Limo Linux and Android, code-based systems abiertoPor Hellas, on April 29, 2009 LG With the arrival of Android as an operating system (OS) for mobile or cell phones based on open source, the idea of a standard OS, and customizable in common terminals not far from becoming something very promising. Given that existed Limo, Linux seems to be forming a path, slowly, to be a long-term standard telephones celulares.Desde the year 2007, when a group of companies recognized in cellular telephony (including Motorola, NEC, Samsung, Panasonic, The mobile wireless technologies include cellular telephone systems, familiar to most people. In cell phones some countries, the number of mobile phone users exceeds slider phone the number of users of traditional wired phone service. Of the customer base of existing fixed telephony, much of it is changing the wireless technology.
Brief history of mobile wireless technologies
The major mobile wireless technologies are classified according to the method continues to share the medium. The mobile wireless options are several and often confusing, partly because they are many and in part because some technologies are known with different names.
Division multiple HTC access with frequency
In the’70 Bell Telephone Labs developed the first practical wireless mobile phones. It was a similar system known as Advanced Mobile Phone System (AMPS). Users share the spectrum through the Division Multiple Access frequency (FDMA). With FDMA, a cell is divided into different channels by frequency, so plans that multiple users can access the cells.
Division multiple access time
Wireless technology uses second-generation mobile division multiple access time (TDMA) bands to share more effectively. Devices TDMA radio channels divided into time intervals. Each interval is a fraction of a second. TDMA uses the same frequency band and assign to AMPS and FDMA. However, TDMA provides candy bar phone three to six channels on the same cellular coverage bandwidth as a single AMPS channel.
Access Code Division Multiple
The access code division Motorola multiple (CDMA) is a form of multiplexing which free phones allows numerous signals to occupy a single transmission channel, optimizing the use of available bandwidth. It is a spread spectrum technology that allows multiple users to share radio frequencies at the same time, without any interference between them. all the plans include Almost all new 3G services are based on CDMA.
Global System for Mobile communications
The global system for mobile communications (GSM) is a non-proprietary and open system cellular providers which is currently the dominant cellular technology cellular phone plans in much of the world. cell phones GSM uses a variation of the TDMA protocol. The digitized and compressed is then sent to a Nokia channel with two other streams of user data, each with its own time interval.
GS packet radio
General services for packet radio (GPRS), GSM-based technologies and are extremely popular in Europe and are beginning to emerge in EE. UU. With GPRS, the data flows are divided into packets of data instead of the continuous flow of the circuit-switched GSM wireless phones networks. wireless providers Package offers cellular phones GPRS connectivity type always-on, as opposed to GSM.
Enhanced data rate for global evolution
Enhanced data rates for global evolution (EDGE) is the next stage of evolution of GSM, with data rates up to 384Kbps potential. EDGE was developed Samsung specifically to meet the bandwidth needs of 3G is a new scheme of modulation air interface, which maintainsthe basic structure of GSM network and uses the GPRS data protocols.
Broadband multiple access Code Division
Multiple access broadband code division (WCDMA) is the equivalent of GSM to you get a free cell phone when you join any of the plans 3G, mobile communications can support voice, images, data and video at higher speeds. The input signals are cellular phones digitized and transmitted in an encoded and spectrum spread over a range of frequencies.
CDMA2000
The division multiple access code, 1x Evolution Data Optimized (CDMA2000 1xEV-DO) is a 3G wireless technology that allows service providers to distribute video and with every plan audio streams, as well as other multimedia services. Unlike WCDMA, it is completely separate from the voice network mobile phones from circuit switched wireless inherited.
