Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
19 Cards in this Set
- Front
- Back
|
he original IEEE 802.11 standard established in 1999 was for WLANs operating at what maximum speed?
|
2Mbps
|
|
|
The maximum mandatory speed of an IEEE 802.11a WLAN, according to the standard is _________.
|
54Mbps
|
|
|
IEEE 802.11a achieves its increase in speed and flexibility over 802.11b by each of the following except .
|
lower bandwdth
|
|
|
The Unlicensed National Information Infrastructure (U-NII) band operates at the frequency.
|
5Ghz
|
|
|
The Federal Communications Commission (FCC) has segmented the 300 MHz of the original U-NII spectrum into three segments or bands and each band has a maximum power limit. True or False?
|
True
|
|
|
The 5 GHz bands are available to WLANs worldwide. True or false?
|
False
|
|
|
Although other devices such as 2.4 GHz cordless phones, microwave ovens, and Bluetooth devices may cause interference problems with 802.11b networks in the 2.4 GHz ISM band, these devices are not a problem with 802.11a. True or false?
|
True
|
|
|
Within each frequency channel in an 802.11a WLAN there is a channel 20 MHz wide that supports 52 carrier signals. True or false?
|
True
|
|
|
A problem with 802.11a WLANs is the multipath distortion of the radio frequency (RF) signals that bounce off walls and furniture and are delayed reaching the receiver. True or false?
|
False
|
|
|
OFDM uses _______ subchannels for data, and four are used for error correction.
|
48
|
|
|
Although 54 Mbps is the "official" top speed of 802.11a, the IEEE specification also allows for vendor-implemented higher speeds known as turbo or ___________.
|
2x or 108 Mbps
|
|
|
The IEEE __________ standard incorporates the stable and widely accepted features of 802.11b with the increased data transfer rates to those similar to 802.11a.
|
802.11g
|
|
|
Using 8 channels in a single area, 802.11a allows you to have a maximum data bandwidth of ____________.
|
432 Mbps
|
|
|
Explain the benefit of 802.11e for WLANs.
|
802.11e adds QoS capabilities and enhances the MAC protocol. It will permit 802.11 WLANs to prioritize voice and video traffic.
|
|
|
What are the types of systems with which HiperLAN/2 can connect?
|
Cellular telephone systems, Asynhronous Transfer Mode, IEEE 1394 (Firewire)
|
|
|
What are some advantages and disadvantages of IEEE 802.11a WLANs?
|
Faster than 802.11b and g, operates on 5 GHz band and is not subject to interference from cordless phones, microwaves or Bluetooth, 8 simultaneous channels. Not backwards compatible with 802.11b, shorter range than 802.11b, also does not support QoS.
|
|
|
What are the maximum transmitter power specifications for each of the three original UNII frequency bands?
|
UNII Low 40 mW, Middle 200 mW, High 800 mW
|
|
|
What is authentication? What is the disadvantage of the authentication included in the 802.11 standards and what kind of authentication should be considered for WLANs?
|
Authentication is the process of establishing if a user is authorized to communicate on the network. 802.11 authenticates the device only, but not the user. RADIUS authentication should be considered to increase the security of WLANs.
|
|
|
List three shortcomings of WEP.
|
24 bit IV is sent unencrypted; uses a weak implementation of the RC4 algorithm; uses static keys; uses a single pair of keys for the entire network
|
