Fourth generation wireless technology

     Dear friends today i m going to discuss about future communication technology. Mobile communication is one of the hottest areas that are developing at a booming speed, with advance techniques emerging in field of mobile and wireless communication. This article is all about the fourth generation of wireless communication and data transfer system. 4G is the higher version of wireless communication based on internet capable of transmitting at a speed ranging from 100Mbps to 1Gbps. Basic technologies and development of wireless system is also discussed in this article systematically. In comparison of 3G and 2G wireless system, 4G gives more secure, fast, economically cheaper, and high quality data transfer.


INTRODUCTION.
 Fourth generation wireless telecommunication is an evolution in wireless technology based on internet protocol with high speed data transfer rates, remote connectivity anywhere in the world, less signal attenuation, ultra-broadband Internet access, IP telephony, gaming services, and high quality faster multimedia streaming. The sophisticated communication system prevailing today can be redefined using the 4G concepts. It has different meaning in different context, but according to (WWRF) Wireless World Research Forum 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).It provide high quality and high point security and low cost set up, officially named by IEEE as Beyond 3G(B3G).

Wireless communication systems and technology-
Starting of wireless communication system was with the invention of wireless telegraph in1896 by G. Marconi. Over the last century, advances in wireless technologies have led to the radio, the television, the mobile telephone, and communication satellites. Of all the advances in data communication and telecommunication perhaps the most revolutionary is the development of digital cellular networks which came in existence around 1990. Before this analog signal were used for wireless communication which were only capable of low data transfer rates due to less bandwidth. Digital signal came with high data rates and high channel capacity.


Analysis of early generation of wireless systems-
Development of any technology doesn’t take place in a single day it is the result of continuous step by step process in which each new generation contains some advance technology and ideas along with the solution of problems in earlier generation technology. 4G fourth generation of wireless technology is also the result of continuous advancement over earlier generations. Development of wireless system was started in 1896 but the first mobile phone was invented in the United States back in the 1960s by Bell Labs and this was 0th generation of mobile communication which was using technologies like MTS, MTA, MTB, MTC, MTD, OTL, AMTS (advanced mobile telephone system), and autoradiopuhelin. This generation of wireless system was working on radio based analog signals. Mainly the advanced wireless communication started in 1980 with first generation of wireless communication which was based on analog signals and was provided with circuit switching and other more advanced features like less conjunction in network, more coverage etc.
From 1991 a new era of wireless mobile communication started with the use of digital signals rather than early used analogue signals. Use of digital signal increased the security of communication, more clarity to the conversion, less congestion, wide coverage, and economically efficient. With further increment in technology GPRS and EDGE technology features attached to 2G wireless service. These are sometimes also called as transitional generation (2.5G and 2.7G) respectively.
After 10 years third generation wireless 3G systems came into existence, having a very wide bandwidth, video calling, multimedia streaming, and high speed internet excess and all other features of 2G. 3G wireless was a replacement of radio transmission technology (RTT) by long term evolution (LTE) technology. Even today 3G is not fully implemented but its next generation technology came to existence, with launch of 4G Mobile initiative program in 2000 based on ITU standards. Generations followed by the technologies are tabularized below.  

1G
AMPS family :  AMPS · TACS · ETACS      
Other : NMT · Hicap · Mobitex · DataTAC    

2G
GSM/3GPP family : GSM · CSD      
3GPP2 family : CdmaOne (IS-95)      
AMPS family : D-AMPS (IS-54 and I-136)      
Other : CDPD · iDEN · PDC · PHS    

2G transitional (2.5G, 2.75G)
GSM/3GPP family : HSCSD · GPRS · EDGE/EGPRS      
3GPP2 family : CDMA2000 1xRTT (IS-2000)      
Other : WiDEN
     
3G (IMT-2000)
3GPP family : UMTS (UTRAN) · WCDMA-FDD ·WCDMA-TDD · UTRA-TDD LCR (TD-SCDMA)
3GPP2 family : CDMA2000 1xEV-DO (IS-856)
     
3G transitional (3.5G, 3.75G, 3.9G)  
3GPP family :  HSPA · HSPA+ · LTE (E-UTRA)  
3GPP2 family : EV-DO Rev.A  · EV-DO Rev.B      
Other : Mobile WiMAX (IEEE 802.16e-2005) · Flash-OFDM · IEEE 802.20
     
4G (IMT-Advanced)
3GPP family : LTE Advanced      
WiMAX family :    IEEE 802.16m    

5G
unconfirmed : Unconfirmed

Specifics of 4G-
4G is the next generation is the next step into wireless and cellular technologies. This technology is still under the phase of development, but it hopes to overcome the limitations of its bequests. The overall mission of researchers and network developers is to make secure and high speed data connection. With its flexible channel bandwidth it can replace 3G and 2G technologies entirely. This technology would be blessing for digital portable gadgets freaks because this technology would provide high speed connectivity with less signal attenuation. It is a multi-purpose and versatile technology hence it can utilize almost the entire packet switched technologies. It can use both orthogonal frequency division multiplexing (OFDM) and orthogonal frequency division multiple access (OFDMA). OFDM mechanism splits a digital signal into different narrowband and frequencies. The reason why 4G makes use of this technology lies in its ability to minimize the intervention among symbols and channels associated to data streaming.4G is also capable of using multiple input / multiple output technology (MIMO), this antenna technology is used to optimize the data speed and reduce the errors in the networks. Universal Mobile Telecommunication Service (UMTS) which is basically a broadband 3G technology is also a part of 4G. This broadband technology transfers data in the form of frames or packets. Hence it is capable of carrying voice, video, text and other types of multimedia datagram with the speed of 2Mb. UMTS is part of 4G because it can enables 4G to make use of international mobile phone roaming via using GSM (Global system for Mobile Communications).another wireless telecommunication technology known as time division synchronous code division multiple access (TD-SCDMA) provides support to 4G to transfer both circuit switched data like video and voice and packet switched data. This technology is a shift from today's traditional transmission-specific radio technology to an interface-based technology in order to be more compatible with computer system architecture. The future mobile device will therefore be first and foremost a computer, then an open wireless architecture (OWA) low-power terminal. The systems of 4G are similar with satellite internet, since both technologies have excellent portability and can maintain a connection even while moving. However, satellite is far more expensive since the person has to buy a satellite dish that communicates with a satellite floating in space. In contrast, 4G is much more affordable. The signal only operates within city limits, since the signal still comes from one headquarters.  In 4G systems this mobility is provided by the mobile IP protocol, part of IP version 6, and while in earlier cellular generations it was only provided by physical layer and data link layer protocols. In addition to seamless mobility, 4G provides flexible interoperability of the various kinds of existing wireless networks, such as satellite, cellular wireless, WLAN, PAN and systems for accessing fixed wireless networks. 4G wireless communication systems is best described in a word ‘MAGIC’ i.e. Mobile multimedia Anytime Anywhere Global mobility support, integrated wireless and personalized services.

DEVELOPMENT OF 4G.
The 4G system was originally envisioned by the Defense Advanced Research Projects Agency (DARPA). The DARPA selected the distributed architecture, end-to-end Internet protocol (IP), and believed at an early stage in peer-to-peer networking in which every mobile device would be both a transceiver and a router for other devices in the network eliminating the spoke-and-hub weakness of 2G and 3G cellular systems. The idea came from development of 2.5GPRS systems, in which cellular systems were provided with dual infrastructures: packet switched nodes for data services, and circuit switched nodes for voice calls. In 3g and 4G systems, the circuit-switched infrastructure is abandoned, and only a packet-switched network is provided.


Pillars of development of 4G and pre 4G:

• 4G Mobile initiative program launched in 2000.
• In 2002, the strategic vision for 4G-which ITU designated as IMT-Advanced—was laid out.
• In 2005, OFDMA transmission technology is chosen as candidate for the HSOPA downlink, later renamed 3GPP Long Term Evolution (LTE) air interface E-UTRA.
• In November 2005, KT demonstrated mobile WiMAX service in Busan, South Korea.
• In February 2007, the Japanese company NTT DoCoMo tested a 4G communication system prototype with 4x4 MIMO called VSF-OFCDM at 100 Mbit/s while moving, and 1 Gbit/s while stationary. 
• In January 2008, a U.S. Federal Communications Commission (FCC) spectrum auction for the 700 MHz former analog TV frequencies began.
• In 2008, ITU-R established the detailed performance requirements of IMT-Advanced, by issuing a Circular Letter calling for candidate Radio Access Technologies (RATs) for IMT-Advanced.
• April 2008, just after receiving the circular letter, the 3GPP organized a workshop on IMT-Advanced where it was decided that LTE Advanced, an evolution of current LTE standard, will meet or even exceed IMT-Advanced requirements following the ITU-R agenda.
• On 3 March 2009, Lithuania's LRTC announcing the first operational "4G" mobile WiMAX network in Baltic states.
• On 4 June 2010, Sprint Nextel released the first 4G Smartphone, the HTC Evo 4G.
• On July 2010, Uzbekistan's MTS deployed LTE in Tashkent, and On 12 December 2010, VivaCell-MTS launches in Armenia 4G/LTE commercial test network with a live demo conducted in Yerevan.

OBJECTIVES OF 4G WIRELESS SYSTEMS.
The 4G technology is expected to cover data rate deficiency in previous generations like 1G, 2G, and 3G etc. This service is also expected to achieve quality of services. It may provide many multimedia services which would not only include only voice chat and video calls but also MMS, HDTV, video chat and voice over the internet. This network provides interactive roaming with existing LAN and digital broadcasting system. This network’s goal is to provide a speed of 100 mbps data rate of moving customers and 1GBps for stationary users. By getting this, the consumers get and connectivity with high speed anywhere across the uninterrupted service world. This system has very smooth handover over heterogeneous networks. The next target of this 4G technology is to provide flawless connectivity and international roaming across innumerable networks of the world .It will also provide high multimedia support in order to get approval from ITU. The interoperability with existing network infrastructure is another prominent feature of this technology. It is an all IP switched network and several working groups purpose that it should offer an open internet protocol. The early 4G technology comprises of flash OFDM, 802.16e, wireless or mobile Wi-max and HC SDMA. In the today’s world, the demand of wireless network users combined with the efforts of 4G working groups’ technology and edge over its previous counterparts. This 4G technology would revolutionize the world of cellular networks with amazing Wireless broadband speed. Due to this new technology, job opportunities for many people must be fulfilled. ITU is the deciding factor for further development in the 4G technology.

ITM ADVANCE REQUIREMENTS AND 4G WIRELESS STANDERDS.

• IMT-Advanced cellular system stands for international mobile telecommunication cellular system. This system uses 4G. Firstly I would like to explain the requirements of this system.  This cellular system must have following requirements:-
• It should be based on an all IP packet switched network.
• It must have peak data rates of up to approximately 100 Mbits/s for high mobility such as mobile access & up to 1Gbit/s for low mobility such as local wireless access according to ITU.
• It should dynamically share and utilizes the network resources to support more simultaneous per cell.
• It has scalable channel bandwidth of 5 to 20 MHz, optionally up to 40 MHz
• It has System spectral efficiency of up to 3 bit/s/Hz/cell in the downlink and 2.25 bit/s/Hz/cell for indoor usage.
• It has peak link spectral efficiency of 15 bit/s/Hz in the downlink, and 6.75 bit/s/Hz in the uplink (meaning that 1 Gbit/s in the downlink should be possible over less than 67 MHz bandwidth) .
• It should provide Smooth handovers across heterogeneous networks.   
• It has ability to offer high quality of service for next generation multimedia support.                

The technology proposals for 4G are basically based on two technologies:-
LTE advanced standardized by the 3GPP.
802.16m standardized by IEEE (i.e. WiMAX).

TECHNICAL PRESPECTIVE.
4G refers to the fourth generation of cellular wireless standards which is succeeding technology to 3G and based on IP version 6. Pre-4G technologies includes Flash-OFDM, 802.6e IEEE mobile version of WiMAX, HC-SDMA, and first-release 3G Long term evolution (LTE). These are often branded as 4G. The current versions of these technologies did not fulfill the original ITU-R requirements of data rates approximately up to 1 Gbit/s for 4G systems.   ITU has decided that “LTE Advanced” and “WirelessMAN-Advanced” should be accorded the official designation of IMT-Advanced.

Principal technologies for 4G.
4G is based on all IP data transfer system. In this wireless system core network is directly connected to users via terminals and application. In this system fixed backbone is completely removed, thus errors in signal and congestion of network is also minimized. For achieving this, adaptive terminals, smart antennas, and intelligent software are used.
Main technologies used for fourth generation wireless system are following: -
It includes physical layer transmission technologies which are as under;

1.  Multiple inputs and multiple outputs (MIMO):- To      attain ultra-high spectral efficiency by means of spatial   processing including multi-antenna multi-user MIMO.
2.  Frequency domain equalization. E.g. multi-carrier modulation (OFDM) in the downlink or single-carrier frequency –domain – equalization (SC-0FDE) in the uplink; to exploit the frequency selective channel without complex equalization.
3.  Frequency domain statistical multiplexing, for e.g. (OFDMA) or (single carrier-FDMA) in the uplink: variable bit rate by assigning different sub channels to different users based on the channel conditions.
4.  Turbo principle error correcting codes: - To minimize the required SNR at the reception side.
5.  Channel dependent scheduling: - To utilize the time varying channel.
6.  Link Adaption: - Adaptive modulation and correcting codes.
7.  Relaying, including fixed relay networks (FRNs), and the cooperative relaying concept known as multi-mode concept.etc.

Data rate comparison.
Comparison of 4G candidate system with 3G and other competing technologies:

Wireless security.
After development of mobile phones the first problem which was encountered was that an abuser may use a cloned phone for telephone calls and it was charged to legal costumers, because the early generation was analog radio signal based phones. In attempting to avoid security problems like these it is necessary to design security in every aspect of system. Wireless security really means combination of wireless channel security (security of radio transmission) and network security (security of wired network through which data flows). But in digital realm information security is also too important.

Information security model

One of the other important security issues comes due to interference of signals as a lot of users use the same electromagnetic spectrum.
As 4G system is not in proper use today, so we can only think of the threats based on experience of wireless and wired networks. One of the biggest issues for security may be due to new layers of technology applied, older layer may be a leak in security. Also future smartphones which will operate on 4G will be application based and any untrusted application may be a leakage to security to network. On the types of threats that may attack to the wireless security system, a complete, efficient, effective, extensible, user-friendly security system is designed for 4G wireless system.

4G PREDECESSORS AND CANDIDATE SYSTEMS.
The wireless telecommunications industry as a whole has early assumed the term 4G as short term hand way to describe those advanced cellular technologies that are based on or employ wide channel OFDMA and SC-FDE technologies, MIMO transmission and all IP based architecture. Mobile-WIMAX , first release LTE ,IEEE802.80 as well as flash OFDM meets these early assumptions , and have been considered as 4G candidate system  but do not yet meet more recent ITU-R IMT-Advanced requirements.
4G candidate systems: -
Long-term-evolution Advanced is a candidate for IMT-Advanced standard, formally submitted by the 3GPP organization to ITU-T in the fall 2009, and expected to be released in 2012. The target of 3GPP LTE Advanced is to reach and surpass the ITU requirements. LTE and LTE Advanced will also make use of additional spectrum and multiplexing to allow it to achieve higher data speeds. Coordinated Multi-point Transmission will also allow more system capacity to help handle the enhanced data speeds. Release 10 of LTE is expected to achieve the LTE Advanced speeds. Release 8 currently supports up to 300 Mbit/s download speeds which is still short of the IMT-Advanced standard and also known as pre 4G.
Data speeds of LTE Advanced:-

LTE Advanced
Peak download  : 1 Gbit/s
Peak upload : 500Mbit/s

The IEEE 802.16m or WirelessMAN Advanced evolution of 802.16e is under development, with the objective to fulfill the IMT-Advanced criteria of 1 Gbit/s for stationary reception and 100 Mbit/s for mobile reception.

4G predecessors and discontinued candidate systems: -
3GPP Long Term Evolution (LTE):-The pre-4G technology 3GPP Long Term Evolution (LTE) is often branded "4G", but the first LTE release does not fully comply with the IMT-Advanced requirements. LTE has a theoretical net bit rate capacity of up to 100 Mbit/s in the downlink and 50 Mbit/s in the uplink if a 20 MHz channel is used — and more if multiple-input multiple-output (MIMO), i.e. antenna arrays, are used. The physical radio interface was at an early stage named High Speed OFDM Packet Access (HSOPA), now named Evolved UMTS Terrestrial Radio Access (E-UTRA). The first LTE USB dongles do not support any other radio interface.
Mobile WiMAX (IEEE 802.16e):-The Mobile WiMAX (IEEE 802.16e-2005) mobile wireless broadband access (MWBA) standard (also known as Wi-Bro in South Korea) is sometimes branded 4G, and offers peak data rates of 128 Mbit/s downlink and 56 Mbit/s uplink over 20 MHz wide channels. The world's first commercial mobile WiMAX service was opened by KT in Seoul, South Korea on 30 June 2006.Sprint Nextel has begun using Mobile WiMAX, as of September 29, 2008 branded as a "4G" network even though the current version does not fulfill the IMT Advanced requirements on 4G systems.
ULTRA MOBILE BROADBAND: - UMB also known as UWB (ultra wide-band) was the brand name for a discontinued 4G project within the 3GPP2 standardization group to improve the CDMA2000 mobile phone standard for next generation application and requirements. The secret of UMB is that it is detected as noise. This highly specific kind of noise doesn’t cause interference with current radio frequency devices but can be decoded by other device that recognize UMB and can reassemble it back into signal. Since the signal is disguised as noise, it use any part of frequency spectrum, which means that it can use frequencies that are currently in use by other radio frequency devices. An UMB device works by emitting a series of short, low powered electrical pulses that are not directed at one particular frequency but rather are spread across the entire spectrum. Generally it uses a frequency between 3.1 to 10.6 GHz.

UMB provides greater bandwidth-as much as 60 Mbits/s (6 times greater than today’s wireless network). It also uses significantly less power, since it transmit pulses instead of continuous signals. To tune and aim the UWB signals, special smart antennas are needed, as strength of these signals is very weak. UMB’s lead sponsor, QUALCOMM announced in Nov, 2008 that it was ending development of the technology, favoring LTE instead. The objective was to achieve the data speeds of over 275 Mbps downstream and over 75Mbps upstream.
FLASH-OFDM:-The flash-OFDM system was expected to be further developed into a 4G standard at an early stage.
iBurst and MBWA (IEEE802.80) Systems:-The iBurst system or HC-SDMA, High capacity spatial division Multiple Access was considered as a 4G predecessor at an early stage. It was later further developed in to the Mobile Broadband Wireless Access (MBWA) system, also known as IEEE 802.80.

COMPONENTS.
For the successful implementation of 4G technologies there is a need of new access techniques as well as compatible hardware and software which can hold the increased data rates and provide the services efficiently.

Access schemes.
As the wireless standards evolved, the access techniques used also exhibited increase in efficiency, capacity and scalability. Access schemes like Orthogonal FDMA (OFDMA), Single Carrier FDMA (SC-FDMA), Interleaved FDMA and Multi-carrier CDMA (MC-CDMA) are gaining more importance for the 4th generation and other upcoming generation systems. These are based on efficient FFT algorithms and frequency domain equalization, resulting in a lower number of multiplications per second. They also make it possible to control the bandwidth and form the spectrum in a flexible way. However, they require advanced dynamic channel allocation and traffic adaptive scheduling. WiMax is using OFDMA in the downlink and in the uplink. For the next generation UMTS, OFDMA is used for the downlink. By contrast, IFDMA is being considered for the uplink since OFDMA contributes more to the PAPR related issues and results in nonlinear operation of amplifiers. IFDMA provides less power fluctuation and thus avoids amplifier issues. Similarly, MC-CDMA is in the proposal for the IEEE 802.20 standard. These access schemes offer the same efficiencies as older technologies like CDMA. Apart from this, scalability and higher data rates can be achieved. The other important advantage of the above mentioned access techniques are that they require less complexity for equalization at the receiver. This is an added advantage especially in the MIMO environments since the spatial multiplexing transmission of MIMO systems inherently requires high complexity equalization at the receiver. In addition to improvements in these multiplexing systems, improved modulation techniques are being used. Whereas earlier standards largely used Phase-shift keying, more efficient systems such as 64QAM are being proposed for use with the 3GPP Long Term Evolution standards.

Hardware.
The performance of radio communications depends on an antenna system, termed smart or intelligent antenna. Recently, multiple antenna technologies are emerging to achieve the goal of 4G systems such as high rate, high reliability, and long range communications. Smart antennas can optimize available power, increase base station range and coverage, reuse available spectrum, increase bandwidth, and lengthen the battery life of wireless devices.  Today’s Smart antennas based on, spatial multiplexing, gained importance for its bandwidth conservation and power efficiency. Spatial multiplexing involves deploying multiple antennas at the transmitter and at the receiver. Independent streams can then be transmitted simultaneously from all the antennas. This technology, called MIMO (as a branch of intelligent antenna), multiplies the base data rate by (the smaller of) the number of transmit antennas or the number of receive antennas. Apart from this, the reliability in transmitting high speed data in the fading channel can be improved by using more antennas at the transmitter or at the receiver. This is called transmit or receive diversity. Both transmit/receive diversity and transmit spatial multiplexing are categorized into the space-time coding techniques, which does not necessarily require the channel knowledge at the transmitter. The other category is closed-loop multiple antenna technologies, which require channel knowledge at the transmitter. Two generally used antennas for implementation of 4G are;
Switched beam antennas have fixed beams of transmission, and can switch from one predefined beam to another when the user with phone moves throughout the sector.
Adaptive array antennas represents the most advanced smart antenna approach to data using a verity of new signal processing algorithms to locate and track the user, minimize interference and maximize intended signal reception.

Software.
Along with smart antennas advanced software is also the need to process data on both sending and receiving side. This software should be flexible as the future wireless world will likely to be a heterogeneous mix of technologies.
SDR i.e. software defined radio is one that can be configured to any radio frequency standard by the help of software. A SDR in context of 4G would be able to work on different broadband networks and would be able to transfer to another network seamlessly while travelling outside the user’s home network.
Packet layer is a layer of abstraction that separates the data being transmitted from the way that it is being transmitted. The internet relies on packets to move files, pictures, videos, and other information over the same hardware. This system is more secure, reliable, flexible, extensible, and also proven quality of standard. Today IPv4 is in general use but for 4G IPv6 is recommended.  In the context of 4G, IPv6 support is essential in order to support a large number of wireless-enabled devices. By increasing the number of IP addresses, IPv6 removes the need for network address translation (NAT). VoIP (voice over internet protocol) is the new standard of voice over data networks, which is the principle theory of 4G.
Encryption is used to protect data in transit. Two encryption/decryption techniques are commonly used: symmetric and asymmetric. In symmetric encryption keys are the same but the encrypting and decrypting algorithms are inverse to each other, while asymmetric encryption is just opposite. For more safe and efficient data transmission 4G uses asymmetric encryption.
Software should be flexible so they can be modified and also it should be loaded with anti-virus for secure network.

4G IN TODAYS WORLD.
The 4G technology is now-a-days the latest mobile and internet services with a high speed of up to 1GBps. There is some of the detailed information about the implementation of 4G technology in today’s world:-
1st operational “4G” Wi-MAX network was announced by Lithuania’s LRTC in Baltic States, Europe the on 03rd march 2009.
Sprint began advertising “4G” service in selected cities in USA, despite average speeds of only 3-6 Mbps with peak speed of 10 Mbps.
The 1st commercial LTE deployment was in the scandivian capitals Stockholm and Oslo by the network operator Telia Sonera and Netcom on dec14 2009. Telia Sonera used spectral bandwidth of 10 MHz and single- in-single-out which should provide net bit rates of up to 50Mbps and 25 Mbps uplink and in Stockholm 42.8Mbps downlink & 5.3 Mbps in uplink.
 Estonia’s EMT opened LTE “4G” network working in test regime on25 February 2010.
Sprint Nextel released the 1st 4G smart phone (HTCEvo4G) on 4th June 2010.
 Latvia’s LMT opened LTE”4G” network working in test regime 50% of territory on25th august 2010.
Viva Cell-MTS launched 4G/LTE commercial test network with alive demo conducted in Yerevan on 12th Dec, 2010.
So many techniques are used till now under brand name of 4G but no one satisfies ITU-R standards. It is expected that with launch of LTE Advanced in 2012 4G will officially come into existence.

BEYOND 4G WIRELESS SYSTEM.
User requirements are growing faster than ever and the limitations of the current mobile communication system have   enforced the researchers to come up with the more advanced and efficient technologies. 4G technology is the next step in this direction but it is not the end. It is expected that this service will provide its customers a better speed and an all IP based multimedia services. 4G is all about an integrated, global network that 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, but the most important work in this field is still to be done that is to make it more user friendly,  more energy efficient and economically efficient systems. Today, we have many technologies each capable of performing functions like supporting voice traffic using voice over IP, broadband data access in mobile environment etc., but there is a great need of deploying such technologies in to an integrated unified system. 4G presents a solution of this as it is a mix of heterogeneous technologies and technologies are getting advanced day by day. Research and tests are continuously being performed to make 4G compatible for all upcoming technologies and applications simultaneously. When a lot of application will work simultaneously then there will be greater probability of security leakage, so there is also a need to design more security systems for secure network. The race to implement 4G is accelerating and quiet challenging in the today’s world. Researches are also being performed for fifth generation of wireless communication, to exceed the limits of 4G. Although status of 5G technologies is unconfirmed today but wireless companies are thinking it as revolution and its key features are decided as under;
The advanced billing interfaces of 5G technology makes it more attractive and effective.
5G technology offers high resolution for crazy cell phones and bi-directional large bandwidth shaping.

1. This technology will also provide subscriber supervision tools for fast action.
2. The high quality services of 5G based on policy to avoid error.
3. This technology will provide large broadcasting of data in Gigabits which will support almost 65000 connections.
4. The 5G technology will also offer transporter class gateway with unparalleled consistency.   
5. The traffic statistics by 5G technology makes it more accurate.
6. A user can get better and fast solution through remote management in 5G.
7. The 5G technology will provide 25 Mbps connectivity speed.
8. The uploading and downloading speed of 5G technology will touch the peak.

Thus the fourth generation wireless 4G is going to start a new era of wireless communication with incredible speed and high secure network. Also it will revolutionize telecom industry and more compact and multi-tasking upgradable smart phones will be available in market. Data transfer will be more and easier, faster and secure. 4G can be said a giant step towards wireless world.

Finally i am very grateful to my coligue Pawan Singh for his great help in preparing this article.waiting for valuable comments.