mobile phones - evolution,operating systems,connectivity and networking
TRANSCRIPT
G Rajesh [U4ECE 13117]
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Mobile Phones
Introduction
A mobile phone (also known as a cellular phone, cell phone, hand phone, or simply a phone) is a phone that can make and receive telephone calls over a radio link while moving around a wide geographic area.
History
The first official mobile phone used in Sweden by the Swedish police in 1946;
could make 6 phone calls before car's battery was drained
John F. Mitchell and Martin Cooper of Motorola in 1973, - First Commercial Cell Phone.
1983 Motorola DynaTAC 8000X made commercially available: 2 lbs, $3,500
1991 Motorola MicroTac Lite the lightest phone: $1,000
Dr, Martin Cooper
Researcher for Motorola
Credited with inventing the first cellular phone
1973 made the first call to rival Joel Engel, Head Researcher from Bell Labs
Motorola first to use cell technology without the use of an automobile
Evolution
Manufacturers
Features of a Mobile Phone
A modern day mobile phone has the following features(but are not mandatory or limited to) in common
Screen
Battery
Processors
Operating System
Memory
Camera
Sound Output & Input
Sensors
Screen
Once Used only to display numbers
But then the trend changed:
8 bit games –Bigger
Camera – Sharper
Video- Refresh Rate
The first screen appeared in 1996 on Various phones ,slightly greater than 1 inch
Siemens S10 – the first mobile phone with a full colour screen (1998)
Now – Over 5.5 inch
Various Types of screens
TFT-LCD
(thin-film transistor liquid crystal display)
The only type used in phones now
need to have a light behind them,
hence not Thin
Used in Google Nexus 7,HTC Desire C
AMOLED(Active-matrix organic light-emitting diode)based on organic compounds high image qualityvery low power usageCostly ,Difficult to ManufactureUsed for HTC Desire ;replaced with LCD
Super AMOLED & Super AMOLED+
Derived form of AMOLED
Includes capacitive touch screen while mfg
doesn't have to be overlaid later
Increased Brightness & lower power usage
Used in Samsung Galaxy S2
Retina displaymarketing term created by Applepixel density high enough such that human eye is unable to make outNo pixilation Used in all apple devices
Platform
Platform- Operating System +Processors
Processors System-on-a-Chip (SoC) SoC is made of
CPU GPU sub-processors like video encoders & decoders
What’s a processor?
A processor executes what you want your Smartphone to do.
What’s a core?
Its an element found in the main processor that reads and executes instructions.
What’s the benefit of multiple cores?
The more cores, the faster they can divvy up the work
Is an octa-core smartphone twice as fast as a quad-core one?
No
What other factors are involved?
GPU,RAM,etc
Operating Systems
Interface between hardware and the User
The 4 main OSs are :
IOS – Apple Inc
Blackberry OS
Windows Mobile OS
Android OS
Other OSs :
Ubuntu Touch
Sailfish OS
Tizen
Android – Google
Unveiled in 2007Initially developed by Android Inc, bought by GoogleMost used OS till date
Versions:Android v1 2007 to Android 6 2015
UI flavors/ROMS:Cyanogen ModMIUIAOSPMokee
Connectivity
Few ways in which a phone can connect with other machines :
BluetoothWiFiUSB RadioInfrared
WiFi1st version of the 802.11 protocol in 1997,2 Mbit/sUpdated to 802.11b in 1999,11 Mbits/sLocal area wireless computer networking technologyUses the 2.4 ghz and 5 ghz radio bandsless secure than wired connectionsRange depends on
frequency band radio power output antenna gain and antenna type
WiFi –Protected System (WPS)Uses:
Internet access City Wide Connectivity Campus Wide Connectivity
Bluetooth
Invented by telecom vendor Ericsson in 1994Ideal for data exchange over short distancesUses short-wavelength UHF radio wavesoperates at frequencies between 2400 and 2483.5 MHz Managed by Bluetooth Special Interest GroupRange :Typically less than 10m, up to 100mLow power consumption compared to WiFiUses:
Phone to phone data transfer Wireless Controlling Bluetooth speakers,earphones
USB
Universal Serial Bus
developed in the mid-1990
currently developed by the USB Implementers Forum
designed to standardize the connection of computer peripherals
Size - Standard , mini, micro
USB 1.X , 1996 1.5 Mbit/s
USB 2.0 , 2000 480 Mbit/s
USB 3.0,2008 3.2 Gbit/s
Phone to Phone Call
Mobile Phones are ‘radio’ phones
Operating at microwave /radio frequencies
Handset power minimised by having a network of local transmitters and receivers
Each colour represents a base
station operating at a slightly different frequency
Making a mobile-to-mobile call
Network Control Knows in which cell every telephone is
Originating Telephone
Receiving Telephone
Screen
Linking to base stations
Mast power between
• 60 watts and 120 watts
•Handset power
• less than 1 watt
•Handset sends signals every few minutes to establish which is the nearest mast
Screen
Anatomy of a GSM Signal
2G or GSM phone
217 Pulses per second per telephone call
Each frequency channel can carry 7 calls
Thank You