Mobile phones
mobile telphone
Generations of mobile phone
1 - the first generation in 1980
Appeared in the year 1970 and was the first commercial use in 1980, was
The cellular voice service is given only to eat over the phone
Any room. ((Voice
The systems used primitive Mobile networks with the use of frequencies
Regular
Using the alteration system fm Alchaphy. (Analog frequency
moduletion)
fdma used as access Mtaatadp (frequency division muliple
accec)
* Examples of the People's Popular Aanizp
amps: advanced mobile phone system
* jtaace: japanesc total accec communication sysstem
* Second-generation 1990
- Founded on the basis of the digital transmission system (digital tranmission)
Given voice services and short messaging service quickly
Low. ((Voice + sms
voice ... rate ... 13k / s
study mobile service) .. sms ... raet = 9.6k / s
Better spectral efficiency (speectral) with a secret in the sound and the ability of the
Documentation
Used various means such as fdma.tdma.cdma
fdma: frequency division multiple access
cdma: code division multiple access.
* Examples of popular and famous Aanizp
gsm: glodal system for mobile coomunication (europe)
cdmane: is-95: code division multiple access.usa
* Final generation the second generation
System is used gprs: general packet radio service
System, also known gsm-ip: global system mobile inlernel
prolocol
And given the efficiency of Hmaalnzam faster and easier and speed up the transfer of information
170kbps is given to the various services
Internet-connected user
3 - the third generation in 2000
Uses up to 2GHZ Hizatrdd and plans for action in 2002
Uses MULTIMEDIA
* Third-generation systems, any given set of packet communications
And services with speed and efficiency are available on fixed networks, as well as
Means the arrival of alleged Internet
* Examples of systems known
cdma: code division multiple access atyeer2000.
The executive summary of this generation use the roaming feature out of the country
And features (voice + sms + mms)
4 - fourth generation
New model is characterized by the side of the third generation is given Ancharsria and wide
Saving Services
Means Almtaatadp (maltimedia) and applications used on the move
And means of waste Almtaatadp any time, any place and in any language and the use of
All kinds
* The factors that lead to the proliferation of cell phone and updated the system
1 - limited service limited service per capaility
How to control the length of the transmission Huaicheng mobile
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