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This article is about the mobile phone standard. For other uses see 4G (disambiguation).. For other uses, see 4G (disambiguation).

Fourth Generation wireless communication

4G (or 4-G) is short for fourth-generation, the successor wireless access technology to 3G. It is not used consistently, but generally describes several different, but overlapping ideas. The IEEE (Institute of Electrical and Electronics Engineers) official name for 4G is "3G and beyond".

Objectives

To cater the quality of service and rate requirements set by the forth coming applications like multimedia messaging, mobile TV, High definition TV content, DVB and minimal service like voice and data at anytime & anywere, the 4G working groups have defined the following as the objectives of the 4G wireless communication standard

    • Spectrally efficient system (8 bits/s/Hz)
    • High network capacity (atleast 10 times greater than 3G)
    • Nominal data rate at high speeds (100Mbps at stationary conditions and 20Mbps at 100miles/hr)
    • Smooth handoff across heterogeneous network
    • 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)
    • Interoperable with the existing wireless standards
    • All IP system, packet switched network

In summary, the 4G system should dynamically share and utilise the network resource to meet the minimal requirements of all the 4G enabled users.

Evolution of Wireless standards

First generation standards Most of the devices which came from this generation had military/Defence as its orgin and then moved to civilian services. Almost all of them are analog systems where voice was considered to be the main traffic. Some of the standards are NMT, AMPS, Hicap, CDPD, Mobitex, DataTac

Second generation standards All the standards belonging to this generation are commercial centric and they are digital in form. Two main groups have evolved one from Europe and another from America. Around 60% of the current market is domincated by European standards. The second generation standards are GSM, iDEN, D-AMPS, IS-95, PDC, CSD, PHS, GPRS, HSCSD, WiDEN, CDMA2000 (1xRTT/IS-2000), EDGE (EGPRS)

Third generation standards To meet the growing demands in the number of subscribers (increase in network capacity), rates required for high speed data transfer and multimedia applications 3G standards started evolving. The systems in this standard is basically a linear enhancement of 2G systems. Currently, transistion is happening from 2G to 3G systems. Some of the 3G standards are W-CDMA, UMTS (3GSM), FOMA, 1xEV-DO/IS-856, TD-SCDMA, GAN/UMA, 3.5G - HSDPA, 3.75G - HSUPA

Fourth generation standards According to 4G working groups, the infrastructure and the terminals will have almost all the standards from 2G to 3G implemented. The system will also serve as an open platform where the new innovations can go with it. Some of the standards which pays way for 4G systems are WiMax, WiBro, 3GPP LTE (Long Term Evolution).

The Evolution of the wireless standard with respect to data rate is illustrated the following figure

Important 4G components

Multi antenna systems

To foster the growing data rate needs of 4G, deploying mulitple antennas at the transmitter and at the receiver will increase the data rate.

Software Defined Radio (SDR)

SDR is one form of open wireless architecture (OWA). Since 4G is the collection of wireless standards, the final form of the 4G device will constitute all standards. This can be realized using SDR technology.

Smart antennas and Beamforming

Adaptive modulation and Coding

The modulation and coding techniques change according to the network resource, user requirement and physical channel conditions. Cross layer techniques are being proposed for 4G.

Access schemes

The scarced resource frequency and network infrastructure is accessed using the channel accesing schemes. The existing wireless standards use TDMA, FDMA, CDMA and combinations of these. Recently, new access schemes like OFDMA and MC-CDMA gain more importance in 802.16e and 802.20 standards.

IPv6

It is generally believed that 4th generation wireless networks would support a great number of wireless devices that are addressable and routable. Therefore in the context of 4G, IPv6 is an important network layer technology and standard that can support a great number of wireless enabled devices. In addition to increasing the number of IP addresses, IPv6 also removes the need for Network Address Translation (NAT), a technique used in 3G and other networks to make private IP addresses work with Internet applications.

In the context of 4G, IPv6 also enables a number of applications with better multi-cast, security and route optimization capabilities. With the available address space and number of addressing bits in IPv6, many innovative coding schemes can be developed for 4G devices and applications that could aid deployment of 4G networks and services.

Mesh networks

Possible network architectures

Heterogeneous Network

Co-operative Network

  1. 4G technology stands to be the future standard of wireless devices. The Japanese company NTT DoCoMo and Samsung are testing 4G communication at 100 Mbit/s while moving, and 1 Gbit/s while stationary [citation needed]. NTT DoCoMo plans on releasing the first commercial network in 2010 and Samsung plans on commercialising this service by 2010 at Jeju Island, South Korea. Despite the fact that current wireless devices seldom utilize full 3G capabilities, there is a basic attitude that if you provide the pipeline then services for it will follow.
  2. Pervasive networks. An amorphous and presently entirely hypothetical concept where the user can be simultaneously connected to several wireless access technologies and can seamlessly move between them (See handover, IEEE 802.21). These access technologies can be Wi-Fi, UMTS, EDGE or any other future access technology. Included in this concept is also smart-radio (also known as cognitive radio technology) to efficiently manage spectrum use and transmission power as well as the use of mesh routing protocols to create a pervasive network.

In general, a new generation is defined by the result of technology changes over a 10-15 year time frame. Thus, 4G would refer to whatever is deployed in the 2010-2015 period, assuming 3G deployment spans the 2000-2009 period. However, 3G is regarded by many as being a bit of a 'flop', so telecommunications companies are planning to roll out 4G earlier (possibly as early as 2008). The Chancellor of the Exchequer in the United Kingdom will auction 4G frequencies in autumn 2006.

Typically, a new standard means a new air-interface with higher data rates in the least, and some see change in the way data transport is handled end-to-end.

Ideally, 4G would provide users with on demand high quality video and audio. The killer application of 4G is not clear, but video is one of the big differences between 4G and 3G. 4G may use OFDM (Orthogonal Frequency Division Multiplexing), and also OFDMA (Orthogonal Frequency Division Multiple Access) to better allocate network resources to multiple users. 4G devices may use SDR (Software-defined radio) receivers which allows for better use of available bandwidth as well as making use of multiple channels simultaneously.

Unlike the 3G networks which are a jumble of circuit switched and packet switched networks, 4G will be based on packet switching only. This will allow low-latency data transmission.

According to a Visant Strategies study (quoted in Wireless Week on February 1st, 2006), there will be multiple competitors in this space, and gave the following projections:

  • WiMAX - 7.2 million units by 2010
  • Flash-OFDM - 13 million subscribers in 2010
  • UMTS FDD - Valued at $2 billion in 2010

See also

External links and sources

source: https://en.wikipedia.org/w/index.php?title=4G&oldid=80206439

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