HCIA-WLAN key terms

The human-readable network name broadcast in WLAN beacon and probe frames so that clients can identify and join a specific wireless service. It is a logical label, not a security mechanism.

The 48-bit MAC address that uniquely identifies a basic service set, typically the radio interface address of the access point or the address of a specific virtual access point.

A basic service set is the smallest WLAN building block: one access point radio serving a group of associated client stations on a single channel.

An extended service set joins multiple basic service sets, usually on different channels and access points, under one logical network name so clients can roam while keeping the same SSID.

A management frame a WLAN access point transmits periodically to advertise its SSID, supported rates, security settings, and capabilities, allowing nearby stations to discover the network.

A management frame a client station sends to discover nearby WLANs, either naming a specific SSID or asking for any network; access points answer with probe responses.

The process by which a client station joins an access point after authentication, agreeing on capabilities and rates so the access point can forward its traffic onto the wired network.

Carrier sense multiple access with collision avoidance is the 802.11 channel access method in which stations wait for an idle medium, back off, and use acknowledgements because they cannot reliably detect collisions.

The distributed inter-frame space is the fixed waiting period a station observes after the medium becomes idle before starting a backoff countdown for normal data transmission.

An optional handshake in which a station sends a request-to-send frame and the access point replies with clear-to-send, reserving the medium and reducing hidden-node collisions at the cost of overhead.

A station that can reach the access point but cannot hear another station on the same channel, so its transmissions may collide at the access point without being detected.

The process in which a client moves between access points or bands while keeping its session, involving scanning, choosing a target, and re-authenticating or re-associating with the new access point.

An early WLAN amendment operating in the 5 GHz band with orthogonal frequency-division multiplexing and a maximum data rate of 54 Mbit/s; it is not interoperable with 2.4 GHz-only devices.

A 2.4 GHz WLAN amendment that uses OFDM to reach 54 Mbit/s while remaining backward compatible with 802.11b devices, which forces protection mechanisms and lowers real throughput.

The amendment that introduced MIMO, wider 40 MHz channels, and frame aggregation, raising theoretical rates to 600 Mbit/s and supporting both 2.4 GHz and 5 GHz operation.

A 5 GHz-only amendment adding wider channels, more spatial streams, and downlink multi-user MIMO, with rates in the gigabit range and mandatory support for 80 MHz channels.

Also called Wi-Fi 6, this amendment improves efficiency in dense environments using OFDMA, uplink and downlink multi-user MIMO, higher-order modulation, and better power saving.

Orthogonal frequency-division multiplexing splits a channel into many closely spaced subcarriers, each carrying low-rate data, which improves robustness against multipath and is the basis of modern WLAN rates.

Orthogonal frequency-division multiple access assigns subsets of subcarriers, called resource units, to different clients within one transmission, letting an access point serve many stations efficiently at once.

Multiple-input multiple-output uses several transmit and receive antennas to send parallel spatial streams or to improve signal reliability, multiplying throughput without extra spectrum.

Combining adjacent channels into a wider one, such as 40, 80, or 160 MHz, to raise peak data rates, at the cost of fewer non-overlapping channels and more chance of interference.

Degradation caused when multiple access points or clients transmit on the same channel in overlapping coverage, forcing them to share airtime and contend for the medium.

The share of time a radio spends transmitting or receiving a given traffic class; airtime utilization is a key capacity metric because WLAN clients contend for a shared medium.

A virtual access point is a logical WLAN service instance on a physical access point radio, each with its own SSID, security policy, and VLAN mapping, allowing one radio to serve multiple networks.

A configuration container on a Huawei access controller that groups access points so that common profiles, such as radio, VAP, and security settings, are applied consistently to all members.

The control and provisioning of wireless access points protocol tunnels management traffic over UDP between access points and an access controller, carrying configuration and optionally client data.

An access controller centralizes WLAN management: it provisions access points, enforces security policy, and can forward client traffic, depending on whether it operates in tunnel or direct-forwarding mode.

An access point bridges wireless clients onto the wired LAN, terminating 802.11 radio links and forwarding traffic either through the controller tunnel or locally depending on its forwarding mode.

A Huawei access point model that does not run standalone and must obtain configuration from an access controller, which simplifies management and is typical for enterprise deployments.

A Huawei access point model that runs its full configuration locally without a controller, suitable for small sites but lacking centralized management, roaming coordination, and unified policy.

A forwarding mode in which the access point sends client traffic straight onto the local wired network rather than tunneling it to the controller, reducing controller load and latency.

A forwarding mode in which all client traffic is encapsulated to the access controller before reaching the network, centralizing policy enforcement but consuming controller bandwidth.

The Huawei mechanism of attaching reusable configuration profiles, such as radio, VAP, and regulatory profiles, to an AP group so member access points inherit settings automatically.

Power over Ethernet delivers DC power to access points over the same twisted-pair cable as data, following standards such as 802.3af and 802.3at that differ in available wattage.

A WLAN security mode using a pre-shared key with AES-based CCMP encryption, common in small networks where no central authentication server is deployed.

A WLAN security mode in which each client authenticates to a RADIUS server through 802.1X/EAP and derives unique encryption keys, avoiding a shared pre-shared key.

A port-based access control standard that keeps a client unauthorized until it completes an EAP exchange with an authenticator and an authentication server.

The difference in decibels between received signal strength and background noise; higher values mean cleaner reception, and low values cause retries, lower rates, or disconnection.

Received signal strength indicator reports the power level at which a client or access point hears a signal, usually in dBm; it guides coverage checks and roaming thresholds.

The planning and validation process of measuring coverage, interference, and capacity at a site so that access point placement, channels, and power settings meet design goals.

A condition in which two nearby radios use channels whose frequency ranges intersect, such as adjacent 2.4 GHz channels, causing interference that degrades both networks.