Definizioni

Access control

The prevention of unauthorized usage of resources.

Access point (AP)

Any entity that has station functionality and provides access to the distribution services, via the wireless medium (WM) for associated stations.

Ad hoc network

A network composed solely of stations within mutual communication range of each other via the wireless medium (WM). An ad hoc network is typically created in a spontaneous manner. The principal distinguishing characteristic of an ad hoc network is its limited temporal and spatial extent. These limitations allow the act of creating and dissolving the ad hoc network to be sufficiently straightforward and convenient so as to be achievable by nontechnical users of the network facilities; i.e., no specialized "technical skills" are required and little or no investment of time or additional resources is required beyond the stations that are to participate in the ad hoc network. The term ad hoc is often used as slang to refer to an independent basic service set (IBSS).

Association

The service used to establish access point/station (AP/STA) mapping and enable STA invo-cation of the distribution system services (DSSs).

Authentication

The service used to establish the identity of one station as a member of the set of stations authorized to associate with another station.

Basic service area (BSA)

The conceptual area within which members of a basic service set (BSS) may communicate.

Basic service set (BSS)

A set of stations controlled by a single coordination function.

Basic service set (BSS) basic rate set

The set of data transfer rates that all the stations in a BSS will be capable of using to receive frames from the wireless medium (WM). The BSS basic rate set data rates are preset for all stations in the BSS.

Broadcast address

A unique multicast address that specifies all stations.

Channel

An instance of medium use for the purpose of passing protocol data units (PDUs) that may be used simultaneously, in the same volume of space, with other instances of medium use (on other channels) by other instances of the same physical layer (PHY), with an acceptably low frame error ratio due to mutual interference. Some PHYs provide only one channel, whereas others provide multiple channels.

Clear channel assessment (CCA) function

That logical function in the physical layer (PHY) that determines the current state of use of the wireless medium (WM).

Confidentiality

The property of information that is not made available or disclosed to unauthorized individuals, entities, or processes.

Coordination function

The logical function that determines when a station operating within a basic service set (BSS) is permitted to transmit and may be able to receive protocol data units (PDUs) via the wire-less medium (WM). The coordination function within a BSS may have one point coordination function (PCF) and will have one distributed coordination function (DCF).

Coordination function pollable

A station able to (1) respond to a coordination function poll with a data frame, if such a frame is queued and able to be generated, and (2) interpret acknowledgments in frames sent to or from the point coordinator.

Deauthentication

The service that voids an existing authentication relationship.

Directed address

See: Unicast frame.

Disassociation

The service that removes an existing association.

Distributed coordination function (DCF)

A class of coordination function where the same coordination function logic is active in every station in the basic service set (BSS) whenever the network is in operation.

Distribution

The service that, by using association information, delivers medium access control (MAC) service data units (MSDUs) within the distribution system (DS).

Distribution system (DS)

A system used to interconnect a set of basic service sets (BSSs) and integrated local area networks (LANs) to create an extended service set (ESS).

Distribution system medium (DSM)

The medium or set of media used by a distribution system (DS) for communications between access points (APs) and portals of an extended service set (ESS).

Distribution system service (DSS)

The set of services provided by the distribution system (DS) that enable the medium access control (MAC) to transport MAC service data units (MSDUs) between stations that are not in direct communication with each other over a single instance of the wireless medium (WM).
These services include transport of MSDUs between the access points (APs) of basic service sets (BSSs) within an extended service set (ESS), transport of MSDUs between portals and BSSs within an ESS, and transport of MSDUs between stations in the same BSS in cases where the MSDU has a multicast or broad-cast destination address or where the destination is an individual address, but the station sending the MSDU chooses to involve DSS. DSSs are provided between pairs of IEEE 802.11 MACs.

Extended rate set (ERS)

The set of data transfer rates supported by a station (if any) beyond the extended service set (ESS) basic rate set. This set may include data transfer rates that will be defined in future physical layer (PHY) standards.

Extended service area (ESA)

The conceptual area within which members of an extended service set (ESS) may communicate. An ESA is larger than or equal to a basic service area (BSA) and may involve several basic service sets (BSSs) in overlapping, disjointed, or both configurations.

Extended service set (ESS)

A set of one or more interconnected basic service sets (BSSs) and inte-grated local area networks (LANs) that appears as a single BSS to the logical link control layer at any station associated with one of those BSSs.

Gaussian frequency shift keying (GFSK)

A modulation scheme in which the data is first filtered by a Gaussian filter in the baseband and then modulated with a simple frequency modulation.

Independent basic service set (IBSS)

A BSS that forms a self-contained network, and in which no access to a distribution system (DS) is available.

Infrastructure

The infrastructure includes the distribution system medium (DSM), access point (AP), and portal entities. It is also the logical location of distribution and integration service functions of an extended service set (ESS). An infrastructure contains one or more APs and zero or more portals in addition to the distribution system (DS).

Integration

The service that enables delivery of medium access control (MAC) service data units (MSDUs) between the distribution system (DS) and an existing, non-IEEE 802.11 local area network (via a portal).

Medium access control (MAC) management protocol data unit (MMPDU)

The unit of data exchanged between two peer MAC entities to implement the MAC management protocol.

Medium access control (MAC) protocol data unit (MPDU)

The unit of data exchanged between two peer MAC entities using the services of the physical layer (PHY).

Medium access control (MAC) service data unit (MSDU)

Information that is delivered as a unit between MAC service access points (SAPs).

Minimally conformant network

An IEEE 802.11 network in which two stations in a single basic service area (BSA) are conformant with ISO/IEC 8802-11: 1999.

Mobile station

A type of station that uses network communications while in motion.

Multicast

A medium access control (MAC) address that has the group bit set. A multicast MAC service data unit (MSDU) is one with a multicast destination address. A multicast MAC protocol data unit (MPDU) or control frame is one with a multicast receiver address.

Network allocation vector (NAV)

An indicator, maintained by each station, of time periods when transmission onto the wireless medium (WM) will not be initiated by the station whether or not the station’s clear channel assessment (CCA) function senses that the WM is busy.

Point coordination function (PCF)

A class of possible coordination functions in which the coordination function logic is active in only one station in a basic service set (BSS) at any given time that the network is in operation.

Portable station

A type of station that may be moved from location to location, but that only uses net-work communications while at a fixed location.

Portal

The logical point at which medium access control (MAC) service data units (MSDUs) from a non-IEEE 802.11 local area network (LAN) enter the distribution system (DS) of an extended service set (ESS).

Privacy

The service used to prevent the content of messages from being read by other than the intended recipients.

Reassociation

The service that enables an established association [between access point (AP) and station (STA)] to be transferred from one AP to another (or the same) AP.

Station (STA)

Any device that contains an IEEE 802.11 conformant medium access control (MAC)

and physical layer (PHY) interface to the wireless medium (WM).

Station basic rate

A data transfer rate belonging to the extended service set (ESS) basic rate set that is used by a station for specific transmissions. The station basic rate may change dynamically as frequently as each medium access control (MAC) protocol data unit (MPDU) transmission attempt, based on local considerations at that station.

Station service (SS)

The set of services that support transport of medium access control (MAC) service data units (MSDUs) between stations within a basic service set (BSS).

Time unit (TU)

A measurement of time equal to 1024 µs.

Unauthorized disclosure

The process of making information available to unauthorized individuals, entities, or processes.

Unauthorized resource use

Use of a resource not consistent with the defined security policy.

Unicast frame

A frame that is addressed to a single recipient, not a broadcast or multicast frame. Syn: Direct sddress.

Wired equivalent privacy (WEP)

The optional cryptographic confidentiality algorithm specified by IEEE 802.11 used to provide data confidentiality that is subjectively equivalent to the confidentiality of a wired local area network (LAN) medium that does not employ cryptographic techniques to enhance privacy.

Wireless medium (WM)

The medium used to implement the transfer of protocol data units (PDUs) between peer physical layer (PHY) entities of a wireless local area network (LAN).

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