Networking & Cellular
E08 Wi-Fi Standards — Study Guide
This guide covers Wi-Fi Standards as part of Networking & Cellular. Start with the vocabulary, then try to answer each question before revealing the answer. Connect these facts to a real network or cellular connection and practice the subject in the arcade when you are ready.
Acronyms first
| Term | Meaning |
|---|---|
| ISM | Industrial, Scientific, and Medical |
| WEP | Wired Equivalent Privacy |
Key facts
'Wi-Fi' is a marketing name.
True
An Access Point is also called a…
Base Station
Which device adds desktops and peripherals in remote locations without cables?
Wi-Fi Bridge
In an ad hoc network, what happens when the computer sharing its internet disconnects?
All other users are disconnected too
Which device combines router functions with a wireless access point?
Wireless router
Which basic device connects multiple computers together (no smart forwarding)?
Hub
Which device uses packet switching to receive, process, and forward data to the destination device?
Switch
Standard 2.4 GHz open-air range?
Up to 100 meters
Practical 2.4 GHz range (buildings degrade signal)?
~10–35 meters
Approximate 5 GHz coverage area?
1,200–2,800 sq ft
Approximate 6 GHz coverage area?
800–1,800 sq ft
In 1974, which network connected the Hawaiian islands with wireless data?
ALOHAnet
Who is regarded as the 'Father of Wi-Fi'?
Vic Hayes
When did the FCC release the ISM band for unlicensed use?
1985
NCR with AT&T invented the 802.11 predecessor in 1991 called…
WaveLAN
Which year saw the Wi-Fi Alliance form and the 'Wi-Fi' trademark created?
1999
Which company created the term 'Wi-Fi'?
Interbrand
Wi-Fi was originally called…
IEEE 802.11b Direct Sequence
The Wi-Fi Alliance ensures products meet which body's 802.11 standards?
IEEE
802.11 standards used which RF bands?
2.4, 3.7, 5, and 6 GHz
ESS (in Wi-Fi Standards key terms) means…
All components of a particular WLAN
Changing what on an AP can help reduce interference?
The channel
Which modulation uses complementary sequences — less spreading for higher rates, shorter range — at 5.5 or 11 Mbps?
CCK (Complementary Code Keying)
A device that operates in BOTH 2.4 and 5 GHz at the same time is…
Concurrent dual band
Which technique adds error-checking code so the RECEIVER can correct errors (a.k.a. channel coding)?
Forward Error Correction (FEC)
Only devices that operate in the same frequency band can communicate with one another.
True
Which term = amount of data sent from one location to another in a specific time (bps, Mbps)?
Throughput
Which term = the physical data transmission in a wireless network?
Spatial stream
Original 802.11 was introduced in…
1997
Original 802.11 data rate?
1 or 2 Mbps
Original 802.11's two RF variations?
FHSS and DSSS
Original 802.11 FHSS channels are how wide?
1 MHz
Which spread spectrum spreads the base signal over a larger bandwidth, lowering interference and needing less power?
DSSS
802.11b max data rate?
11 Mbps
802.11b was the first Wi-Fi standard in which band?
2.4 GHz
802.11b modulation?
DSSS with CCK
802.11 uses which collision method?
CSMA/CA
802.11a: band and max rate?
5 GHz; 54 Mbps
802.11a modulation?
OFDM
802.11a bandwidth allows how many non-overlapping channels?
12
802.11a hardware is compatible with 802.11b.
False
802.11g approved…
June 2003
802.11g: band and max rate?
2.4 GHz; 54 Mbps (OFDM)
Which standard is fully backward compatible with 802.11b?
802.11g
Which amendment (June 2004) implemented WPA2 to replace reliance on WEP?
802.11i
IEEE 802.11-2007 merged which amendments?
a, b, and g (with others)
802.11n was added in…
2009
802.11n max net data rate?
54–600 Mbps
Which standard added MIMO antennas?
802.11n
The 2012 802.11 revision merged how many amendments?
10
802.11ad is branded as…
WiGig
802.11ad operates in which band?
60 GHz
802.11ad peaks at 7 Gbps if the client is within…
11 feet
802.11ac is also known as…
Wi-Fi 5
802.11ac approved…
December 2013
802.11ac max data rate?
3.46 Gbps
Which standard introduced Multi-user MIMO (MU-MIMO)?
802.11ac
802.11af is called…
White-Fi / Super Wi-Fi
802.11af operates in…
TV white space (54–790 MHz; 54–698 MHz in US)
802.11af uses ____ radio technology to transmit on unused TV channels.
cognitive
802.11af APs determine their position using…
a satellite positioning system and the internet
802.11ah is also known as…
Wi-Fi HaLow
802.11ah operates…
below 1 GHz (license exempt)
802.11ah is used for…
large-scale sensor networks, extended-range hotspots, outdoor Wi-Fi
802.11ax is known as…
Wi-Fi 6 (6e adds 6 GHz)
802.11ax primary focus?
Boosted speed in highly congested areas
802.11ax total network speed?
9.6 Gbps (300% increase)
802.11ax modulation supports up to…
1024-QAM with OFDMA and two-way MU-MIMO
802.11be (Wi-Fi 7) theoretical max?
23 Gbps
Which Wi-Fi 7 system transmits on multiple bands simultaneously?
MLO (Multi-Link Operation)
Wi-Fi 7 modulation?
4K-QAM with OFDMA
Wi-Fi 7 is called…
Extremely High Throughput
802.11bn (Wi-Fi 8) focuses on…
Ultra High Reliability, not speed
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