18-09-2014, 10:23 AM
4G TECHNOLOGY
[attachment=68079]
ABSTRACT
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.
Service Evolution
The evolution from 3G to 4G will be driven by services that offer better quality (e.g. Video and sound) thanks to greater bandwidth, more sophistication in the association of a large quantity of information, and improved personalization. Convergence with other network (enterprise, fixed) services will come about through the high session data rate. Machine-to-machine transmission will involve two basic equipment types: sensors (which measure arameters) and tags (which are generally read/write equipment). It is expected that users will require high data
Grow rapidly as they become more users friendly. Fluid high quality video and network creactivity are important user requirements. Key infrastructure design requirements include: fast response, high session rate, high capacity, low user charges, rapid return on investment for operators, investment that is in line with the growth in demand, and simple autonomous terminals
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. As shown in Figure 5, the signal is split into orthogonal subcarriers, on each of which the signal is “narrowband” (a few kHz) and therefore immune to multi-path effects, provided a guard interval is inserted between each OFDM symbol.
Coverage
Coverage is achieved by adding new technologies (possibly in overlay mode) and progressively enhancing density. Take a WiMAX deployment, for example: first the parent coverage is deployed; it is then made denser by adding discontinuous Pico cells, after which the Pico cell is made denser but still discontinuously. Finally the Pico cell coverage is made continuous either by using MIMO or by deploying another Pico cell Coverage in a different frequency band (see Figure 9). The ultimate performances of the various technologies are shown in Figure 10. Parent coverage performance may vary
From 1 to 20 bit/s/Hz/km, while Pico cell technology can achieve from 100 to 500
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.
The provision of megabit/s data rates to thousands of radio and mobile terminals per square kilometer presents several challenges. Some key technologies permit the progressive introduction of such networks without jeopardizing existing investment. Disruptive technologies are needed to achieve high capacity at low cost, but it can still be done in a progressive manner. The key enablers are:
• Sufficient spectrum, with associated sharing mechanisms.
• Coverage with two technologies: parent (2G, 3G, and WiMAX) for real-time delivery, and discontinuous Pico cell for high data rate delivery.
• Caching technology in the network and terminals.
• OFDM and MIMO.
• IP mobility.
• Multi-technology distributed architecture.
• Fixed-mobile convergence (for indoor service).
• Network selection mechanisms.
Many other features, such as robust transmission and cross-layer optimization, will contribute to optimizing the performance, which can reach between 100 and 500 bit/s/Hz/km2. The distributed, full IP architecture can deployed using two main products: base stations and the associated controllers. Terminal complexity depends on the number of technologies they can work with. The minimum number of technologies is two: one for the radio coverage and one for short range use (e.g. PANs). However, the presence of legacy networks will increase this to six or seven.
[attachment=68079]
ABSTRACT
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.
Service Evolution
The evolution from 3G to 4G will be driven by services that offer better quality (e.g. Video and sound) thanks to greater bandwidth, more sophistication in the association of a large quantity of information, and improved personalization. Convergence with other network (enterprise, fixed) services will come about through the high session data rate. Machine-to-machine transmission will involve two basic equipment types: sensors (which measure arameters) and tags (which are generally read/write equipment). It is expected that users will require high data
Grow rapidly as they become more users friendly. Fluid high quality video and network creactivity are important user requirements. Key infrastructure design requirements include: fast response, high session rate, high capacity, low user charges, rapid return on investment for operators, investment that is in line with the growth in demand, and simple autonomous terminals
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. As shown in Figure 5, the signal is split into orthogonal subcarriers, on each of which the signal is “narrowband” (a few kHz) and therefore immune to multi-path effects, provided a guard interval is inserted between each OFDM symbol.
Coverage
Coverage is achieved by adding new technologies (possibly in overlay mode) and progressively enhancing density. Take a WiMAX deployment, for example: first the parent coverage is deployed; it is then made denser by adding discontinuous Pico cells, after which the Pico cell is made denser but still discontinuously. Finally the Pico cell coverage is made continuous either by using MIMO or by deploying another Pico cell Coverage in a different frequency band (see Figure 9). The ultimate performances of the various technologies are shown in Figure 10. Parent coverage performance may vary
From 1 to 20 bit/s/Hz/km, while Pico cell technology can achieve from 100 to 500
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.
The provision of megabit/s data rates to thousands of radio and mobile terminals per square kilometer presents several challenges. Some key technologies permit the progressive introduction of such networks without jeopardizing existing investment. Disruptive technologies are needed to achieve high capacity at low cost, but it can still be done in a progressive manner. The key enablers are:
• Sufficient spectrum, with associated sharing mechanisms.
• Coverage with two technologies: parent (2G, 3G, and WiMAX) for real-time delivery, and discontinuous Pico cell for high data rate delivery.
• Caching technology in the network and terminals.
• OFDM and MIMO.
• IP mobility.
• Multi-technology distributed architecture.
• Fixed-mobile convergence (for indoor service).
• Network selection mechanisms.
Many other features, such as robust transmission and cross-layer optimization, will contribute to optimizing the performance, which can reach between 100 and 500 bit/s/Hz/km2. The distributed, full IP architecture can deployed using two main products: base stations and the associated controllers. Terminal complexity depends on the number of technologies they can work with. The minimum number of technologies is two: one for the radio coverage and one for short range use (e.g. PANs). However, the presence of legacy networks will increase this to six or seven.