The Internet of Things is increasingly becoming reality. Ever more machines, devices, objects and – last but not least – people are becoming interlinked. Wireless technologies are making a considerable contribution to this development, as these are what make such simple, flexible networking possible in the first place.
Household appliances, cars, machines, wearables – all of these are becoming integrated into the Internet of Things (IoT). A growing proportion of these “things” uses wireless technology to connect to the Internet.
“The emerging IoT movement is impacting virtually all stages of industry and nearly all market areas – from raw materials to production to distribution and even the consumption of final goods,” reflects Jenalea Howell, Research Director for IoT Connectivity and Smart Cities at IHS Markit. “This represents a constantly evolving movement of profound change in how humans interact with machines, information and even each other.”
Data traffic between smartphones, tablets, mobile PCs and routers alone will exceed 100 exabytes (EB) per month in 2023 according to the current edition of the Ericsson Mobility Report. In 2017, the volume still amounted to around 17 EB per month. For reference, 1 EB corresponds to roughly the storage capacity of 250 million DVDs.
The wireless landscape is becoming more complex
A vast range of wireless technologies is used to transmit this volume of data securely. These are differentiated by data rate, latency, range, energy consumption and many other characteristics. To date, three main technologies have dominated this wireless world: cellular networking, Wi-Fi and Bluetooth.
However, the wireless landscape is becoming increasingly complex: new solutions such as Bluetooth Low Energy (BLE) or mesh networks like Zigbee and Thread seek to fulfil specific requirements from various applications. 5G mobile telephony will play a major role when it is introduced in the future. Also in vogue are a number of low-power wide area networks (LPWANs), which are able to transmit data over long distances using very little energy.
The semiconductor industry offers solutions for fast wireless integration
The semiconductor industry offers special chips with appropriate interfaces for quickly and easily equipping a variety of products with wireless technologies. In this case, there is a differentiation between systems-on-a-chip (SoC) and modules. An SoC is a microchip which already combines all electronic switching circuits and components required for the wireless function into one integrated circuit. This solution offers good value for money and requires little space.
On the other hand, it does require some engineering when integrated into the device to be networked. What’s more, the system still needs to be certified after integration has taken place. Wireless modules represent the faster solution. These likewise contain an SoC, but also boast all required components, shielding, licenses and certificates. Modules thus cost considerably more than an SoC and require more space because they are installed on a dedicated board – even though current modules are only a few millimetres tall.
Solutions for greater flexibility
Nonetheless, one conundrum remains for the integration of wireless technology: which wireless standard should be chosen? Nowadays, the industry offers systems and modules which make it easier to answer that question by integrating multiple wireless interfaces into one single chip.
One other solution is software-defined radio (SDR). In this case, the frequency band, protocol and functionality can be modified by downloading and updating software instead of replacing the hardware in its entirety.
Antenna technology increases wireless capacity
All the same, the massively increasing volume of data transferred via wireless technologies results in a dilemma: the capacity of the radio-frequency band is finite. In addition, there is a danger that the growing number of RF transmitters might interfere with one another.
Modern antenna technology offers solutions for this scenario. Using MIMO technology (multiple-input, multiple-output), the data flow is transmitted via multiple transmitting and receiving antennas, which enables the capacity of the wireless network to be significantly increased.
At the same time, a transmitter featuring multi-antenna technology can transmit separate signals in different directions by means of “beamforming”, allowing the frequency band to be more effectively utilised and interference to be reduced. Yet despite these technologies, the RF frequency band will still reach its limits in the foreseeable future.
Transmission by light
The alternative is to tap into another frequency band alongside the existing one. Light is one option in this case. After all, the bandwidth of visible light is 10,000 times larger than that of the RF band. In actual fact, there are already systems poised to be launched onto the market which can transfer data using light.
These solutions – referred to as “LiFi” – modulate the light at a speed that is imperceptible to the human eye. A few companies are already launching the first such solutions onto the market. “LiFi has enormous potential in today’s digital age,” states Olivia Qiu, Chief Innovation Officer of Philips Lighting. “While we are increasingly seeing bottlenecks for data transfer in RF bands, the visible light spectrum has a large bandwidth and is a hitherto untapped resource when it comes to the stable, simultaneous connection of multiple IoT devices.”
All of these new technologies pave the way for wirelessly transferred data volumes to grow further – and for many new applications within the Internet of Things.