Connecting the Internet of Things by Unknown

Author:Unknown
Language: eng
Format: epub, pdf

Chapter 3 Wi-Fi

• Transmission Scheduling based on trigger frames

enables centralized management of downlink and

uplink transmissions and improved efficiency

compared to the purely best effort scheduling

techniques of previous versions of the Wi-Fi.

• BSS Colors enables spatial division multiplexing by

specifying that user devices are associated with a

specific color or Access Point; this becomes important

when client devices are at the edge of the coverage area

of one Access Point and close to the coverage area of an

adjacent Access Point.

• Target Wake Time is a feature that is valuable for

battery-powered IoT devices. Instead of remote

devices keeping their Wi-Fi radios on continuously and

draining their batteries, TWT enables the devices to

sleep and wake up at pre-set intervals to send their data

to the AP.

Wi-Fi 6E (2020)

Wi-Fi 6E is the Extended version of Wi-Fi 6 and adds the new 6GHz

unlicensed band for Wi-Fi. This new band provides 1.2GHz of bandwidth

for unlicensed radio technologies and is being approved in various

countries around the world starting in 2020. The addition of this band

increases the total bandwidth available to Wi-Fi to 2GHz and reduces

Wi-Fi congestion in crowded networks and offers a tremendous advantage

for high throughput applications.

A summary of Wi-Fi bands is shown in Table 3-1.

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Chapter 3 Wi-Fi

Table 3-3. Wi-Fi bands

Band

Lower Freq

Upper Freq Total Bandwidth (MHz)

(MHz)

(MHz)

2.4

2400

2500

100

5

5150

5895

745

6 (USA and

5925

7125

1200

others)

6 (European

5925

6425

500

Union

While Wi-Fi 6 offers improvements in Quality of Service over Wi-Fi 5,

Wi-Fi 6 still suffers the limitations of the 2.4 and 5GHz unlicensed bands.

In particular, the 5GHz band offers limited support for 80 and 160MHz

channels.

The Wi-Fi Alliance notes: “6GHz addresses Wi-Fi spectrum shortage

by providing contiguous spectrum blocks to accommodate 14 additional

80 MHz channels and 7 additional 160 MHz channels which are needed

for high-bandwidth applications that require faster data throughput such

as high-definition video streaming and virtual reality. ”12, 13

12 www.testandmeasurementtips.com/what-you-should-know-about-

wi-fi-6-and-the-6-ghz-band/

13 www.techradar.com/uk/news/wi-fi-6e-looks-to-use-6ghz-spectrum-for-

even-faster-wireless-connections

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