Mobile Phones Flashcards
What time of access does 2G uses?
- FDMA
- TDMA
- CDMA
What access does 3G uses?
- CDMA-2000
- WCDMA
- TDSCMA
What access does 3.5G uses?
HSDPA - High speed Downlink Packet Access
What access does 4G uses?
LTE - Long term evolution
How does radio transmission works?
perform either AM/FM modulation at input and then demodulation at output.
What is half duplex Radio Communication
- Use single frequency for transmission
3. Only 1 user can talk at a time
What is Full duplex Radio Communication
- 2 way frequency transmission
2. both can talk at the same time
How does Data Network get transmitted?
- City is divided into many small cells.
- Each cell has a base station.
- Frequency will be bump across cells to reach targeted area
- Controlled by MSC - Mobile Switching Centre
What is frequency reuse?
Assigning same radio frequency to non-adjacent cell.
Explain the advantages of frequency reuse
WIth this method, users can be x10 bc of the shared bandwidth
What is mobile phone channels?
Full duplex communication mode whereby both users can talk at the same time
What is cell to cell handover?
It’s when a signal leaves a certain cell and into a new cell, the signal is picked up by the new cell region
How is cell to cell handover?
Thru Mobile Switching Centre
What is Data Roaming?
The ability to use mobile network outside of your own country.
How does data roaming work?
- Signal is detected by visited network.
- verify for access right.
- Once granted, will create temp subscriber record and take over the signal.
How Many mobile phone code are there?
- ESN - electronic serial number (32Bit)
- MIN - mobile identification number (10D)
- SID - system identification code (5D)
- IMEI - International mobile equipment identity (15D)
What is SIM?
aka Subscriber Identity Module
store IMSI and contact info
How many channel access methods are there?
- FDMA
- TDMA
- CDMA
What is FDMA?
Frequency Division Multiple Access that assign frequency to a call.
What is TDMA
Time division multiple access that assign a short time to multiple calls.
What is CDMA
Code Division Multiple Access where a random pseudocode is assign to a call.
Why is CDMA good?
Because of the random pseudocode assigned, hackers cannot eavesdrop nor locate/ hack the call. thus improving its security
What communication access does the 3G mobile uses?
CMDA-2000
WCDMA
TDSCMA
What is PDA?
Personal Digital Assistant. Electronic planner that helps to organize daily shecdule.
What does PDA do?
Performs PIM
Personal Information Management
What does PDA include of?
LED / LCD screen
built in qwerty keyboard
support stylus pen and touchscreen
What OS does the PDA run on?
- Microsoft mobile OS
- Palm OS
- Blackberry OS
- Linux OS
- Symbian OS
