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| SCIENCE TRIBUNE | Thursday, May 2, 2002, Chandigarh, India |
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Light may turn to gravity and vice versa |
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The future of internet telephony An average of 900 million voicemail messages are exchanged during the course of a business day. Dependence on e-mail is also rising, with IDC projecting that in a few years there will be more e-mail accounts in the USA than either telephone lines or television sets. And wireless adoption continues to experience overwhelming growth: China Mobile alone serves more than 100 million handsets. How can service providers accommodate the increasing global demand for new and existing communications services ? The answer lies in convergence - delivering voice and data services over one network versus multiple networks , and using technology that will allow carriers to bring new communications services to market more quickly. The migration of voice to sophisticated and flexible IP networks is leading the communications revolution. Both established and next-generation telecommunications service providers from around the globe are using this technology to build intelligent networks that will deliver voice, data, fax and multimedia services over the same connection. Today, VoIP connects long-distance callers from around the world. As adoption of the Internet continues to grow, the convergence of voice and data over the local loop will be inevitable. In the long run, fundamental forces will make widespread VoIP use a near certainty. Location -based telecoms vs VoIP Today’s telecoms networks are dependent on physical locations, with a telephone number identifying a particular location. This means a person travelling from place to place leaves a trail of multiple phone numbers in his or her wake. Payment for telecoms services also reflects the system’s dependence on physical location. While wireless phones may offer more mobility than landline phones, a person’s wireless phone number still identifies a physical home base through which calls are routed. The changes VoIP brings will eventually touch every wireline and wireless phone user, changing the way people communicate with world. These changes will start with telephone numbers. VoIP wipes away the physical location identity, enabling the user’s identity to move with him and allowing people to reach him through the same number wherever he is located. Eventually, voice will become a standard service over every IP connection. VoIP users will access IP lines as they would electricity — plugged into a grid and paying for the initial access and the amount of access they use — regardless of whether they are using a voice, data or video application. Wherever a person plugs in, the local provider will recognise the user, linking them to his or her correct VoIP provider. This frees people from hassles such as having to use special access dial-up numbers or special "out-of-service-area" arrangements. Delivering VoIP VoIP has the advantage of using transmission space efficiently. Where conventional voice transmission sends signals through bulky circuit switching, VoIP uses the more compressed, efficient method of packet switching. This allows more traffic to travel simultaneously and large amounts of data — and even video transmissions — to travel alongside voice transmissions. Based on the increased global demand for Internet access, IP traffic is projected to overwhelm voice traffic in the next two or three years. Already, roughly half of all traffic in backbone telecommunications networks travels over IP. Soon carriers will shift away from their huge , circuit -switched legacy networking infrastructure and install "next-generation" networks, designed and built to carry packets instead of using circuits. Solutions such as the software -driven Clarent Next Generation Network enable telecoms service providers to migrate smoothly from traditional circuit-switched communications networks to lower cost, application-rich packet-switched networks. It is designed to meet both existing and future needs of telecommunication service providers and offers a clear migration path with options such as Internet offload ( a non VoIP feature) building a converged VoIP network. Unlike today’s conventional telephone systems, VoIP uses open, distributed and scaleable architecture , allowing the network to expand easily and with few restrictions. It rests on a powerful centralised management platform, with the potential to deliver limitless applications over an ever-expanding network. With its foundation in familiar IP structures , VoIP uses will allow application developers to create a wide variety of services and features to anticipate and meet changing consumer needs. IP-based voice transmission lends itself far better to developing software that works across many platforms, paving the way for applications with the promise of making loves easier, such as universal messaging , call following and self provisioning — using voice to coordinate e-mails, calendars and documents. VoIP capabilities With VoIP, customers will have extensive control over their communication and messaging. They will have the ability to purchase VoIP service whenever they need it — and for the amount they need — via a personalised Web browser. VoIP gives businesses and individuals the benefit of quick provisioning and a higher quality of service, enabling them to easily create and modify their own service through the Web connection. Accessing information on all the devices people use today - from PDA and laptops to mobile phones — requires a legion of numbers, log-ins, passwords and even more devices. With a PDA-like display and an electronic contact file, IP phones will give people access to all of their messages - whether it be voice-mail, e-mail, or instant messaging — in addition to faxes and other critical data. VoIP will bring information sources together and, in reality, service providers can offer the sophistication of call centres to consumers on a personal level. With the capabilities provided by IP, companies can now create applications that truly add value and have familiar and intuitive user interfaces - applications that give forward- thinking service providers a real competitive advantage. Though customisation services are available today that identify and route specified calls, VoIP will expand these offerings. For example, one could program one’s phone to leave a family member a personalised message whereas unknown numbers or business callers receive a standard "not available" voice message. VoIP can also integrate call screening and priority notification, perhaps triggering a mobile device in certain cases and sending other calls directly to voicemail. The service can then use a unique announcement to identify the caller. VoIP can provide users with more sophisticated call waiting that signals incoming calls where they have the real-time option of answering the call at home, at work or on a cellphone - and the option of sending the call to a pager, voicemail, or e-mail. IP phone will also be able to integrate a person’s address book with speed dialing capabilities , essentially synchronising their PDA, office directly, PC and phone. Similar to the location transparency of the Internet, VoIP users will find connecting to their own phone service possible from anywhere in the world. They will simply log onto their phone as they would the Internet, and the network will identify them , regardless of their geographic location. When a call comes in for a user, the VoIP system can contact any location the user has identified , including several locations at once. When travelling, users can redirect calls , adding new numbers and temporarily removing others. If a user prefers that calls be routed to a laptop as text messages, he or she can then reply vis instant messaging or e-mail. Many large enterprises will find significant savings and added convenience in VoIP technology. In many cases, the network is already in place: most enterprises have and use high-speed data networks linking employees in various office locations. Moving ahead with VoIP With VoIP connections, companies can connect distant offices through private or internet-based networks. This not only adds efficiency, but also provides reliable and flexible security. Sensitive calls can travel under the protection of familiar and highly secured encryption systems. The two calling parties do not need to purchase specially designed phones, since they can easily access encryption systems, such as PGP (pretty good privacy), SSL (secure socket layer) and IP-SEC (IP security). Because these encryption systems are standard and manageable for nearly all of today’s computers, users will find them far less cumbersome than secured telephone scramblers. VoIP will also allow companies to create a single , unified view of each of their customers, regardless of the various ways in which customers contact the company ( via e-mail, phone or fax) . VoIP systems can easily log and track calls and messages , making it easier for workers to identify appropriate customer contacts and be kept up to date on customer activities. As it decentralises access to IP networks , VoIP will help the world connect more completely and efficiently. Two regions where VoIP adoption has been the most evident are Asia and Latin America. About 40% of the VoIP calls terminating in the USA and Europe originate in Asia, while one-third of VoIP traffic travels between North America and Latin America. In addition to improved quality, and reliability VoIP increases network and helps carriers save money , who in turn share these cost savings with customers via cheaper calling rates. Delivering new applications to the masses will require significant commitment , including upgrades in the local loop. Software-driven IP telephony solutions such as Clarent’s bridge the transition from legacy systems to VoIP, preparing networks for future communications advances while allowing them to maximise existing investments. With high quality voice, easy network interconnection and scalability, the packet-switched infrastructure being established today will deliver more intelligent and powerful applications to both individuals and enterprises. Service provider demand for VoIP software and equipment has already stimulated impressive market growth in recent years. According to frost & Sullivan, IP telephony services will reach the $ 43 billion mark in 2002. In turn use of the technology is also increasing. It is estimated to grow to 6.2 billion voice minutes this year — representing more than 4 percent of all international calls and a growth rate of 120% over the previous year. These figures are a mere hint of IP telephony’s market and usage potential in the next few years. The author is DGM(VLSI) with
Semiconductor Complex.
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Light may turn to gravity and vice versa A scientist in California is trying to turn electromagnetic radiation such as microwaves and light into waves of gravity, and vice versa. This could lead to telephones that can dial up the nearby star Alpha Centauri and televisions and radios that could receive signals through buildings or even the Earth as easily as if they were not there — if it works. "This simple experiment is at present being performed," Raymond Chiao, a physicist at the University of California in Berkeley told United Press International. "If this experiment is successful, superconductors can serve as a basis for practical devices in gravity radio." The experimental device envisioned by Chiao and his colleagues relies on a combination of mysterious substances known as superconductors — which act like superhighways for electricity — and even more mysterious gravity waves, which exist in theory but have eluded detection. Chiao explained his basic experimental array will have two pieces, a transmitter and a receiver, each with a slab of a black superconducting ceramic made from yttrium, barium and copper oxide called YBCO. Both pieces will be encased in metal cages so no microwaves can escape and they will be separated by other barriers. The superconductors are being used because they reflect magnetic fields: If you drop a magnet onto a superconductor, it will levitate or float. Superconductors also cause electrons inside and around them to move in powerful, united currents called a "Meissner effect." The electrons have mass, and mass creates a gravitational field. Chiao believes that if a beam of electromagnetic radiation such as microwaves or visible light is aimed at the combined magnetic, electrical and gravitational fields associated with a superconductor, as much as 25 per cent of the beam could be reflected as gravity waves. The opposite may also be true — just as a microphone can turn the sound waves of the human voice into electrical current and a speaker can turn that current back into sound waves, if gravity waves strike a superconductor, they may create electromagnetic radiation. In the experiment, the scientists will activate a microwave source in the transmitter. If a microwave signal is detected by the receiver, it means gravity waves have traveled between the two. If Chiao is right and gravity waves can be harnessed, the possibilities are fantastic. Just like radio signals, gravity waves travel at the speed of light. But unlike radio and TV signals, which can be affected by such facts as walls, tunnels and even the weather, gravity waves pass right through. Chiao’s idea has stirred up a lot of excitement — and doubts —among scientists. "It would indeed be a truly extraordinary result and instantly earn him a Nobel — if true," said quantum physicist Samuel Raunstein at the University of Wales in Bangor. "If it works I’d be in complete awe — if it works." Braunstein told UPI: "You could have an incredibly low power cell phone which could communicate with the moon or Alpha Centauri. It would still be limited by the speed of light, but it could work everywhere — not be blocked by buildings or the Earth or anything." A gravity wave telescope could even look at the most powerful explosion in history — the Big Bang — and observe the beginning of time, as well as learn more about how the universe might end. Despite the exotic nature of the idea and its potentially cosmic consequences, Chiao is using a low-budget approach. The experiment’s components consist of off-the-shelf parts and 25-cents-a-litre liquid nitrogen to cool the superconductor. "You could go to your backyard and build this thing. It would be easy to check the authenticity of any results. (NASA’s Jet Propulsion Laboratory) routinely makes superconducting circuitry, and could knock one of these things out in short order," Braunstein said. Colleagues of Chiao, although hopeful, remain very cautious. "A Meissner effect for the gravitational field would demand very strong mass currents ... and I don’t see how that is possible," said physicist Jon Magne Leinaas of the University of Oslo in Norway. "This may imply a much weaker effect than suggested by Chiao. In any case Raymond Chiao’s idea clearly deserves a more thorough study." Could Chiao’s experiments lead to
science fiction-style artificial gravity allowing travelers to walk
around spaceships as if on Earth? Could this even lead to black hole
factories? These questions and others will remain unanswered until
Chiao performs his experiment. "If it works, it heralds a whole
new set of possibilities, some of which you can’t predict,"
Braunstein said. UPI |
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SCIENCE & TECHNOLOGY CROSSWORD Crossword Clues: Across
Solution to last week’s Crossword
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1.
Process of extraction of metals from their ores and refining them.