Tag Archives: CCNA Wireless chapter 3

CCNA Wireless Chapter 3, 4 and 5 Exam Answers

1.Wavelength can be described as…
The distance between successive crests of a wave

2.What is the wavelength of AM radio waves?
400-500M

3.What is the wavelength of satellite waves?
1MM

4.As frequency increases, distance travelled
Decreases

5. 1mhz is 1 million cycles per second

6. 1ghz is 1 billion cycles per second

7. Gain provided by antennae helps to cancel out ___________ from cabling
Loss

8.The EIRP calculation is…
EIRP = transmitter O/P power – cable loss + antenna gain

9.Free path loss is a result of attenuation and not interference

10. As amplitude increases range increases

11.Reduction of amplitude is aka absorption

12.Absorption creates heat

13.The main issue presented by reflection is Multi path interference

14.What is multipath interference?
When two copies of the same signal arrive out of phase with eachother, and weaken or cancel eachother out

15.What is scattering
When a signal is reflected by objects which are reflective but have jagged edges

16.What is refraction
The changing or bending of a wave as it passes through something of a different density

17.Dryness refracts signals away from earth

18.Humidity refracts signals towards earth

19.RSSI is received signal strength indicator

20.A potential replacement for RSSI is receive channel power indicator

21.What is SNR?
Signal to noise ratio, how much stronger a received signal is than the underlying noise, it is measured in dB

22.What is link budget?
Value which accounts for gains/losses between tx and rx

23.What is the link budget equation?
Received power (dBm) = (tx power + gains – losses)

24.3 types of polarization for antennae are:
1) Vertical
2) Horizontal
3) Circular

25.In an electromagnetic field, the magnetic field is perpendicular  to the electric field

26.Cisco antennae all have vertical polarization

27.What is diversity?
The use of two antennae for each radio to increase the odds of a better signal

28.What has to be the same about each antennae in a diversity scenario?
Their orientation

29.Diversity is used to fight…
Multi path interference issues

30. 2 main types of antennae are
1) Directional
2) Omnidirectional

31. The h-plane of an antenna is aka
The azimuth

32.The e-plane shows how a signal would propagate vertically

33.The 2.2 dBi dipole antenna is aka the rubber ducky antenna

34.The loss incurred by a cable is usually referred to as the cable loss specification

35.3 types of antenna connectors are…
1) RP-TNC
2) N-connector
3) SMA (2 types)

36.2 subtypes of SMA connectors are
RP-SMA and SMA-RS

37.Attenuators reduce signal

38.Amplifiers add active gain to compensate for cable loss

39.Active gain means gain is added without focus change

40.What shunts lightning surges before they reach the wired LAN lightning arrestors

41.Do lightning arrestors protected against direct strikes?
no

42.What are used to send a signal in two different directions?
Splitters

43.The range of a WPAN would be..
<5-10m, or 20 feet

44.WPAN’s use the 2.4ghz spectrum

45.Bluetooth is an example of a WPAN

46.Bluetooth uses what for an emission method
FHSS

47.Generally, clients in a WLAN are _______ or less from the access point
100m

48.An example of a WMAN is WiMAX

49.WiMAX could possibly replace T1 AND T3 technologies

50.Is it ideal for a WMAN to use ISM frequencies?
no

51.Do WWAN’s have high data rates?
no

52.The most popular versions of WWAN’s are… (2)
1) GSM
2) CDMA

53.Two original versions of 802.11 topologies:
1) Ad-hoc, no central point
2) Infrastructure, has a central point

54.The coverage area of an AP is called the
BSA

55.The wired network is aka the…
Distribution system

56.2 or more BSA’s make an…
ESA

57.The process of clients moving AP’s called…
Roaming

58.An SSID is a combination of what two things
MAC address and network name

59.AP’s can have up to __ SSID’s
16

60.An AP offering more than one NW called a
MBSSID

61.What is an AWGB
Connects to upstream AP’s and allows wired ethernet clients to connect as non-standard clients

62.What is an UWGB
Allows single wired device to be bridged upstream to an AP as a standard device

63.Overlap needed for a wireless repeater is…
50%

64.Original AP in a repeated wireless network is called…
The root device

65.Outdoor wireless bridges operate at what layer of the OSI model
L2

66.What is used to determine the best path in a wireless mesh network?
AWPP protocol