4g Technology

4G Technology 2009 A SEMINAR REPORT ON

4G TECHNOLOGY Given By

Gaurav Bajaj Under The Guidance Of

MR. ROHIT TRIPATHI Submitted To

DEPARTMENT OF ELECTRONICS AND COMMUNICATION

UTTAR PRADESH TECHNICAL UNIVERSITY 2009 – 2010.

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4G Technology 2009

CERTIFICATE This is to certify that Gaurav Bajaj have have delivered delivered aa seminar seminar on on the the topic, topic,

“4G Technology” as a partial fulfillment of

Final Year of Electronics & Communication

for the year

2009-2010.

(Dr. Mrs. Geeta S. Lathkar)

MR. ROHIT TRIPATHI (LECTURE, EC DEPTT)

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4G Technology 2009

ACKNOWLEDGMENT

I feel great pleasure in submitting this seminar report on “4 4G Technology”. I wish to express true sense of gratitude towards my seminar guide and Lecture of EC Department Mr. ROHIT TRIPATHI who at very discrete step in study of this seminar contributed his valuable guidance and help to solve every problem that arose and opening the doors of the department towards the realization of the seminar report. Most likely I would like to express my sincere gratitude towards my family for always being there when I needed them the most. With all respect and gratitude, I would like to thank all the people, who have helped us directly or indirectly, I owe my all success to them.

Gaurav Bajaj

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4G Technology 2009

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 harmonize 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 won’t 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 won’t happen overnight, it is estimated that it will be implemented by 2012, and if done correctly, should take off rather quickly. 4G networks i.e. 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. Some possible standards for the 4G system are 802.20, WiMAX (802.16), HSDPA, TDD UMTS, UMTS and future versions of UMTS. 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 their 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.

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4G Technology 2009

CONTENT Chapter

Page No.

1. Introduction to 4G……………………………………………………………... 07 2. History of 4G…………………………………………………………………... 08 3. What is 4G……………………………………………………………………....10 4. Features of 4G…...……………………………………………………………....14 5. What is needed to build 4G network?...................................................................15 6. Implementation Using 4G.....................................................................................17 7. Architecture in prospects………………………………………………………...20 7.1 End to end architecture………………….………………………………….20 7.2 Middleware architecture………………..………………………………..... 21 7.3 Relay network architecture………………………….……………………...21 7.4 Overlay network….……………………..………...……………….……..... 24 8. Basic model for 4G……………………………………………………………….26 9. Transmission........................................…………………………………………...28 10. Wireless Technologies Used in 4G......…………………………………………...30 10.1 Orthogonal Frequency Division Multiplexing....…………………………. 31 10.1.1 Error Correcting.......................................................................... .. 33 10.2 Ultra Wide Band..........………………..……………………………….. .. 34 10.3 Millimeter wireless......………………..……………………………….. .. 37 10.4 Smart Antenna..............………………..……………………………….. ..38 10.5 Long term Power Prediction................................…………………………. 41 10.6 Scheduling Among User......................................…………………………. 42 10.7 Adaptive Modulation and Power Control...........…………………………. 43 11. Issues....................................................………………………………………….. 44 12. Mobile Management...........................…………………………………………... 47 13. Quality of service…………......………………………………………………… 48 14. Security…………………………………………………………………………...50 15. Applications……………………………………………………………………... 51 16. Conclusion……………………………………………………………………….. 53 17. References………………………………………………………………………...54 Page 5

4G Technology 2009 FIGURE INDEX Figure

Page No.

1.

History of mobile networks……………………………………………………..9

2. 3.

4G mobile communication……………………………………………………...13 Implementatian daigram of 4G… ……………………………………………...19

4.

Multihop architecture…………………………………………………………....23

5.

Overlay networks………………………………………………………………..25

6.

Basic model of 4G……………………………………………………………....27

7.

OFDM Modulation...…………………………………………………………....29

8.

OFDM Multiplexing.…………………………………………………………....32

9.

MIMO......................………………………………………………………….....40

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1. INTRODUCTION 4G (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. The approaching 4G (fourth generation) mobile communication systems are projected to solve still-remaining problems of 3G (third generation) systems and to provide a wide variety of new services, from high-quality voice to high-definition video to high-data-rate wireless channels. The term 4G is used broadly to include several types of broadband wireless access communication systems, not only cellular telephone systems. One of the terms used to describe 4G is MAGIC-Mobile multimedia, anytime anywhere, Global mobility support, integrated wireless solution, and customized personal service. As a promise for the future, 4G systems, that is, cellular broadband wireless access systems have been attracting much interest in the mobile communication arena. The 4G systems not only will support the next generation of mobile service, but also will support the fixed wireless networks. Researchers and vendors are expressing a growing interest in 4G wireless networks that support global roaming across multiple wireless and mobile networks—for example, from a cellular network to a satellite-based network to a high-bandwidth wireless LAN. With this feature, users will have access to different services, increased coverage, the convenience of a single device, one bill with reduced total access cost, and more reliable wireless access even with the failure or loss of one or more networks. 4G networks will also feature IP interoperability for seamless mobile Internet access and bit rates of 50 Mbps or more.

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4G Technology 2009 2. 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 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. The 1G or First Generation 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. 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 their 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 are to provide these services anytime, 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. 384Kbps locally, and upto 2Mbps for fixed stations, i.e. in a building.

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Fig 1: - History of Mobile Networks

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4G Technology 2009 3. What is 4G? Fourth generation (4G) wireless was originally conceived by the Defense Advanced Research Projects Agency (DARPA), the same organization that developed the wired Internet. It is not surprising, then, that DARPA chose the same distributed architecture for the wireless Internet that had proven so successful in the wired Internet. Although experts and policymakers have yet to agree on all the aspects of 4G wireless, two characteristics have emerged as all but certain components of 4G: end-to-end Internet Protocol (IP), and peer-to-peer networking. An all IP network makes sense because consumers will want to use the same data applications they are used to in wired networks. A peer-to-peer network, where every device is both a transceiver and a router/repeater for other devices in the network, eliminates this spoke-and-hub weakness of cellular architectures, because the elimination of a single node does not disable the network. The final definition of “4G” will have to include something as simple as this: if a consumer can do it at home or in the office while wired to the Internet, that consumer must be able to do it wirelessly in a fully mobile environment. Let’s define “4G” as “wireless ad hoc peer-to-peer networking.” 4G technology is significant because users joining the network add mobile routers to the network infrastructure. Because users carry much of the network with them, network capacity and coverage is dynamically shifted to accommodate changing user patterns. As people congregate and create pockets of high demand, they also create additional routes for each other, thus enabling additional access to network capacity. Users will automatically hop away from congested routes to less congested routes. This permits the network to dynamically and automatically self-balance capacity, and increase network utilization. What may not be obvious is that when user devices act as routers, these devices are actually part of the network infrastructure. So instead of carriers subsidizing the cost of user devices (e.g., handsets, PDAs, of laptop computers), consumers actually subsidize and help deploy the network for the carrier. With a cellular infrastructure, users contribute nothing to the network. They are just consumers competing for resources. But in wireless ad hoc peer-to-peer networks, users cooperate – rather than compete – for network resources.

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4G Technology 2009 Thus, as the service gains popularity and the number of user increases, service likewise improves for all users. And there is also the 80/20 rule. With traditional wireless networks, about 80% of the cost is for site acquisition and installation, and just 20% is for the technology. Rising land and labor costs means installation costs tend to rise over time, subjecting the service providers’ business models to some challenging issues in the out years. With wireless peer-topeer networking, however, about 80% of the cost is the technology and only 20% is the installation. Because technology costs tend to decline over time, a current viable business model should only become more profitable over time. The devices will get cheaper, and service providers will reach economies of scale sooner because they will be able to pass on the infrastructure savings to consumers, which will further increase the rate of penetration. This new generation of wireless is intended to complement and replace the 3G systems, perhaps in 5 to 10 years. Accessing information anywhere, anytime, with a seamless connection to a wide range of information and services, and receiving a large volume of information, data, pictures, video, and so on, are the keys of the 4G infrastructures. The future 4G infrastructures will consist of a set of various networks using IP (Internet protocol) as a common protocol so that users are in control because they will be able to choose every application and environment. Based on the developing trends of mobile communication, 4G will have broader bandwidth, higher data rate, and smoother and quicker handoff and will focus on ensuring seamless service across a multitude of wireless systems and networks. The key concept is integrating the 4G capabilities with all of the existing mobile technologies through advanced technologies. Application adaptability and being highly dynamic are the main features of 4G services of interest to users. These features mean services can be delivered and be available to the personal preference of different users and support the users' traffic, air interfaces, radio environment, and quality of service. Connection with the network applications can be transferred into various forms and levels correctly and efficiently. The dominant methods of access to this pool of information will be the mobile telephone, PDA, and laptop to seamlessly access the voice communication, highspeed information services, and entertainment broadcast services. Figure 1 illustrates elements and techniques to support the adaptability of the 4G domain. The fourth generation will encompass all systems from various networks, public to private; operator-driven broadband networks to personal areas; and ad hoc networks. The 4G systems will interoperate with 2G and Page 11

4G Technology 2009 3G systems, as well as with digital (broadband) broadcasting systems. In addition, 4G systems will be fully IP-based wireless Internet. This all-encompassing integrated perspective shows the broad range of systems that the fourth generation intends to integrate, from satellite broadband to high altitude platform to cellular 3G and 3G systems to WLL (wireless local loop) and FWA (fixed wireless access) to WLAN (wireless local area network) and PAN (personal area network), all with IP as the integrating mechanism. With 4G, a range of new services and models will be available. These services and models need to be further examined for their interface with the design of 4G systems.

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Fig 2: - 4G Mobile Communication

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4. FEATURES • Support for interactive multimedia, voice, streaming video, Internet, and  other broadband services  • IP based mobile system  • High speed, high capacity, and low cost‐per‐bit  • Global access, service portability, and scalable mobile services  • Seamless switching, and a variety of Quality of Service‐driven services  • Better scheduling and call‐admission‐control techniques  • Ad‐hoc and multi‐hop networks (the strict delay requirements of voice make  multi‐hop network service a difficult problem)  • Better spectral efficiency  • Seamless network of multiple protocols and air interfaces (since 4G will be  all‐IP, look for 4G systems to be compatible with all common network  technologies, including 802.11, WCDMA, Bluetooth, and Hyper LAN).   • An infrastructure to handle pre‐existing 3G systems along with other wireless  technologies, some of which are currently under development. 

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4G Technology 2009 5. What is needed to Build 4G Networks of Future? A number of spectrum allocation decisions, spectrum standardization decisions, spectrum availability decisions, technology innovations, component development, signal processing and switching enhancements and inter-vendor cooperation have to take place before the vision of 4G will materialize. We think that 3G experiences - good or bad, technological or business - will be useful in guiding the industry in this effort. We are bringing to the attention of professionals in telecommunications industry following issues and problems that must be analyzed and resolved:

*

Lower Price Points Only Slightly Higher than Alternatives - The business visionaries

should do some economic modeling before they start 4G hype on the same lines as 3G hype. They should understand that 4G data applications like streaming video must compete with very low cost wireline applications. The users would pay only a delta premium (not a multiple) for most wireless applications. *

More Coordination Among Spectrum Regulators Around the World - Spectrum

regulation bodies must get involved in guiding the researchers by indicating which frequency band might be used for 4G. FCC in USA must cooperate more actively with International bodies like ITU and perhaps modify its hands-off policy in guiding the industry. When public interest, national

security

interest

and

economic

interest

(inter-industry

a

la

TV

versus

Telecommunications) are at stake, leadership must come from regulators. At appropriate time, industry builds its own self-regulation mechanisms. *

More Academic Research: Universities must spend more effort in solving fundamental

problems in radio communications (especially multiband and wideband radios, intelligent antennas and signal processing. *

Standardization of wireless networks in terms of modulation techniques, switching

schemes and roaming is an absolute necessity for 4G. *

A Voice-independent Business Justification Thinking: Business development and

technology executives should not bias their business models by using voice channels as economic determinant for data applications. Voice has a built-in demand limit - data applications do not.

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4G Technology 2009 *

Integration Across Different Network Topologies: Network architects must base their

architecture on hybrid network concepts that integrates wireless wide area networks, wireless LANS (IEEE 802.11a, IEEE 802.11b, IEEE 802.11g, IEEE 802.15 and IEEE 802.16, Bluetooth with fiber-based Internet backbone. Broadband wireless networks must be a part of this integrated network architecture. *

Non-disruptive Implementation: 4G must allow us to move from 3G to 4G.

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6.IMPLEMENTATION USING 4G                      The  goal  of  4G  is  to  replace  the  current  proliferation  of  core  mobile  networks  with  a  single  worldwide  core  network  standard,  based  on  IP  for control, video, packet data, and voice. This will provide uniform video, voice,  and data services to the mobile host, based entirely on IP.  

                    The  objective  is  to  offer  seamless  multimedia  services  to  users  accessing  an  all  IP‐based  infrastructure  through  heterogeneous  access  technologies.  IP  is  assumed  to  act  as  an  adhesive  for  providing  global  connectivity and mobility among networks.  

                      An  all  IP‐based  4G  wireless  network  has  inherent  advantages  over its predecessors. It is compatible with, and independent of the underlying  radio  access  technology.  An  IP  wireless  network  replaces  the  old  Signaling  System  7  (SS7)  telecommunications  protocol,  which  is  considered  massively  redundant.  This  is  because  SS7  signal  transmission  consumes  a  larger  part  of  network bandwidth even when there is no signaling traffic for the simple reason 

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that it uses a call setup mechanism to reserve bandwidth, rather time/frequency  slots in the radio waves. IP networks, on the other hand, are connectionless and  use the slots only when they have data to send. Hence there is optimum usage of  the  available  bandwidth.  Today,  wireless  communications  are  heavily  biased  toward voice, even though studies indicate that growth in wireless data traffic is  rising  exponentially  relative  to  demand  for  voice  traffic.  Because  an  all  IP  core  layer  is  easily  scalable,  it  is  ideally  suited  to  meet  this  challenge.  The  goal  is  a  merged data/voice/multimedia network.  

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IMPLEMENTATION DIAGRAM OF 4G  

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4G Technology 2009 7. Architectures in Prospects

7.1 End-to-end Service Architectures for 4G Mobile Systems:A characteristic of the transition towards 3G systems and beyond is that highly integrated telecommunications service suppliers fail to provide effective economies of scale. This is primarily due to deterioration of vertical integration scalability with innovation speed up. Thus, the new rule for success in 4G telecommunications markets will be to provide one part of the puzzle and to cooperate with other suppliers to create the complete solutions that end customers require. A direct consequence of these facts is that a radically new end-to-end service architecture will emerge during the deployment of 3G mobile networks and will became prominent as the operating model of choice for the Fourth Generation (4G) Mobile Telecommunications Networks. This novel end-to-end service architecture is inseparable from an equally radical transformation of the role of the telecommunications network operator role in the new value chain of end service provision. In fact, 4G systems will be organized not as monolithic structures deployed by a single business entity, but rather as a dynamic confederation of multiple— sometimes cooperating and sometimes competing—service providers. End-to-end service architectures should have the following desirable properties: • Open service and resource allocation model. • Open capability negotiation and pricing model. • Trust management. Mechanisms for managing trust relationships among clients and

service providers, and between service providers, based on trusted third

party monitors. • Collaborative service constellations. • Service fault tolerance.

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4G Technology 2009 7.2 Middleware Architecture:The service middleware is decomposed into three layers; i.e. user support layer, service support layer and network support layer. The criterion for using a layered approach is to reuse the existing subsystems in the traditional middleware. The user support layer has autonomous agent aspects that traditional service middleware lacks. It consists of 4 sub-systems: ‘Personalization’, ‘Adaptation’, ‘Community’ and ‘Coordination’, to provide mechanisms for context awareness and support for communities and coordination. Introduction of this functional layer enables the reduction of unnecessary user interaction with the system and the provision of user-centric services realized by applying agent concepts, to support analysis of the current context, personalization depending on the user’s situation, and negotiation for service usage. The middle layer, the service support layer, contains most functionality of traditional middleware. The bottom layer, the network layer supports connectivity for all-IP networks. The dynamic service delivery pattern defines a powerful interaction model to negotiate the conditions of service delivery by using three subsystems: ‘Discovery & Advertisement’, ‘Contract Notary’ and ‘Authentication & Authorization’.

7.3

Cellular

Multihop

Communications:

Infrastructure-Based

Relay

Network Architecture:It is clear that more fundamental enhancements are necessary for the very ambitious throughput and coverage requirements of future networks. Towards that end, in addition to advanced transmission techniques and antenna technologies, some major modifications in the wireless network architecture itself, which will enable effective distribution and collection of signals to and from wireless users, are sought. The integration of “multihop” capability into the conventional wireless networks is perhaps the most promising architectural upgrade.

In a Multihop network, a signal from a source may reach its destination in multiple hops (whenever necessary) through the use of “relays”. Since we are here concerned with infrastructure-based networks, either the source or destination is a common point in the network Page 21

4G Technology 2009 - base station (or, access point, in the context of WLANs). The potential advantage of relaying is that it allows substituting a poor-quality (due to high path loss) single-hop wireless link with a composite, two- or more hop, better-quality link whenever possible. Relaying is not only efficient in eliminating black spots throughout the coverage region, but more importantly, it may extend the high data rate coverage range of a single BS; therefore cost-effective high data rate coverage may be possible through the augmentation of the relaying capability in conventional cellular networks.

Advantages:• Property owners can install their own access points. – Spreads infrastructure cost. • Reduced network access operational cost. – Backbone access through wireless. – Wired access through DSL at aggregation points. • Ad hoc-like characteristics: – Access points configure into access network. – Some access points may be moving (bus, train). • Multihop also could reduce costs in heterogeneous 3G networks. – 802.11 to GPRS for example.

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Fig.3: - Example of Heterogeneous Network Multihop Architecture

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5.4 Overlay network:In this architecture, a user accesses an overlay network consisting of several universal access points. These UAPs in turn select a wireless network based on availability, QoS specifications, and user defined choices. A UAP performs protocol and frequency translation, content adaptation, and QoS negotiation-renegotiation on behalf of users. The overlay network, rather than the user or device, performs handoffs as the user moves from one UAP to another. A UAP stores user, network, and device information, capabilities, and preferences. Because UAPs can keep track of the various resources a caller uses, this architecture supports single billing and subscription.

Figure1. Possible 4G wireless network architectures. (a) A multimode device lets the user, device, or network initiate handoff between networks without the need for network modification or interworking devices. (b) An overlay network—consisting of several universal access points (UAPs) that store user, network, and device information—performs a handoff as the user moves from one UAP to another. (c) A device capable of automatically switching between networks is possible if wireless networks can support a common protocol to access a satellite-based network and another protocol for terrestrial networks.

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Fig 4: -Overlay Networks Viral N. Patel

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4G Technology 2009 8. A Basic Model for 4G Networks QoS, security and mobility can be viewed as three different, indispensable aspects in 4G networks; however all are related to network nodes involving the controlling or the processing of IP packets for end-to-end flows between an MN and the CN. I show in this section how we view the 4G network infrastructure.

Two Planes: Functional Decomposition Noting that an IP network element (such as a router) comprises of numerous functional components that cooperate to provide such desired service (such as, mobility, QoS and/or AAA – Authentication, Authorization and Accounting), we identify these components in the SeaSoS architecture into two planes, namely the control plane and the data plane. Fig. 5 illustrates this method of flexible functional composition in 4G networks. As we are mainly concerned with network elements effectively at the network layer, we do not show a whole end-to-end communication picture through a whole OSI or TCP/IP stack. The control plane performs control related actions such as AAA, MIP registration, QoS signaling, installation/maintenance of traffic selectors and security associations, etc., while the data plane is responsible for data traffic behaviors (such as classification, scheduling and forwarding) for endto-end traffic flows. Some components located in the control plane interact, through installing and maintaining certain control states for data plane, with data plane components in some network elements, such as access routers (ARs), IntServ nodes or DiffServ edge routers. However, not all control plane components need to exist in all network elements, and also not all network elements (e.g., AAA server) are involved with data plane functionalities. I refer these cases as path-decoupled control and other cases as path coupled control. We argue the separation and coordination of control plane and data plane is critical for seamless mobility with QoS and security support in 4G networks, with the reasons as follows. Per-flow or per-user level actions occur much less frequent than per-packet actions, while per-packet actions are part of critical forwarding behavior, which involves very few control actions (which are typically simply to read and enforce according the install state during forwarding data). Actually, Page 26

4G Technology 2009 this separation concept is not new – routing protocols have the similar abstraction together used with the traditional IP packet delivery, this abstraction is recently being investigated in the IETF ForCES working group. However, we emphasize the three critical dimensions of future 4G networks: mobility, QoS and security, as well as other new emerging or replacement components might appear, integrated into a unified framework and allowing more extensibility for 4G networks design.

Fig.5: - The decomposition of control plane and data plane functionalities

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4G Technology 2009

9.TRANSMISSION  

 

An  OFDM  transmitter  accepts  data  from  an  IP  network, 

converting  and  encoding  the  data  prior  to  modulation.  An  IFFT  (inverse  fast  Fourier  transform)  transforms  the  OFDM  signal  into  an  IF  analog  signal,  which  is  sent  to  the  RF  transceiver.  The  receiver  circuit  reconstructs  the  data  by  reversing  this  process.  With  orthogonal  sub‐carriers,  the  receiver  can  separate  and  process  each  sub‐carrier  without  interference  from  other  sub‐carriers.  More  impervious  to  fading  and  multi‐path  delays  than  other  wireless  transmission  techniques,  ODFM  provides better link and communication quality. 

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4G Technology 2009

IP NETWORK

MODULATION

OFDM TRANSMITTER

RF TRANSMITTER

IFFT making IF analog

                                                 

OFDM MODULATION

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10.Wireless Technologies Used In 4G 1. OFDM  2. UWB  3. MILLIMETER  WIRELESS  4. SMART ANTENNAS  5. LONG TERM POWER PREDICTION  6. SHEDULING AMONG USERS  7. ADAPTIVE MODULATION AND POWER CONTROL 

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4G Technology 2009 10.1 Orthogonal Frequency Division Multiplexing:                OFDM,  a  form  of  multi‐carrier  modulation,  works  by  dividing  the  data  stream  for  transmission  at  a  bandwidth  B  into  N  multiple  and  parallel  bit  streams, spaced B/N apart (Figure 8). Each of the parallel bit streams has a much  lower bit rate than the original bit stream, but their summation can provide very  high  data  rates.  N  orthogonal  sub‐carriers  modulate  the  parallel  bit  streams,  which are then summed prior to transmission.                An  OFDM  transmitter  accepts  data  from  an  IP  network,  converting  and  encoding  the  data  prior  to  modulation.  An  IFFT  (inverse  fast  Fourier  transform) transforms the OFDM signal into an IF analog signal, which is sent to  the  RF  transceiver.  The  receiver  circuit  reconstructs  the  data  by  reversing  this  process. With orthogonal sub‐carriers, the receiver can separate and process each  sub‐carrier  without  interference  from  other  sub‐carriers.  More  impervious  to  fading  and  multi‐path  delays  than  other  wireless  transmission  techniques,  ODFM provides better link and communication quality.  

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   Fig 8: :Orthogonal Frequency Division Multiplexing:

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10.1.1Error Correcting:                4Gʹs error‐correction will most likely use some type of concatenated  coding  and  will  provide  multiple  Quality  of  Service  (QoS)  levels.  Forward  error‐correction  (FEC)  coding  adds  redundancy  to  a  transmitted  message  through  encoding  prior  to  transmission.  The  advantages  of  concatenated  coding  (Viterbi/Reed‐Solomon)  over  convolutional  coding  (Viterbi)  are  enhanced  system  performance  through  the  combining  of  two  or  more  constituent codes (such as a Reed‐Solomon and a convolutional code) into one  concatenated code. The combination can improve error correction or combine  error correction with error detection (useful, for example, for implementing an  Automatic  Repeat  Request  if  an  error  is  found).  FEC  using  concatenated  coding  allows  a  communications  system  to  send  larger  block  sizes  while  reducing bit‐error rates. 

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10.2 Ultra Wide Band :                A UWB transmitter spreads its signal over a wide portion of the RF  spectrum,  generally  1  GHz  wide  or  more,  above  3.1GHz.  The  FCC  has  chosen  UWB frequencies to minimize interference to other commonly used equipment,  such as televisions and radios. This frequency range also puts UWB equipment  above the 2.4 GHz range of microwave ovens and modern cordless phones, but  below 802.11a wireless Ethernet, which operates at 5 GHz.                 UWB  equipment  transmits  very  narrow  RF  pulses—low  power  and  short  pulse  period  means  the  signal,  although  of  wide  bandwidth,  falls  below  the threshold detection of most RF receivers. Traditional RF equipment uses an  RF carrier to transmit a modulated signal in the frequency domain, moving the  signal  from  a  base  band  to  the  carrier  frequency  the  transmitter  uses.  UWB  is  ʺcarrier‐freeʺ, since the technology works by modulating a pulse, on the order of  tens  of  microwatts,  resulting  in  a  waveform  occupying  a  very  wide  frequency  domain. The wide bandwidth of a UWB signal is a two‐edged sword. The signal  is  relatively  secure  against interference  and  has  the  potential  for  very  high‐rate  wireless broadband access and speed. On the other hand, the signal also has the  potential  to  interfere  with  other  wireless  transmissions.  In  addition,  the  low‐ power  constraints  placed  on  UWB  by  the  FCC,  due  to  its  potential  interference   

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with other RF signals, significantly limits the range of UWB equipment (but still  makes it a viable LAN technology). 

               One  distinct  advantage  of  UWB  is  its  immunity  to  multi‐path  distortion  and  interference.  Multi‐path  propagation  occurs  when  a  transmitted  signal  takes  different  paths  when  propagating  from  source  to  destination.  The  various  paths  are  caused  by  the  signal  bouncing  off  objects  between  the  transmitter  and  receiver—for  example,  furniture  and  walls  in  a  house,  or  trees  and buildings in an outdoor environment. One part of the signal may go directly   to the receiver while another; deflected part will encounter delay and take longer  to  reach  the  receiver.  Multi‐path  delay  causes  the  information  symbols  in  the  signal  to  overlap,  confusing  the  receiver—this  is  known  as  inter‐symbol  interference  (ISI).  Because  the  signalʹs  shape  conveys  transmitted  information,  the  receiver  will  make  mistakes  when  demodulating  the  information  in  the  signal.  For  long‐enough  delays,  bit  errors  in  the  packet  will  occur  since  the  receiver canʹt distinguish the symbols and correctly interpret the corresponding  bits.                 The  short  time‐span  of  UWB  waveforms—typically  hundreds  of  picoseconds to a few nanoseconds—means that delays caused by the transmitted  signal bouncing off objects are much longer than the width of the original UWB 

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4G Technology 2009 pulse,  virtually  eliminating  ISI  from  overlapping  signals.  This  makes  UWB  technology  particularly  useful  for  intra‐structure  and  mobile  communications  applications, minimizing S/N reduction and bit errors. 

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10.3 Millimeter Wireless:                Using the millimeter‐wave band (above 20 GHz) for wireless service  is  particularly  interesting,  due  to  the  availability  in  this  region  of  bandwidth  resources  committed  by  the  governments  of  some  countries  to  unlicensed  cellular  and  other  wireless  applications.  If  deployed  in  a  4G  system,  millimeter  wireless would constitute only one of several frequency bands, with the 5 GHz  band most likely dominant.

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10.4 Smart Antennas:           A  smart  antenna  system  comprises  multiple  antenna  elements  with  signal processing to automatically optimize the antennasʹ radiation (transmitter)  and/or reception (receiver) patterns in response to the signal environment. One  smart‐antenna  variation  in  particular,  MIMO,  shows  promise  in  4G  systems,  particularly  since  the  antenna  systems  at  both  transmitter  and  receiver  are  usually a limiting factor when attempting to support increased data rates.                          MIMO  (Multi‐Input  Multi‐Output)  is  a  smart  antenna  system  where  ʹsmartnessʹ  is  considered  at  both  transmitter  and  the  receiver.  MIMO  represents  space‐division  multiplexing  (SDM)—information  signals  are  multiplexed  on  spatially  separated  N  multiple  antennas  and  received  on  M  antennas. Figure 9 shows a general block diagram of a MIMO system. Some  systems may not employ the signal‐processing block on the transmitter side. 

Multiple  antennas  at  both  the  transmitter  and  the  receiver  provide  essentially  multiple  parallel  channels  that  operate  simultaneously  on  the  same  frequency band and at the same time.  This results in high spectral efficiencies in 

             

 

 

 

 

 

 

 

 

 

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a rich scattering environment (high multi‐path), since you can transmit multiple  data  streams  or  signals  over  the  channel  simultaneously.  Field  experiments  by  several organizations have shown that a MIMO system, combined with adaptive  coding  and  modulation,  interference  cancellation,  and  beam‐forming  technologies,  can  boost  useful  channel  capacity  by  at  least  an  order  of  magnitude.

             

 

 

 

 

 

 

 

 

 

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Fig 8 : Multiple Input Multiple Output

             

 

 

 

 

 

 

 

 

 

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4G Technology 2009 10.5 Long Term Power Prediction:                Channels  to  different  mobile  users  will  fade  independently.  If  the  channel  properties  of  all  users  in  a  cell  can  be  predicted  a  number  of  milliseconds ahead, then it would be possible to distribute the transmission load  among the users in an optimal way while fulfilling certain specified constraints  on  throughput  and  delays.  The  channel  time‐frequency  pattern  will  depend  on  the scattering environment and on the velocity of the moving terminal.                 In order to take the advantage the channel variability, we use OFDM  system  with  spacing  between  subcarrires  such  that  no  interchannel  interface  occurs for the worst case channel scenario  (Low coherence bandwidth).A time‐frequency grid constituting of regions of  one  time  slot  and  several  subcarriers  is  used  such  that  the  channel  is  fairly  constant over each region. These time‐frequency regions are then allocated to the  different users by a scheduling algorithm according to some criterion.

             

 

 

 

 

 

 

 

 

 

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4G Technology 2009 10.6 Scheduling among Users:                To  optimize  the  system  throughput,  under  specified  QoS  requirements and delay constraints, scheduling will be used on different levels:  

      6.1     Among  sectors:‐In  order  to  cope  with  co‐channel    interference  among neighboring sectors in adjacent cells, time slots are allocated according to  the  traffic  load  in  each  sector  .Information  on  the  traffic  load  is  exchanged  infrequently  via  an  inquiry  procedure.  In  this  way  the  interference  can  be  minimized and higher capacity be obtained.                 After  an  inquiry  to  adjacent  cells,  the  involved  base  stations  determine  the  allocation  of  slots  to  be  used  by  each  base  station  in  each  sector.  The    inquiry  process  can  also  include  synchronization  information  to  align  the  transmission  of  packets  at  different  base  stations  to  further  enhance  performance. 

           6.2         Among  users:‐Based  on  the  time  slot  allocation  obtained  from  inquiry  process,  the  user  scheduler  will  distribute  time‐frequency  regions                among the users of each sector based on their current channel predictions. Here  different degrees of sophistication can be used to achieve different transmission  goals.  

 

 

 

 

 

 

 

 

 

 

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10.7 Adaptive modulation and power control:                In a fading environment and for a highly loaded system there  will almost exist users with good channel conditions. Regardless of the choice of    criterion, which could be either maximization of system throughput or  equalization to user satisfaction, the modulation format for the scheduled  selected according to the predicted signal to noise and   interference ratio. user is                 By using sufficiently small time‐frequency bins the channel can be  made approximately constant within bins. We can thus use a flat fading AWGN  channel assumption. Furthermore since we have already determined the time  slot allocation, via the inquiry process among adjacent cells described above we  may use an aggressive power control scheme, while keeping the interference on  an acceptable level. 

               For  every  timeslot,  the  time‐frequency  bins  in  the  grid  represent  separate channels. For such channels the optimum rate and power allocation for                maximizing  the  throughput  can  be  calculated  under  a  total  average  power  constraint.  The  optimum  strategy  is  to  let  one  user,  the  one  with  best  channel,  transmit in each of the parallel channels. 

 

 

 

 

 

 

 

 

 

 

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ISSUES:                The first issue deals with optimal choice of access technology, or how  to  be  best  connected.  Given  that  a  user  may  be  offered  connectivity  from  more  than one technology at any one time, one has to consider how the terminal and  an overlay network choose the radio access technology suitable for services the  user is accessing.                  There are several network technologies available today, which can be  viewed as complementary. For example, WLAN is best suited for high data  rate  indoor  coverage.  GPRS  or  UMTS,  on  the  other  hand,  are  best  suited  for  nation  wide  coverage  and  can  be  regarded  as  wide  area  networks,  providing  a  higher  degree  of  mobility.  Thus  a  user  of  the  mobile  terminal  or  the  network  needs  to  make  the  optimal  choice  of  radio  access  technology  among  all  those  available.  A  handover  algorithm  should  both  determine  which  network  to  connect  to  as  well  as  when  to  perform  a  handover  between  the  different  networks.  Ideally,  the  handover  algorithm  would  assure  that  the  best  overall  wireless  link  is  chosen.  The  network  selection  strategy  should  take  into  consideration  the  type  of  application  being  run  by  the  user  at  the  time  of  handover. This ensures stability as well as optimal bandwidth for interactive and  background services.  

 

 

 

 

 

 

 

 

 

 

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4G Technology 2009                The  second  issue  regards  the  design  of  a  mobility  enabled  IP  networking  architecture,  which  contains  the  functionality  to  deal  with  mobility  between  access  technologies.  This  includes  fast,  seamless  vertical  (between  heterogeneous  technologies)  handovers  (IP  micro‐mobility),  quality  of  service  (QoS), security and accounting. Real‐time applications in the future will require  fast/seamless handovers for smooth operation.                  Mobility  in  IPv6  is  not  optimized  to  take  advantage  of  specific  mechanisms that may be deployed in different administrative domains. Instead,  IPv6  provides  mobility  in  a  manner  that  resembles  only  simple  portability.  To  enhance Mobility in IPv6, ‘micro‐mobility’ protocols (such as Hawaii[5], Cellular  IP[6] and Hierarchical Mobile IPv6[7]) have been developed   for  seamless  handovers  i.e.  handovers  that  result  in  minimal  handover  delay,  minimal packet loss, and minimal loss of communication state.                    The  third  issue  concerns  the  adaptation  of  multimedia  transmission  across  4G  networks.  Indeed  multimedia  will  be  a  main  service  feature  of  4G  networks, and changing radio access networks may in particular result in drastic                changes  in  the  network  condition.  Thus  the  framework  for  multimedia  transmission  must  be  adaptive.  In  cellular  networks  such  as  UMTS,  users  compete for scarce and expensive bandwidth.  

 

 

 

 

 

 

 

 

 

 

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4G Technology 2009                Variable  bit  rate  services  provide  a  way  to  ensure  service  provisioning at lower costs. In addition the radio environment has dynamics that  renders  it  difficult  to  provide  a  guaranteed  network  service.  This  requires  that  the services are adaptive and robust against varying radio conditions.                  High variations in the network Quality of Service (QoS) leads to  significant variations of the multimedia quality. The result could sometimes be  unacceptable to the users. Avoiding this requires choosing an adaptive encoding  framework for multimedia transmission. The network should signal QoS  variations to allow the application to be aware in real time of the network  conditions. User interactions will help to ensure personalized adaptation of the  multimedia presentation.  

             

 

 

 

 

 

 

 

 

 

 

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11.MOBILITY MANAGEMENT Features of mobility management in Ipv6:   ¾ 128‐bit address space provides a sufficiently large number of addresses   ¾  High  quality  support  for  real‐time  audio  and  video  transmission, short/bursty    connections of web applications, peer‐to‐peer applications,  etc.   ¾  Faster packet delivery, decreased cost of processing – no header checksum  at each relay, fragmentation only at endpoints.   ¾  Smooth handoff when the mobile host travels from one subnet to another,  causing a change in its Care‐of Address.    

             

 

 

 

 

 

 

 

 

 

 

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4G Technology 2009 13. Quality of Service (QoS):The Internet provides users with diverse and essential quality of service (QoS), particularly given the increasing demand for a wide spectrum of network services. Many services, previously only provided by traditional circuit-switched networks, can now be provided on the Internet. These services, depending on their inherent characteristics, require certain degrees of QoS guarantees. Many technologies are therefore being developed to enhance the QoS capability of IP networks. Among these technologies, differentiated services (DiffServ) and MPLS are paving the way for tomorrow’s QoS services portfolio. DiffServ is based on a simple model where traffic entering a network is classified, policed, and possibly conditioned at the edges of the network, and assigned to different behavior aggregates. Each behavior aggregate is identified by a single DS code point (DSCP). At the core of the network, packets are fast forwarded according to the per-hop behavior (PHB) associated with the DSCP. By assigning traffic of different classes to different DSCPs, the DiffServ network provides different forwarding treatments and thus different levels of QoS. MPLS integrates the label swapping forwarding paradigm with network layer routing. First, an explicit path, called a label switched path (LSP), is determined, and established using a signaling protocol. A label in the packet header, rather than the IP destination address, is then used for making forwarding decisions in the network. Routers that support MPLS are called label switched routers (LSRs). The labels can be assigned to represent routes of various granularities, ranging from as coarse as the destination network down to the level of each single flow. Moreover, numerous traffic engineering functions have been effectively achieved by MPLS. When MPLS is combined with DiffServ and constraint-based routing, they become powerful and complementary abstractions for QoS provisioning in IP backbone networks. Supporting QoS in 4G networks will be a major challenge due to varying bit rates, channel characteristics, bandwidth allocation, fault-tolerance levels, and handoff support among heterogeneous wireless networks. QoS support can occur at the packet, transaction, circuit, user, and network levels. • Packet-level QoS applies to jitter, throughput, and error rate. Network resources such as buffer space and access protocol are likely influences.

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4G Technology 2009 • Transaction-level QoS describes both the time it takes to complete a transaction and the packet loss rate. Certain transactions may be time sensitive, while others cannot tolerate any packet loss. • Circuit-level QoS includes call blocking for new as well as existing calls. It depends primarily on a network’s ability to establish and maintain the end-to-end circuit. Call routing and location management are two important circuit-level attributes. • User-level QoS depends on user mobility and application type. The new location may not support the minimum QoS needed, even with adaptive applications. In a complete wireless solution, the end-to-end communication between two users will likely involve multiple wireless networks. Because QoS will vary across different networks, the QoS for such users will likely be the minimum level these networks support.

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4G Technology 2009 14. Security Security in 4G networks mainly involves authentication, confidentiality, ntegrity, and authorization for the access of network connectivity and QoS resources for the MN’s flows. Firstly, the MN needs to prove authorization and authenticate itself while roaming to a new provider’s network. AAA protocols (such as Radius, COPS or Diameter [10]) provide a framework for such support especially for control plane functions (including key establishment between the MN and AR, authenticating the MN with AAA server(s), and installing security policies in the MN or ARs’ data plane such as encryption, encryption, and filtering), but they are not well suited for mobility scenarios. There needs to an efficient, scalable approach to address this. The Extensible Authentication Protocol (EAP) [6], a recently developed IETF protocol, provides a flexible framework for extensible network access authentication and potentially could be useful. Secondly, when QoS is concerned, QoS requests needs to be integrity-protected, and moreover, before allocating QoS resources for an MN’s flow, authorization needs to be performed to avoid denial of service attacks. This requires a hop-by-hop way of dynamic key establishment between QoS-aware entities to be signaled on. Finally, most security concerns in this paper lie in network layer functions: although security can also be provided by higher layers above the network layer.

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4G Technology 2009 15. Applications 1) Application to Admission Control in Cellular Packet Networks:Based on the developing trends of mobile communication, 4G will have broader bandwidth, higher data rate, and smoother and quicker handoff and will focus on ensuring seamless service across a multitude of wireless systems and networks. The key concept is integrating the 4G capabilities with all of the existing mobile technologies through advanced technologies. Application adaptability and being highly dynamic are the main features of 4G services of interest to users. Emerging wireless technologies such as 4G tend to be packet-switched rather than circuit-switched because the packet-based architecture allows for better sharing of limited wireless resources. In a packet network, connections (packet flows) do not require dedicated circuits for the entire duration of the connection. Unfortunately, this enhanced flexibility makes it more difficult to effectively control the admission of connections into the network.

2) 4G in normal life:2.1 Traffic Control:Beijing is a challenging city for drivers, with or without an Olympics going on. The growing middle class, and their new-found ability to purchase automobiles, is increasing the number of passenger vehicles on the road at a staggering annual rate of 30%. 4G networks can connect traffic control boxes to intelligent transportation management systems wirelessly. This would create a traffic grid that could change light cycle times on demand, e.g., keeping some lights green longer temporarily to improve traffic flow. It also could make vehicle-based ondemand “all green” routes for emergency vehicles responding to traffic accidents, reducing the likelihood that those vehicles will themselves be involved in an accident en route. Using fiber to backhaul cameras means that the intelligence collected flows one way: from the camera to the command center. Using a 4G network, those images can also be sent from the command center back out to the streets. Ambulances and fire trucks facing congestion can query various cameras to choose an alternate route. Police, stuck in traffic on major

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4G Technology 2009 thoroughfares, can look ahead and make a decision as to whether it would be faster to stay on the main roads or exit to the side roads.

2.2 Sensors on Public Vehicles:Putting a chemical-biological-nuclear (CBN) warning sensor on every governmentowned vehicle instantly creates a mobile fleet that is the equivalent of an army of highly trained dogs. As these vehicles go about their daily duties of law enforcement, garbage collection, sewage and water maintenance, etc., municipalities get the added benefit of early detection of CBN agents. The sensors on the vehicles can talk to fixed devices mounted on light poles throughout the area, so positive detection can be reported in real time. And since 4G networks can include inherent geo-location without GPS, first responders will know where the vehicle is when it detects a CBN agent.

3) Security:Beijing has already deployed cameras throughout the city and sends those images back to a central command center for the OLYMPIC games2008. This is generally done using fiber, which limits where the cameras can be hung, i.e., no fiber, no camera. 4G networks allow Beijing to deploy cameras and backhaul them wirelessly. And instead of having to backhaul every camera, cities can backhaul every third or fifth or tenth camera, using the other cameras as router/repeaters.

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4G Technology 2009 16. Conclusion As the history of mobile communications shows, attempts have been made to reduce a number of technologies to a single global standard. Projected 4G systems offer this promise of a standard that can be embraced worldwide through its key concept of integration. Future wireless networks will need to support diverse IP multimedia applications to allow sharing of resources among multiple users. There must be a low complexity of implementation and an efficient means of negotiation between the end users and the wireless infrastructure. The fourth generation promises to fulfill the goal of PCC (personal computing and communication)—a vision that affordably provides high data rates everywhere over a wireless network. Although 4G wireless technology offers higher bit rates and the ability to roam across multiple heterogeneous wireless networks, several issues require further research and development. It is not clear if existing 1G and 2G providers would upgrade to 3G or wait for it to evolve into 4G, completely bypassing 3G. The answer probably lies in the perceived demand for 3G and the ongoing improvement in 2G networks to meet user demands until 4G arrives.

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4G Technology 2009 17. References 1.” eMobility Technology Platform Whitepaper” edited by Didier Bourse (Motorola Labs) and Rahim Tafazolli (University of Surrey, CCSR) 2.”Intuitive Guide to Principle of Communications” copyright 2004 Charan Langton 3.”Paper on 4g evolution” By Abhijit Hota 4. www.wikipedia.com 5. www.4g.co.uk 6. www.wiley.com 7. www.mobilecomms-technology.com

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