4g Mobile Interface

4G Mobile interface Mansoor tamimy, Student of fourth Semester; Telecomm Engg; Military College of Signals; National University of Sciences and Technology, Rawalpindi. Abstract: Wireless communication is defined as transmission of data or information without any use of wires. Wireless is poised to become the next major event in the history of technology. Wireless communication will revolutionize how we live. Just as personal computers in 1980s forever altered how we work. Also internet in 1990s dramatically changed how we acquire information, similarly wireless technologies in 2000s will have an even greater and more far reaching effect. The IT industry and consumer market place are already seeing dramatic changes based on wireless technology. It is truly becoming a wireless world. There are number of different technologies in wireless communication. Like :SWAP Bluetooth Satellite WAP Fixed Broad band Wireless WLAN Digital Cellular Technology I. INTRODUCTION igital Cellular Technology is one of the most deceptive technologies in wireless. The most competitive and complex of all wireless communication technologies. Reason  As there is no single underlying digital technology. There are varieties of computing technologies with such familiar names GSM CDMA2000, TXO across the world. Advantages:Wireless applications can be found in any industry whose employees need the mobility and freedom to conduct the business without being confined by a specific location. Some of the advantages are:       

D

 Mobility      

Easier and less expensive installation Increased reliability Disaster recovery Education Military Business

 Entertainment  Health care Disadvantages:As with any new technology there are some merits and demerits so wireless communication is not an exception. Some of the disadvantages are:  Radio Signal Interference  Health risks  Security Technologies: Digital Cellular Technology consists of four complex Generations namely:   

First Generation Second Generation Second Generation Third Generation

1 G 2 G 2.5 G 3 G

Emerging Digital Cellular Technology: Fourth Generation 4G 4G is the emerging cellular technology and it is believed that 4G will bring true multimedia capabilities such as high-speed data access and video conferencing to the handset. It is also envisioned that 4G systems will be deployed with software-defined radios, allowing the equipment to be upgraded to new protocols and services via software upgrades. 4G also hold the promise of worldwide roaming using a single handheld device. The approaching 4G (fourth generation) mobile communication systems are projected to solve stillremaining problems of 3G (third generation) systems and to provide a wide variety of new services, from high-quality voice to high-definition video to highdata-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 any- where, Global mobility support, Integrated wireless solution, and Customized personal service. As a promise for the future, 4G systems, that is, cellular broadband wire- less access systems, have been attracting much interest in the

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mobile communication arena. The 4G systems not only will support the next generation of mobile service, but also will support the fixed wireless networks. 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.

Carrier CDMA) Forward Convolutional Concatenated Error rate 1/2, 1/3 coding Correction scheme

Optimized Component antenna Design design, multiband adapters

Comparing Key Parameters of 4G with 3G

3G (including 4G 2.5G, sub3G) Major Predominantly Converged Requirement voice driven data and Driving data was voice over IP Architecture always add on

Network Architecture

Wide area cell-based

Speeds

384 Kbps to 2 Mbps

Hybrid Integration of Wireless LAN (WiFi, Bluetooth) and wide area

20 to 100 Mbps in mobile mode

Dependent on country or Higher Frequency continent frequency Band (1800-2400 bands (2-8 MHz) GHz)

Bandwidth

Switching Design Basis

5-20 MHz

Circuit and Packet

100 MHz (or more) All digital with packetized voice

W-CDMA, Access 1xRTT, Edge OFDM and Technologies MC-CDMA (Multi

IP

Smarter Antennas, software multiband and wideband radios

A number of air link protocols, All IP (IP6.0) include ing IP 5.0

ARCHITECTURES 1. Architectural Core 4G wireless system is expected to be built on an IPbased core network for global routing along with more customized local area network that supports dynamic hand off mechanism and Ad-Hoc routing. Mobile IPv6 (MIPv6) is the standardized IP- based mobility protocol for IPv6. In 4G LANs will be installed everywhere like in trains, vehicles etc or might be formed in an Ad-Hoc basis by random collection of devices that happens to come in a specific radio range. New routing protocols have to be designed for such systems. 1.2Core Architectural Model In 4G mobile systems, each terminal is assigned a home agent, which has a permanent home IP address. When terminal moves to another location it obtains a new temporary address called the careof address. The user terminal regularly updates the home agent with its current care-of address. If the user is at home, another device can communicate with the user using its home IP address. When the user moves to some other location communication is carried out using another procedure. If a host wants to communicate with the user, it first sends a setup message to the user’s home agent (which the host knows). The home agent knows the care-of address of the user and it forwards the setup

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message to the user terminal. The home agent also forwards the care-of address of the user to the host so that future messages can be sent directly to the user. 1.3Proposed Architectures Multimode Devices: In this configuration, a single terminal employs multiple interfaces to access different wireless system.The requirement for this scheme is that the device should incorporate the required hardware necessary to access the different technologies. The flaw with this is that it increases the complexity of the user device which might make it more expensive to the common user. One advantage of this architecture is that it does not require any network modification or internetworking devices. The QoS handling for this type of Architecture still remains an open issue.

Internet mobility support is one of the main trends. So, it seems very natural to think that network-layer mobility will be a key issue in the mobility management for the 4G system.  Mobile IP represents a simple and scalable global mobility solution. However, it lacks support for real-time location management and fast and seamless handoff mechanism. Additionally, QoS in the mobile IP environment using DiffServ and/or IntServ/RSVP need to be addressed.

4G Core Network

1.4Overlay network: In this type of architecture, a user can access an overlay network which consists of several UAP (universal access points).The UAP selects an access point depending on user choice, availability and desired QoS. In this case the overlay network performs the major operations such as hand off, frequency translation, content adaptation etc, instead of the terminal performing it. So the overlay network will suffer an increase in complexity.

2.Mobility Management Mobility management contains two components: I. Location management II. Handoff management 2.1Mobility Management in 4G System

fig2.1 Location Management  When a mobile node moves among networks, networks must update the mobile node's location and its routes. Mobile IP provides a simple and elegant location registration and update scheme. However, it lacks support for real-time location tracking and optimal route selection. We propose an efficient network architecture and intelligent route optimization schemes which will be able to solve these problems.

 Mobility management is very important in the 4G wireless network systems. Mobility usually involves mobile users roaming among different network segments. Link-layer mobility support is usually restricted to homogeneous networks, while network-layer mobility support is provided for any kind of networks without regard to link-layer techniques employed. Moreover,

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Network-layer

Mobility

This is not merely a numbers game. 4G is intended to provide high speed, high capacity, low cost per bit, IP based services. 4. 4G processing

Fig2.2 Handoff Management  Mobile IP does not provide fast and seamless handoff scheme. Therefore, a mobile node experiences data losses and delays during the handoff process. For real-time multimedia applications and reliable transport protocols, those data losses should be avoided and delays should be reduced . We propose efficient signaling and handoff protocols which will be helpful in providing solutions to these problems. The proposed scheme will also consider user's mobility pattern and geolocation information to improve the performance. 3.Fundamental Changes Required Modulation and Signal processing for 4G

As 4G is based on a multicarrier technique, key baseband components for the transmitter and receiver are the FFT and its inverse (IFFT). In the transmit path the data is generated, coded, modulated, transformed, cyclically extended, and then passed to the RF/IF section. In the receive path the cyclic extension is removed, the data is transformed, detected, and decoded. If the data is voice, it goes to a vocoder. The baseband subsystem will be implemented with a number of ICs, including digital signal processors (DSPs), microcontrollers, and ASICs. Software, an important part of the transceiver, implements the different algorithms, coding, and overall state machine of the transceiver. The base station could have numerous DSPs. For example, if smart antennas are used, each user needs access to a DSP to perform the needed adjustments to the antenna beam. 4.1Receiver section 4G will require an improved receiver section, compared to 3G, to achieve the desired performance in data rates and reliability of communication. As shown in Equation, Shannon's Theorem specifies the minimum required SNR for reliable communication:

in

While 3G hasn't quite arrived, designers are already thinking about 4G technologies. With it comes challenging RF and base band design headaches. Cellular service providers are slowly beginning to deploy third-generation (3G) cellular services. As access technology increases, voice, video, multimedia, and broadband data services are becoming integrated into the same network. The hope once envisioned for 3G as a true broadband service has all but dwindled away. It is apparent that 3G systems, while maintaining the possible 2Mbps data rate in the standard, will realistically achieve 384-kbps rates. To achieve the goals of true broadband cellular service, the systems have to make the leap to a fourth-generation (4G) network.

where C is the channel capacity (which is the data rate), and BW is the bandwidth. For 3G, using the 2-Mbps data rate in a 5-MHz bandwidth, the SNR is only 1.2 dB. In 4G, approximately 12-dB SNR is required for a 20Mbps data rate in a 5-MHz bandwidth. This shows that for the increased data rates of 4G, the transceiver system must perform significantly better than 3G. 4.2Transmitter section The purpose of the transmitter is to generate and send information. As the data rate for 4G increases, the need for a clean signal also increases. One way to increase capacity is to increase frequency reuse. As the cell size gets smaller to accommodate more

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frequency reuse, smaller base stations are required. Smaller cell sizes need less transmit power to reach the edge of the cell, though better system engineering is required to reduce intra-cell interference. One critical issue to consider is spurious noise. The regulatory agencies have stringent requirements on the amount of unwanted noise that can be sent out of the range of the spectrum allocated. In addition, excess noise in the system can seriously diminish the system's capacity. With the wider bandwidth system and high PAVR associated with 4G, it will be difficult to achieve good performance without help of linearity techniques (for example, predistortion of the signal to the PA). To effectively accomplish this task, feedback between the RF and baseband is required. The algorithm to perform the feedback is done in the DSP, which is part of the baseband data processing. Power control will also be important in 4G to help achieve the desired performance; this helps in controlling high PAVR - different services need different levels of power due to the different rates and QoS levels required. Therefore, power control needs to be a very tight, closed loop. Baseband processing is just as critical whether dealing with the receiver or transmitter sections. As we've seed, RF and baseband work in tandem to produce 4G signals. The baseband processing of a 4G transmitter will obviously be more complicated than in a 3G design. Let's consider the chain of command. The digital-to-analog converter (DAC) is an important piece of the transmit chain. It requires a high slew rate to minimize distortion, especially with the high PAVR of the MCM signals. Generally, data is oversampled 2.5 to 4 times; by increasing the oversampling ratio of the DAC, the step size between samples decreases. This minimizes distortion. In the baseband processing section of the transmit chain, the signal is encoded, modulated, transformed using an IFFT, and then a cyclic extension is added. Dynamic packet assignment or dynamic frequency selection are techniques which can increase the capacity of the system. Feedback from the mobile is needed to accomplish these techniques. The baseband processing will have to be fast to support the high data rates.

Even as 3G begins to roll out, system designers and services providers are looking forward to a true wireless broadband cellular system, or 4G. To achieve the goals of 4G, technology will need to improve significantly in order to handle the intensive algorithms in the baseband processing and the wide bandwidth of a high PAVR signal. Novel techniques will also have to be employed to help the system achieve the desired capacity and throughput. High-performance signal processing will have to be used for the antenna systems, power amplifier, and detection of the signal. 5.APPLICATIONS OF 4G 5.1MULTIMEDIA – VIDEO SERVICES 4G wireless systems are expected to deliver efficient multimedia services at very high data rates. Basically there are two types of video services: bursting and streaming video services. Streaming is performed when a user requires real time video services, in which the server delivers data continuously at a playback rate. Streaming has little memory requirement as compared to bursting. The drawback of streaming video is that it does not take advantage of available bandwidth. Even if the entire system bandwidth is available for the user, streaming video service will transmit data only at a particular playback rate. Bursting is basically file downloading using a buffer and this is done at the highest data rate taking advantage of the whole available bandwidth. The flaw with this type of transmission is that it demands a large memory requirement. So work is being done to come up with a new scheme that limits the memory requirements and can exploit the available bandwidth of the system. 5.2Virtual Presence: This means that 4G provides user services at all times, even if the user is off-site. 5.3Virtual navigation: 4G provides users with virtual navigation through which a user can access a database of the streets, buildings etc of large cities. This requires high speed data transmission. 5.4Tele-Medicine: 4G will support remote health monitoring of patients. A user need not go to the hospital and can

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I. Connection to many radio access networks

get videoconference assistance for a doctor at anytime and anywhere.

(RANs) using a multimode device.

5.5Tele-geoprocessing applications:

II. (2) Assistance for decision, execution, and adaption processes handovers,

This is a combination of GIS (Geographical Information System) and GPS (Global Positioning System) in which a user can get the location by querying.

support real-time services.

IV. (4) Related management issues such as

Natural disasters can cause break down in communication systems. In today’s world it might take days or weeks to restore the system. But in 4G it is expected to restore such crisis issues in a few hours.

For people who are interested in life long education, 4G provides a good opportunity. People anywhere in the world can continue their education online in a cost effective manner. 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. 4G T his 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. 6.Vision and prospects: 4G vision poses the challenge of seamless networking, which involves

vertical

III. (3) Minimization of latency effects to

5.6Crisis management:

5.7Education:

during

access control, accounting, and security in the new consolidated platform. 7.Conclusion 4G is the emerging cellular technology and it is believed that 4G will bring true multimedia capabilities such as high-speed data access and video conferencing to the handset. It is also envisioned that 4G systems will be deployed with software-defined radios, allowing the equipment to be upgraded to new protocols and services via software upgrades. 4G also hold the promise of worldwide roaming using a single handheld device. 4G seems to be a very promising generation of wireless communication that will change the people’s life in the wireless world. There are many striking attractive features proposed for 4G which ensures a very high data rate, global roaming etc. New ideas are being introduced by researchers throughout the world, but new ideas introduce new challenges. There are several issues yet to be solved like incorporating the mobile world to the IP based core network, efficient billing system, smooth hand off mechanisms etc. 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. .

8. REFERNCES

I have prepared this term paper from following sources. 1. www.jacksons.net/tac/First %20Term/ Nowak%20Motorola %204G%20FCC%20TAC %20Dec00.ppt 2. www.bechteltelecoms.com/docs/A rticle2.pdf

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3. www.docomoeurolabs.de/pdf/publi cations/ FNL-active-networksIWAN-02.pdf 4. www.kn-s.dlr.de/Groups/ Mobile/Welcome/group_mobile_u s.html - 9k

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