Wireless LAN Topologies

Question 1

What are the 4 types of wireless networks?

Answer 1

WPAN (wireless personal-area network)
WLAN (wireless local-area network)
WMAN (wireless metropolitan-area network)
WWAN wireless wide-area network)

Question 2

With WPAN, what IEEE standard is it based on and how large an area does it cover?

Answer 2

802.15 (includes technologies like bluetooth and zigbee)

Usually covers about 20 to 30 feet.

Question 3

Wit WLAN, what IEEE standard is it based on and how large an area does it cover?

Answer 3

802.11

Covers up to 300 feet.

Question 4

What frequencies are usually used for WPAN?

Answer 4

Unlicensed ISM frequencies including 2.4GHz.

Question 5

With WMAN, what IEEE standard is it based on and what frequencies are commonly used?

Answer 5

802.16 (one example - WiMAX)

Licensed frequencies are commonly used.

Question 6

What is the typical device used in WWAN?

Answer 6

Mobile phone

Question 7

Wifi communications operate at what kind of duplex?

Answer 7

Half-duplex

Question 8

What does BSS stand for and what is it?

Answer 8

Basic Service Set

Closed group of mobile devices that forms around a fixed device (AP)

Question 9

What does BSA stand for and what is it?

Answer 9

Basic Service Area

Area where the AP’s signal is usable which is also referred to as a cell.

Question 10

What does BSSID stand for and what is it?

Answer 10

Basic Service Set Identifier

AP uses a unique BSS identifier to advertise itself and it is based on the AP’s own radio MAC address.

Question 11

What does SSID stand for and what is it?

Answer 11

Service Set Identifier

A non-unique, human-readable name that identifies a wireless service.

Question 12

What is membership with the BSS called?

Answer 12

Association

Question 13

What is a device that has associated to an AP called?

Answer 13

Client or 802.11 station (STA)

Question 14

What is the upstream wired Ethernet for the wireless BSS called?

Answer 14

Distribution system (DS)

Question 15

What does ESS stand for and what is it?

Answer 15

Extended Service Set

Multiple APs that are connected by a common switched infrastructure.

Question 16

What does IBSS stand for and what is it?

Answer 16

Independent Basic Service Set

IBSS allows two or more wireless clients to communicate directly without an AP.

Question 17

What is another name for IBSS?

Answer 17

Ad hoc network

Question 18

What is the function of an AP configured for repeater mode?

Answer 18

It takes the signal it receives and repeats or retransmits it.

Question 19

What does a workgroup bridge do?

Answer 19

Connects a device’s wired network adapter to a wireless network.

Question 20

What are two types of workgroup bridges and how do they differ?

Answer 20

Universal workgroup bridge (uWGB - only allows a single wired device to be bridged - can associate with Cisco and non-Cisco access points)

Workgroup bridge (WGB - Cisco proprietary implementation that allows multiple wired devices to be bridged - only associate with Cisco access point)

Question 21

How does a mesh network typically work?

Answer 21

Multiple AP leverage their dual radios to provide a wireless infrastructure. Clients may be associated using the 2.4GHz band while traffic is backhauled to APs with a wired infrastructure on the 5GHz bands.