4G4G (also known as Beyond 3G), an abbreviation for Fourth-Generation, is a term used to describe the next complete evolution in wireless communications. A 4G system will be able to provide a comprehensive IP solution where voice, data and streamed multimedia can be given to users on an "Anytime, Anywhere" basis, and at higher data rates than previous generations.
4G is the short term for fourth-generation wireless, the stage of broadband mobile communications that will supercede the third generation (3G). While neither standards bodies nor carriers have concretely defined or agreed upon what exactly 4G will be, it is expected that end-to-end IP and high-quality streaming video will be among 4G's distinguishing features. Fourth generation networks are likely to use a combination of WiMAX and WiFi.
Technologies employed by 4G may include SDR (Software-defined radio) receivers, OFDM (Orthogonal Frequency Division Multiplexing), OFDMA (Orthogonal Frequency Division Multiple Access), MIMO (multiple input/multiple output) technologies, UMTS and TD-SCDMA. All of these delivery methods are typified by high rates of data transmission and packet-switched transmision protocols. 3G technologies, by contrast, are a mix of packet and circuit-switched networks.
When fully implemented, 4G is expected to enable pervasive computing, in which simultaneous connections to multiple high-speed networks provide seamless handoffs throughout a geographical area. Network operators may employ technologies such as cognitive radio and wireless mesh networks to ensure connectivity and efficiently distribute both network traffic and spectrum.
The high speeds offered by 4G will create new markets and opportunities for both traditional and startup telecommunications companies. 4G networks, when coupled with cellular phones equipped with higher quality digital cameras and even HD capabilities, will enable vlogs to go mobile, as has already occurred with text-based moblogs. New models for collaborative citizen journalism are likely to emerge as well in areas with 4G connectivity.
A Japanese company, NTT DoCoMo, is testing 4G communication at 100 Mbps for mobile users and up to 1 Gbps while stationary. NTT DoCoMo plans on releasing their first commercial network in 2010. Other telecommunications companies, however, are moving into the area even faster. In August of 2006, Sprint Nextel announced plans to develop and deploy a 4G broadband mobile network nationwide in the United States using WiMAX. The United Kingdom's chancellor of the exchequer announced a plan to auction 4G frequencies in fall of 2006.
4G technologies are sometimes referred to by the acronym "MAGIC," which stands for Mobile multimedia, Anytime/any-where, Global mobility support, Integrated wireless and Customized personal service.
As the second generation was a total replacement of the first generation networks and handsets; and the third generation was a total replacement of second generation networks and handsets; so too the fourth generation cannot be an incremental evolution of current 3G technologies, but rather the total replacement of the current 3G networks and handsets. The international telecommunications regulatory and standardization bodies are working for commercial deployment of 4G networks roughly in the 2012-2015 time scale. At that point it is predicted that even with current evolutions of third generation 3G networks, these will tend to be congested.
There is no formal definition for what 4G is; however, there are certain objectives that are projected for 4G. These objectives include: that 4G will be a fully IP-based integrated system. 4G will be capable of providing between 100 Mbit/s and 1 Gbit/s speeds both indoors and outdoors, with premium quality and high security.
Many companies have taken self-serving definitions and distortions about 4G to suggest they have 4G already in existence today, such as several early trials and launches of WiMAX, which is part of the formal ITU standard for 3G. Other companies have made prototype systems calling those 4G. While it is possible that some currently demonstrated technologies may become part of 4G, until the 4G standard or standards have been defined, it is impossible for any company currently to provide with any certainty wireless solutions that could be called 4G cellular networks that would conform to the eventual international standards for 4G. These confusing statements around "existing" 4G have served to confuse investors and analysts about the wireless industry.
The technology called 4G has redefined the whole concept of today’s sophisticated communication. According to the Wireless World Research Forum (WWRF), 4G is a combination of wired and wireless networks in computer, consumer electronics and communication technology systems based on the internet technology, that can merge applications like the Wi-Fi and WiMAX capable of transmitting at a speed ranging from 100 Mbps (in cell-phone networks) to 1 Gbps (in local Wi-Fi networks).This collection of technologies and protocols delivers high quality of service at both ends and high point security. Officially named by IEEE as Beyond 3G (B3G) it provides with the lowest cost wireless network.
Objective and approach
Objectives
4G is being developed to accommodate the quality of service (QoS) and rate requirements set by forthcoming applications like wireless broadband access, Multimedia Messaging Service (MMS), video chat, mobile TV, HDTV content, Digital Video Broadcasting (DVB), minimal service like voice and data, and other streaming services for "anytime-anywhere". The 4G working group has defined the following as objectives of the 4G wireless communication standard:
A spectrally efficient system (in bits/s/Hz and bits/s/Hz/site),
High network capacity: more simultaneous users per cell,
A nominal data rate of 100 Mbit/s while the client physically moves at high speeds relative to the station, and 1 Gbit/s while client and station are in relatively fixed positions as defined by the ITU-R,
A data rate of at least 100 Mbit/s between any two points in the world,
Smooth handoff across heterogeneous networks,
Seamless connectivity and global roaming across multiple networks,
High quality of service for next generation multimedia support (real time audio, high speed data, HDTV video content, mobile TV, etc)
Interoperability with existing wireless standards, and
An all IP, packet switched network
In summary, the 4G system should dynamically share and utilise network resources to meet the minimal requirements of all the 4G enabled users.
Approaches
As described in 4G consortia including WINNER, WINNER - Towards Ubiquitous Wireless Access, and WWRF, a key technology based approach is summarized as follows, where Wireless-World-Initiative-New-Radio (WINNER) is a consortium to enhance mobile communication systems.
Consideration points
Coverage, radio environment, spectrum, services, business models and deployment types, users
Principal technologies
Baseband techniques
OFDM: To exploit the frequency selective channel property
MIMO: To attain ultra high spectral efficiency
Turbo principle: To minimize the required SNR at the reception side
Adaptive radio interface
Modulation, spatial processing including multi-antenna and multi-user MIMO
Relaying, including fixed relay networks (FRNs), and the cooperative relaying concept, known as multi-mode protocol
It introduces a single new ubiquitous radio access system concept, which will be flexible to a variety of beyond-3G wireless systems.
Fourth generation: According to the 4G working groups, the infrastructure and the terminals of 4G will have almost all the standards from 2G to 4G implemented. Although legacy systems are in place to adopt existing users, the infrastructure for 4G will be only packet-based (all-IP). Some proposals suggest having an open platform where the new innovations and evolutions can fit. The technologies which are being considered as pre-4G are the following: Flash-OFDM, WiMax, WiBro, iBurst, and 3GPP Long Term Evolution. One of the first technology really fulfilling the 4G requirements as set by the ITU-R will be LTE Advanced as currently standardized by 3GPP. LTE Advanced will be an evolution of the 3GPP Long Term Evolution. Higher data rates are for instance achieved by the aggregation of multiple LTE carriers that are currently limited to 20MHz bandwidth.
Applications
The killer application of 4G is not clear, though the improved bandwidths and data throughput offered by 4G networks should provide opportunities for previously impossible products and services to be released. Perhaps the "killer application" is simply to have mobile always on Internet, no walled garden and reasonable flat rate per month charge. Existing 2.5G/3G/3.5G phone operator based services are often expensive, and limited in application.
Already at rates of 15-30 Mbit/s, 4G should be able to provide users with streaming high-definition television. At rates of 100 Mbit/s, the content of a DVD-5, for example a movie, can be downloaded within about 5 minutes for offline access.
