This post covers some of the basic communication protocols used by Internet of Things (IoT) devices. You can read the first part here, or scan the recap below.
IoT connects things in the physical world to the digital world. Just about anything found in the physical world can be connected. For example, imagine your breakfast cereal jar knows when it runs out of cereal and can reorder cereal on its own using the Internet or any other communication channel. This is Internet of Things where the “thing” is not a computer—it could be an electric car, a watch, a thermostat, or a jar, as in my simple example. It’s important to keep the 5 A’s in mind when you discuss IoT: Anything, Anywhere, Anytime, Anyway, Anyhow. To be part of IoT, “things” are expected to be able to find information quickly, delegate, and communicate. However, there are various levels of intelligence in IoT devices, including passive (communicate only when required, as in QR codes and RFID), active (communicate when needed, as in sensors and home automation) aware (take action based on computation, as in medical devices), and autonomous (make decisions based on rules, as in smart cars and smart power grids).
IoT devices should communicate with each other and exchange data (device to device, D2D) or collect data and send it to a server infrastructure (device to server, D2S). The protocols for IoT govern the communication between “things,” and enable D2D or D2S communication.
Bluetooth Low-Energy (BLE) or Bluetooth Smart is a substantial protocol for IoT applications. Although it offers similar range to Bluetooth, it has been designed to offer significantly reduced power consumption so that devices can communicate without pairing themselves. By 2018, about 90% of smart devices are expected to be Bluetooth Smart ready.
- Standard: Bluetooth 4.x core specification
- Frequency: 2.4GHz (ISM)
- Range: 50–150m (Smart/BLE)
- Data rates: 1Mbps (Smart/BLE)
The ZigBee protocol is traditionally used in industrial settings and was designed for the special requirements of device-to-device communication. ZigBee PRO and ZigBee Remote Control (RF4CE) are based on the IEEE802.15.x protocol, an industry-standard wireless networking technology operating at 2.4GHz. ZigBee is suitable for applications that require infrequent data exchanges at low data-rates, usually operating within a 100m range, such as in a home or building. ZigBee RF4CE’s advantages include low-power operation, high security, robustness, high scalability, and high node counts. ZigBee is well placed to take advantage of wireless control and sensor networks in M2M and IoT applications.
- Standard: ZigBee 3.0 based on IEEE802.15.4
- Frequency: 2.4GHz
- Range: 10-100m
- Data rates: 250kbps
The Z-Wave protocol is a low-power RF communication technology primarily designed for home automation products such as lamp controllers and sensors. Z-Wave is optimized for reliable, low-latency communication with data rates up to 100kbit/s. It operates in the sub-1GHz band and is impervious to intervention from WiFi and other wireless technologies in the 2.4-GHz range such as Bluetooth or ZigBee. This highly scalable protocol supports full-mesh networks without the need for a coordinator node and enabling control of up to 232 devices.
- Standard: Z-Wave Alliance ZAD12837 / ITU-T G.9959
- Frequency: 900MHz (ISM)
- Range: 30m
- Data rates: 9.6/40/100kbit/s
6LoWPAN is a low-power wireless mesh network in which every node has its own IPv6 address, allowing it to connect directly to the Internet using open standards. This is a network protocol with encapsulation and header compression mechanisms. The standard has a wide band frequency and physical layer and can be used across multiple communications platforms, including Ethernet, Wi-Fi, and sub-1GHz ISM
- Standard: RFC6282
- Frequency: (adapted and used over a variety of other networking media including Bluetooth Smart (2.4GHz) or ZigBee or low-power RF (sub-1GHz)
- Range: N/A
- Data rates: N/A
My next post will continue the discussion of IoT protocols.