Frequency Bands

Question 1

List of unlicensed frequencies

Answer 1

ISM (Industrial, scientific, medical)
Personal Communication Systems
National Information Infrastructure
Milimeter Wave

Question 2

Info of ISM

Answer 2

Frequency
902 - 928 mhz
2.4 - 2.4835 ghz
5.725 - 5.825 ghz
Total bandwidth
234.5 mhz
Cordless phone

Question 3

Info of Personal Communcation System

Answer 3

1910 - 1930 mhz
2390 - 2400 mhz
30 mhz
WLANs, wpbe

Question 4

Info of national information infrastructure

Answer 4

5.15 - 5.25
5.25 - 5.35
5.725 - 5.85
300 mhz
Wlan, wpbe, campus application

Question 5

What is milimeter wave?

Answer 5

59.64 ghz

5 ghz Home network applications

Question 6

Three spots of ISM

Answer 6

900 mhz: 902-928mhz

2. 4 ghz: 2.4 - 2.5
3. 8 ghz: 5.725 - 5.875

Question 7

What is 900 mhz ism band?

Answer 7

902 - 928 mhz

used for baby monitors

Question 8

2.4 Ghz band

Answer 8

Most common

used my microwaves, cordless home telephones, baby monitors

Question 9

5.8 ghz band

Answer 9

5.725 - 5.875

Question 10

What is UNII?

Answer 10

Unlicensed National Information Infrastructure bands

Question 11

Types of UNII?

Answer 11

UNII 1 - Lower
UNII 2 - Middle
UNII 2 Ext - Middle Extended
UNII 3 - Upper

Question 12

UNII 1

Answer 12

5.15 Ghz - 5.25 Ghz
40 mW
Indoors

Question 13

UNII 2

Answer 13

5.25 ghz - 5.35 ghz
200 mW IR
FCC 250 mW IR
Indoor or outdoor

Question 14

UNII 2 Ext

Answer 14

5.470 - 5.725 GHZ
255 Mhz wide
11 channels
200 mW
Indoor - Outdoor

Question 15

What is DFS?

Answer 15

Dynamic Frequency Selection

Question 16

What is TPC?

Answer 16

Transmit Power Control

Question 17

UNII 3

Answer 17

5.725 - 5.825 Ghz
800 pW
Outdoor point to point

Question 18

Why would white space?

Answer 18

Because of the longer range

Question 19

What is a narrowband?

Answer 19

Its a signal that uses very little bandwidth

Transmitted using higher power

Question 20

What is a spread spectrum?

Answer 20

Uses more bandwidth than is necessary to carry its data

Spreads the data accross frequencies

Question 21

What is FHSS?

Answer 21

Frequency Hopping Spread Spectrum

Question 22

What is DSSS?

Answer 22

Direct Sequence Spread Spectrum

Question 23

What does DSSS do?

Answer 23

Transmits data across a frequency wide range
DSSS - 1 - 2 mbps
HR-DSSS - 5.5 - 11 mbps

Question 24

How is narrowband spread?

Answer 24

By chiping sequence

Question 25

What is OFDM?

Answer 25

Ortogonal Frequency Division Multiplexing
It divides the whole bandwidth into 52 subcarriers
48 of them carry data
4 of them are pilot subcarriers that contain reference to phase or ampitude

Question 26

Throughput vs Bandwidth?

Answer 26

Bandwidth is the maximum amount of data that can travel

Throughput how much data actually travels

Question 27

What does data throughput depend on?

Answer 27

Frequency bandwidth
Data encoding
Modulation
Medium contention
Encryption
Number of current users