4G-TECHNOLOGY AND ITS APPLICATION IN AUTOTARGETTING

ABSTRACT:

                                                                    The fourth generation of mobile networks will truly turn the current mobile phone networks, in to end to end IP based networks, couple this with the arrival of IPv6, every device in the world will have a unique IP address, which will allow full IP based communications from a mobile device, right to the core of the internet, and back out again. If 4G is implemented correctly, it will truly harmonise global roaming, super high speed connectivity, and transparent end user performance on every mobile communications device in the world.

4G is set to deliver 100mbps to a roaming mobile device globally, and up to 1gbps to a stationary device. With this in mind, it allows for video conferencing, streaming picture perfect video and much more.

It wont be just the phone networks that need to evolve, the increased traffic load on the internet as a whole (imagine having 1 billion 100mb nodes attached to a network over night) will need to expand, with faster backbones and oceanic links requiring major upgrade.

4G wont happen over night, it is estimated that it will be implemented by 2010, and if done correctly, should take off rather quickly.

 INTRODUCTION:

This paper presents an overview of current technology trends in the wireless technology market, a historical overview of  the evolving wireless technologies and an examination of how the communications industry plans to implement 4G wireless technology standards to address the growing demand for wireless multimedia services. The rapid and efficient deployment of new wireless data and Internet services has emerged as a critical priority for communications equipment manufacturers. Network components that enable wireless data services are fundamental to the next-generation network infrastructure. Wireless data services are expected to see the same explosive growth in demand that Internet services and wireless voice services have seen in recent years.

4G HISTORY:

At the end of the 1940’s, the first radio telephone service was introduced, and was designed to users in cars to the public land-line based telephone network. Then, in the sixties, a system launched by Bell Systems, called IMTS, or, “Improved Mobile Telephone Service", brought quite a few improvements such as direct dialling and more bandwidth. The very first analog systems were based upon IMTS and were created in the late 60s and early 70s. The systems were called "cellular" because large coverage areas were split into smaller areas or "cells", each cell is served by a low power transmitter and receiver.

The 1G, or First Generation. 1G was an analog system, and was developed in the seventies, 1G had two major improvements, this was the invention of the microprocessor, and the digital transform of the control link between the phone and the cell site.

1G analog system for mobile communications saw two key improvements during the 1970s: the invention of the microprocessor and the digitization of the control link between the mobilephone and the cell site.

Advance mobile phone system (AMPS) was first launched by the US and is a 1G mobile system. Based on FDMA, it allows users to make voice calls in 1 country

2G, or Second Generation

2G first appeared around the end of the 1980’s, the 2G system digitized the voice signal, as well as the control link. This new digital system gave a lot better quality and much more capacity (i.e. more people could use there phones at the same time), all at a lower cost to the end consumer. Based on TDMA, the first commercial network for use by the public was the Global system for mobile communication (GSM).

3G, or Third Generation

3G systems promise faster communications services, entailing voice, fax and Internet data transfer capabilities, the aim of 3G is to provide these services any time, anywhere throughout the globe, with seamless roaming between standards. ITU’s IMT-2000 is a global standard for 3G and has opened new doors to enabling innovative services and application for instance, multimedia entertainment, and location-based services, as well as a whole lot more. In 2001, Japan saw the first 3G network launched.

3G technology supports around 144 Kbps, with high speed movement, i.e. in a vehicle. 384 Kbps locally, and up to 2Mbps for fixed stations, i.e. in a building.

To understand 4G, we need to know about 3G. So how did 3G start? The idea didn’t come from network operators, but from device manufactures. In 1996 Nippon Telephone & Telegraph (NTT) and Ericsson started development of 3G; then in 1997 in the USA the TIA (Telecommunications Industry Association) chose CDMA (Code Division Multiple Access) as a technology for 3G; and then in 1998 the ETSI (European Telecommunications Standards Institute) also chose CDMA; in the end, in 1998 wideband CDMA or W-CDMA and cdma2000 were decided for the Universal Mobile Telecommunications System (UMTS).

The two major radio standards used for 3G are W-CDMA (wideband code division multiple access), and CDMA2000. W-CDMA is used in Europe, where CDMA2000 is used in the USA. In CDMA, one signal carries the data, this is then multiplied with a signal with a faster rate, that his more bandwidth, it uses TDM (Time Division Multiplexing). CDMA200 uses CDM (common code division multiplexing).

Now we need to discuss the different access technologies, these are FDMA, TDMA and CDMA.

The most common analog system is FDMA, or, Frequency Division Multiple Access. It is a method where the spectrum is cut up into different frequencies and then this chunk given to the users. At one time only one user is assigned to a frequency. Because of this the frequency is closed, until the call is ended, or it is passed on to another frequency. For a proper call to take place, two frequencies are needed, one for sending and one for receiving, FDMA has been used for first generation analog systems only, this is due to the large bandwidth wastage highlighted above.

TDMA, or Time Division Multiple Access makes use of the whole available spectrum, unlike FDMA. Instead of splitting the slots by frequency, it splits them by time, over all of the frequency. Each subscriber is given a time slot, as opposed to a frequency. Therefore many uses can sit on one frequency, and have different time slots, because the time slots are switched so rapidly, it seems like the channel is permanently connected. TDMA is used for 2G networks

Code Division Multiple Access uses the spread spectrum method, the way it works means its highly encrypted, so its no surprise it was developed and used by the military. Unlike FDMA, CDMA allows the user to sit on all of the available frequencies at the same time, and hop between then. Each call is identified by its unique code, hence the term Code Division. CDMA is very bandwidth efficient.

Onto 4G...
4G will provide unconceivable amounts of bandwidth to the palm of a user. Matching current Local Area Network speeds, 4G networks will provide 100MBps on the move. This is enough for studio quality video, multi channel surround sound and much more. 4G will be based on OFDM – the next generation in access technologies (read the technical section for more info on OFDM),

A handful of wireless technologies are set to join existing 2.5G and 3G standards, , as 4G and NGN vendors find a foothold in the mobile market. “The current race is ultimately to wrestle control from the UMTS and CDMA2000 platforms.

Service Providers are considering new protocols in search of a migration to an all IP network, a move expected to lower high-speed data costs and enable new services. Some of these solutions are considered 3.5G or even 4G.

FIG:2

                       

4G TECHNOLOGY:

Some possible standards for the 4G system are 802.20, WiMAX (802.16), HSDPA, TDD UMTS, UMTS and future versions of UMTS and proprietary networks from ArrayComm Inc., Navini Networks, Flarion Technologies, and 4G efforts in India, China and Japan.

The design is that 4G will be based on OFDM (Orthogonal Frequency Division Multiplexing), which is the key enabler of 4G technology. Other technological aspects of 4G are adaptive processing and smart antennas, both of which will be used in 3G networks and enhance rates when used in with OFDM.

Currently 3G networks still send there data digitally over a single channel, OFDM is designed to send data over hundreds of parallel streams, thus increasing the amount of information that can be sent at a time over traditional CDMA networks.

Mobile devices are getting smaller, lighter, and more powerful; they have bigger screens and longer battery life, more features and more capabilities. Things like watching the football game on your mobile device, watching movies, videoconferencing, paying your bills and downloading music to the palm of your hand will become second nature in the near future. Bandwidth will always be the limiting factor in the development of applications and devices, be it wired, or wireless.

                     FIG:1

The 4G data rates will vary depending on the number of channels that are available, and can be used. The channels that can be used will be cleaner thanks to technologies like adaptive processing, which detects interference on a channel and improves reception by actively switching channels to avoid interference.

4G networks will also use smart antenna technology, which is used to aim the radio signal in the direction of the receiver in the terminal from the base station. When teamed up with adaptive techniques, multiple antennas can cancel out more interference while enhancing the signal.

                           

                            FIG:3

The 4G plans are still years away, but transitioning from 3G to 4G should be seamless for customers because 4G will have evolved from 3G. Users won't even have to get new phones. Digital applications are getting more common lately and are creating an increasing demand for broadband communication systems. The technical requirements for related products are very high but solutions must be cheap to implement since we are essentially talking about consumer products. For Satellite and for Cable; such cost-efficient solutions are already about for the terrestrial link (i.e. original TV broadcasting) the requirements are so high that the 'standard' solutions are no longer an option. Orthogonal Frequency Division Multiplexing (OFDM) is a technology that allows transmitting very high data rates over channels at a comparable low complexity. Orthogonal Frequency Division Multiplexing is the choice of the transmission method for the European digital radio (DAB) and Digital TV (DVB-T) standard. Owing to its great benefit’s OFDM is being considered for future broadband application such as wireless ATM as well.

Technology	3G	4G
Frequency band	1.8 - 2.5GHz	2 - 8GHz
Bandwidth	5-20MHz	5-20MHz
Data rate	Up to 2Mbps	100Mbps moving - 1Gbps stationary
Access	W-CDMA	VSF-OFCDM and VSF-CDMA
FEC	Turbo-codes	Concatenated codes
Switching	Circuit/Packet	Packet

PRINCIPLE 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

HOW OFDM WORKS:

First of all the FDM part - Frequency division multiplexing is a technology that transmits several signals at the same time over a single transmission path, in a medium such as a cable or wireless system. Each signal is transmitted inside its own unique frequency range (the carrier frequency), which is then modulated by the data that is needing to be transmitted.

Orthogonal FDM's spread spectrum technique spreads the data over a lot of carriers that are spaced apart at precise frequencies. This spacing provides the "orthogonality" in this method which prevents the receivers/demodulators from seeing frequencies other than their own specific one. The main benefit of OFDM is high spectral efficiency, but with OFDM you also get; high resiliency to RF interference, and the multi-path distortion is lower. This is handy because in a standard terrestrial broadcasting situation there are high amounts of multipath-channels (e.g. the signal that was sent arrives at the receiving end using multiple paths of different lengths). Since the various versions of the signal interfere with each other, known as inter symbol interference (ISI) it becomes incredibly hard to extract the original information.

When OFDM was first implemented, it was by using banks of sinusoidal generators, e.g. just placing up a whole lot of single carriers in parallel. The use of the discrete Fourier transform (DFT) was originally proposed in 1971 by Weinstein and Ebert, which greatly reduces the implementation complexity of OFDM systems. This was further reduced by the development of the fast Fourier transform (FFT). Shortly after an equalisation algorithm was implemented in order to help suppress both ISI and intersubcarrier interference, which is caused by the channel impulse response and timing and frequency errors.

In OFDM the subcarrier pulse which is

used for transmission is rectangular. This is why the capability of pulse forming and modulation can be performed by an IDFT, which can be generated very efficiently as an IFFT. Because of this, the receiver only needs a FFT to reverse this process. Taking into account the theories of the Fourier Transform the rectangular pulse shape will end up as a sin(x)/x style of spectrum of the subcarriers.

                    

                           

APPLICATION:

At the present rates of 15-30 Mbit/s, 4G is capable of providing 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

OUR IDEA OF IMPLEMENTATION:

• IF  an auto flyer in embedded with the 4G technology ….
• A picture taken by the GOOGLE EARTH is assigned as the target (say a factory)
• Thus when the “auto-flyer” passes above the target and as the frames of the picture matches with the predestinated picture of the target then  a signal is given to ammunitions to fire such that the target is hit.

ADVANTAGES OF AUTO-TARGETING

• ACCURACY
• EFFECTIVE USE OF AMMUNITION
• 4G  IS  COST  EFFECTIVE  THUS  MAKING THE  WHOLE  SYSTEM  GETS COST  EFFECTIVE

CONCLUSION:

                                  Nowadays,wireless technology is getting popular and important in the network and the Internet field.In this paper, I briefly introduced the history background of 1G to 4G, compared the differences of 3G and 4G, and illustrated how 4G may work for more convenient and powerful in the future.4G just right started from 2002 and there are many standards and technologies, which are still in developing process. Therefore, no one can really sure what the future 4G will look like and what services  it will offer to people. 

REFERENCES:

   "4G - Beyond 2.5G and 3G Wireless Networks". MobileInfo.cm. Retrieved on 2007-03-26. 

  Jawad Ibrahim (December 2002). "4G Features" (PDF). Bechtel Telecommunications Technical Journal. Retrieved on 2007-03-26. 

   Young Kyun, Kim; Prasad, Ramjee (2006). 4G Roadmap and Emerging Communication Technologies. Artech House 2006. pp. 12–13. ISBN 1-58053-931-9. 

 "Mobility Management Challenges and Issues in 4G Heterogeneous Networks". ACM Proceedings of the first international conference on Integrated internet ad hoc and sensor networks. May 30 - 31, 2006. Retrieved on 2007-03-26.