Sensors, and other things connected to the internet, need a method of transmitting and receiving information. This is the topic of personal area network (PAN) and near-range communication. In an IoT ecosphere, communication to a sensor or actuator can be a copper wire or a Wireless Personal Area Networks (WPANs). In this chapter, we concentrate on the WPAN as that is the prevalent method for industrial, commercial, and consumer connections to the things of the internet. Wire-based connectivity is still used, but primarily in legacy industries and areas that are not radio-frequency friendly. There is a wide variety of different communication channels between the endpoint and the internet; some may be built on a traditional IP stack (6LoWPAN) and others use non-IP (internet protocol) communication to maximize energy savings (BLE).
We separate out IP and non-IP, as IP-based communication systems need further detail that non-IP communication doesn't necessarily need. Non-IP communication systems are optimized for cost and energy usage, whereas IP-based solutions usually have fewer constraints (for example, 802.111 Wi-Fi). The next chapter will detail the overlap of IP on the WPAN and WLAN.
This chapter will cover non-IP standards of communication, various topologies of WPAN networks (mesh, star), and constraints and goals of WPAN communication systems. These types of communication systems operate in the near meter to about 200-meter range (although some can reach much further). We will go deep into the Bluetooth® wireless protocol and the new Bluetooth 5.0 specification, as it sets a foundation to understand other protocols and is a prevalent and powerful part of IoT solutions.
This chapter will include technical details on proprietary and open standards. Each communication protocol has been adopted for certain reasons and use cases; they too will be covered in this chapter. Focus topics of this chapter include:
- RF signal quality and range
- Wireless spectrum allocation
- Bluetooth wireless protocol with special focus on the new Bluetooth 5 specification
- 802.15.4
- Zigbee®
- Z-Wave®