The IEEE and telecommunications industry standards for wireless data communications cover both the data link and physical layers.
Four common data communications standards that apply to wireless media are:
- Standard IEEE 802.11: Wireless LAN (WLAN) technology, commonly referred to as Wi-Fi, uses a contention or non-deterministic system with a Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA) media access process.
- Standard IEEE 802.15: Wireless Personal Area Network (WPAN) standard, commonly known as "Bluetooth", uses a device pairing process to communicate over distances from 1 to 100 meters.
- Standard IEEE 802.16: Commonly known as Worldwide Interoperability for Microwave Access (WiMAX), uses a point-to-multipoint topology to provide wireless broadband access.
The figure highlights some of the differences between wireless media.
Note: Other wireless technologies such as cellular and satellite communications can also provide data network connectivity. However, these wireless technologies are out of scope for this chapter.
In each of the above examples, physical layer specifications are applied to areas that include:
- Data to radio signal encoding
- Frequency and power of transmission
- Signal reception and decoding requirements
- Antenna design and construction
Note: Wi-Fi is a trademark of the Wi-Fi Alliance. Wi-Fi is used with certified products that belong to WLAN devices that are based on the IEEE 802.11 standards.