Wi-Fi Systems Broadband Wireless: Future Telecom
Wi-Fi Systems Broadband Wireless: Future Telecom
Wi-Fi Systems Broadband Wireless: Future Telecom
Life has undeniably changed for the global telecom industry. For India, which saw- sify-announcing it had setup 120 Wi-Fi hotspots in Bangalore last year, technology for people has always been an issue. As the world moves to broadband internet (an estimated 30 million Wi-Fi networks have been installed worldwide and are being added at the rate of one every seven seconds), the Bangalore example shows that technologies being used around the world are touching the lives of Indians too. One such emerging technology is Wi-MAX, touted by Maloney as the big brother of Wi-Fi. While the latter allows the user to surf the internet at speeds of over 384 kbps in a limited area like an airport lounge or a coffee shop, Wi-MAX stretches the possibility further. In technical terms, Wi-MAX refers to the 802.16a standard for wireless metropolitan area network (WMAN) technology hat will provide a wireless alternative to cable, digital subscriber line and t1, e1 for last mile broadcast access. It will also be used for connecting 802.11 (Wi-Fi) hotspots to the internet. For users, Wi-MAX will mean more broadband access choices, particularly in urban centers where building access is difficult, in the suburbs where the user is too far from the central office and in rural areas which have poor telecom infrastructure. Unlike Wi-Fi, which provides access within a limited area (300 ft), its big brother version provides up to 70 km of service area range. It provides total data rates of up to 280 Mbps per base station, enough to support thousands of users. Wi-MAX solutions will hit the market by the year-end.
Maloney, who believes that a majority of people will access the internet through the wireless technology in the future, best describes the relevance of these technologies. He feels that Wi-Fi and WiMAX will work together to enable companies to reach out. And, he makes it a point to underline the potential of these technologies for developing countries like India where the traditional wireless infrastructure is yet to reach a vast majority. For Indian customers, perhaps the most cost conscious in the world, the possibility of voice becoming free, even as other value-added data services are being charged, is a tantalizing prospect.
Spectrum regulation making it broadly available by the government. Also a rich set of service providers-existing ones or new telecom companies- to start up and rolling out such networks in the country. Not just surfing on the internet, but unique applications such as voice-over-internet protocols (VOIP), which can be very interesting in India as voice services are still comparatively weakly deployed in the country. That would potentially be a key demand driver. The beauty of Wi-Fi technology is that the cost of infrastructure is quite low. In places like India, it is going to be an interesting test.
The Wi-Fi call is absolutely clear and almost in stereo. The clarity of a Wi-Fi system is as clear as of a CD player.
What is GSM-R??
GSM-R is meant for the railways and is solution that provides effective communication on rail networks. There are six GSM-R networks in the world including Germany, Italy, Slovak republic and Sweden. Essentially GSM-R creates a group call application for a railway communication network.
division of spectrums for Wi-Fi by the government. So far only 802.11b standard having capacity of 11mbps has been open up while 802.11a/g offering 54mbps is yet to opened due to its usage by defense services. India is a turning into a value sensitive market rather then cost sensitive. Initially Wi-Fi applications are expected to be expensive. But as market size increases, the prices will come down substantially.
Wireless communication
Wireless communication system includes cellular telephones, radios, telegraphs, satellite telephones, laptop computers etc. they are used primarily to transmit private communication. It allows people great flexibility while communicating because they do not need to remain at a fixed location. Wireless communication devices are useful in places where communication services are only temporarily needed such as outdoor festivals or large sporting events. These technologies are also useful for communicating in remote locations such as mountains, deserts, where wireless based telephone devices might not exist. Business people use wireless devices such as cellular phones to stay in contact with colleagues and clients while traveling. All wireless communication devices use radio waves to transmit and receive signals. These devices operate on different radio frequencies so that signals from one device will not overlap and interfere with nearby transmissions from other devices. Currently, telecommunication companies throughout the world are activating more wireless service subscriptions. Wireless communication is becoming increasingly popular because of the convenience and mobility it affords; the expanded availability of radio frequencies for transmitting which make it possible to handle a large volume of
calls; &improvement in technology, which have added other services such as internet access and improved the clarity of voice transmission.
Modes of transmission
Wireless communication system involves either one-way transmission in which a person merely receives a notice of a message. Pager is a simple example of one-way transmission. When a person dials a pager number, the pager company sends a radio signal to the desired pager. The encoded signal triggers the pager circuitry and notifies the customer carrying the pager of the incoming call with a ton e or a vibrator. The other is two-way transmission which requires both a transmitter as well as a receiver for sending and receiving signals. The common example of two-way transmission is cellular phones so that back-&forth communication between two people can be maintained.
Voice recognition (VR) technology makes computers recognize your speech and even talk to you. It makes life easier and faster. VR essentially enables the conversation of sound, words or phrases spoken into electrical signals. These are then transformed into coding patterns at one end and decrypted at the other to retain its meaning. Your computer can recognize your voice in two ways- by template matching where he program is first trained with the users voice input before the users voice is recognized. Example: voice activated phone books in many mobile phones. Although this application has an accuracy of 98%, there is a limitation on the number of user profiles that can be created due to memory constraint. The other method of VR does not need a program trained by the user. It simply attempts to match the expected inputs and the digitized voice inputs. Newer technology now allows you to dictate up to 160 words a minute and some program can also understand slang. Voice recognition is rapidly increasing its presence in business and corporate mainstreams. The technology has found a critical use in the case of people suffering from problems like dyslexia or a stress injury like carpal tunnel syndrome, the bane of typists. VR software can perform all the functions that windows doesediting, reading out the menus and even web search. In India, VR software is marketed by IBM Dragon. Dragon was among the first to launch its Naturally Speaking product. A couple of Dragon products also come with a digital recorder, which makes it convenient to dictate text on the move or when you arent near a personal computer. Voice recognition software also make mistakes- loud external noises, inarticulate or slurred speech, similar sounding words and slang in most cases will most probably give strange results. It is
more convenient to use a combination of mouse, keyboard and speech as this saves you a lot of repetition. Voice recognition is fast gaining grounds with improvements being made by the day. Speech integration and embedded technology will give it a wider usage.
sufficiently large-scale service deployments were needed. For network operators to deploy services, sufficiently high-quality handsets, infrastructure and content were required. Each attempt at defining a standard had been initiated by one of these industry segments, but each eventually failed to gain the necessary acceptance from other segments. A single standard for the mobile internet was clearly needed to help galvanize and unify the market. The Wireless data market, 1997:
Software and hardware providers and tool vendors Handset manufacturers
content developers
Awaiting large market of enterprise and consumer users and large-scale service deployments
DEADLOCK
Awaiting nonproprietary and low-cost availability of quality handsets, infrastructure and content
Network operators
phone.com). Each of these companies had previously made an independent effort or attempt to develop and deploy a wireless data solution. The resulting efforts to develop a standard, known as the wireless application protocol (WAP), were announced on June 26, 1997.
contents protocols
networking designs by dividing them into functional layers and assigning protocols to perform each layers task in addition to exposing an interface to the layer above it, each layer may expose an interface directly to application and services. The WAP Architecture:
Application layer (WAE) Session layer (WSP) Transaction layer (WTP) Security layer (WTLS) Datagram transport layer (WDP)
enabled handsets offer consumers a big edge. Java has made movies or short clips possible in cell phones. JSPs (Java Server Pages) provide a method for supporting the separation of data and data representation. In this environment, the data is encapsulated in a Java Bean. The JSP document is compiled, using a JSP compiler, into a servlet, that is installed on the application server. Markup contained in the JSP is transformed into Java commands to output that text directly to the output stream. When the request reaches the application server, logic analyses it to determine the most appropriate JSP to apply. The corresponding servlet is then invoked. The servlet outputs the final document, which essentially merges the static markup contained in the original JSP with the dynamic data provided by the Java Bean. In this way, the data source can provide data in any format- including XML- and a Java Bean will supply an interface to that data. A multimode application serves a collection of JSPs for delivering content in markup languages that are suitable for a variety of client browsers. Supporting a new browser markup language simply involves writing and completing a new JSP at the application server. Most important, this does not require modifications to the existing JavaBeans or data.
construction workers, film crews, event planners and security personnel. Simple 2-way radios, called walkie-talkie, have been popular children toys of years. Most walkie-talkies broadcast on channel 14 of the Citizen Band (CB), a range of frequencies grouped into channels and allocated for public use. CB radios can transmit and receive on 40 different channels. An un-licensed radio service, the family radio service, allows individuals to use high frequency wireless devices with a range of up to 32 kilometers.
Shortwave Transceivers
Long range broadcast services and frequencies, in what is known as the shortwave radio band (with frequencies of 3 to 30 MHz), are available for amateur or ham radio operators. Shortwave radio broadcasts can travel long distances because of the concentration of ionized, or electrically charged, particles in the layer of atmosphere known as ionosphere. The ionosphere reflects radio signals, so that signals transmitted upwards are reflected back to the earth. The skipping of waves against the ionosphere can greatly increase the range of transmission. These broadcasts can travel thousands of kilometers. Under certain conditions & on special clear channel frequencies, listeners of AM radio can receive a signal from several time zones away. Shortwave radio listeners sometimes can receive signals from the other side of the world. The degree of reflectivity of ionosphere depends on the time of day. During daylight hours, the ionosphere has the concentration of ions necessary for reflecting radio waves only at the higher frequencies of the shortwave band. At night, the ionosphere has the concentration necessary for reflecting lower frequencies within the lower parts of the shortwave band. If there is an adequate concentration of ions, the radio waves simply continue through the ionosphere into space.
Satellite Communication
Satellite communication services connect users directly to the telephone network from almost anywhere in the world. Special telephones are available to consumers that communicate directly with communication satellites orbiting earth. The satellites transmit these signals to the ground stations that are connected to the telephone system. These satellite services, while more expensive than cellular or other wireless services, give users access to the telephone network in areas of the world where no wireless or cellular services exists. Satellite phones are also able to deliver video images through videophones that are tiny cameras and transmit their images via satellite phone.