introduction sur 3g
TRANSCRIPT
contents
• What is 3G?
• Evolution to 3G
• Technical specification
• Different types of 3G
• Devices that uses 3G
• Disadvantages of 3G
What is 3G ?
3G stands for third generation, and is a wireless industry term for a collection of international standards and technologies aimed at increasing efficiency and improving the performance of mobile wireless networks.
Why is it important?
3G wireless services offer enhancements to current applications, including greater data speeds, increased capacity for voice and data and the advent of packet data networks versus today’s switched networks.
1G
.1G refers to the first generation of wireless technology wich was first itroduced in 1980s and completed in 1990s
.a speed up to 2,4 kbps
.Allows the voice calls in one country
.uses analog signal
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• Poor voice quality
• Poor battery life
• Large phone size
• Limited capacity etc…
2g
• Refers to the 2nd generation wich is based on GSM
• Was launched in 1991
• Uses Digital signals
• Data speed up to 64 kbps
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• Requires strong digital signals so the phone can work
• Unable to manage complex data like videos etc…
technical terms of 3g
• The transfer rate for 3G networks is between 128 and 144 kbps (kilobits per second) for devices that are moving fast and 384 kbps for slow ones. For fixed wireless the speed goes beyond 2 Mbps
technical terms of 3g
• It is comprised of basically the CDMA ( Code Division Multiple Access ) technology
• CDMA uses :
• FDMA ( Frequency Division Multiple Access)
• TDMA (Time Division Multiple Access)
fdm
a • Frequency Division Multiple Access
• Used by the 1st genration (1G)
• Divides the frequency band available into little segments
TD
MA
• Time Division Multiple Access
• Used by the 2nd generation (2G)
• The mobile phone system splits up everyone's calls into little digital parts
• sends each chunk at a slightly different time down the same frequency channel
CD
MA
• Code division multiple access
• Used by the 3rd generation (3G)
• Works by splitting calls up into pieces
• giving each piece a code that identifies where it's going
WC
DM
A • Basic CDMA evolved into an even higher-capacity system called Wideband CDMA (WCDMA), which sends data packets over a wide band of radio frequencies so they travel with less interference, and more quickly and efficiently
Types of 3G
• HSPA ( High speed packet access) :
Composed of HSDPA (High Speed Downlink Packet Access) and HSUPA (High Speed Uplink Access)
• HSPA+
What is required for using 3g
• The first thing you require is a device that is 3G compatible. This is where the name 3G phone comes from - a phone that has 3G functionality; nothing to do with the number of cameras or the memory it has. An example is the iPhone 3G.
What is required for using 3g
you need to be subscribed to a service provider to get 3G network connectivity
What is required for using 3g
• Your device is connected to the 3G network through its SIM card (in the case of a mobile phone) or its 3G data card (which can be of different types: USB,etc.), which are both generally provided by the service provider.
disadvantages of 3g
• Huge capital to build 3G infrastructure services worldwide
• Health impact because of the electromagnetic waves
• High prices of 3G mobile services• Takes time for some countries to catch up with this
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