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Mobile Computing A Brief Report Shakir Ali Mohammed Dept. of Computer Science University at Albany.

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Presentation on theme: "Mobile Computing A Brief Report Shakir Ali Mohammed Dept. of Computer Science University at Albany."— Presentation transcript:

1 Mobile Computing A Brief Report Shakir Ali Mohammed Dept. of Computer Science University at Albany.

2 Mobile Computing Introduction Market of Mobile and Wireless Communication Difference between Mobile and traditional Computing. Network Architecture for Mobile Computing Applications and Products Challenges in Mobile Computing Some Useful Resources. Conclusion.

3 Introduction Ubiquitous Computing i.e. Anywhere Anytime Computing Mobile Computing is Portable Computers + Wireless n/w Portable Computers + modem + Telephone Network Workstation + Wired n/w +mobile users

4 Computers Everywhere 4 Vision of ubiquitous computing: hundreds of computers per person, various sizes and capabilities 4 Marc Weiser: Scientific American article: The Computer for the 21st Century

5 Some Recent Outlook Numbers (Mid 2000) By the year 2004, Revenue from wireless data will reach $33.5 Billion Globally ( Source Strategies Group) By the Year 2010, there will one billion wireless subscribes worldwide on 3G Networks. ( Source Strategies Group)

6 What does Mobile Computing Offer? Untethered and/or tiny computers yield: –A choice of work environments In your garden (but watch out for birds!) Coffee shops In the field –Remote access to important data Clients office (no: "can I borrow your computer") Meetings (e.g., quick access to statistics, reports) In the grocery store!

7 Offerings Contd. –Electronic note-taking –While touring a new city Where am I? What is this building? How do I get to Lane Avenue? Im hungry! –Diversion E-books: stored, downloadable Games: e.g., chess, solitaire, poker –Ubiquitous communication , Web voice video

8 Mobile Devices A variety of computing and communication devices for mobile users –Watch-sized devices (and usually a watch!) –PDA (Personal Digital Assistants) –Multifunction cellular phones –Palm-sized computers –Wearable computers –Notebook computers

9 Characteristics of Mobile Devices 4 Resource-poor compared to their desktop counterparts –Limited processing power –Limited battery life –Limited network connectivity –Poor availability…they sleep a lot! –Poor display resolution (except notebooks) –Tedious data input (except notebooks

10 Characteristics Contd. 4 Limitations are a result of tradeoffs between portability and horsepower: –Very small size limits traditional I/O methods New ones: handwriting recognition, voice input Must work well or extreme frustration... 4 Notebook computers fare better in the comparison with desktops because they ride the edge –Reasonable screen size –Decent keyboards –Mouse substitutes –Ample memory

11 Mobile System Architecture Mobile Computing System consists of Static Host and Mobile Host. Static Host have fixed geographical locations. Mobile host can move and have a Unique Network Address Some Static Host with required infrastructure are designated as Mobile Support Service MSS

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13 Mobile System Architecture Communication among the MSS is done using Backbone Network Communication between MSS and MH in its cell is done over wireless medium. Each MH has a Home agent (MSS) which maintains information such as current location, services subscribed, etc.

14 Mobile System Architecture Each MSS is incharge of a Cell, Picocells (about 100m in diameter), macrocells, or global cells - A Handoff is involved when a MH crosses cell boundary HANDOFF: MSS Broadcasts MSS specific information, MH keeps track of this information and checks with the information previously stored, if the MH changes the cell, this information received from MSS is different from stored, thus MH knows about the change of MSS, and thus a Handoff is said to be taken place.

15 Network Architecture for Heterogeneous Mobile computing A Paper presented by Eric A. Brewer, Radny H. Katz summuarizes the resu;ts of BARWAN Project which focused on enabling truly useful mobile networks and mobile devices. Overlay Networks as discussed in this paper shows that lower levels are comprised of high bandwidth wireless cells that cover a relatively small area, Higher levels in the hierarchy provide a lower bandwidth per unit area connection over a large geographic area.

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17 Vertical Handoff There is difference between Upward and downward Vertical Handoffs. Upward vertical Handoff is a handoff to an overlay with a larger cell size and lower bandwidth/area. Downward vertical Handoff is a handoff to an overlay with smaller cell size and higher bandwidth/area.

18 Wireless Application Protocol WAP and wireless markup language WML WAP allows mobile phones and other mobile devices to connect to the internet WAP and WML are extension to HTTP and HTML specially designed for the wireless technologies. Unlike pages in HTML WML has Cards, files in WML are called as Decks WML script is similar to Java script which can be used to validate User, send messages etc.

19 Hello from WML! Wml

20 Applications Various Business Applications like for mobile computing both horizontla applications that are used by workers and professionals across the industries as well as specific to bussiness process in a vertical industry. Horizontal applications Internet messaging, Paging etc, Database Inquiry, File Transfer, Sales Force Automation.

21 Applications Contd. Vertical Applications Airline and Railway Industries, Construction Industry, Distribution Industry, Electronic News Communication, Financial Industry.

22 Mobile Computing Challenges 4 Challenges in mobile computing directly related to the resource-poor nature of the devices… 4 Mobile computing isnt a simple extension of distributed computing –Power-poor –Hostile environment –Poor (or no) network bandwidth –Higher error rates –Frequent disconnection –Variable latency –Mobility

23 Challenges contd. Result: Must rethink many issues; cant just plug in classic distributed systems theory Adaptability to deal with varying conditions Transcoding proxies--scale content (e.g., images) to match available bandwidth Mobile proxies to convert content (e.g., Postscript ASCII) More clever ways of checking for data consistency Application callbacks to monitor conditions (network, battery power, etc.)

24 Challenges Contd. 4 Prevalent network protocols require work…or workarounds… to give good performance for wireless –Schemes for mobility –TCP hacks 4 Schemes for intelligent handoff between network interfaces –Tradeoffs between cost, bandwidth, availability

25 References and Resources Mobile computing : An Introduction Sandeep Gupta Dept of Comp Science Colorado State University, Co. A Network Architecture for Heterogeneous Mobile computing, Eric A. Brewer, Randy H. Katz, Mobile Computing : Prof. olden G. Richard III, University of New Orleans.

26 Conclusion 4 Mobile computing is the computing of 21 century 4 Vision of ubiquitous computing: Hundreds of computers per person, various sizes and capabilities 4 Prevalent Network Protocols require work to improve performance 4 Schemes for intelligent Handoffs required 4 Development of Applications are done keeping in mind the limited resources of mobile devices.


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