Currently there are two contending technologies for fourth generation mobile telephony. On one side is WiMAX (Worldwide Interoperability for Microwave Access), and on the other LTE (Long-Term Evolution).
WiMAX is a wireless digital communication system defined in the IEEE 802.16 standard for metropolitan area networks (MAN, Metropolitan Area Network). It provides broadband communications with coverage up to 31 miles for fixed stations or 3 to 9 miles for mobile stations. The 802.16m standard, known as mobile WiMAX, will be used by cellular companies for 4G services.
LTE , meanwhile, is a technology defined by the organization 3GPP (3rd Generation Partnership Project) in which more than 60 operators, manufacturers and research institutes are participating together to define standards for LTE.
Both technologies are technically very similar in form to transmit signals and data rates. Both LTE and WiMAX use MIMO, ie the information is sent in two or more cell antennas to improve reception. Both systems also use OFDM (Orthogonal Frequency Division Multiplexing), a technology that supports streaming video and multimedia. OFDM is a mature and highly proven technology that works by separating the signal into multiple frequency narrow, with bits of data sent at the same time in parallel.
Many experts have questioned if LTE and WiMAX are rivals or complementary technologies. For example, such 2G, 2.5G and 3G TDMA-based technologies as GSM, went in a different direction than CDMA-based technologies, because they had totally different modulation schemes and incompatible. By contrast, LTE and WiMAX have the same modulation scheme (OFDM) and the same way to send signals to multiple antennasair (MIMO) as well, both will be based on the IP protocol.
On the possibility of LTE and WiMax are complementary technologies, some experts say that both technologies can co-exist in some regions, and that operators can use WiMAXand LTE for some services to others.
Predictions about trends in integrating these technologies are very striking. LTE is currently growing faster than WiMAX, thanks largely to the support of the industry, operating at both thecommunications and infrastructure and mobile terminals.
As forecast at different analysis say, this trend will continue for the next few years, until in 2014 the number of subscribers to LTE is nine times greater than WiMAX users. This year, WiMAX will continue to maintain the first position and at the end of 2011 it will get 15 million subscribers, while LTE, which has appeared in the market later, will have 10.4 million subscribers.
During 2012 the sense will change, since LTE is expected to double in number of subscribers to its rival, thanks to the efforts of large companies like AT&T and Verizon in the U.S. andT elia Sonera and Vodafone in Europe.
As currently operates 10 of them are currently serving 4G LTE and is expected at the end of 2011 this figure increased to 30.
It inevitble that over time, mobile telephony evolves to flat rate voice , data (and possibly content) over IP networks. The well-established companies of telecommunications,in general, are more interested in LTE, while the new companies are more interested in offering WiMax. The deployment of the networks also go at different speeds in each country, because the concessions for the use of radio spectrum depend on national governments.