Monday, 28 January 2013

Twitter

         Twitter is an online social networking service and microblogging service that enables its users to send and read text-based messages of up to 140characters, known as "tweets".
         It was created in March 2006 by Jack Dorsey and launched that July. The service rapidly gained worldwide popularity, with over 500 million registeredusers as of 2012, generating over 340 million tweets daily and handling over 1.6 billion search queries per day. Since its launch, Twitter has become one of the ten most visited websites on the Internet, and has been described as "the SMS of the Internet." Unregistered users can read tweets, while registered users can post tweets through the website interface, SMS, or a range of apps for mobile devices.
         Twitter Inc. is based in San Francisco, with additional servers and offices in New York City, Boston, and San Antonio.

(Reference: http://en.wikipedia.org/wiki/Twitter)

Tuesday, 22 January 2013

My Webpage


This is my webpage --> http://monthicha.webng.com/, so I hope you enjoy visitting my webpage.

Tuesday, 8 January 2013

1G 2G 3G 4G


Understanding 1G vs. 2G vs. 3G vs. 4G




         The nomenclature of the cellular wireless generations (G) generally refers to a change in the fundamental nature of the service, non-backwards compatible transmission technology, and new frequency bands. New generations have appeared about every ten years since the first move from 1981 analog (1G) to digital (2G) transmission in 1992. This was followed, in 2001, by 3G multi-media support, spread spectrum transmission and peak throughputs of 200 kbit/s; and in 2011 by 4G, which refers to all-IP switched networks, mobile ultra-broadband (gigabit speed) access and multi-carrier transmission.
 
What is 1G?
        First generation refers to the analog “brick phones” and “bag phones” as they were first introduced for mobile cellular technology. Cell phones began with 1G and signify first generation wireless analog technology standards that originated in the 1980s. 1G was replaced by 2G wireless digital standards.
  
What is 2G?
         2G signifies second generation wireless digital technology. Fully digital 2G networks have replaced analog 1G, which originated in the 1980s. 2G networks first commercially began on the Global System for Mobil Communications, or GSM, standard. 2G on GSM standards was first used in commercial practice in 1991 by Radiolinja, a Finnish GSM operator that was founded on September 19, 1988. Radiolinja is now part of Elisa, which was known in the 1990s as the Helsinki Telephone Company. In addition to the GSM protocol, 2G also utilizes various other digital protocols, including CDMA, TDMA, iDEN and PDC. GSM is based on TDMA.
 
What is 2.5G?
             2.5G wireless technology is a stepping stone that bridged 2G to 3G wireless technology and is sometimes used to describe those evolved technologies that were first considered as being 2G. While 2G and 3G have been officially defined as wireless standards by the International Telecommunication Union (ITU), 2.5G has not been defined and was created only for the purposes of marketing. As an interim step up from 2G, 2.5G has seen some of the advances inherent in 3G networks (including packet-switched systems). The evolution from 2G to 3G has ushered in faster and higher-capacity data transmission. Several technologies that have been considered as the evolutionary step to 3G include EDGE (part of the GSM family) and CDMA 2000 1X; at times these technologies are called 3G as they both meet some of the ITU requirements for 3G standards.
  
What is 3G?
         3G is the third generation of mobile phone standards and technology. 3G supersedes 2G technology and precedes 4G technology. Current 3G systems have been established through ITU’s project on International Mobile Telecommunications 2000 (IMT-2000). 3G technologies have enabled faster data transmission speeds, greater network capacity and more advanced network services. In May 2001, NTT DoCoMo (Japan) launched the first pre-commercial 3G network – branded as FOMA. Following the first pre-commercial launch, NTT DoCoMo again made history on October 1, 2001, with the first commercial launch of 3G in Japan.
 
UMTS-HSPA is the world’s leading 3G technology. By 2015, UMTS-HSPA and LTE 3G technologies are expected to account for 3.9 billion global subscriptions, compared to 569 million CDMA EV-DO subscriptions and 59 million WiMAX subscriptions.
  
What is 3.5G?
             Similar to the 2.5G acronym, the reference to 3.5G is not an officially recognized standard by the ITU. It is an interim or evolutionary step to the next generation of cellular technology that will be known as IMT-Advanced according to definitions by the ITU. IMT-Advanced will comprise the fourth generation of cell phone technology. The acronym 3.5G is also known as “beyond 3G.” 4G Americas does not use the terms 3.5G (or 2.5G) in respect of the official definitions provided by the ITU. The technologies within the GSM family that are considered as beyond 3G include HSPA+ and LTE. These 3.5G technologies are often called pre-4G as well.
  
What is 4G?
           4G is the term used to refer to the fourth generation of mobile wireless services that has been defined by the ITU and its Radiocommunication Sector (ITU-R) and established as an agreed upon and globally accepted definition in IMT-Advanced.

(Source : http://www.4gamericas.org/index.cfm?fuseaction=page&sectionid=361)
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