Rack of Ethernet switches.

Wireless LAN Specifications

Wireless Networking

Wireless Local-Area Networks, known as Wireless LAN or simply WLAN technology, provide network connections over microwave links typically around 2.4 and 5 GHz. Most of what is called WLAN today is based on the IEEE 802.11 family of standards and marketed as Wi-Fi.

Another general family of wireless network technology is based on digital mobile telephony, carrying IP networking over the worldwide GSM internetwork. Look here for an example of GSM IP networking in Bulgaria, where in 2011 they had the third-fastest Internet service in the world.

WLAN Development

The U.S. Federal Communications Commission released the 2.5 GHz ISM band for unlicensed use in 1985. (that is, the Industrial, Scientific, and Medical radio bands used by microwave ovens, medical diathermy, and industrial RF heating)

By 1991 NCR and AT&T developed an 802.11 precursor, intended for use by cash register systems. The technology was called WaveLAN and provided 1 and 2 Mbps data rates.

802.11b was the first widely accepted wireless networking standard. It appeared around 1999. 802.11b uses the 2.5 GHz band and provides about 11 Mbps data rate. It is divided into channels that are 22 MHz wide and spaced every 5 MHz with significant overlap.

Only channels 1 through 11 are allowed in the U.S. and similarly regulated nations, including all of North America and parts of Central and South America. Channels 1, 6, and 11 are used in these regions, as they are the only way to used three non-overlapping channels. European nationals commonly use channels 1, 5, 9, and 13, four channels with some overlap.

Channel 1 2 3 4 5 6 7 8 9 10 11 12 13 14
Start 2.401 2.406 2.411 2.416 2.421 2.426 2.431 2.436 2.441 2.446 2.451 2.456 2.461 2.473
Center 2.412 2.417 2.422 2.427 2.432 2.437 2.442 2.447 2.452 2.457 2.462 2.467 2.472 2.484
End 2.423 2.428 2.433 2.438 2.443 2.448 2.453 2.458 2.463 2.468 2.473 2.478 2.483 2.495

Since 802.11b and 802.11g use the shared 2.4 GHz ISM band, they may suffer interference from microwave ovens, cordless telephones, cordless headphones, and Bluetooth devices. DSSS and OFDM (that is, Direct-Sequence Spread Spectrum and Orthogonal Frequency-Division Multiplexing) helps to limit the interference.

802.11a and 802.11g came out next, in 2003. They use the 5 GHz band, with at least 23 non-overlapping channels. Their modulation schemes provide data rates of 54 Mbps.

802.11n appeared in 2009. It provides data rates up to 248 Mbps, with users getting single stream links up to 150 Mbps.

802.11ac appeared in 2013, providing single spatial streams with link speeds up to 866 Mbps. The 802.11ac standard specifies up to 8 spatial streams, meaning that a single user could get a total data rate of 6.97 Gbps.

The other standards, c-f, h, and j, are amendments that extend the scope of existing standards, and in some cases make corrections.

802.11ax is scheduled for release in 2019. It is expected to provide around 10 Gbps data rates.

WiFi and WiMax Characteristics

Standard Frequency Max data rate Spectrum sharing Modulation
802.11 (Wi-Fi) 802.11a 5.15-5.825 GHz
54 Mbps OFDM BPSK, QPSK, 16-QAM, 64-QAM
802.11b 2.4-2.5 GHz
11 Mbps DSSS CCK
802.11g 2.4-2.5 GHz
54 Mbps OFDM BPSK, QPSK, CCK
802.11n 2.4-2.5, 5.15-5.825 GHz 248 Mbps OFDM 64-QAM
802.11ac 5.15-5.825 GHz
88-866 Mbps OFDM BPSK, QPSK, 16-QAM, 64-QAM, 256-QAM
802.11ad 47-66 GHz
6.76 Gbps SC, OFDM BPSK, QPSK, 16-QAM, 64-QAM
802.11af 54-88, 470-596, 614-790 MHz
27-569 Mbps SC, OFDM BPSK, QPSK, 16-QAM, 64-QAM, 256-QAM
802.11ah 900 MHz
1-16 Mbps SC, OFDM BPSK, QPSK, 16-QAM, 64-QAM
Bluetooth 802.15.1 2.4-2.484 MHz 1-3 Mbps FHSS GFSK, DQPSK, 3DPSK
802.16 (WiMAX) 802.16d Licensed: 2.5, 3.5 GHz
Unlicensed: 5.2, 5.8 GHz
70 Mbps OFDM BPSK, QPSK, 16-QAM, 64-QAM
802.16e Various: 2.3, 2.5, 3.3, 5 GHz 70 Mbps SOFDMA BPSK, QPSK, 16-QAM, 64-QAM

At 5 GHz, devices in the US may operate at 5.250-5.350 GHz and 5.470-5.725 GHz. In Europe, 5.150-5.725 GHz is used.

5G wireless networks will use millimeter-wave frequencies. WRC-15, the World Radiocommunication Conference in November 2015, proposed these mm-wave bands:
24.25-27.5, 31.8-33.4, 37-40.5, 40.5-42.5, 45.5-50.2, 50.4-52.6, 66-76, and 81-86 GHz.

Digital Mobile Telephone Specifications

System Band, MHz Uplink, MHz Downlink, MHz Channel Number Regions of Use
GSM 400 450 450.4 — 457.6 460.4 — 467.6 259 — 293 Tanzania
GSM 400 480 478.8 — 486.0 488.8 — 496.0 306 — 340 Tanzania
GSM 850 850 824.0 — 849.0 869.0 — 894.0 128 — 251 USA, Canada, many other countries in the Americas.
GSM 900
(P-GSM)
900 890.0 — 915.0 935.0 — 960.0 1 — 124 Europe, Middle East, Africa, most of Asia, Brazil, Falklands, St Pierre & Miquelon, some Caribbian countries
GSM 900
(E-GSM)
900 880.0 — 915.0 925.0 — 960.0 975 — 1023
(0, 1 — 124)
Europe, Middle East, Africa, most of Asia
GSM R
(R-GSM)
900 876.0 — 915.0 921.0 — 960.0 955 — 973
(0, 1 — 124,
975 — 1023)
Europe, Middle East, Africa, most of Asia
GSM 1800
(DCS 1800)
1800 1710.0 — 1785.0 1805.0 — 1880.0 512 — 885 Europe, Middle East, Africa, most of Asia, Brazil, Uruguay, some Caribbian countries
GSM 1900
(PCS 1900)
1900 1850.0 — 1910.0 1930.0 — 1990.0 512 — 810 USA, Canada, many other countries in the Americas.

Wireless Frequency and Encryption Specifications

Technology Frequency (US) Encryption
GPRS (2G) GSM 850/1900 MHz GEA2/GEA3/GEA4
EDGE (2G) GSM 850/1900 MHz A5/4, A5/3
UMTS (3G) HSDPA/USUPA 850/1700/1900 MHz USIM
LTE (4G) 700-2600 MHz SNOW stream cipher

Acronyms

OFDM Orthogonal Frequency-Division Multiplexing
SOFDMA Scalable Orthogonal Frequency-Division Multiple Access
BPSK Binary Phase-Shift Keying
QPSK Quadrature Phase-Shift Keying
QAM Quadrature Amplitude Modulation
CCK Complementary Code Keying
OpenBSD with Linksys WPC55AG 802.11a+g WLAN card, with Atheros chipset capable of 802.11i / WPA2 security.

OpenBSD notebook with Linksys WPC55AG WLAN card. Its Atheros chipset is capable of 802.11i/WPA2 security.

Soviet Багта-50 telephone interfaced to the GSM network.

A Soviet Багта-50 rotary-dial telephone from around 1955, which I have interfaced to the GSM network.


Other Pages

Kismet sniffing packets and detecting wireless activity.  Running in a BSD xterm window.

Kismet running in an OpenBSD xterm window, sniffing packets and observing wireless network activity at the Greyhouse coffeeshop in West Lafayette, Indiana. And yes, they really want you to use their WLAN, so you'll hang out there and buy more coffee.