Mobile Phone Networks Dr. Hassan Nojumi1 MOBLIE PHONE NETWORKS Dr. Hassan Nojumi.
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Transcript of Mobile Phone Networks Dr. Hassan Nojumi1 MOBLIE PHONE NETWORKS Dr. Hassan Nojumi.
Mobile Phone Networks Dr. Hassan Nojumi 4
Functions of Mobile Phones
• Send/Receive Voice Message
• Send/Receive E-Mail
Mobile Phone Networks Dr. Hassan Nojumi 5
Functions of Mobile Phones
• Send/Receive Voice Messages
• Send/Receive E-Mail
• Internet Connection
Mobile Phone Networks Dr. Hassan Nojumi 6
Functions of Mobile Phones
• Send/Receive Voice Messages
• Send/Receive E-Mail
• Internet Connection
• Complementing PDAs, GPS Receivers, etc.
Mobile Phone Networks Dr. Hassan Nojumi 8
Functionality
Combination of
Telephone Technology
And
. . .
Mobile Phone Networks Dr. Hassan Nojumi 9
Functionality
Combination of
Telephone Technology
And
Wireless Communication
Mobile Phone Networks Dr. Hassan Nojumi 11
Basic Notion
Geographical Division into
Cells
Result:
Possibility of simultaneous use of frequency bands by users
Mobile Phone Networks Dr. Hassan Nojumi 12
Basic Technology
Each Cell
• About 10 square miles About 26 square kilometers
Mobile Phone Networks Dr. Hassan Nojumi 13
Basic Technology
Each Cell
• About 10 square miles About 26 square kilometers
• With a Base Station with transmission equipment and antenna
Mobile Phone Networks Dr. Hassan Nojumi 14
Basic Technology
• Communication can be made using the same frequencies in different cells.
Mobile Phone Networks Dr. Hassan Nojumi 15
Basic Technology
• Communication can be made using the same frequencies in different cells.
• Several service providers may use one Tower.
Mobile Phone Networks Dr. Hassan Nojumi 18
Communication Channels
Half-Duplex: Two-Way
One at a time
Mobile Phone Networks Dr. Hassan Nojumi 19
Communication Channels
Full-Duplex: Two-Way
Simultaneously
Mobile Phone Networks Dr. Hassan Nojumi 20
Communication Channels
Full-Duplex: Two-Way
Simultaneously
Mobile Phone Networks Dr. Hassan Nojumi 21
Communication Channels
Each cell
• About 56 Voice Channels (Full-Duplex)
Mobile Phone Networks Dr. Hassan Nojumi 22
Communication Channels
Each cell
• About 56 Voice Channels (Full-Duplex)
• Several Control Channels
Mobile Phone Networks Dr. Hassan Nojumi 23
Communication Channels
Each cell
• About 56 Voice Channels (Full-Duplex)
• Several Control Channels
• Three-fold increase possible by TDMA
Mobile Phone Networks Dr. Hassan Nojumi 24
Analog Versus Digital
Digital signals can be manipulated, compressed, etc., more easily.
Mobile Phone Networks Dr. Hassan Nojumi 25
Analog Versus Digital
Digital signals can be manipulated, compressed, etc., more easily.
FSK (Frequency Shift Keying) for Tower/Phone Connection
Mobile Phone Networks Dr. Hassan Nojumi 27
Access Technologies
FDMA
Frequency Division
Multiple Access
Mobile Phone Networks Dr. Hassan Nojumi 28
Access Technologies
FDMA
Frequency Division
Multiple Access
Available frequency band is divided and each part assigned separately.
Mobile Phone Networks Dr. Hassan Nojumi 30
Access Technologies
FDMA
• Traditional radio transmission
Mobile Phone Networks Dr. Hassan Nojumi 31
Access Technologies
FDMA
• Traditional radio transmission
• Not efficient for digital transmission
Mobile Phone Networks Dr. Hassan Nojumi 33
Access Technologies
TDMA
Time Division
Multiple Access
Available time is divided and each part assigned separately.
Mobile Phone Networks Dr. Hassan Nojumi 35
Access Technologies
TDMA
Suitable for digital transmission as compression techniques can greatly reduce needed transmission time.
Mobile Phone Networks Dr. Hassan Nojumi 37
Access Technologies
TDMA
• “Multiprogramming” idea
• Has typically three times the capacity of an analog system
Mobile Phone Networks Dr. Hassan Nojumi 39
Access Technologies
TDMA
• IS- 54: 800 MHz Band
• IS-136: 1900 MHz Band
Mobile Phone Networks Dr. Hassan Nojumi 40
Access Technologies
TDMA
• IS- 54: 800 MHz Band
• IS-136: 1900 MHz Band
• Dual-Band phones can operate in both bands.
Mobile Phone Networks Dr. Hassan Nojumi 41
Access Technologies
TDMA/GSM
Global System for
Mobile Communications
Specialized TDMA used for mobile phone communication
Mobile Phone Networks Dr. Hassan Nojumi 42
Access Technologies
TDMA/GSM
Encryption methods are used to make the call more secure.
Mobile Phone Networks Dr. Hassan Nojumi 43
Access Technologies
TDMA/GSM
To Connect to different service providers, users change their
SIM (Subscriber Identification Module) Cards that contain necessary data for connection
Mobile Phone Networks Dr. Hassan Nojumi 45
Access Technologies
CDMA
Code Division
Multiple Access
Communication data is digitized and distributed
over the available band.
Mobile Phone Networks Dr. Hassan Nojumi 46
Access Technologies
CDMA
Code Division
Multiple Access
Each call is assigned a Sequence Code. Calls are
overlaid over available band.
Mobile Phone Networks Dr. Hassan Nojumi 49
Communication Cells
• Each cell About 26 Km
• Many Base Stations and Transmission Towers required for a large city (paid off by many customers)
2
Mobile Phone Networks Dr. Hassan Nojumi 50
Communication Cells
All Base Stations in a region are controlled by an MTSO (Mobile Telephone Switching Office)
Mobile Phone Networks Dr. Hassan Nojumi 51
Cell Phone Codes
ESN
Electronic Serial Number
Unique 32-bit number programmed into the phone at manufacture
- Permanent and Unchangeable -
Mobile Phone Networks Dr. Hassan Nojumi 52
Cell Phone Codes
MIN
Mobile Identification Number
10-digit number derived from
mobile phone number
- Assigned When Phone Activated -
Mobile Phone Networks Dr. Hassan Nojumi 53
Cell Phone Codes
SID
System Identification Number
5-Digit Carrier Code
- Assigned When Phone Activated -
Mobile Phone Networks Dr. Hassan Nojumi 54
Cell Phone Codes
Each phone user has a unique MIN&ESN identification, used by the phone company for billing.
Mobile Phone Networks Dr. Hassan Nojumi 55
Cell Phone Codes
MIN&ESN identification may be captured by scanning the call and used by a third party for making fraudulent calls.
Mobile Phone Networks Dr. Hassan Nojumi 58
Cell Phone Communication
Startup
• Phone turned on.
• Device sends Registration Request to MTSO
Mobile Phone Networks Dr. Hassan Nojumi 59
Cell Phone Communication
Startup
• Phone turned on.
• Device sends Registration Request to MTSO
• An SID is looked for on a Control Channel.
Mobile Phone Networks Dr. Hassan Nojumi 60
Cell Phone Communication
Startup
If SID not found, Out of Range.
Mobile Phone Networks Dr. Hassan Nojumi 61
Cell Phone Communication
Startup
If SID not found, Out of Range.
If SID found, comparison is made with the programmed SID in the phone device
Mobile Phone Networks Dr. Hassan Nojumi 62
Cell Phone Communication
Startup
If SID not found, Out of Range.
If SID found, comparison is made with the programmed SID in the phone device
Matched SID Means Home
Mobile Phone Networks Dr. Hassan Nojumi 63
Cell Phone Communication
Startup
If SID Not matched, MTSO contacts the Home MTSO to verify that SID in the phone device is valid.
Mobile Phone Networks Dr. Hassan Nojumi 64
Cell Phone Communication
Connection
Destination is dialed.
Mobile Phone Networks Dr. Hassan Nojumi 65
Cell Phone Communication
Connection
Destination is dialed.
MTSO selects and assigns a frequency channel for call
Mobile Phone Networks Dr. Hassan Nojumi 66
Cell Phone Communication
Connection
Cell Change is done by coordination between cells and MTSO using signal strengths.
Mobile Phone Networks Dr. Hassan Nojumi 70
Other Cellular Phone Details:
• Hardware/Software
• Analog-to-Digital Conversion
Mobile Phone Networks Dr. Hassan Nojumi 71
Other Cellular Phone Details:
• Hardware/Software
• Analog-to-Digital Conversion
• Digital-to-Analog Conversion
Mobile Phone Networks Dr. Hassan Nojumi 72
Other Cellular Phone Details:
• Hardware/Software
• Analog-to-Digital Conversion
• Digital-to-Analog Conversion
• Display
Mobile Phone Networks Dr. Hassan Nojumi 73
Other Cellular Phone Details:
• Hardware/Software
• Analog-to-Digital Conversion
• Digital-to-Analog Conversion
• Display
• Power/Batteries