一些用在wlan技术上的专用缩写

2368阅读 0评论2009-04-10 laicai2003
分类:系统运维


                          GLOSSARY and ACRONYMS
                Access point (AP)
                    Transmitter/receiver (transceiver) device
                    that commonly connects and transports data
                    between a wireless network and a wired network.
 
                AIFS
                    Arbitration Interframe Space. It is one of the
                    five different IFSs defined to provide priority
                    levels for access to the wireless media. It shall
                    be used by QSTAs to transmit data type frames
                    (MPDUs) and management type frames (MMPDUs).
 
                BSS
                    IEEE 802.11 Basic Service Set (Radio Cell). The
                    BSS of an AP comprises of the stations directly
                    associating with the AP.
 
                CW
                    Contention Window. It is the time period between
                    radio signal collisions caused by simultaneous
                    broadcast from multiple wireless stations.
                    The contention window is used to compute the
                    random backoff of the radio broadcast. The IEEE
                    802.11b does not specify the unit for the time
                    period. 
 
                CWP Factor
                    Contention Window Persistence Factor. It indicates
                    the factor used in computing new CW values on every
                    15 unsuccessful attempt to transmit an MPDU or an
                    MMPDU of a traffic category. It is a scaling factor
                    in units of 1/16 ths.
 
                IFS
                    Inter-Frame Space is the time interval between
                    frames. A STA shall determine that the medium
                    is idle through the use of the carrier sense
                    function for the interval specified. In other
                    words, the size of the IFS determines the length
                    of the backoff time interval of a device to the
                    medium. In this case, the medium is the radio
                    wave spectrum. The IEEE 802.11b standard does not
                    specify any unit for the time interval.
 
                BSS
                    IEEE 802.11 Basic Service Set (Radio Cell). The
                MAC
                    Medium Access Control. Layer 2 in the network
                    model.
 
                MPDU
                    MAC protocol data unit. The unit of data exchanged
                    between two peer MAC entities using the services
                    of the physical layer (PHY).
 
                MMPDU
                    Management type MAC protocol data unit.
 
                MSDU
                    MAC service data unit. Information that is
                    delivered as a unit between MAC service access
                    points.
 
                QBSS
                    Quality of service basic service set.
 
                QSTA
                    QoS station.
 
                STA (WSTA)
                    A non-AP IEEE 802.11 wireless station."
 
                AES
                    Advanced Encryption Standard
 
                AP  
                    Access point
               
                AID
                    Association IDentifier for wireless stations. 
 
                BSS
                    IEEE 802.11 Basic Service Set.
 
                CCMP
                    Code Mode/CBC Mac Protocol
                CEPT
                    European Conference of Postal and
                    Telecommunications Administrations.
 
                CRC
                    Cyclic Redundancy Check. 
 
                DSSS   
                    Direct-Sequence Spread Spectrum. 
               
                EAP
                    Extensible Authentication Protocol. 
 
                ERP
                    Extended Rate PHY
 
                FHSS   
                    Frequency-Hopping Spread Spectrum. 
               
                IAPP
                    Inter-Access-Point Protocol. 
               
                ICV
                    Integrity Check Value. 
 
                ISM
                    Industrial, Scientific, and Medical.
 
                MBSSID
                    Multiple Broadcast SSID
 
                MIC
                    Message Integrity Check. 
 
                MMH
                    Multi-Modal Hashing.
               
                OFDM
                    Orthogonal Frequency Division Multiplexing. 
 
                PHY
                    Physical Layer (Layer 1 in network model).
 
                PLCP
                    Physical Layer Convergence Procedure. 
 
                PMD
                    Physical Medium Dependent. 
 
                PSPF
                    Public Secure Packet Forwarding.
 
                RF
                    Radio Frequency.
 
                SS   
                    Spread-spectrum.
               
                SSID
                    Radio Service Set ID. 
               
                STA
                    IEEE 802.11 wireless station.
 
                U-NII 
                    Unlicensed National information Infrastructure
                  
                VLAN
                    Virtual LAN.
               
                WEP
                    Wired Equivalent Privacy.
               
                WGB
                    Work-group Bridge
 
                WPA
                    WiFi Protected Access
                         
                Access point   
                    Transmitter/receiver (transceiver) device
                    that commonly connects and transports data
                    between a wireless network and a wired network.
               
                Association
                    The service used to establish access point
                    or station mapping and enable STA invocation
                    of the distribution system services.
                    (Wireless clients attempt to connect to
                    access points.)
               
                Basic Rate
                    A data rate that is mandatory for client
                    devices to support in order for them to achieve
                    successful association.
 
                Basic Service Set
                    The IEEE 802.11 BSS of an AP comprises of the
                    stations directly associating with the AP.
 
                Bridge   
                    Device that connects two or more segments
                    and reduces traffic by analyzing the
                    destination address, filtering the frame,
                    and forwarding the frame to all connected
                    segments.
               
                Bridge AP
                    It is an AP that functions as a transparent
                    bridge between 2 wired LAN segments. 
 
                Broadcast SSID
                    Clients can send out Broadcast SSID Probe
                    Requests to a nearby AP, and the AP will
                    broadcast its own SSID within its beacons
                    to response to the clients. Clients can use
                    this Broadcast SSID to associate and
                    communicate with the AP. 
 
                Cyclic Redundancy Check
                    CRC is an error detect mechanism that applies
                    to frame transmission.
               
                Direct-Sequence Spread Spectrum
                    DSSS combines a data signal at the sending
                    station with a higher data rate bit sequence,
                    which many refer to as a chipping code (also
                    known as processing gain).  A high processing gain
                    increases the signals resistance to interference. 
                    DSSS sends a specific string of bits for each data
                    bit sent.
 
                ERP-CCK Modulation
                    This signal modulation technique is supported in
                    PHY implementing IEEE 802.11b/g Protocol.
               
                ERP-OFDM Modulation
                    This signal modulation technique is supported in
                    PHY implementing IEEE 802.11g Protocol.    
    
                Extensible Authentication Protocol
                    EAP acts as the interface between a wireless
                    client and an authentication server, such as a
                    RADIUS server, to which the access point
                    communicates over the wired network.
 
                Extended Rate PHY
                    This PHY implements the IEEE 802.11g Protocol.
 
                Frequency-Hopping Spread Spectrum
                    In FHSS, a hopping code determines the frequencies
                    the radio will transmit and in which order.  To
                    properly receive the signal, the receiver must be
                    set to same hopping code and listen to the
                    incoming signal at the right time and correct
                    frequency.  The code pattern maintains a single
                    logical channel.
               
                IEEE 802.11   
                    Standard to encourage interoperability among
                    wireless networking equipment.
               
                IEEE 802.11b   
                    High-rate wireless LAN standard for wireless
                    data transfer at up to 11 Mbps.
               
                IEEE P802.11g
                    Higher Speed Physical Layer (PHY) Extension to
                    IEEE 802.11b, will boost wireless LAN speed to 54
                    Mbps by using OFDM (orthogonal frequency division
                    multiplexing).  The IEEE 802.11g specification is
                    backward compatible with the widely deployed IEEE
                    802.11b standard.
 
                Inter-Access-Point Protocol
                    The IEEE 802.11 standard does not define how
                    access points track moving users or how to
                    negotiate a handoff from one access point to the
                    next, a process referred to as roaming.  IAPP is
                    a Cisco proprietary protocol to support roaming. 
                    However, IAPP does not address how the wireless
                    system tracks users moving from one subnet to
                    another.
               
                Independent network   
                    Network that provides peer-to-peer connectivity
                    without relying on a complete network
                    infrastructure.
               
                Integrity Check Value
                    The WEP ICV shall be a 32-bit value containing
                    the 32-bit cyclic redundancy code designed for
                    verifying wireless data frame integrity.  
 
                Message Integrity Check
                    A MIC can, optionally, be added to WEP-encrypted
                    802.11 frames.  MIC prevents attacks on encrypted
                    packets.  MIC, implemented on both the access point
                    and all associated client devices, adds a few bytes
                    to each packet to make the packets tamper-proof. 
               
                Native VLAN ID
                    A switch port and/or AP can be configured with a
                    'native VLAN ID'.  Untagged or priority-tagged
                    frames are implicitly associated with the native
                    VLAN ID.  The default native VLAN ID is '1' if
                    VLAN tagging is enabled.  The native VLAN ID is '0'
                    or 'no VLAN ID' if VLAN tagging is not enabled.
               
                Node   
                    Device on a network; has its own unique network
                    address and name.
               
                Non-Root Bridge
                    This wireless bridge does not connect to the main
                    wired LAN segment.  It connects to a remote wired
                    LAN segment and can associate with root bridges and
                    other non-root bridges that accept client
                    associations.  It also can accept associations from
                    other non-root bridges, repeater access points,
                    and client devices.
               
                Physical Layer Convergence Procedure
                    In IEEE 802.11 wireless LANs, PLCP defines a method
                    of mapping the IEEE 802.11 MAC sublayer protocol
                    data units into a framing format suitable for
                    sending and receiving user data and management
                    information between two or more wireless stations
                    using the associated PMD system. 
 
                Physical Medium Dependent
                    In IEEE 802.11 wireless LANs, a PMD system, whose
                    function defines the characteristics of, and method
                    of transmitting and receiving data through, a
                    wireless medium between two or more wireless
                    stations each using the DSSS.
 
                Preamble
                    The radio preamble are data at the head of a
                    packet that contains information access points
                    and client devices required by IEEE 802.11 when
                    sending and receiving packets.
 
                Primary LAN
                    In an AP, if the destinations of inbound unicast
                    frames are unknown, the frames are sent toward
                    the primary LAN defined on the device.
               
                Radio carrier   
                    Radio waves that deliver energy to a remote
                    receiver; in other words, radio waves in a
                    wireless LAN environment.
               
                Repeater   
                    Device that connects multiple segments,
                    listening to each and regenerating the signal
                    on one to every other connected one; so that
                    the signal can travel further.
               
                Repeater or Non-root Access Point   
                    The repeater access point is not connected
                    to the wired LAN.  The Repeater is a wireless
                    LAN transceiver that transfers data between
                    a client and another access point, another
                    repeater, or between two bridges.  The repeater
                    is placed within radio range of an access point
                    connected to the wired LAN, another repeater, or
                    an non-root bridge to extend the range of the
                    infrastructure.
               
                Radio Frequency
                    Radio wave and modulation process or operation.
 
                Root Access Point   
                    This access point connects clients to the main
                    wired LAN.
               
                Root (Wireless) Bridge   
                    This wireless bridge connects to the main wired
                    LAN.  It can communicate with non-root wireless
                    bridges, repeater access points, and client
                    devices but not with another wireless root
                    bridge.  Only one wireless bridge in a wireless
                    LAN can be set as the wireless root bridge. 
               
                Spread-spectrum
                    Wideband radio frequency technique that
                    consumes more bandwidth than the narrow-band
                    alternative but produces a signal that is louder
                    and easier to detect.  There are two types of
                    spread-spectrum radio: frequency hopping and
                    direct sequence.
               
                Radio Service Set ID
                    SSID is a unique identifier that APs and clients
                    use to identify with each other.  SSID is a simple
                    means of access control and is not for security. 
                    The SSID can be any alphanumeric entry up to 32
                    characters.
               
                Tag header
                    A 'tag header' is as defined in the IEEE 802.1Q
                    standard.  An 802.1Q tag header contains a 3-bit
                    priority field and a 12-bit VLAN ID field.  
                    A 'priority tag' has a VLAN ID of 0, to indicate
                    'no VLAN ID'.  A 'VLAN tag' has a non-zero
                    VLAN ID.
               
                Virtual LAN
                    VLAN defined in the IEEE 802.1Q VLAN standard
                    supports logically segmenting of LAN
                    infrastructure into different subnets or
                    workgroups so that packets are switched only
                    between ports within the same VLAN. 
               
                VLAN ID
                    Each VLAN is identified by a 12-bit 'VLAN ID'.  
                    A VLAN ID of '0' is used to indicate
                    'no VLAN ID'.  Valid VLAN IDs range from '1' to
                    '4095'.  VLAN of ID '4095' is the default VLAN
                    for Cisco VoIP Phones.
               
                Wired Equivalent Privacy
                    WEP is generally used to refer to 802.11
                    encryption.
 
                Work-group Bridge
                    It is a client to APs or wireless root bridges.
                    The radio port of a WGB serves as the uplink to
                    the main network and the Ethernet port provides
                    network access for devices like PC or IP phone.
 
                Upgrade of Frequencies
                    As per the latest regulations proposed by the
                    Japanese Government, the four channels 34
                    ( 5170 GHz ), 38 ( 5190 GHz), 42 ( 5210 ) and
                    44 ( 5230 ) in the 5150-5250 MHz band has been
                    shifted by 10 MHz. Thus, the new channels in the
                    5150-5250 MHz band  are 36 ( 5180 ), 40 ( 5200 )
                    and 44 ( 5220 ) and 48 ( 5240 )."
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