MIS 410 Mid Term Study Guide Chapter 6
There is an access point that serves eight wireless hosts. On how many channels will these devices transmit and receive during the course of an hour or two?
1
The 5 GHz band usually supports about ________ non-overlapping 20 MHz channel(s).
12
A wireless host sends a packet to a server on the company's wired Ethernet LAN via an access point. How many frames will be involved in this one-way transmission?
2
In 802.11g, channel bandwidth usually is ________.
20 MHz
The 2.4 GHz band supports ________ possible non-overlapping 20 MHz channel(s).
3
In the 5 GHz band, how many channels can you have with 802.11ac with 80 GHz channels?
6
We use the terms Wi-Fi and ________ interchangeably in this book.
802.11
Wi-Fi Standards come from the ________ Working Group
802.11
Today, Wi-Fi sales are dominated by ________.
802.11ac
Which of the following is the newest Wi-Fi standard?
802.11ac
Which of the following only operates in the 5 GHz band?
802.11ac
The standard for roaming among access points is ________.
802.11r
Which of the following is more efficient and faster?
CSMA/CA+ACK
________ is a technique for preventing two wireless stations from transmitting at the same time and therefore interfering with each other.
Media access control
An access point can transmit to more than one wireless client at a time with ________.
Multiuser MIMO
A channel extends from 55 MHz to 60 MHz. Its bandwidth is ________.
None of these
Wireless network standards are ________ standards.
OSI
In ________, when a wireless host wishes to send, it first sends a message to the wireless access point asking for permission to send. When the access point sends back a response, the host sending the original message may transmit. All other hosts must wait.
RTS/CTS
To use an access point, you need to know its ________.
SSID
What happens if two nearby access points use the same channel?
They will interfere with each other.
________ have SSIDs.
Wireless access points
The other wireless device is far away in a known direction. It would be better to use ________.
a dish antenna
At 10 meters, a signal has a strength of 100 mW. About how strong will it be at 40 meters?
about 6 mW
What propagation problem is especially bad in moist air?
absorptive attenuation
In CSMA/CD+ACK, when a wireless NIC wishes to transmit, it listens for traffic. If there is traffic, it waits. When the traffic stops, it may transmit immediately.
always false
802.11 standards are being developed to work in the ________ unlicensed band.
both 2.4 GHz and 5 GHz
Which of the following uses OFDM?
both 802.11ac and 802.11n
Media access control governs transmission by ________.
both access points and wireless hosts
An extended service set (ESS) is a group of BSSs that ________.
both are connected to the same distribution system and have the same SSID
Beamforming can allow an access point to ________.
both direct power to individual clients and send signals to two different clients at the same time
Channels with wide bandwidths are called ________ channels.
broadband
To handle multiple conversations in radio transmission, you normally use multiple ________.
channels
If two products both comply with 802.11 ac, they should have close to the same performance.
false
Radio transmission is measured in terms of ________.
frequency
Wireless radio transmission speed is usually measured in terms of ________.
frequency
Frequency is measured in terms of ________.
hertz
Wider channel bandwidth ________.
increases transmission speed
If more users move to an access point, this decreases ________.
individual throughput
Spread spectrum transmission is used in WLANs because ________.
it is required by regulators
Companies are moving to the 5 GHz band because there is ________ than in the 2.5 GHz band
more bandwidth
Spread spectrum transmission is used in WLANs for ________.
more reliable transmission
The most serious problem with wireless transmission in WLANs is ________.
multipath interference
In an extended service set, each access point ________.
must have the same SSID
A cellular telephone uses a(n) ________.
omnidirectional antenna
Access points take ________ from wireless devices and send them on to devices on the wired LAN. They also do the converse.
packets
CSMA/CD+ACK is ________.
reliable
Wireless access points typically link wireless clients to ________.
servers on the wired network
2.4 GHz and 5 GHz are ________.
service bands
A channel has more bandwidth than is necessary given data transmission speeds requirements in ________ transmission.
spread spectrum
Wireless network standards operate at ________.
the data link layer
MIMO ________.
transmits multiple signals in the same channel
Compared to wired transmission, propagation problems in radio transmission are ________.
worse
