologies designed for IoT applications, the power consumption of Wi-Fi is significantly higher.

Since the radio technologies Wi-Fi and BLE use the unlicensed 2.4 GHz band, interference can occur. Performance losses are possible due to reduced range and data transfer rates, for example. It also becomes critical if connection interruptions disrupt data communication. This is particularly true when sensor data or position data is affected. Overall, interference can therefore have a negative impact.

The range of BLE can be up to 50 meters. Available frequency bands are 2.4 GHz or 5 GHz. A higher transmission rate and stability can be achieved with 5 GHz, albeit with the expense of range.

RFID is a Key Technology for Digitalization

The RFID transponder consists of an electronic microchip, the storage medium, a capacitor for short-term energy storage, and an antenna. The antenna is the coupling element. It can be printed, applied, or etched. Both components, chip and antenna, are also referred to as an inlay. The RFID inlay is sensitive to mechanical and chemical stresses.

RFID inlays are therefore packaged in “protective sleeves”. For example in foil, paper, or plastic. The RFID transponder is particularly resistant if the inlay is encapsulated in a plastic housing. The memory size of an RFID microchip ranges from a few bytes to more than 100 kilobytes. Memory sizes between 4 bytes and 8 kbytes are available commerically. Only 1-bit memories are used in anti-theft protection – for electronic article surveillance.

RFID systems are used in every conceivable sector, from industry and logistics, to healthcare and retail. The designs of the RFID transponders adapt to the respective application. These designs come in the form of key fobs, labels, glass transponders, or even chip cards. Automatic and contactless data capture is possible over long ranges (up to 10 m), depending on the frequency. Special RFID transponders are used in environments with interfering materials such as metal or liquids.

Modern UHF RFID readers are particularly suitable for the pulse reading method. The reading accuracy is almost 100 percent.

BLE Can Send Signals Over Years

BLE is a variant of Bluetooth 4.0 that consumes significantly less energy. The result: A BLE beacon can be used for several years. Compared to other technologies, it transmits a one-way signal, similar to NFC. This means that it cannot receive information from other devices, and can only send signals. As a result, a BLE system achieves an extremely low energy consumption of just 75 nJ/bit.

The range is around 10 meters indoors, and up to 50 meters outdoors. The transmission speed varies depending on the distance; in normal operation, between 1 Mbit/s and 2 Mbit/s per second can be achieved. A major advantage of BLE over similar systems is its widespread use, as practically all common Bluetooth devices also support Bluetooth Low Energy.

Energy-Efficient and Cost-Effective Tracking

Outdoor asset tracking with LPWAN (Low Power Wide Area Network) offers advantages, but also requires consideration of some important aspects. LPWAN is a wireless network technology that is particularly suitable for IoT applications where long battery life and wide coverage are required. The most important LPWAN technologies are LoRaWAN (Long Range Wide Area Network), Sigfox, NB-IoT (Narrowband IoT), mioty, and LTE-M (LTE for Machines).

LPWAN networks have a long range and are well suited for outdoor applications. They enable assets to be tracked over long distances, even in rural or remote areas, without the need for a constant connection to a mobile network. LPWAN devices score highly in terms of energy efficiency. They consume little energy and therefore have a long battery life. This is particularly important for outdoor applications where it can be difficult to regularly replace or recharge batteries. LPWAN is considered robust and weatherproof. This is an important aspect for outdoor installations.

In terms of precise localization of assets with LPWAN, the same accuracy cannot typically be achieved as with GPS. However, triangulation or the use of additional sensors can improve positioning accuracy. As with all wireless transmission technologies, the data generated with LPWAN technology must also be secured.

Positioning Up to 200 Meters Away

Ultra-wideband (UWB) is a wireless transmission technology that was specially developed for short distances. In the USA, UWB occupies the frequency range between 3.1 and 10.6 GHz. The approved frequency band in Germany is between 6.0 and 8.5 GHz. UWB offers high positioning accuracy with low energy consumption.

In terms of range, UWB works optimally up to 50 meters, but can also locate up to 200 meters away. Line of sight is important.

The maximum data rate is 480 megabits per second, while the transmission power usually remains below one milliwatt. The integration of UWB chips in numerous end devices has opened up more and more areas of application in recent years.

The greatest advantage of UWB lies in the very precise positioning of devices. This capability makes UWB particularly attractive for end devices such as smartphones. While conventional technologies such as Bluetooth Low Energy (BLE) or GPS often have an accuracy of up to two meters, UWB enables localization with an accuracy of just a few centimeters.

6G Should Be Available in 2030

The 4G/LTE standard is based on Orthogonal Frequency Division Multiplexing (OFDM). This is a digital modulation process in which a signal is divided into several narrowband channels on different frequencies and transmitted faster. With 4G LTE, data transmission rates of up to 150 Mbit/s can be achieved. The average download speed of an LTE connection is 20.83 Mbit/s, the upload speed is 1.48 Mbit/s and the average response time is 54.17 ms.

The 5G network has been under construction in Germany since 2019. With 5G, peak data rates of nominally 20 Gbit/s with a latency of 1 ms are possible. The technological innovation in 5G lies primarily in the antenna. In order to be able to supply more end users per radio mast, many additional antennas are installed on the radio mast, enabling Massive Multiple Input, Multiple Output (Massive MIMO).

Secondly, telecommunications providers use different frequency bands: Long-wave with greater range in the GHz band in rural areas, where a single radio mast can cover a larger area, and short-wave for urban areas, where the number of users per unit area is higher. In cities, more 5G antennas or smaller transceivers the size of a pizza box are installed.

Thirdly, the performance of a 5G network is based on network slicing. “Slices” are virtual networks within the overall network that use bandwidth in a resource-efficient manner. Fourthly, 5G devices can communicate directly with each other via sidelinking, without the need for an antenna or transceiver.

6G should be available by 2030. Transmission rates of up to 400 Gbit/s and latency times of less than 100 microseconds are predicted.