Articles
WIRELESS DATA NETWORKS
RADIO AND TV
Wireless radio was invented by Marconi at the turn of the century. In the twenties the AM radio broadcast industry was created. Later the higher quality FM radio was introduced. Interactive radio communication is used by ships, airplanes, remote stations, ham operators. The commercial broadcast TV industry was created after World War II. These industries are all allocated portions of the electromagnetic spectrum for their activities.
SATELLITES
By placing a satellite in an orbit with a radius of 22,000 miles the satellite goes around the earth once a day. If the orbit is about the equator the satellite appears to be stationary with respect to the earth. To minimize interference you must keep these satellites separate(no more than 90 in the orbit). Such satellites are used for broadcast TV and multiplexed phone conversations. Communication from earth to satellite uses microwave communications, which travels through clouds. Low-orbit satellites can also be used for communications systems: however, such a system is much more complicated because the antennas must follow a moving target and shift between satellites as they go over the horizon. Satellites make excellent communication relay stations because you do not need any ground network. Corporations establishing private communication systems outside the telephone system are big users of satellite communications.
Third world countries such as India also make extensive use of satellite communications because it is much cheaper to reach the millions of villages by satellite than try to string copper or fiber cable. The emerging communication system will be a mixture of optical fibers between major nodes and of satellite communications in rural areas.
The disadvantage of satellites at 22,000 miles for voice and video communication is that there is a 1/2 second delay in the communication of the messages because of the distances involved.
Motorola is planning a low earth satellite system with 77 satellites which will eliminate the 1/2 second time delay.
NEW ADVANCES
Currently, there is an explosive growth in wireless phone systems. Current cellular phone technology is analog. Cellular phones will switch to digital to achieve much greater capacity once standards are agreed upon. A new competitor to the cellular phone network is the personal communications network (PCN). This digital technology uses a much larger number of much cheaper transmitters than cellular. This transformation has hit a major snag in the summer of 1995. The economic incentive to switch to digital has not been to provide the customer better service, but rather make more money by tripling capacity. The problem with the first models of the new digital phones is that they produce very poor voice quality. Until this problem is resolved customers will keep their analog equipment. Many corporations are creating worldwide wireless communications networks.
For example, Motorola is in the process of setting up Iridium, a worldwide wireless network using low-orbit satellites mentioned above.In less developed countries it is much faster to set up a wireless telephone system than a modern wired system. This system if installed could in the long run completely bypass the phone systems. This would by a wireless phone system with local towers and the capacity to communicate through the satellites. In the US, Ardis and Ram Mobile Data are building nationwide wireless data networks. At Pitney-Bowes 3,500 repair technicians use the Ardis network to obtain repair information. Federal Express and UPS have their own networks to be able to maintain continuous monitoring of the delivery of parcels.
NETWATCH
HOLLYWOOD ONLINE
In what is one of the most colourful webpages around , Sandra Bullock fans will have a field day.You'll find video clips from her recent movies,have online chat with her ,download some stills from her movies (decent,of course!!) and also some wallpapers and themes. Multimedia capabilities on your system are preffered for optimum benefit.Check out the cool background music as you surf through links.
http://www.sandra-bullock.org
THE WHY FILES
You've seen the x-files, but we give you the Why files.These are a fascinating look at the science behind the news headlines around the world. At this website,there are available amazing facts behind major news stories.You can take a look at the archived itemsin'Filed Why Files'. Topics range from tornadoes to spinal cord
repair,from life on Mars to the mosquito menace. http://whyfiles.news.wisc.edu/
FOR AUTO LOVERS
For all you auto lovers out there,we will be telling you about cool car sites on the web.Brace yourself, for we start with one of the sleekest and costliest cars; yes, that’s right,the Ferrari.Out of all the auto websites,this is the most colourful one.The first thing that you encounter on accessing this site is the historic ‘Silver Horse’ logo.You are welcomed by Mr. G.L. Buitoni, CEO,Ferrari. When you burrow further you are struck with the abundance of yellow and red colours which are a characteristic of the Ferrari.You can download some great allround view pics of the latest as well as past models.Do visit this site,you won’t regret it.
http://www.ferrari.com
BILL GATES
For all you computer users who idolize the Microsoft Corporation CEO,who also happens to be the world's richest man be sure to drop in at the Road Ahead Website.The site contains extracts from his book "The Road Ahead " and its CD-ROM, updates and technology glimpses. A Billboard section describes Billion Bill's recent visits to India,South Africa and travels elsewhere. http://www.roadahead.com
KILLER FONTS (FONT-ASTIC)
If you are tired of garden variety fonts and your Times Roman look in the Windows environment,then we’ve got just the right address for you.The Killer Fonts website has the most bizzare collection of killer fonts along with photos of their infamous owners and a vivid write-up of their dark deeds.You can find scripts of killers like Jack the Ripper,outlaws like Butch Cassidy.There’s also the writings of Presidents like Washington,Lincoln and of iconoclasts like Columbus and
Leonardo Da Vinci.You can get one font free by joining the mailing list at the website.
Tushar Pai
Executive Cell
FUNNY BYTES
Once Albert Einstein was travelling to universities in a chauffeur-driven car,delivering lectures on the theory of relativity.While in transit,the chauffeur said,"Dr Einstein,I’ve heard you deliver that lecture 30 times.I know it by heart and bet I could give it myself." "Well,I’ll give you the chance.Since they don’t know me at the next college,you can give the lecture," Einstein said.
The chauffeur delivered the lecture flawlessly.When he started to leave,one of the professors stopped him and asked a complex equation-filled question.The chauffeur thought fast,"The solution to that problem is simple.I’m surprised you have to ask me.In fact,to show you how simple it is,I’m going to ask my chauffeur to come up here and answer your question."
HOWZZAT
Three mathematics’ students out for a stroll noticed a car broke traffic regulations.None of the students noticed the number of the car, but, being mathematicians they noticed some pecularities about the four-digit number.One said that the first two digits were the same.The second recalled that the last two digits were alike.The third student said that the number was a perfect square.
Is this information enough to find out the license plate number ?
If so,what was the number ?
(No ‘Trial and Error’ method allowed !!! Solution to be given in the next issue.)
TECHNO BUZZ
UK SCIENTIST USES COMPUTER TO TEST FOR
ALZHEIMER’S DISEASE
A British neuropsychologist,
Joanna Iddon is using a computer to determine whether sliight memory loss is just a sign of getting old or an early indication of Alzheimer’s disease. The Cambridge Neuropsychological Test Automated Battery(CANTAB) is designed to evaluate different areas of the brain and the mental abilities associated with them.Other neural disorders like the Parkinson’s disease are evaluated with different computer tests.CANTAB can detect the neurological changes linked to the disease in only six months.
MOTOROLA INTRODUCES REMOTE VU VIDEO SUPPORT FOR THE VANGUARD SERIES OF PRODUCTS
Motorola announced the Remote VU for its Vanguard(R) product family,a complete end-to-end solution for transport of realtime full-motion video over bandwidths as low as 2.4 Kbps.This proves ideal for applications such as security surveillance and remote monitoring.Made to cut costs in applications requiring optimal resolution with fast video frame rates over minimal bandwidths, RemoteVU is based on object recognition and optimises for 10 to 30 percent motion within the frame capture area.
F A Q CORNER
THE ‘Y2K’ PROBLEM
When the clock strikes 2000,millions of computers around the world which now control almost every aspect of our lives may soon land us in trouble. The forthcoming millennium may usher an 'economic meltdown'.Whaddya mean meltdown?Is there going to be a nuclear war?Are we all gonna die or something?So what IS this problem that mankind now faces as we get ready to enter the 21st century?For all dazed computer users engulfed in the throes of the impending global IT calamity,presenting answers to the Y2K FAQs......
WHAT IS THE YEAR 2000 PROBLEM ?
Computers record time and dates as just another number which grows as time progresses so a future date is always larger than a past date.Programmers in the 60s and 70s deleted century digits from dates deeming such data as irrevelant.
Without the century digits,last day of all millennium will be 99-12-31 and after the stroke of midnight many computers will see Jan 1, 2000 as 00-01-01 a smaller number than the day before.Time will appear to have reversed.Hence the name
'Y2K' or 'year 2000 problem'.
HOW SERIOUS IS IT ?
If the century problem is not corrected before 1999,90% of all computer applications will be affected and systems will crash.Moreover ,Jan 1 is a Saturday,so problems caused may not be discovered due to coding errors until the next regular working day allowing enough time for the errors to inflict a great deal of damage.
WHAT ABOUT WINDOWS ? DOES IT HAVE A PROBLEM ?
A problem with windows based calender is that it only accepts years 1980 to 2099.So windows 95 won't have a problem till 100 years later.A win 3.1 application a talking clock literally choked on a post 2020 date interpreting it as 1920!
NAAH,IT CAN'T HAPPEN TO ME...CAN IT ?
To cite examples of the magnitude of the problem affecting daily life:
If you make phone calls just when the century changes over,you might end up footing Rs.17,334,800 as billing for a call lasting 99 yrs @Rs 1 per min. Trains scheduled to run on Jan 1 will not run owing to computers thinking its Jan 1 1900.
SO IS THERE ANY SOLUTION?
Solutions do exist.The trouble is implementing them without effecting current working.And this has to be done well before 2000. Some common approaches are:
1.Century indicator
2.Sliding Window technique
3.Full Date Expansion
4.The Purdue solution
