Vol 2 - 1 Fundamentals of Wireless Networks

Question 1

access point (AP)

Answer 1

A device that provides wireless service for clients within its coverage area or cell, with the AP connecting to both the wireless LAN and the wired Ethernet LAN.

Question 2

ad hoc wireless network

Answer 2

See independent basic service set (IBSS).

Question 3

association

Answer 3

A negotiated relationship between a wireless station and an access point.

Question 4

association request

Answer 4

An 802.11 frame that a wireless client sends to an AP to request an association with it.

Question 5

association response

Answer 5

An 802.11 frame that a wireless access point sends to a wireless client in reply to an association request.

Question 6

band

Answer 6

A contiguous range of frequencies.

Question 7

basic service set (BSS)

Answer 7

Wireless service provided by one AP to one or more associated clients.

Question 7

basic service set identifier (BSSID)

Answer 7

A unique MAC address that is used to identify the AP that is providing a BSS.

Question 8

beacon

Answer 8

An 802.11 frame that an AP broadcasts at regular intervals to advertise the existence of an SSID. Separate beacons are transmitted for each SSID on each channel being used.

Question 9

cell

Answer 9

The area of wireless coverage provided by an AP; also known as the basic service area.

Question 9

channel

Answer 9

An arbitrary index that points to a specific frequency within a band.

Question 10

extended service set (ESS)

Answer 10

Multiple APs that are connected by a common switched infrastructure.

Question 10

distribution system (DS)

Answer 10

The wired Ethernet that connects to an AP and transports traffic between a wired and wireless network.

Question 10

extended service set identifier (ESSID)

Answer 10

The SSID used consistently throughout an ESS.

Question 11

independent basic service set (IBSS)

Answer 11

An impromptu wireless network formed between two or more devices without an AP or a BSS; also known as an ad hoc network.

Question 12

infrastructure mode

Answer 12

infrastructure mode
The operating mode of an AP that is providing a BSS for wireless clients.

Question 13

mesh network

Answer 13

A network of APs used to cover a large area without the need for wired Ethernet cabling; client traffic is bridged from AP to AP over a backhaul network.

Question 13

nonoverlapping channels

Answer 13

Successive channel numbers in a band that each have a frequency range that is narrow enough to not overlap the next channel above or below.

Question 14

point-to-point bridge

Answer 14

An AP configured to bridge a wired network to a companion bridge at the far end of a line-of-sight path.

Question 14

passive scanning

Answer 14

A technique used by a wireless client when it attempts to discover nearby APs by listening for their beacon frames.

Question 15

probe request

Answer 15

A technique used by a wireless client to discover nearby APs by actively requesting a response.

Question 16

reassociation request

Answer 16

An 802.11 frame that a roaming wireless client sends to an AP to request that its existing association be moved to a new AP.

Question 17

repeater

Answer 17

A device that repeats or retransmits signals it receives, effectively expanding the wireless coverage area.

Question 18

roaming

Answer 18

The process a wireless client uses to move from one AP to another as it changes location.

Question 19

Service Set Identifier (SSID)

Answer 19

A text string that is used to identify a wireless network.

Question 20

station (STA)

Answer 20

An 802.11 client device that is associated with a BSS.

Question 21

workgroup bridge (WGB)

Answer 21

An AP that is configured to bridge between a wired device and a wireless network. The WGB acts as a wireless client.