WIRELESS COMMUNICATIONS Flashcards
1
Q
The most prevalent wireless technology
A
Cellphones
2
Q
The WLAN uses a device called
A
Access point
3
Q
Transfer rate for broadcast radio channel
A
upto 4Mbps
4
Q
Transfer rate for microwave radio
A
45Mbps
5
Q
Transfer rate for satellite radio channel
A
50Mbps
6
Q
Transfer rate for cellular radio channel
A
9600bps to 14.4kbps
7
Q
Transfer rate for infrared channel
A
1 to 4 Mbps
8
Q
___________ Transmission is when the original signal such as a voice, or digital signal is put directly into the medium
A
Baseband transmission
9
Q
This high frequency is added to the baseband signal so that it can radiate well in space
A
Carriers
10
Q
It is the process of adding the carrier signal to the baseband signal and then modulated to be amplified and then sent to the antenna
A
Broadband transmission
11
Q
when was the first LAN established?
A
1971
12
Q
The experiment in which the first LAN was established
A
ALOHANET
13
Q
The type of topology the ALOHANET used
A
Star topology network
14
Q
Give the wireless technology for Wireless Ethernet LAN
A
Wi-Fi 802.11
15
Q
Give the wireless technology for short-range wireless (commonly used in audio)
A
Bluetooth
16
Q
Give the wireless technology for home/industrial monitoring control
A
ZigBee 802.15.4
17
Q
Give the wireless technology for high speed and short-range for computer peripherals and video connections
A
Ultrawideband
18
Q
Give the wireless technology for MAN broadband wireless
A
WiMAX 802.16
19
Q
Give the wireless technology for wireless barcode used for tracking and ID
A
RFID
20
Q
Give the wireless technology for ultrashort range for smart cards and ID
A
NFC
21
Q
Give the wireless technology for mixed-used unlicensed short-range telemetry and control
A
ISM
22
Q
Give the wireless technology for optical wireless for control and data
A
IR
22
Q
Give the wireless technology for wireless telemetry and control and internet access
A
White space radio
23
Q
It is the interconnection between nodes
A
Communication link
24
A type of network that covers a large geographical area
WAN
25
Type of network that covers a city, town, or village
MAN
26
The smallest type of network
LAN
27
A short-range wireless network
PAN (Personal Area Network)
28
The generic term which refers to the IEEE 802.11 communications standard for WLAN
Wireless Fidelity (Wi-Fi)
29
WiFi radios that work with the 802.11b and 802.11g standards transmit up to _______
2.4GHz
30
The ISM Band for 802.11a
56GHz
31
radios used for WiFi have the ability to _______ frequencies
Change frequencies
32
It is a method of transmitting signals by rapidly switching the carrier between different frequency channels
Frequency Hopping
33
The advantage of this method is that it is more immune to interference and can allow dozens of WiFi cards to talk simultaneously
Frequency Hopping
34
It is the group of radio bands that are intentionally reserved for these radio frequency energy intended for scientific, medical and industrial requirements rather than for communications
ISM (Industrial, Scientific, Medical)
35
In this frequency band, interference occurs a lot
ISM (Industrial, Scientific, Medical)
36
The earliest useful and most widely adopted version of 802.11 standard
802.11b
37
The access method used in 802.11b
Direct Sequence Spread Spectrum (DSSS)
38
The 802.11b has ___ channels and ___ non-overlapping channels
11, 3
39
ISM Band for 802.11b
2.4GHz
40
the total bandwidth for 802.11b
83.5MHz
41
The maximum data rate for 802.11b
11 Mbps
42
The back-off rates for 802.11b
1, 2, 5.5 Mbps
43
The maximum distance at the maximum data rate of 802.11b
100m
44
The channels in 802.11b are spaced ____ apart over the spectrum
5MHz
45
Each channel in 802.11b is ___ wide, which is why they overlap
22MHz
46
a modulation technique used to achieve faster rates such as 11Mbps and 5.5Mbps
CCK (Complementary Code Keying)
47
This type of modulation technique improves the performance of the signal under noise and multipath conditions due to their unique codes and properties that make them easier to identify and decode
CCK(Complementary Code Keying)
48
The equivalent isotropic radiated power for 802.11b is
1 W
49
when did the IEEE 802 Executive Committee establish the 802.11 working group to create a WLAN standard?
1990
50
UNII meaning
Unlicensed National Information Infrastructure band
51
when did 802.11a come out?
1991
52
What is the ISM band for 802.11a?
5GHz
53
The three authorized frequency segments of 802.11a
5.15 GHz to 5.25 GHz - 50mW power
5.25 GHz to 5.35 GHz - 250mW power
5.725 GHz to 5.825 GHz - 1W max power
54
maximum power for 5.15 GHz to 5.25 GHz 802.11a frequency segment?
50mW power
55
maximum power for 5.25 GHz to 5.35 GHz 802.11a frequency segment?
250mW power
56
maximum power for 5.725 GHz to 5.825 GHz 802.11a frequency segment?
1W max power
57
The access method for the 802.11a standard?
Orthogonal Frequency Division Multiplexing (OFDM)
58
Compared to 802.11b, this standard offers a wide range of data rates. The highest is 54 Mbps
802.11a
59
Channels for 802.11
23 (nonoverlapping)
60
Each channel in the 802.11a standard carries an OFDM signal made up of __ subcarriers, ____ for data, and other _____ for error corrections.
52 subcarriers
48 for data
4 for error corrections
61
Each subcarrier in the 802.11a standard is ____ wide
300khz
62
The maximum data rate for 802.11a standard
54 Mbps
63
The back-off rates for 802.11a standard
48 Mbps, 36 Mbps, 24 Mbps, 18 Mbps, 12 Mbps, 9 Mbps, 6 Mbps
64
The maximum distance at the maximum rate of 802.11a standard
50m
65
The downside of 802.11a standard
short-range (the maximum distance is only 50m)
66
The modulation technique used in 802.11a standard with 6Mbps data rate
BPSK (Binary Phase-Shift Keying)
67
The modulation technique used in 802.11a standard with 12Mbps data rate
QPSK (Quadrature Phase-Shift Keying)
68
The modulation technique used in 802.11a standard with 24Mbps data rate
16- QAM (Quadrature Amplitude Modulation)
69
The modulation technique used in 802.11a standard with 54Mbps data rate
64-QAM 9(Quadrature Amplitude Modulation)
70
What access method is used in 802.11g that enables it to provide a maximum data rate of 54Mbps at 100ft indoors?
OFDM (Orthogonal Frequency Division Multiplexing)
71
The 802.11g is fully ______ compatible with 802.11b
backwards-compatible
72
The ISM band for 802.11g
2.4 GHz
73
This access method is used because it reduces multipath issues
OFDM (Orthogonal Frequency Division Multiplexing)
74
The channels for 802.11g
11 channels (3 non-overlapping)
75
The maximum data rate for 802.11g
54Mbps
76
The maximum distance at the maximum data rate in 802.11g is
100 ft
77
This standard uses Multiple Input Multiple Output antenna systems to improve the reliability of the link
802.11n
78
The access point for 802.11n uses _____ transmit antennas and ____ receive antennas
two or more transmit
three or more receive
79
This arrangement of 802.11n permits data range in the 100-600 Mbps range at a distance of up to 100m
MIMO (Multiple Input, Multiple Output), where multiple antennas are used for both transmitting (Tx) and receiving (Rx) signals.
80
This technology in 802.11 greatly mitigates multipath problems and helps extend the range and reliability of the wireless link
MIMO (Multiple Input, Multiple Output)
81
What standard dominates the Wireless LAN space today?
802.11n
82
What wireless technology is commonly available in laptops, smartphones, and tablets?
802.11n
83
it is the wireless technology of all hot spots and access points, including the millions of home wireless routers
802.11n
84
The 802.11n is backward compatible with _____ and _____
802.11a
802.11b
802.11g
85
The access method for 802.11n
OFDM (Orthogonal Frequency Division Multiplexing)
86
The maximum data rates for 802.11n
100 to 600Mbps
87
The maximum distance at the maximum data rate for 802.11n
100 m
88
This standard is one of the newest versions of 802.11
802.11ac
89
The ISM band for 802.11ac
5GHz
90
The 802.11ac uses ____ technology and ____ access method
MIMO (Multiple Input Multiple Output) antenna systems
OFDM (Orthogonal Frequency Division Multiplexing)
91
As the bandwidth increases in 802.11ac, the number of OFDM subcarriers also increases to a maximum of ____ at 160MHz bandwidth
512
92
It is a wireless LAN transceiver or "base station" that can connect one or many wireless devices simultaneously to the internet
Access Point (AP)
93
They accept the wireless signal and relay information
Wi-Fi cards
94
They are the firewalls and antivirus software, which protect the networks from uninvited users and keep information secure
Safeguards
95
A wifi hotspot is created by installing a/an ______ to an internet connection
Access Point
96
A single access point can support up to ____ users and can function within a range of ____ to ____ indoors and up to ____ outdoors
30 users
100-150 ft indoors
300 ft outdoors
97
Many access points can be connected to each other via ____ to create a single large network
Ethernet Cables
98
A computer's ____ translates data into a radio signal
wireless adapter
99
A _____ receives the signal from the wireless adapter and decodes it
wireless router
100
The wireless router sends the information received from the adapter to the internet via ________
physical wired ethernet connection
101
Wi-Fi radios transmit frequencies of ____ and _____
2.4 GHz to 5 GHz
102
Wi-Fi radios can transmit on any three frequency bands or they can _____ rapidly between bands
frequency hop
103
This helps reduce interference and lets multiple devices use the same wireless connection simultaneously
Frequency Hopping
104
in this Wi-Fi topology, the client communicates through the access point
AP-based topology (infrastructure)
105
The RF coverage is provided by an AP
Basic Service Area (BSA)
106
This extends the coverage network by combining two or more BSA
ESA (Extended service area)
107
The ESA (extended service area allows 10-15% overlap to allow _____
roaming
108
In this topology, access points are not required
Peer to Peer topology (Ad-hoc mode)
109
In this topology, client devices within a cell can communicate directly with each other.
Peer to Peer topology (Ad-hoc mode)
110
This topology is useful for setting up a wireless network quickly and easily
Peer to Peer topology (Ad-hoc mode)
111
This network topology is used to connect a LAN in one building to LANs in the other buildings even if the buildings are miles apart
Point to Multipoint bridge topology
112
The Point to Multipoint bridge topology creates a ____ between buildings
Line of Sight
113
This wifi configuration network is designed for small businesses and individuals operating within limited physical workspaces such as homes or small offices
Home/ SOHO (Small Office Home Office) network
114
This wifi network configuration is used for small public hotspot
Simple Wireless Network
115
This wifi network is used in homes and offices in which the hub, router, and Wi-Fi AP are all in a single device
CombinedWireless Network
116
This wireless security standard is the basic security protocol
WEP (Wireless Equivalent Privacy)
117
This security standard uses RC4 encryption standard and authentication
WEP (Wireless Equivalent Privacy)
118
This security standard may be turned off or on by the user
WEP (Wireless Equivalent Privacy)
119
This wifi security protocol has stronger encryption standards
Wi-Fi Protected Access
(WPA)
120
The IEEE has a wireless LAN standard that provides the ultimate protection. This standard is ________
802.11i
121
This is considered as the most popular PAN
Bluetooth
122
It is a digital radio standard that uses frequency-hopping spread spectrum (FHSS)
Bluetooth
123
What is FHSS that is used in Bluetooth
Frequency-Hopping Spread Spectrum
124
Bluetooth is a digital radio standard that uses frequency-hopping spread system (fhss) in the unlicensed _____ ISM band
2.4GHz
125
It is a wireless technology standard for exchanging data over short distances from fixed and mobile devices and building personal area networks
Bluetooth
126
when did Ericsson, Nokia, IBM, Toshiba and Intel formed the Bluetooth special interest group (SIG)
1998
127
Bluetooth protocol is released in
1999
128
in what year did the IEEE adopted the bluetooth standard, 802.15 working group
2002
129
It is a network of devices connected in an ad-hoc fashion using bluetooth technology
PICONET
130
Piconet can support up to how many devices?
8 devices
131
When a piconet is formed, one device acts as a _____ and the others act as __________
master
slaves
132
Piconet is sometimes called ____
PAN (Personalized Area Network)
133
two or more bluetooth units sharing the same channel form a _____
piconet
134
_____ cannot directly transmit data to one another
slaves
135
slaves can only have links to ___
master
136
____ acts as a switch for the piconet and all the traffic must pass through it
master
137
the slaves in a piconet use master's ___ and ____ to determine the frequency hopping sequence
bluetooth device address
clock
138
slaves ____ with master's clock for duration of the connection
synchronize
139
____ also controls when devices transmit data, since ____ can only transmit when scheduled by the master
master
slave
140
the _____ controls the total available bandwidth to be distributed to the ____
master
slaves
141
It is a group of non-synchronized piconets that share at least one common bluetooth device
Scatternet
142
in a scatternet communication, the blutooth device must have a ______ capability
point to multipoint
143
how many maximum loaded piconets are there in a scatternet
10 loaded piconets
144
it is formed when two or more piconets are interconnected
scatternet
145
____ is a standard for tiny radio frequency chips that can be plugged into your device
Bluetoooth
146
These chips were designed to take all the information wires normally send and transmit it to a special frequency called the __________
receiver bluetooth chip
147
Bluetooth uses _______ to send data
packet-switching
148
it is a device in piconet whose clock and sequence are used to synchronize all other devices in the piconet
Mater
149
This device carry out paging and connection establishment
Master
150
Units within the piconet that are synchronized to the master via its clock and hopping sequence
slaves
151
152
After connection establishment, slaves are assigned to a temporary 3-bit member address know as __________ to reduce the number of addressing bits required
Active Member Address
153
each piconet has a maximum capacity of _____
1Mbps
153
It is the interconnection of multiple piconets
scatternet
154
the _____ defines a protocol stack to enable heterogenous devices to communicate
The Bluetooth Standard
155
_____ includes protocols for the radio layer all the way up to device discovery, service dicovery, etc.
Bluetooth stack
156
It is composed of bluetooth protocols to allow bleutooth devices to locate each other and to create, configure, and manage both physical and logical links that allow higher layer protocols and applications to pass data through these transport protocols
Bluetooth Protocol Stack
