MOBILE NETWORKING NOTES

INTRODUCTION OF MOBILE:

       What is mobile? What is handset? What is SIM?

      What are the digital technologies used for mobile?

      What are the operating frequencies?

      What is dual band? What is dual mode?

      Information about service providers?

      How calling takes place?

One of  the dynamic and an essential industry is communication industry (CI) in CI mobile industry and internet industry from IT are the fastest and latest having upcoming industries.

            Mobile is nothing but the user/man carrying handset having SIM card in it.

            Handset is the hardware or  an electronic device/unit connecting service provider (SP) using SIM card and the user service provider provides differently useful services to the user.

SIM CARD:  Subscribers Identification Module . It is an electronic chip.  Which has the phone number stored in it..

            Handsets works on different digital technologies are mainly divided in to 3 types as follows:

1. TDMA: Time Division in Multiple Access
2. CDMA: Code Division in Multiple Access
3. GSM : Global System for Mobile communication

In India GSM & CDMA technologies are  used for mobile communication in in INDIA operating frequencies for mobile communications are 900 Mhz and 1800 Mhz some handset work on single operating frequencies while some works on both handsets, which work on single frequencies are called as Single  Band handset

Company working on 900 Mhz AIRTEL (IDEA,BPL,BSNL) or company working on 1800 Mhz HUTCH .

In the field of electronics all devices operate in two models either analog model or in digital models the device using both the models is called as DUAL mode device.

SERVICE PROVIDER:  SP  is the main system.  Which manages the mobile communication between mobile and mobile & mobile & telephone user.  Service provider gives the SIM card to the user with the specific communication number which is inserted in the handset.

Airtime, Talktime, Roaming

DOT- Department of Telecommunication

       Mobile is the communication device used for sending and receiving calls, calling can be done in different types as follows:

a.       Mobile to Mobile (Both connections are of same SP)

Calling Mobile-Network Tower-SP-N/W ower-Receiving Mobile

b.      Mobile to Mobile (Both connections are of different SP)

Calling Mobile-Calling mobiles SP’s N/w tower- calling mobiles SP-Receiving mobiles SP’s n/w tower receiving mobile.

c.       Mobile to Landline/Telephone Calling mobile-N/W tower-SP-telephone exchange (DOT)-Landline or Telephone

d.      Telephone to mobile

Landline/Telephone-Telephone exchandge (DOT)-Receiver mobile’s SP-N/W tower-Receiving Mobile.

SIM- Subscriber’s Identification Module

       Without SIM card communication is not possible.  SIM is an electronic chip, which is provided by the SP to the user which holds the specific number.  Which is nothing but your mobile phone number.  Get the SIM card from the SP.  Insert it into your handset in the SIM socket.  Get it activated from the SP.

       SIM cards are of two types credit card size & stamp size.  Now a days only stamp size SIM cards are used.  SP provides different facilities using this SIM card.  Which are useful for the user.

SIM card features:

1)      CLIP- Caller Line Identification Presentation

To see the number of the person calling to you.

2)      Call Waiting:  To give the ring to another person calling to you while you are buzy with another call and at the same time it gives beep to you indicating that another call is waiting for you.

3)      Call Divert:  To divert the call to another mobile number or Landline number.  When you don’t want to receive a call on your mobile.

4)      Call Hold: To hold the call while you want to continue talking with another call.

5)      Voice Mail Box: To divert the incoming calls to voice Mail Box used when user don’t want to divert  incoming calls to any other number.  Its like an answering machine.  Call is stored in the VOICE/AUDIO format.

Uses and Functions of Handset:

Single Band:  Handset is set for only one band either 900 Mhz or 1800 Mhz.

Dual Band: Handset can operate on both frequencies bands.

WAP Enabled: Wireless  application protocol, Internet connectivity.

Call divert : To divert the call at  another number.

Call Bar: To restrict the incoming as well as outgoing numbers

Display lights: Set the display high colors

Key lock: Lock The keypad

Speaker phone: To set the speaker volume.

Phone Book: To store, Edit, Delete, view & read stored contact numbers.

Messages: Send & Receive the messages from Mobile phone.

SMS Chat: To chat  using mobile phone

Games: To play games

Tools: Remainder & Calculator

Settings: Phone set up, Time/Date, Security, N/W selection

Phone Setup: Font size, Screen saver, Adjust contrast, Language selection show, Battery meter call diverting, Call waiting, Change Band

Ring Tones: To set different tunes for incoming calls , messages and Specific numbers.

Default setting: To set the default setting of mobile phone.

SMS: Short message service.

Phone Line: Two lines given by the service provider in India.

Greeting: First screen of the phone

Clock/ Alarm: To set clock and Alaram

Call Register: Call details of Incoming /outgoing calls (Dialed Missed, Answered)

Vibrating alert: Vibrator ON/OFF option

Security setting: To set code numbers for handset lock and SIM card lock

Picture message: To send and store picture messages.

Tone composer: To compose different ringing tunes (Send, download)

Radio

Voice Dialing

MP3

Camera

Infrared

Parts of Handset:

1. Ringer
2. Ringer coil (Siemens C-25 & C-38)
3. Mike
4. mike connector
5. Speaker
6. Speaker Connector
7. Speaker Coil
8. Display
9. Display Connector
10. Display Strip
11. Display card
12. Charger
13. Charging Base
14. Charging connector
15. SIM Tray
16. SIM Base
17. SIM connector
18. Battery
19. B attery connector
20. Back Panel
21. Front Panel
22. Hairing Back Body
23. Antenna
24. Antenna Connector
25. External Antenna Connector
26. Vibrator
27. Keypad
28. Inner Keypad
29. ON/OFF Switch
30. Ground coil
31. LED
32. Mother board connector
33. Mother Board
34. Front Board
35. Hands free socket
36. Scroll Switch
37. Flap
38. Backup Battery
39. Infra Red Sensor
40. Data Cable

Sections of Different Parts of Handset:

1. Ringer- To give the ring at the time of incoming calls and messages
2. Mike- To send the voice call
3. Speaker-To listen to the voice call
4. Display- To display all information
5. Charging Base- To hold the charger connector
6. Charging connector- To charge the battery to connect charger
7. SIM Tray- To insert the SIM card
8. SIM Base- To holdthe connector for SIM card from MB
9. Battery Connector-To connect battery to MB
10. Speaker connector- To connect speaker to MB
11. Back panel- To protect battery
12. Front panel-To hold keypad, to make handset attractive
13. Main housing body-Also called as body to mount all the parts
14. Antena- To catch the signals of mobile SP’s N/W tower
15. Battery- To provide the power supply to handset
16. New battery- Charge it on phone for 24hrs. , go through two or three full charge discharge cycles when new.

Types of Battery:

1. NLCD-Nickel Cadmium

Full discharge and then change for better performance and to climate memory damage

2. NLMH- Nickel Metal  Hydride

Better than NLCD

3. LI-ION – Lithium-Ion

Lighter in weight,

Low self- Discharge rates , Relatively long life cycle batteries are measured in terms of talk time & stand by time.

17. Display Connector – To provide the display signals to  display board available on the MB.
18. Antenna Connector- To connect  the antenna to MB.

19. Keypad- To operate different functions, to enter numbers. To enter text messages.

20. Mike Connector- To connect  Mike to MB.

21. Charger- To charge the battery

22. Display strip- Cable used in between display connector & display board

23. Inner Keypad- Situated below the outer keypad, to connect outer keypad with MB connectors, round shaped connectors with carbon.

24. ON/OFF Switch- To charge the battery

25. Ringer Coil-

26. Speaker Coil-

27. Ground Coil-

28. LED-To provide light  for display & keypad

29. MB connector-To connect MB with display board

30. Mother Board-Main board of the handset which contains all IC’s

(Processor IC, Flash IC, etc.,)

Connectors for all types of internal and external parts

31. Front Board
32. Display Card
33. Data Cable – To connect handset to computer
34. Infra red sensor- To transfer dat from one device to another device
35. External Antenna connector – To connect the external antenna
36. Handsfree socket- To connect external Mike and speaker for the handset just like head phone which will free your hands while calling
37. Scroll Switch- To scroll in between the functional menus of the mobile phone
38. SIM Connector- To connect SIM card and MB
39. FLAP-In different models FLAP  is used for different purpose

i)                    FLAP is used like door

ii)                   In some models displays are on FLAP

iii)                 In some models speaker, Mike are also on FLAP

40. Backup Battery- This is a small extra battery in handset to supply the power for Date and Time in handset.  It’s on all the time.
41. Charger-Car battery 12v- Converter is used to convert in to 30v to protect handset.
42. Housing or Body- To make handset more attractive
43. Hands free kit- Like headphone, Without holding handset we can talk freely Mike and Speaker both the available in this kit.
44. Fancy Items: Lace, Tatto, etc.,

Tools and Equipment Required for Mobile Phone repairing:

1. Digital Multimeter- Meter with Buzzer
2. Adapter - (1.5 to 12 V), 1 Amp
3. Spike guard or extension Box
4. 3 NOSE (for Trium), 4 Nose, 5Nose (for GD 90)
5. T5,T6,T7 these all screw drivers are with 6 Nose but having different diameters
6. Minus screw driver
7. Star plus screw drivers
8. U-shaped screw drivers for  (Ericsson)
9. Cutter
10. Nose Pliers
11. Twiser
12. Small smooth file
13. Fine soldering gun -12volt
14. Solder wire -12 volt
15. De-Soldering wire
16. Jumper wire
17. Flux
18. IP (Isopropyl) - PCB Cleaner- CTC (Carbon Tetra Chlorides)
19. Brush- (Toothbrush will also do)
20. Opener for “ Siemens Handset opener
21. SMD Rework station – Hot Airgun
22. Hair dryer
23. Computer with serial and parallel ports
24. Data cable (DCT3,DCT4, Dongal)

Abbreviations of Handset Equipment:

TDMA                                 -Time Divison in Multiple Access

CDMA                                 - Code Divison in Multiple Access

GSM                                    - Global System for Mobile communication

SP                                         -Service Provider

DOT                                     - Department of Telecommunication

SIM                                      - Subscriber Identification Module

CLIP                                    - Caller Line Identification Presentation

SMS                                     - Short Message Service

WAP                                     - Wireless Application Protocol

PIN                                       - Personal Identification Number

PUK                                     - Pin Unlocking Key.

LED                                     - Light  Emitting Diode

LCD                                     -Liquid Crystal Display

NICD                                   - NICD Cadmium

NIMS                                  - Nickel Metal Hydride

LI-ION                                - Lithimum Ion

SMD                                  - Surface Mounting Device

PCB                                     - Printed Circuit Board

MB                                      - Mother Board

IP                                         -Iso-Propyle

PF                                        -Power Frequency Amplifier

RF                                       - Radio Frequency Amplifier

CPU                                     - Control (Central) Processing Unit

IC                                        - Integrated Circuit

Check the using Multimeter:

Check the using Multimeter on 20v range:

1. Check the battery voltage

(Min 3.6 to 3.7v)

2. Check the charger o/p voltage

(Min 5 to 9v)

3. Check the ON/OFF Switch

(Min 2.5 to 3.6v)

4. Check the display connector voltage

(Min 2.5  or 3.6 v)

5. Check the adapter o/p vg

(Min 1.5 to 12 v)

Check the using Multimeter On BUZZER Range

1.      Ringer: (With Buzzer) (value 8v to 23 v)

Ex.        016  - Ok

             001   - Short

                 1   - Open  

                       

2.      Speaker:(With Buzzer) (value 28 v to 33v)

Ex:    032  - Ok

 001  - Wrong

            1    -  Wrong

3.      Mike: (Without Buzzer)

Any three digits or four digits

4.      Resistance: (With Buzzer)

Ex: 001  - Ok

       105  - Ok

           1 - Open  

           

5.      Capacitor: (Equivalent to Diode)

Ex: 515  -  Without Buzzer Ok

            1  -  Without Buzzer Ok

        001  -  With Buzzer Short

           

6.      Inductor: ( Equivalent to Fues)

Ex: 001  - With Buzzer Ok

            1 – Without Buzzer open

       105 – Without Buzzer open

7.      Diode:

Ex:    1  – Without Buzzer Ok

       106 – Without Buzzer Ok

       001 – With Buzzer short

                       

8.      LED’s  (With Buzzer) (1.5 to 3 v)

Glow                 -  Ok

Without Glow  - Open

9.      Track:

Always Buzzer -Ok

10.  Fue’s

Ex: 001 -  With Buzzer Ok

           1 -  Without Buzzer Open

        102 -  Without Buzzer Open 

Check the using Adapter:

1.      Zap the battery or charge the battery using DC adapter

(9v to 12v)

2.      Checking the vibrator

(1.5 to 12v)

3. Checking the LED’s

(1.5 to 3v)

1.      Assembly and De-Assembly: (IC)

3310,3315,3330,3350

i) PF IC-Power frequency amplifier

ii) RF IC-Radio frequency Amplifier

            It works in the networking section (if any amplifier using N/w section)

2.      Antenna Switch Ic’s:

It have green or white base.  It also works for network section 

3.      Hagar Ic’s or RF Ic’s:

It makes the processing on the signal from RF or PF

(It works in networking or power frequency)

4.      Crystal IC’s:

It generates the frequencies for the handsets 13 Mhz or 26 M hz frequency.

5.      Audio Ic’s or COBA Ic’s:

It gives the powersupply from speaker and Mike.

6.      Charging Control Ic’s:

This is the only one Ic’s with direct supply from the IC.

7.      CPU- Control Processing Unit-

It keeps the controlling all IC’s

8.      EPROM-(Erasable Programmable Read only memory)

The matter which is erasable is stored in this IC’s

9.      Interface IC’s or Logic IC’s-

It gives the Power supply to ringer, vibrator,LED

10.  FLASH Ic’s:

The software is stored in this Ic’s

11.  Power Supply Ic’s or UEM IC:

It works Power supply to the handset.