Evolution of Mobile Communication Technologies

Communication technologies mentioned above had many limitations which had to be over come for the growth of the industry. Each country had deployed their own set of standards for communications which was making impossible to go beyond boundaries. All the systems and services were limited with in the country in which system is deployed and no services were available to be hired from even neighbored countries.

There are number of mobile communication technologies which have been developed ever since from analog days, every now and then new technology is released to cope with telephonic industry demands. Currently we have following mobile and internet communication technologies adopted by different mobile companies in different parts of the world: GSM, CDMA, GPRS, EDGE, VoIP.

What is GSM?

GSM (Global System for Mobile communications) is an open, digital cellular technology used for transmitting mobile voice and data services.

What does GSM offer?

GSM supports voice calls and data transfer speeds of up to 9.6 kbps, together with the transmission of SMS (Short Message Service).

1st GSM operates in the 900MHz and 1.8GHz bands in Europe and the 1.9GHz and 850MHz bands in the US. GSM services are also transmitted via 850MHz spectrum in Australia, Canada and many Latin American countries. The use of harmonised spectrum across most of the globe, combined with GSM’s international roaming capability, allows travellers to access the same mobile services at home and abroad. GSM enables individuals to be reached via the same mobile number in up to 219 countries.

Terrestrial GSM networks now cover more than 90% of the world’s population. GSM satellite roaming has also extended service access to areas where terrestrial coverage is not available. (GSMA, 2012)

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CDMA (Code Division Multiple Access) assigns unique codes to each communication to differentiate it from others in the same spectrum. In a world of finite spectrum resources, CDMA enables many more people to share the airwaves at the same time than do alternative technologies. The CDMA air interface is used in both 2G and 3G networks. 2G CDMA standards are branded cdmaOne™ and include IS-95A and IS-95B. CDMA is the foundation for 3G services: the two dominant IMT-2000 standards, CDMA2000® and WCDMA, are based on CDMA. (Group, 2012)

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GSM vs CDMA

Advantages of GSM

GSM is mature, it maturity means a more stable network with robuts features.

Less signal deterioration inside of bildings

GSM is a open standart, there is no need to pay to utilize it (for operators)

GSM covers all part of world, therefore international roaming is not a problem

Ability to use repeaters

Talk time is higher in GSM phones

Disadvantage

Pulse nature of transmissions interfere with some electronics, especially certain audio amplifiers.

Advantages of CDMA

Capacity is CDMAs biggest asset. It can accommodate more users per MHz of bandwidth than any other technology

CDMA is able to produce a reasonable call with lower signal levels.

CDMA consumes less power and covers large areas so cell size in CDMA is larger

Disadvantage

Breathing of base stations, where coverage area shrinks under load.

Most technologies are patented and must be licensed from Qualcomm

Дата добавления: 2015-11-14