Blueetooth, wifi , Mobile phones similaitrtes and differences. Flashcards Preview

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Flashcards in Blueetooth, wifi , Mobile phones similaitrtes and differences. Deck (18):
1

What are the similarities between all three of these ?

frequencies for all in same range (2 GHz)

 frequencies are all microwave

 Wi-Fi and mobile phones networked 

Wi-Fi and mobile phone signals can go through walls 

Bluetooth® and Wi-Fi over short range



2

What are the differences for microwaves ?

mobile phones communicate over larger distances 

mobile phone transmitters are high powered 

3

Why is Wi-Fi different ?

Wi-Fi allows wider communication 

Wi-Fi range is average house/small office

4

Why is Bluetooth different ?

Bluetooth® is only device to device

Bluetooth® low power



5

Why is mobile phones different ?

mobile phones communicate over larger distances 

mobile phone transmitters are high powered

mobile phones communicate with each other, via a base station 

mobile phones use the lowest of the frequencies bands
55Pearson

6

What is the geographical range for Bluetooth ?

Is limited to about 10 m

7

How do Bluetooth avoid interferences ?

Hop across a range of channels many times with Wi-Fi which operate in the same frequency band .

8

How do mobiles phones avoid Interferences ?

Mobile phones Transceivers Use separate frequencies for uplink and downlink but are nearby channels

9

How do satellites avoid interference ?

Have two dish antennas and use quite different frequency bands for uplink and downlink .A transpder unit on boards receivers filters , amplifies and retransmits on the new frequency .

10

How do Wi-Fi network ?

They connect to a wired local network and together ca cover a whole building .

11

How do mobile phones network ?

Are networked together ti cover the country and also joined to the wider telephone network .

12

How do Bluetooth and infra red network ?

They are not networked just for device -device links .

13

Satellite network ?

Ground stations are linked into communications networks .

14

Mobile phones handshaking ?

Swap from one cell tower to another as a user travels

15

What does handshaking do ?

They stop information getting lost or jumbled by acknowledging when a message has been received

16

What is handshaking ?

A series of short messages sent backwards and forwards allows one device to recognise the another and to set up communication parameters .This is called handshaking .

17

What does each WIFI-Hub have ?

Has a range of 10 to 100 m

18

What are the same region where mobile phones and satellite communication ?

UHF RADIO AND MICROWAVES