Connectivity of things: Wireless for the last 100 m of IoT

Internet of things (IoT) has huge potential for wireless as 90% of the market will be in the last 100 meters, according to some estimates. Which wireless technologies suit what applications?

By Rolf Nilsson March 7, 2014

There is huge potential for the last 100 meters connectivity of things. Indeed, most of the future growth in wireless Internet connectivity will stem from this area. For the real growth to occur, application interaction is needed between various industry segments, so an industry wireless standard is fundamental to the success of Internet of Things (IoT). With the growing availability of devices that can exchange information locally or through the Internet via low power radios, an increased information exchange between these devices is facilitated. This evolution was named the Internet of Things (IoT) a couple of years ago, but its foundation is also well-known through terms such as Internet of Everything (IoE), Web of Things, Embedded Web, Machine to Machine (M2M), and Industry 4.0. 

The last 100 m

A very important concept within IoT is the "last 100 meters connectivity" concept, which refers to the low-power wireless devices that operate in the short-range of 100 meters. These are the devices that represent the growth in IoT.

In fact, 90% of the market share will be in the small things that are in the short range of 50 m to 100 m. The "last 100 meters connectivity" presents a huge potential since today most of these devices are not yet connected to the Internet.

Application for IoT

Typically, future device growth has been centered on personal devices such as smartphones, tablets, laptops, etc. These devices will be important connectivity devices; however, since personal device growth is directly limited to the number of people using devices, the greatest growth will be seen in IoT devices. Exactly how great the growth will be is of course hard to predict; Gartner predicts 26 billion; ABI Research, 30 billion; and companies like Ericsson and Cisco speak of 50 billion devices in 2020.

IoT devices will be the connected small devices in such diverse segments as energy, transportation, education, health care, commerce, travel and tourism, finance, IT, environment, and more. By using the IoT concept in these segments, one can get more efficient and customized medications, remote monitoring, energy consumption tracking, remote control, traffic supervision, security surveillance, and more.

Today, these mentioned segments variedly use wireless technologies and Internet interaction, but typically they each focus on what is common within their industry. The chosen wireless solution needs to adequately address the industries’ concerns regarding connectivity options, robust operation, and security features.

IoT wireless selection

Which wireless technology best fits IoT? There are several proprietary wireless solutions used in every segment as well as standards including 6LoWPAN, ANT+, Bluetooth, Bluetooth low energy, DECT, EDGE, GPRS, IrDA, LTE, NFC, RFID, Weightless, WLAN (also commonly referred to as Wi-Fi), ZigBee, Z-Wave, and others. To successfully grow the IoT connectivity it is, thus, essential to focus on a small selection of the main standard short-range wireless technologies available. To narrow down the list of options, compare the technologies from the following IoT key needs:

  • Cost efficiency. Most IoT devices are of low cost and need affordable radio solutions.
  • Small size. Since these devices are typically of small size, the radio technology needs to physically fit in the housing of the sensor device.
  • Adequate security features. Authentication and data encryption must be adequately supported by the chosen wireless technology. Also, at times end-to-security-from sensors to web services-is required.
  • Low power consumption. Since most IoT devices operate on batteries or energy harvesting technologies, the radio technology must have ultra-low power consumption.
  • Strong available ecosystem. A key driver for IoT is connectivity with smartphones, tablets, PCs, and home gateways. Therefore, the chosen wireless technology needs to exist in these devices as well. Thorough penetration in these markets increases volumes and thus also decreases the radio technology costs. 
  • High reliability. IoT devices will operate under tough circumstances, and thus need a robust wireless solution that already has a proven successful operation under the toughest of conditions.
  • Easy to use. Seamless setup is a must when connecting a device to the existing network as well as to the Internet service.
  • Range extension capability. Though IoT operates in short distances, it is important that the chosen technology can offer enough range coverage or have some range extension capabilities. 

When comparing the above mentioned criteria with the wireless technologies that are used the most in the "last 100 meters connectivity" space, the list of wireless options can be narrowed down to 802.15.4 (where ZigBee is one of the technologies), Bluetooth low energy, Infrared (IrDA), NFC, and WLAN (also commonly referred to as Wi-Fi). Since the chosen wireless technology needs to be a widely adopted technology in a large variety of applications, IrDA and NFC can generically be ruled out except for very specific use cases.

Bluetooth low energy has a high potential to become an important technology for the "last 100 meters" in small, low-power, and low-cost devices thanks to an already manifested ecosystem and tailored functionality for short-range, low-power devices. The 802.15.4-based technologies will primarily be chosen in areas where they are already established. WLAN will particularly be used in devices where cost and low power are less important.

Importance of gateways

In the IoT architecture, gateways are key elements as they serve as the interface between the wide-area network (Internet) and the short-range network. Sometimes the gateways are fixed devices connected to a backbone network, and sometimes they are embedded within other devices such as in an Internet router (ADSL or GSM/3G/4G routers or similar).

Smartphones or other mobile devices can also serve as temporary gateways as, for instance, when the IoT device is carried together with the phone as with a body-worn sensor or when a phone is used for authentication access of an IoT device using an Internet service.

Gateways are also useful as they can help create a system with interconnecting multiple technologies. The gateways are then used to perform the necessary translation to a common backbone.

Range extensions

As mentioned, 90% of the IoT devices will operate in the short range of 50-100 m, but sometimes one would like a longer range. This extension can be done via gateways, WLAN, and Bluetooth low energy. Here, WLAN would serve as an intermediate backbone connecting islands of sensors/devices. This makes use of the multi-radio capability of the short-range radio chips already available, such as chipsets supporting simultaneous use of Bluetooth low energy and WLAN to create miniature gateways. The gateways communicate via Bluetooth low energy downstream and WLAN upstream. The WLAN upstream link is connected to a WLAN router, connected further upward to Internet services.

There will be several short-range low-power radios used in parallel, but Bluetooth low energy is likely the technology that will take the most significant portion of this market, thanks to its already manifested ecosystem and tailored functionality for short-range, low-power devices.

– Rolf Nilsson is the CEO and founder of connectBlue. Edited by Mark T. Hoske, content manager, CFE Media, Control Engineering,


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About the author

Rolf Nilsson, CEO and founder of connectBlue, has more than 30 years of know-how from industrial automation and communication. Before founding connectBlue, Rolf was the president of Eurotherm Scandinavia, and before that he was in leading positions at Alfa Laval Automation/ABB Automation Products. 

About connectBlue

connectBlue is a provider of wireless solutions for the last hundred meters of connectivity. Products are designed and tested for demanding industrial, medical, measurement, data acquisition, and quality assurance applications. Based on Classic Bluetooth, Bluetooth low energy, WLAN, and Multiradio solutions, connectBlue markets ready-to-embed wireless modules and ready-to-use wireless Serial / Ethernet Port Adapters and Access Points. The connectBlue products are radio type approved for European, U.S., Canadian, and Japanese markets; and compliant with EMC, safety, and medical standards, and the Bluetooth qualification program. Sweden has the main connectBlue office; Germany and USA have local offices.