Glossary

Terms we use throughout the wiki with which you should become familiar.

BSS

BSS stands for Basic Service Set. The coverage of an access point is called a BSS.

cfg80211

Kernel side of configuration management for wireless devices. nl80211 is the User-space side of configuration management for wireless devices.

Works together with FullMAC-drivers and also with mac80211-based drivers.

CLI

CLI stands for Command-line interface. These are utilities you can run in the console or terminal emulator.

FullMAC

FullMAC is a term used to describe a type of wireless card where the MLME is managed in hardware. You would not use mac80211 to write a FullMAC wireless driver.

git-describe

git-describe is a git command. It outputs something like this:

v3.12-11297-g6579946

The first part is the tag for the current release. The second part is the number of patches which have been applied since the tag was applied. The last part, after the first g is the SHA1 commit ID of the last commit applied.

IBSS

IBSS stands for Independent Basic Service Set. Its basically Ad-Hoc mode. See Independent Basic Service Set

Information Element

An Information Element (IE) is a part of management frames in the IEEE 802.11 wireless LAN protocol. IEs are a device's way to transfer descriptive information about itself inside management frames. There are usually several IEs inside each such frame, and each is built of Type-length-value (TLVs).

The common structure of an IE is as follows:

|   1   |    1   |     1-255       |
+-------+--------+-----------------+
| Type  | Length |     Data        |
+-------+--------+-----------------+

Whereas the vendor specific IE looks like this:

|   1   |    1   |          4        |    1-251   |
+-------+--------+-------------------+------------+
|  221  | Length |        OUI        |     Data   |
+-------+--------+-------------------+------------+

iw

iw is a new nl80211 based CLI configuration utility for wireless devices.

nl80211

User-space side of configuration management for wireless devices. It is a Netlink-based user-space protocol. cfg80211 is Kernel side of configuration management for wireless devices.

Several user-space applications are available which utilize nl80211. See Developer Docs for nl80211.

mac80211

A driver API for SoftMAC WNICs. See Developer Docs for mac80211.

See also SoftMAC.

MAC

A WNIC works on both, Layer 1 and Layer 2 of the OSI model. MAC is a sub-layer for Layer2. Media Access Control

MLME

MLME Stands for Media Access Control (MAC) Sublayer Management Entity. MLME is the management entity where the Physical layer (PHY) MAC state machines reside. Examples of states a MLME may assist in reaching:

  • Authenticate
  • Deauthenticate
  • Associate
  • Disassociate
  • Reassociate
  • Beacon
  • Probe
  • Timing Synchronization Function (TSF)

mac80211's MLME management implementation is currently handled by net/mac80211/ieee80211_sta.c. This handles only the STA MLME

PHY

A WNIC works on both, Layer 1 and Layer 2 of the OSI model. PHY is abbreviation for physical-layer controller and refers to the hardware components of the WNIC, that are responsible for creating/producing the em waves conforming to the standards specified in the responsible standard, e.g. IEEE 802.11a.

See PHY and also Physical layer.

SoftMAC

SoftMAC is a term used to describe a type of WNIC where the MLME is expected to be managed in software. mac80211 is a driver API for SoftMAC WNIC, for example.

SSID

SSID stands for Service Set IDentifier. The SSID is a code attached to all packets on a wireless network to identify each packet as part of that network. The code consists of a string of 1-32 octets (usually represented as case sensitive alphanumeric characters).

See also SSID

Station (STA)

Station (or STA) is the generic term for a device with a radio that can communicate with other stations in a wireless network. Common forms of a station are access points (AP), computers, or phones.

See also Station_(networking) or Wireless access point.

WE

WE stands for Wireless-Extensions - the old driver API and user <�"> kernel communication transport. Obsoleted by #cfg80211

WEXT

WEXT stands for Wireless-Extensions - the old driver API and user <�"> kernel communication transport. Obsoleted by #cfg80211

WIPHY

Wireless PHY.

WNIC

The Wireless Network Interface Controller always refers to the hardware performing the functionality described in the standards family, i.e. IEEE 802.11. This can be an entire PCB (e.g. a mini PCIe wireless card), a single Chip or the functionality can even be integrated into a SoC.