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[attachment=3688]
Presented By:
SEMINAR
ON
BY
M.L.V.Ramesh
RollNo:05481A0529
ABSTRACT
Mobile communication is continuously one of the hottest areas that are developing at a booming speed, with advanced techniques emerging in all the fields of mobile and wireless communications. Current times are just the beginning for deploying 3G mobile communication systems, while research on the next generation of mobile communications, 4G wireless and mobile networks begin to pave the way for the future. This paper studies the visions of 4G from a technical perspective.We present an overall 4G feature framework based on the kernel concept of integration, in which two key features (diversity and adaptability) of the three targets (terminals, networks, and applications) are described in detail. The concepts of both external and internal diversity of each target are defined to illustrate the causes and solutions of the adaptability feature.
INTRODUCTION
Mobile communications and wireless networks are developing at an astounding speed, with evidences of significant growth in the areas of mobile subscribers and terminals, mobile and wireless access networks, and mobile services and applications. The present time is just right to start the research of 4G mobile communications because of: ?Possibility, according to the historical indication of a generation revolution once a decade, and now we are near the end of 3G standardization phase and the beginning of 3G deployment. ?Necessity: according to 3G goals, 3G is necessary but not sufficient to the mobile communication strategy, in which many problems are only partly solved and there are still many problems left to be solved in the next generation, i.e. 4G.
History
1G:This process began with the designs in the 1970s that have become known as 1G. The earliest systems were implemented based on analog technology and the basic cellular structure of mobile communication.
2G was based on digital signal processing techniques and regarded as a revolution from analogy to digital technology These 2G systems provided circuit- switched data communication services at a low speed. of 9.6 kbps The competitive rush to design and implement digital systems led again to a variety of different and incompatible standards such as GSM ,TDMA,CDMA,PDC.
2.5G: An interim step is being taken between 2G and 3G, the 2.5G. It is basically an enhancement of the two major 2G technologies to provide increased capacity on the 2G RF (radio frequency) channels and to introduce higher throughput for data service, up to 384 kbps. GSM system enhancements like GPRS and EDGE are considered to be 2.5 technologies. GPRS is an attractive solution to mobile operators, because it does not require the same degree of the investment as UMTS.
3G: 3G is deploying a new system with new services instead of only providing higher data up to 2 Mbps and broader bandwidth. Based on intelligent DSP techniques, various multimedia data communications services are transmitted by convergent 3G networks. The 3G system would have higher quality voice channels. The 3G system will have features like fast internet surfing advanced value added service and video telephony .The technologies that are used to boost the speed are UMTS and W-CDMA .
Problems associated with 3G:
??Difficulty in continuously increasing bandwidth and high data rate to meet multimedia services requirements, together with the coexistence of different services needing different QoS and bandwidth.
??Limitation of spectrum and its allocation.
??Difficult to roam across distinct service environment in different frequency bands.
??Lack of end-to-end seamless transport mechanism spanning a mobile sub-network and a fixed one.
Table 1 summarizes the entire development of mobile communications
4G FEATURES:
Different 4G feature frameworks have been defined from the standpoints of service subscriber, service provider, researcher and engineer. In the following we give some
representatives of 4G perspectives.
1) It is easy to say, based on the developing trends of mobile communication, that 4G will have broader bandwidth, higher data rate, smoother and quicker handoff, wider mobile area, more various service, lower cost, etc.
2) Other than the words more, any and/or all are preferred over expressions used by previous generations, e.g. anyone can communicate with anyone else, anywhere and anytime,or enjoy any service of any network operator, through any network of any network service provider
3) DoCoMo introduced the concept of MAGIC for the vision of 4G Mobile multimedia; Anytime, anywhere, anyone; Global mobility support; Integrated wireless solution; and Customized personal service, which mostly focused on public systems and treat 4G as the extension of 3G cellular service.
4) European Commission (EC) presented a perspective focusing on ensuring seamless service provisioning across a multitude of wireless systems and networks, and providing for optimum delivery via the most efficient network available e.g. private systems and ad-hoc networks, optimal resource utilization, multiple radio interfaces, WLAN use, standards for interoperability, etc.
Thus 4G will encompass all systems from public to private,operator driven to Adhoc, broadband to personal area and Ad-hoc networks.it will focus mainly on personalized service
4G FEATURE FRAME WORK: We can summarize proposal of 4G features with one sentence, or even more simply, with one word: integration, i.e. seamless integration of terminals, networks, and applications (together with users).
1) The discussion domain includes three relevant targets, i.e. terminals, networks, and applications. Out of the 4G domain, the user is the only target.
2) The kernel word of the definition is so-called integration, which means the convergence of first the three different targets; second the various modes of each target, which lead to the feature of diversity.
The 4G vision framework presented by us is illustrated in fig1
There are two kinds of diversity: external diversity and internal diversity.
??External diversity is outside the target, which brings along the demand of the adaptability feature to all targets.
??Internal diversity is inside each of the targets, and it acts as the solution for adaptability requirements. In short, the need for adaptability is caused by external diversity, and it is solved by internal diversity. Here both the external and internal diversity of users are the cause of all adaptability requirements, which implies that the user is out of the technical domain of 4G visions. The two main features, i.e. diversity and adaptability of the three targets terminal, network, and application are described in detail in the next section.
4G FEATURE DESCRIPTION:
1) User Diversity: The external diversity of users, i.e. people in different situations, includes e.g. culture, educational background, economic capability, physical property, personal preference, etc. The internal diversity of users, i.e. people with different interfaces, include e.g. vision, hearing, speech, touch sense, hands and fingers, body, etc, Both their external and internal diversity are to be adapted by the other two targets: terminal and application. diversity, with both diversities
2) Network Diversity and Adaptability: The external diversity of networks is obvious. Internet is assorted by nature, while wireless networks keep the same property. For instance air interfaces can integrate all kinds of standards and work on different frequencies. Moreover, multiple operators deploy networks with multiple standards and protocols. The internal diversity of networks means that one network can interconnect with other different networks and transfer various kinds of loads, e.g. cellular systems with various coverage.
Three targets are related to network adaptability. In reference to terminals, network adaptability aims to make multiform mobile devices with a wide range of moving speeds and mobile areas connectable to wireless networks. For applications, there is a requirement that any type and/or quality of service can be delivered through diverse fixed and mobile networks in the most suitable and efficient way. The target for networks themselves is to make it easy to build a new network or remove an old one, and to make interoperability with one s neighbours seamless despite its heterogeneous nature.
3) Application Diversity and Adaptability: The external diversity of applications will be a reasonable property, and this need not mean that 4G services and applications must be multifarious, in all the aspects of quantity, quality, and type. With internal diversity we mean that one application can be tailored into e.g. multiple levels of quality, various styles, and different kinds of release shape, etc. Application adaptability is a main feature of 4G services. To users, this means that services can be delivered automatically according to personal preferences of different users.
4G TECHNICAL PERSPECTIVE:
It is obvious that 4G, just like all the previous generations, is driven not only by technology, but also by market requirements. This section mainly discusses, from a more technical perspective, possible topics for research and promising techniques of 4G, and focuses mainly on those techniques that give support to the main feature of adaptability by internal diversity of targets in the 4G domain.
A. Terminals
In order to adapt to the diverse applications and networks, together with the various requirements of users, the terminal domain must possess both internal and external diversity. Support techniques of the field may include the following:
1) User interfaces of terminals vary from traditional keyboard, display, and tablet, to new interfaces based on speech, touch, vision, soft buttons, etc. This will be common at a time when one terminal has multiple user interfaces.
2) Adaptive techniques such as smart antennas, software radio, and smart transceivers, enhance interoperability through simultaneous support of several radio interfaces in a single terminal. This makes a terminal roamable across any air interface standard and connectable to any wireless access point by exchanging configuration software. These approaches can also be used on wireless access points as an advanced smart base station.
3) An intelligent terminal is able to dynamically improve its processing capability in order to contain various services. Some function modules can even be downloaded to a terminal when needed.
B. Networks
More advances in networks are needed to keep pace with the rapidly changing terminals and applications, as follows:
1) Smart antenna, software radio, together with advanced base station are the key techniques to achieve adaptability of wireless access points to diverse terminals, i.e. to make radio systems and air networks re-configurable.
.
2) Network layer hierarchical mobility management based on Mobile IPv6 and Cellular IP brings quick and seamless handoff to terminals. The Mobile IPv6 also presents a great contribution to the adaptability of heterogeneous networks.
.
3) Applications that transmits data while the user os moving -using Hotspots area also being developed. Hotspots are certain areas in which data is received at a higher rate. So when the user passes through this hotspot, the data packets ontended to him are transmitted at a very fast rate.this can also be considered on a system of HSDPA designed on H2.
C. Applications
Adaptability will be one of the basic requirements to the development and delivery of new mobile services. Promising techniques and possible topics may include:
1) Mobile application should refer to a user s profile so that it can be delivered in a way most preferred by the subscriber, such as context-based personalized services. This also brings the applications with adaptability to terminals that are moving in varying locations and speeds. Micro-sensors and GPS receivers are the main driven techniques.
2) Techniques such as adaptive multimedia and unified messaging take the terminal characteristics into account and ensure that the service can be received and run on a terminal with the most suitable form to the host type.
3) Intelligent mobile software agent is a common technique to all of the three targets, which act as a platform for service development, delivery, and auto-configuration.
4) Applications can negotiate with networks so that they can be transferred with the most efficient channel, e.g. indoor networks or WLAN or cellular systems in a wide area. Services will be tailorable in order to fit the different network environments and the varying traffic conditions.
The 4G vision can be summarized by following figure
4G PRESPECTIVE IN INDIA :
The Indian Government has established the centre of Excellence in Wireless Technologies (CEWT) in collaboration wi th IITs to work on 4G wireless communications.But however Indi a is now confined to 3G.
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.4G will bring true human like interaction with wearable electronics and disposable devices. Terminals will encompass speech, hearing,sight, as well as environmental data pertinent to the application, making the user permanently connected to both the cyber-workd as well as the real world .The services will provide affordless access to the other people And other devices around us with highest possibility of security and Integration. The fourth generation promises to fulfill the goal of PCC (personal computing and communication) a vision that affordably provides high data rates everywhere over awireless network.
REFERENCES
1. FROM 2.5G TO 3G OR 4G?
- Electronics For You
July-2005
2.wikipedia.com
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4G MOBILE COMMUNICATION SYSTEM
A SEMINAR REPORT
Submitted by
SUBRAT SUMAN
COMPUTER SCIENCE & ENGINEERING
SCHOOL OF ENGINEERING
COCHIN UNIVERSITY OF SCIENCE AND TECHNOLOGY,
ABSTRACT
4G (also known as Beyond 3G), an abbreviation for Fourth-Generation, is a term used to describe the next complete evolution in wirelesscommunications. 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. As the second generation was a total replacement of the first generation networks and handsets; and the third generation was a total replacement of second generation networks and handsets; so too the fourth generation cannot be an incremental evolution of current 3G technologies, but rather the total replacement of the current 3G networks and handsets. The international telecommunications regulatory and standardization bodies are working for commercial deployment of 4G networks roughly in the 2012-2015 time scale. There is no formal definition for what 4G is; however, there are certain objectives that are projected for 4G. These objectives include, that 4G will be a fully IP-based integrated system. 4G will be capable of providing between 100 Mbit/s and 1 Gbit/s speeds both indoors and outdoors, with premium quality and high security.
1.INTRODUCTION
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. This paper presents an overall vision of the 4G features, framework, and integration of mobile communication. The features of 4G systems might be summarized with one word- Integration.The 4G systems are about seamlessly integrating terminals, networks, and applications to satisfy increasing user demands. The continuous expansion of mobile communication and wireless networks shows evidence of exceptional growth in the areas of mobile subscriber, wireless network access, mobile services, and applications. An estimate of 1 billion users by the end of 2003 justifies the study and research for 4G systems.
2.HISTORY
The history and evolution of mobile service from the 1G (first generation) to fourth generation are discussed in this section. Table 1 presents a short history of mobile telephone technologies. This process began with the designs in the 1970s that have become known as 1G. The earliest systems were implemented based on analog technology and the basic cellular structure of mobile communication. Many fundamental problems were solved by these early systems. Numerous incompatible analog systems were placed in service around the world during the 1980s.The 2G (second generation) systems designed in the 1980s were still used mainly for voice applications but were based on digital technology, including digital signal processing techniques. These 2G systems provided circuit-switched data communication services at a low speed. The competitive rush to design and implement digital systems led again to a variety of different and incompatible standards such as GSM (global system mobile), mainly in Europe; TDMA (time division multiple access) (IS-54/IS- 136) in the U.S.; PDC (personal digital cellular) in Japan; and CDMA (code division multiple access) (IS-95), another U.S. system. These systems operate nationwide or internationally and are today's mainstream systems, although the data rate for users in these system is very limited. During the 1990s, two organizations worked to define the next, or 3G, mobile system, which would eliminate previous incompatibilities and become a truly global system. The 3G system would have higher quality voice channels, as well as broadband data capabilities, up to 2 Mbps. Unfortunately, the two groups could not reconcile their differences, and this decade will see the introduction of two mobile standards for 3G. In addition, China is on the verge of implementing a third 3G system. An interim step is being taken between 2G and 3G, the 2.5G. It is basically an enhancement of the two major 2G technologies to provide increased capacity on the 2G RF (radio frequency) channels and to introduce higher throughput for data service, up to 384 kbps. A very important aspect of 2.5G is that the data channels are optimized for packet data, which introduces access to the Internet from mobile devices, whether telephone, PDA (personal digital assistant), or laptop. However, the demand for higher access speed multimedia communication in today's society, which greatly depends on computer communication in digital format, seems unlimited. According to the historical indication of a generation revolution occurring once a decade, the present appears to be the right time to begin the research on a 4G mobile communication system.
Symbols:
1xRTT = 2.5G CDMA data service up to 384 kbps
AMPS = advanced mobile phone service
CDMA = code division multiple access
EDGE = enhanced data for global evolution
FDMA = frequency division multiple access
GPRS = general packet radio system
GSM = global system for mobile
NMT = Nordic mobile telephone
PDC = personal digital cellular
PSTN = pubic switched telephone network
TACS = total access communications system
TDMA = time division multiple access
WCDMA = wideband CDMA
3.VISION OF 4G
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, high-speed 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 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. Figures 2 and 3 demonstrate the key elements and the seamless connectivity of the networks.
4.KEY 4G TECHNOLOGIES
Some of the key technologies required for 4G are briefly described below:
4.1 OFDMA
Orthogonal Frequency Division Multiplexing (OFDM) not only provides clear advantages for physical layer performance, but also a framework for improving layer 2 performance by proposing an additional degree of free- dom. Using ODFM, it is possible to exploit the time domain, the space domain, the frequency domain and even the code domain to optimize radio channel usage. It ensures very robust transmission in multi-path environments with reduced receiver complexity. OFDM also provides a frequency diversity gain, improving the physical layer performance .It is also compatible with other enhancement Technologies, such as smart antennas and MIMO.OFDM modulation can also be employed as a multiple access technology (Orthogonal Frequency Division Multiple Access; OFDMA). In this case, each OFDM symbol can transmit information to/from several users using a different set of sub carriers (sub channels). This not only provides additional flexibility for resource allocation (increasing the capacity), but also enables cross-layer optimization of radio page link usage.
4.2 SOFTWARE DEFINED RADIO
Software Defined Radio (SDR) benefits from today s high processing power to develop multi-band, multi-standard base stations and terminals. Although in future the terminals will adapt the air interface to the available radio access technology, at present this is done by the infrastructure.
Several infrastructure gains are expected from SDR. For example, to increase network capacity at a specific time (e.g. during a sports event),an operator will reconfigure its network adding several modems at a given Base Transceiver Station (BTS). SDR makes this reconfiguration easy. In the context of 4G systems, SDR will become an enabler for the aggregation of multi-standard pico/micro cells. For a manufacturer, this can be a powerful aid to providing multi-standard, multi-band equipment with reduced development effort and costs through simultaneous multi-channel processing.
4.3 MULTIPLE-INPUT MULTIPLE OUTPUT
MIMO uses signal multiplexing between multiple transmitting antennas (space multiplex) and time or frequency. It is well suited to OFDM, as it is possible to process independent time symbols as soon as the OFDM waveform is correctly designed for the channel. This aspect of OFDM greatly simplifies processing. The signal transmitted by m antennas is received by n antennas. Processing of the received signals may deliver several performance improvements:range, quality of received signal and spectrum efficiency. In principle, MIMO is more efficient when many multiple path signals are received. The performance in cellular deployments is still subject to research and simulations . However, it is generally admitted that the gain in spectrum efficiency is directly related to the minimum number of antennas in the link.
4.4 HANDOVER AND MOBILITY
Handover technologies based on mobileIP technology have been considered for data and voice. Mobile IP techniques are slow but can be accelerated with classical methods (hierarchical, fast mobile IP).
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This article is presented by: Toshio Miki
Tomoyuki Ohya
Hitoshi Yoshino
Narumi UmedaThe Overview of the 4th Generation Mobile
Communication System
ABSTRACT
In order to satisfy the expectation of the users to have more advanced wireless access even in the mobile environments, research and development efforts for realizing the Fourth- Generation (4G) mobile communication system has been discussed. This paper outlines the requirements for the system, technical challenges to be solved, and finally describes the activities related to the standardization of the 4G mobile communication system..
INTRODUCTION
The users of the Third-Generation (3G) International Mobile Telecommunications-2000 (IMT-2000) [1] mobile communication services, which was launched in October 2001, has already reached about 34 million subscribers in Japan. The system provides a variety of advanced multimedia services such as video communications and high speed internet access. It is expected that this will lead to the mobile communication more important to our daily lives and will expand the role as a lifestyle basis in the next ten years. It is also expected that such an era requires a more advanced wireless communications system, such as the Fourth-Generation (4G) mobile communication system, which far surpasses the capability of the existing IMT-2000 as shown in Figure 1. The development process of the new mobile systems consists of developing the requirements, providing solutions satisfies the requirements, showing evidences for each technology to satisfy the requirements, as well as building international consensus through the standardization activities. In this article, we describe a basic approach to the technical issues and system configuration involved in achieving the capability and performance required of the 4G system. We also describe the trends in standardization concerning mobile communication systems. II. SYSTEM OBJECTIVES A. Applications for 4G systems The improvements in media communication quality have been one of the most perceptible advancements and only the perceptible advancements noted by the customers. For example, the size and resolution of LCD (Liquid Crystal Display) screens, the number of pixels in built-in camera, and the wide variety of ringer tones have been key to the popularity of mobile handsets. However, current mobile terminals still have much room in terms of improving communication reality. The ultimate objective of enhanced-reality media communications is to provide a transparent environment that is indistinguishable from face-to-face communications. The applications, which require more advanced wireless capabilities, are discussed in [2]. In the article, three main directions for enhancing media communication reality, that is 3D audio communications, 3D visual communications and biological information communications, as shown in Figure 2, were analyzed, and as a conclusion, it is expected that the future customers will be able to full use of 1 Mbit/s to 100 system, introduced the i-mode services, which enabled the Internet access, electronic commerce and e-mail from mobile terminals, and mainly used for the text-based data communications. The IMT-2000 system offers high bit rate transmission service from 64 kbit/s to 384 kbit/s, and it is expected that the proportion of the amount of data traffic to the voice traffic would continue to increase. Moreover, the rising popularity of broadband services such as Asymmetric Digital Subscriber Line (ADSL) and optical fiber access systems and office or home LANs is likely to lead to a demand for comparable services in the mobile communication environment. 2) Low Cost To make broadband services available to the user to exchange various kinds of information, it is necessary to lower charges dramatically in order to keep the cost at or below the cost of existing service. The IMT-2000 system aimed at lower bit cost and economical charge rates, however for the 4G system, a broadband channel and an even lower bit cost are both required. 3) Wide Area Coverage One feature of mobile communications is that it is available for use anytime and anywhere. That advantage is important for future mobile communication as well. In particular, it is important to maintain the service area in which the terminals of the new system can be used during the transition from the existing system to a new system. It can be assumed that terminals that have relatively large display screens, such as Personal Digital Assistants (PDAs) or personal computers are used indoors rather than outdoors. Accordingly, better coverage of indoor service areas is needed. 4) Capable for Wide Variety of Services Mobile communication is for various types of users. In the future, we expect to make the advanced system performance and functionality to introduce a variety of services not only the ordinary telephone service but to transfer information about the five sensual modes. Those services must be made easier for anyone to use.
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[attachment=14664]
CHAPTER 1
INTRODUCTION
Wireless mobile communications systems are uniquely identified by generation designations. Introduced in the early 1980s, first generation (1G) systems were marked by analog frequency modulation and used primarily for voice communications. Second generation (2G) wireless communications systems, which made their appearance in the late 1980s, were also used mainly for voice transmission and reception The wireless system in widespread use today goes by the name of 2.5G an in between service that serves as a stepping stone to 3G. Whereby 2G communications is generally associated with Global System for Mobile (GSM) service, 2.5G is usually identified as being fueled by General Packet Radio Services (GPRS) along with GSM.
In 3G systems, making their appearance in late 2002 and in 2003, are designed for voice and paging services, as well as interactive media use such as teleconferencing, Internet access, and other services. The problem with 3G wireless systems is bandwidth these systems provide only WAN coverage ranging from 144 kbps (for vehicle mobility applications) to 2 Mbps (for indoor static applications). Segue to 4G, the next dimension of wireless communication. The 4g wireless uses Orthogonal Frequency Division Multiplexing (OFDM), Ultra Wide Radio Band (UWB), and Millimeter wireless and smart antenna. Data rate of 20mbps is employed. Mobile speed will be up to 200km/hr.Frequency band is 2 8 GHz. it gives the ability for world wide roaming to access cell anywhere
CHAPTER 2
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
Adhoc 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.
CHAPTER 3
HISTORY
The history and evolution of mobile service from the 1G(first generation) to fourth generation are as follows. The process began with the designs in the 1970s that have become known as 1G. The earliest systems were implemented based on analog technology and the basic cellular structure of mobile communication.
Many fundamental problems were solved by these early systems. Numerous incompatible analog systems were placed in service around the world during the 1980s.The 2G (second generation) systems designed in the 1980s were still used mainly for voice applications but were based on digital technology, including digital signal processing techniques. These 2G systems provided circuit switched data communication services at a low speed. The competitive rush to design and implement digital systems led again to a variety of different and incompatible standards such as GSM (global system mobile), TDMA (time division multiple access); PDC (personal digital cellular) and CDMA (code division multiple access).These systems operate nationwide or internationally and are today s mainstream systems, although the data rate for users in these system is very limited.
During the 1990 s the next, or 3G, mobile system, which would eliminate previous incompatibilities and become a truly global system. The 3G system would have higher quality voice channels, as well as broadband data capabilities, up to 2 Mbps.An interim step is being taken between 2G and 3G, the 2.5G. It is basically an enhancement of the two major 2G technologies to provide increased capacity on the 2G RF (radio frequency) channels and to introduce higher throughput for data service, up to 384 kbps.
A very important aspect of 2.5G is that the data channels are optimized for packet data, which introduces access to the Internet from mobile devices, whether telephone, PDA (personal digital assistant), or laptop. However, the demand for higher access speed multimedia communication in todays society, which greatly depends on computer communication in digital format, seems unlimited. According to the historical indication of a generation revolution occurring once a decade, the present appears to be the right time to begin the research on a 4G mobile communication system
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[attachment=15268]
Mobile System Generations
First Generation (1G) mobile systems were designed
to offer a single service, i.e., speech.
Second Generation (2G) mobile systems were also
designed primarily to offer speech with a limited capability to offer data at low rates.
Third Generation (3G) mobile systems are expected
to offer high-quality multi-media services and operate
in different environments.
SHORT HISTORY of MOBILE TELEPHONE TECHNOLOGIES
THIRD GENERATION (3G)
Major technologies
Bluetooth
Wireless LAN (IEE 802.x standards) WiFi
Short range wireless communications
Highly utilized and very popular: offices, airports, coffee shops, universities and schools
Two basic modes of operations:
-Ad-hoc networking: computers send data to one another
-Access point: sending data to the base station
Limitations of 3G
Difficulty of CDMA to provide higher data rates
Need for continuously increasing data rate and
bandwidth to meet the multimedia requirements
Limitation of spectrum and it s allocation
Inability to roam between different services
To provide a seamless transport end-to-end
Mechanism
To introduce a better system with reduces cost
4G Concept
The user has freedom and flexibility
to select any desired service with
reasonable QoS and affordable price,
anytime, anywhere.
Design Objectives
Next Generation will also have specifically needs to resolve it s own multiple issues
Heterogeneous networks
Access, handover
Location coordination, resource coordination
Adding new users
Support for multicasting
QoS, wireless security and authentication
Network failure backup
Pricing and billing
Heterogeneous Networks
Network Selection
Most Appropriate Network Selection Criteria
Service Type
-Data rate
-QoS
Available Resources
User Context
- Environment (When and Where)
- Mobility
- User preferences
Key 4G Technologies
OFDM (Orthogonal Frequency Division Multiplexing)
SDR (Software Defined Radio)
MIMO (Multiple-input multiple-output)
Interlayer Optimization
Handover and Mobility
Benefits
Convergence of Cellular Mobile Networks and WLANs
Benefits for Operators
Higher bandwidths, Lower cost of networks and equipment,The use
of licence-exempt spectrum, Higher capacity and Qos enhancement,
higher revenue.
Users
Access to broadband multimedia services with lower cost and here
mostly needed, Inter-network roaming.
Convergence of Mobile Communication and Broadcasting
Benefits for Operators
Cellular operators will benefit from offering their customers a
range of new broadband multi-media services in vehicular
environments.
Users
Users will benefit from faster access to a range of broadband multi-
media services with reasonable QoS and lower cost.
Wireless System Discovery
A multimode terminal attaches
to the WLAN and
scans the available
systems.
It can download
suitable software
manually or
automatically.
Applications
Virtual Presence
Virtual navigation
Tele-geoprocessing applications
Tele-Medicine and Education
Crisis management
Multimedia Video Services
CONCLUSION
As the history of mobile communications shows
attempts have been made to reduce a number of
technologies to a single global standard.
4G seems to be a very promising generation of
wireless communication that will change the
people s life in the wireless world.
4G is expected to be launched by 2010 and the
world is looking forward for the most intelligent
technology that would connect the entire globe.
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Abstract
Mobile communication is continuously one of the hottest areas that are developing at a booming speed, with advanced techniques emerging in all the fields of mobile and wireless communications. Current times are just the beginning for deploying 3G mobile communication systems, while research on the next generation of mobile communications, 4G wireless and mobile networks begin to pave the way for the future. This paper studies the visions of 4G from a technical perspective. After a brief review on the development history and status of mobile communications and related 4G perspectives, we present an overall 4G feature framework based on the kernel concept of integration, in which two key features (diversity and adaptability) of the three targets (terminals, networks, and applications) are described in detail. The concepts of both external and internal diversity of each target are defined to illustrate the causes and solutions of the adaptability feature. Then, along the entire 4G domain, each feature in the framework is deeply discussed from a technical standpoint, in which promising techniques and possible research issues for sufficient support of adaptability are also proposed. Finally, a short summary on 4G visions is presented as a continuum of features in the development of the mobile communications world.
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This artile is presented by:
Juha Ylitalo
Markku Juntti
Centre for Wireless CommunicationsUniversity of Oulu
Finland
MIMO Communications with Applications to (B)3G and 4G Systems
For more information about this article,please follow he link:
http://googleurl?sa=t&source=web&cd=1&ve...torial.pdf&ei=sCW3TLTZC4WKlweT1uy-DA&usg=AFQjCNE4P5MwMFg_AZM9H1u7RANH-Ym5ew
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What is fourth generation (4G) mobile systems
Fourth generation mobile communications systems that are characterised by high-speed data rates at 20 to 100 Mbps, suitable for high-resolution movies and television, virtual . Initial deployments are anticipated in 2006-2010.
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