Published on March 21, 2010
Slide 2: 4G Mobile technology - The mobile race to innovation. Slide 3: Welcome to the 4G The fourth generation of mobile networks will truly turn the current mobile phone networks, in to end to end IP based networks ,If 4G is implemented correctly, it will truly harmonise global roaming. It wont be just the phone networks that need to evolve, the increased traffic load on the internet 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. Slide 4: About 4G Mobile devices are getting smaller, lighter, and more powerful; they have bigger screens and longer battery life, more features and more capabilities. Bandwidth will always be the limiting factor in the development of applications and devices, be it wired, or wireless. The short fall of 3G networks is clear, it’s just not fast enough, offering 384kbps doesn’t meet the requirements of what the end user has come to expect these days. Some people see 3G as a stop-gap, until a fully integrated IP network is created; some countries have even chosen to bypass 3G and head straight to 4G, a method which has its advantages, and its disadvantages. Slide 5: About 4G 4G is set to be available around 2010, getting it right first time will make it a general winner with the one billion mobile users around the world. The end user can expect low cost per data bit, as well as speed and reliability, something which is greatly needed, and will become second nature in the future. Technology Companies with 4G networks are knocking on the door and mobile operators are beginning to answer. 4G networks and Next Generation Networks (NGNs) are becoming fast and very cost-effective solutions for those wanting an IP built high-speed data capacities in the mobile network. Slide 6: 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. In the sixties, a system launched by Bell Systems, called IMTS, or, “Improved Mobile Telephone Service", brought quite a few improvements such as direct dialing 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. Slide 7: 1G, or First Generation 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 mobile phone 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 Slide 8: 2G, or Second Generation 2G phones using global system for mobile communications (GSM) were first used in the early 1990s in Europe. GSM provides voice and limited data services, and uses digital modulation for improved audio quality. Multiple digital systems. The development of 2G cellular systems was driven by the need to improve transmission quality, system capacity, and coverage Speech transmission still dominates the airways, but the demand for fax, short message, and data transmission is growing rapidly. 2G cellular systems include GSM, digital AMPS (D-AMPS), code-division multiple access (CDMA), and personal digital communication (PDC). Slide 9: 2G, or Second Generation The core network. This network links together all the cells into a single network, coordinates resources to hand over your call from one cell to another as you move, discovers where you are so that you can receive incoming calls, links to the fixed network so that you can reach fixed-line phones, and communicates with roaming partners. The 2G architecture. The existing mobile network consists of the radio access network (comprising cells and backhaul communications) and the core network (comprising trunks, switches, and servers). Mobile switching centres (MSCs) are intelligent servers and the whole network is data-driven, using subscription and authentication information held in the home location register (HLR) and authentication centre (AuC). Slide 10: 3G, or Third Generation The 3G technology adds multimedia facilities to 2G phones by allowing video, audio, and graphics applications. Over 3G phones, you can watch streaming video or have video telephony. The idea behind 3G is to have a single network standard instead of the different types adopted in the US, Europe, and Asia. Telecommunications System (UMTS) or IMT-2000, will sustain higher data rates and open the door to many Internet style applications. The main characteristics of IMT-2000 3G systems are: 1. A single family of compatible standards that can be used worldwide for all mobile applications. 2. Support for both packet-switched and circuit-switched data transmission. 3. Data rates up to 2 Mbps (depending on mobility). 4. High spectrum efficiency. Slide 11: 3G, or Third Generation 3G promises increased bandwidth, up to 384 kbps when the device holder is walking, 128 kbps in a car, and 2 Mbps in fixed applications. A new air interface called enhanced data GSM environment (EDGE) has been developed specifically to meet the bandwidth needs of 3G. EDGE is a faster version of GSM wireless service. FOMA Launched in October 2001, DoCoMo’s Freedom of Multimedia Access (FOMA) service provides fast, high-quality voice and image transmission through packetbased networks. FOMA’s secure access can be used for mobile banking and e-commerce, e-mail, and i-mode compatible Websites. Its high-speed packet transmission network allows the i-mode structure to handle more multimedia content for 3G and 4G wireless Internet services. Slide 12: DRAWBACKS BY GENERATION 2G 1G 3G 1.High bandwidth requirement. 2. High spectrum licensing fees. 3. Huge capital. The GSM is a circuit switched, connection oriented technology, where the end systems are dedicated for the entire call session. This causes inefficiency in usage of bandwidth and resources. The GSM-enabled systems do not support high data rates. They are unable to handle complex data such as video. Poor voice quality, Poor battery life, Large phone size, No security, frequent call drops, Limited capacity and poor handoff reliability. Slide 13: 4G, or Forth Generation For 1 and 2G standards, bandwidth maximum is 9.6 kbit/sec, This is approximately 6 times slower than an ISDN (Integrated services digital network). Rates did increase by a factor of 3 with newer handsets to 28.8kbps. This is rarely the speed though, as in crowded areas, when the network is busy, rates do drop dramatically. Third generation mobile, data rates are 384 kbps (download) maximum, typically around 200kbps, and 64kbps upload. Fourth generation mobile communications will have higher data transmission rates than 3G. 4G mobile data transmission rates are planned to be up to 100 megabits per second on the move and 1000gigbits per second stationary, this is a phenomenal amount of bandwidth, only comparable to the bandwidth workstations get connected directly to a LAN. Slide 14: 4G, or Forth Generation Now we need to discuss the different access technologies, these are FDMA, TDMA and CDMA. FDMA-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 frequencyTDMA-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. CDMA-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. Slide 15: 4G, or Forth Generation 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. Slide 16: 4G, or Forth Generation How OFDM works 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). Slide 17: COMPARISION Slide 18: APPLICATIONS Virtual Presence: 4G system gives mobile users a "virtual presence" (for example, always-on connections to keep people on event). Virtual navigation: a remote database contains the graphical representation of streets, buildings, and physical characteristics of a large metropolis. Blocks of this database are transmitted i rapid sequence to a vehicle Tele-geoprocessing: Queries dependent on location information of several users, in addition to temporal aspects have many applications. Crisis-management applications Education Slide 19: CONCLUSION 4G is still at research stage, available after 2010 (?)... ... While the impact of 3G is still uncertain! Employing the discussed techniques, 4G has a significant potential for capacity improvements over 3G systems. The Japanese market and industries (NTT DoCoMo) seem to be leaders in mobile technologies. Therefore we should have a look on their innovations… Slide 20: WEBOGRAPHY 1.www.four-g.net. 2.Advanced wireless networks- savo Glisic.