Assistant Professor, MCA Department

4G Networks: Mobility Issues

Saroj Bala

Assistant Professor, MCA Department

E-mail:

ABSRACT

Numerous different network technologies with their individual pros and cons are existing globally. 4G or Fourth Generation networks are designed to facilitate improved wireless capabilities, network speeds and visual technologies. The growing interest in 4G networks is driven by the set of new services, will be made available for the first time such as accessing the Internet anytime from anywhere, global roaming, and wider support for multimedia applications. This article discusses some of the mobility issues in 4G networks along with a little coverage of the evolution of different generations.

1. INTRODUCTION

With the huge worldwide increase in the number of mobile users each day and with emerging demands like totally user-centric services, high speed streaming Internet multimedia services, seamless global roaming with ubiquitous coverage and unrestricted QOS support, 3G systems have started showing their limitations with bandwidth availability, spectrum allocation, air interference standards and lack of seamless transport mechanisms between different networks[2]. The 4G systems is a potential smooth merger of all the existing heterogeneous technologies with a natural progression to support seamless cost-effective high data rate, global roaming, efficient personalized services, typical user-centric integrated service model, high QOS and overall stable system performance[4].

The article is structured as follows: section 2 introduces the evolution and section 3 discusses the mobility issues in 4 G networks. The conclusion is presented in section 4.

2. THE EVOLUTION

0G Networks represents the 1st Generation of mobile telephony, where satellite phones were developed and deployed for boats mainly. 1G Network provided the facilities of making voice calls and sending text messages. (NMT, AMPS, TACS) are considered to be the first analog cellular systems, which started in early 1980s. The greatest disadvantage 1G had was that it only allowed to contact within the premises of that particular nation. 2G Network (GSM) represents the 2nd Generation of mobile telecommunications and is still the most widespread technology in the world but with a slow rate of 9.6 Kbytes/sec. 2.5G Network, mid generation offered a higher data rate than 2G technology and enabled the delivery of basic data services like text messaging but not enough to

download an image or browse a website with data rate upto 144 kbps. GPRS, EDGE and CDMA 2000 were 2.5 technologies. 2.75G Network enabled watch streaming video and download mp3 files faster upto 180kbps.

3G Network represents the 3rd Generation designed to overcome all the limitations of above technologies. GSM 3G networks are termed UMTS in US and wideband CDMA (WCDMA) worldwide. UMTS supports global roaming capabilities and speed is 3 times that of a GSM. 3.5G or 3G+ NETWORKoffers 7.2 and 14.4 Mbps on cell phones. 4G Networks is the future.Some basic 4G research is being done, but no frequencies have been allocated. The Fourth Generation could be ready for implementation around 2012. 4G should support at least 100 Mbps peak rates in full-mobility wide area coverage and 1Gbps in low-mobility local area coverage”. Some of the limitations of 3G [3] which originated 4G can be listed as:

1) All the problems are partly solved, doesnot have sufficient capabilities.

2) Difficulty in increasing bandwidth.

3) Limitation of spectrum and its allocation.

4) Difficult to roam across distinct serviceenvironment.

The 4G mobility management includes additional mobility related features, absent in previous generation networks, such as; Moving Networks, Seamless Roaming and Vertical Handover.

3. MOBILITY MANAGEMENT ISSUES

According to the mobility scenarios for future, referred in ongoing researches the following mobility management issues can be highlighted:

3.1 Connectivity

Triggering. Different kinds of events can trigger mobility management actions that may result in some conflicts. A general framework is required to resolve conflicting triggers generated simultaneously by different components, on the basis of predefined policies and rules.

Handover. In the emerging 4G networks which are both multi-domain and multi-technology, handover requests could be based on a number of different needs or policies such as cost reduction criteria, network resource optimization etc. Various handover solutions have been devised to provide seamless transfer of services across heterogeneous boundaries. One is IP-Based. Many researchers agree that Mobile IP will be the key for providing efficient interworking between different technologies. Others are IDMP-based or Agent based.

3.2 Location Management

Location management involves two operations; location registration and call delivery. Location registration involves the mobile terminal periodically updating the network about its new location (access point).This allows the network to keep a track of the mobile terminal. In the second operation the network is queried for the user location profile and the current position of the mobile host is retrieved.

3.3 Routing Group Formation

Moving networks are a prominent component of future networking scenarios. a typical example can be of moving users with several terminals forming temporary moving clusters and network hierarchies while traveling on a train. A common characteristic for this kind of scenarios is that some mobile entities that are close by move together, forming a cluster,, be joined together into a unified network. The formation of this unified network will be highly dynamic, and somekind of hierarchy will be needed in order to integrate them into encapsulating moving networks.

3.4 Seamless Mobility

Seamless mobility must be a set of solutions that will provide easy, uninterrupted access to information, entertainment, communication, monitoring and control – when, where and how we want, regardless of the device, service, network or location. Instead of experiencing a disconnect as movement occurs between different devices, environments and networks, seamless mobility will deliver experiences that span the home, vehicle, office and beyond.

3.5 Mobility Context Management

It is assumed that the future terminals, applications and networks will be able to provide a versatile set of information about themselves, their surroundings and the situation where they are used. The mobility management component needs access to the Context Information Base, CIB, within the network that is responsible for maintaining user policy and context information, and that is updated by mobility triggers from the mobility events.

3.6 Paging

Current paging solutions are dependent on thelink layer technology and network structure. The 4G Network

requires the facility to be able to page across heterogeneous network technologies.

3.7 Network composition

Composition, as a new architectural element, canenable new type of dynamic networks where newbusiness models and roles evolve: anyone can become a network/service operator. In this view, everything is a network and a terminal is a network itself. Composition of networks will be possible, independently from the technologies of composing networks.

3.8 Migration

Backward compatibility and migration is one of the basic requirements in the evolution and deployment of heterogeneous networks. Although migration from current technologies and compatibility is different, similar approaches that address both these issues exist.Backward compatibility enables smooth migration. So, such a design should be aimed that interoperate with existing technologies using their original interfaces.

4. CONCLUSION

4G wireless networks not only enable more efficient, scalable, and reliable wireless services but also provides wider variety of services. The article discussed the evolution of network generations from 0G to 4G networks. It mainly discussed the significant mobility issues within 4G heterogeneous networks which are the hot issues in todays research. The future research will overcome these challenges and integrate newly developed services to 4G networks making them available to everyone, anytime and everywhere.

REFERENCES

[1] Sadia Hussain, Zara Hamid and Naveed S. Khattak, “Mobility Management Challenges and Issues in 4G Heterogeneous Networks”, InterSense '06. Proceedings of the First International Conference on Integrated Internet Ad hoc and Sensor Networks, May 30-May 31 2006, Nice, France

[2] Hassan Gobjuka, “4G Wireless Networks: Opportunities and Challenges”

[3] U. Varshney, R. Jain, ”issues in emerging 4G wireless networks”,

[4] Sayan Kumar Ray, IETE Technical ReviewVol 23, No 4, July-August 2006, pp 253-265

INKLESS PRINTING TECHNOLOGY: ZINK

Suchitra Singh

Assistant Professor, MCA Department

E-mail :

Abstract

It's a digital world... and it's about to get even better. Digital content has exploded to permeate, and change, every part of our lives. ZINK is a revolutionary digital approach to full color printing that is mobile, embeddable in any device, simple to use, easy to maintain and has dramatically less waste. . In the ZINK world, when you have a desire to hold a hard copy of whatever digital content you want in your hands, all it takes is the touch of a button. Your laptop will be able to print. Your televisions and receivers will be able to print. And your stand-alone printer won't be standing alone - it'll be coming with you.

1.Introduction

ZINK stands for Zero Ink - an amazing new way to print in full color without the need for ink cartridges or ribbons. The ZINK Technology encompasses both the ZINK Paper and the intelligence embedded in every ZINK-enabled device.ZINK Technology is based on advances in chemistry, engineering, physics, image science, and manufacturing

2. HOW ZINK WORKS

At the heart of the ZINK Technology is the ZINK Paper, an advanced composite material with cyan, yellow, and magenta dye crystalsembedded inside, and a protective polymer overcoat layer outside. The crystals are colorless before printing, so ZINK Paper looks like regular white photo paper. Heat from a ZINK-enabled device activates the crystals, forming all the colors of the rainbow. The printing process is now radically simple. Just add ZINK Paper.

2.1 The Magic Paper

The ZINK Paper is an advanced composite material with cyan, yellow, and magenta dye crystals embedded inside and a protective polymer overcoat layer outside. Before printing, ZINK Paper looks like regular white photo paper.

Through an advanced manufacturing process, the ZINK color forming layers are coated as a colorless thin multi-layer "stack" onto a base layer. The total thickness of all the layers combined is about the thickness of a single human hair. The cyan, magenta, and yellow crystal layers are colorless at room temperature and are activated by heat during the printing processto create color.

2.2ZINK Amorphochromic Dye Crystals

The proprietary dye crystals that give ZINKits color, named Amorphochromic crystals, represent an entirely new class of molecules. The properties of each dye crystal are finely tuned to achieve the color palette and image stability required for beautiful, full-color digital prints.Each of the crystals are activated independently using heat pulses of precisely determined duration and temperature to achieve any color in the rainbow.

2.3The Physics : Time + Temp = every coclor imaginable

Previously direct thermal printing in a single printing pass has been possible only in low quality, black and white applications. Now, with ZINK Technology, it is possible to do full-color single-pass direct thermal printing. This is possible, not only by the invention of special dye crystals, but also by another of the fundamental mechanisms of ZINK - the physics of controlling time and temperature. Each color forming layer within the ZINK Paper structure is addressed individually to create the colors required for every image. The various colors in a print are created by controlling the temperature and time of the heat pulses delivered from the print head in the device to the ZINK Paper. This pulse pattern determines which crystals in which layers are melted and thereby which colors are formed

As the ZINK Paper passes beneath the print head, hundreds of millions of heat pulses are delivered by a linear array of heating elements, in a line-by-line fashion, to produce the desired colors at each printed pixel.

2.4 Key Features of ZINK Paper

* Zero inkrequired. No need for ink cartridgesor ribbons. All you need for full-color photos isright in the ZINK Paper. Just add ZINK Paper.
* Capable of reproducingmillions of vivid colors at very high resolution.
* EarthFriendly.Lesswaste-No cartridges,noextra packaging to throw away.
* Protected by apolymerovercoat, providing water resistance and image durability.
*Affordablefor everyday use.
* Not sensitive to light.
* Longlasting and designed to resist fading from exposure to light, heat and humidity.

3. Conclusion

In the ZINK world, the touch of a print button brings an entirely new experience that results in a whole new sense of freedom, spontaneity by making printing more readily available, simpler and unlocking the full value of the digital content like never before - whether at home, on-the-go, at work, or at play.Xerox is working on an inkless printer which will use a special reusable paper coated with a fewmicrometers of UV light sensitive chemicals. The printer willuse a special UV light bar which will be able to write and erase the paper.

REFERENCES

[1]

[2]

[3]

KNOWLEDGE REPRESENTATION AND REASONING METHODS

Snehlata Kaul

Assistant Professor, MCA Department

E-mail:

ABSTRACT

Knowledge Representation and reasoning is a central problem in Artificial Intelligence (AI) today. Its importance stems from the fact that the current design paradigm for "intelligent" systems stresses the need for expert knowledge in the system along with associated knowledge-handling facilities. A present paper gives brief introduction to knowledge representation and reasoning and also describes different methods of knowledge representation and reasoning

1. INTRODUCTION

Knowledge representation is an area of artificial intelligence fundamental goal is to represent knowledge in a manner that facilitates inference (i.e. drawing conclusions) from knowledge. It analyzes how to formally think - how to use a symbol system to represent a domain of discourse (that which can be talked about), along with functions that allow inference (formalized reasoning) about the objects. Generally speaking, some kind of logic is used both to supply formal semantics of how reasoning functions apply to symbols in the domain of discourse, as well as to supply operators such as quantifiers, modal operators, etc. that, along with an interpretation theory, give meaning to the sentences in the logic[1].

When we design a knowledge representation (and a knowledge representation system to interpret sentences in the logic in order to derive inferences from them) we have to make choices across a number of design spaces. The single most important decision to be made, is the expressivity of the KR. The more expressive, the easier and more compact it is to "say something". However, more expressive languages are harder to automatically derive inferences from.

Reasoning is the cognitive process of looking for reasons, beliefs, conclusions, actions or feelings. When we require any knowledge system to do something it has not been explicitly told how to do it must reason. The system must figure out what it needs to know from what it already knows[3].

One approach to the study of reasoning is to identify various forms of reasoning that may be used to support or justify conclusions. The main division between forms of reasoning that is made in philosophy is between deductive reasoning and inductive reasoning. Formal logic has been described as "the science of deduction "The study of inductive reasoning is generally carried out within the field known as informal logic or critical thinking.

2.DIFFERENT METHODS OF KNOWLEDGE REPRESENTATION

Mind Map

An exceedingly effective way of organizing information in hierarchical, “brain-friendly” format is representing it visually, in a form of a “map”. Visualizing information helps structure it in the most comprehensive and clear manner.

A powerful, yet simple technique for representing knowledge is Mind Map. Mind Map is a graphical tool that mirrors the way the brain thinks. Mind map can be used in a wide range of human activities. This method helps enhance human learning, brainstorm processes and manage projects, highlighting the key ideas, questions and current objectives. A mind map usually starts with one main topic or idea and expands in a radiant fashion with other relevant ideas and notes added to the branches growing from the main topic[1].

Concept Map

In contrast to mind map, a concept map may contain perspectives and ideas of the whole team. It is usually based on a number of principal, most inclusive concepts, placed at the top of the map. Other less general concepts should be arranged in the hierarchical fashion below, linked by lines or arrows showing the relationships between the concepts. Concept mapping can be used as a learning or an evaluation tool to enhance and assess the knowledge level of the group of individuals. It is also an indispensable technique for group brainstorming and activities planning [1].

Process map

Representing information in a form of a process map gives extremely high results in managing multiple work processes. Properly organized information represents all the process associated activities and provides the view of the complete business system. Process map includes such information as process complexity, the number of people involved and time and cost issues. This can be the basis for process reengineering on a comprehensible customer-oriented basis.

3. REASONINGMETHODSANDARGUMENTATION

Deductive reasoning

Reasoning in an argument is valid if the argument's conclusion must be true when the premises (the reasons given to support that conclusion) are true. One classic example of deductive reasoning is that found in syllogisms like the following[3]:

Premise 1: All humans are mortal.

Premise 2: Socrates is a human.

Conclusion: Socrates is mortal.

The reasoning in this argument is valid, because there is no way in which the premises, 1 and 2, could be true and the conclusion, 3, be false.