Chapter 4

Wi-Fi Connectivity

Wi-Fi networks are the most widely used wireless computer networks in the world. They have become indispensable for connecting our devices to the internet whether we are at home, in the office, or using public internet hotspots.

Wi-Fi or wireless LAN systems are based on the IEEE 802.11 family of standards. Each standard serves a specific application area:

  • 802.11a/b/g/n/ac/ax/be are the most familiar standards used for high-speed internet connectivity around the home or office.
  • 802.11ad/ay are intended for short-range high-throughput applications such as streaming digital video between a TV and phone.
  • 802.11az is for next -generation positioning and super-resolution ranging.
  • 802.11ah is a sub-1 GHz long-range, low-power Wi-Fi variant for IoT applications.
  • 802.11p/ba is used for vehicular communications (V2X).
Standard Bandwidth (MHz) MIMO Designation
802.11ax 20,40,80,160 OFDMA and MU-MIMO HE High Efficiency
802.11ad 2160 Beamforming DMG Directional Multi-Gig.
802.11ac 20,40,80,160 Up to 8 spatial streams, MU-MIMO VHT Very High Throughput
802.11n 20,40 Up to 4 spatial streams HT - High Throughput
802.11ah 1,2,4,8,16 MU-MIMO S1G
802.11g 20 N/A Non-HT
802.11a 5,10,20 N/A Non-HT
802.11b 20 N/A Non-HT
802.11p 5,10 N/A Non-HT
802.11j 10 N/A Non-HT

Wi-Fi system design challenges are very similar to those of cellular networks.


Waveform Generation

To ensure Wi-Fi systems conform to the IEEE 802.11 specifications, it is essential to generate waveforms for the supported family of standards. Using the Wireless Waveform Generator app, available with WLAN Toolbox™, makes waveform generation easy and interactive.


System-Level Simulations

Wi-Fi system designers need to model communication links with multiple nodes. Wi-Fi systems operate across a protocol stack that includes physical (PHY), medium access control (MAC), and application layers. Designers need to measure quantities such as throughput, latency, interference, and packet loss at the node and network levels. They also need to investigate the coexistence of WLAN signals with other signals such as Bluetooth, 5G, and LTE.


Positioning and Localization

The IEEE 802.11az standard is commonly used as next-generation technology for high-resolution indoor positioning. Designers need to effectively extract temporal information, such as time of arrival (ToA), or spatial information, such as angle of arrival (AoA), from a multipath signal to compute a distance or range between devices. Combining estimates from three or more devices, or trilateration, can then be used to compute a position estimate.