Wireless Technology

The word wireless technology is normally used to refer to any type of electrical or electronic operation which is accomplished without the use of a “hard wired” connection. Wireless communication is the transfer of information over a distance without the use of electrical conductors or “wires”. The distances involved may be short (a few meters as in television remote control) or very long (thousands or even millions of kilometers for radio communications). When the context is clear the term is often simply shortened to “wireless”. Wireless communications is generally considered to be a branch of telecommunications.It encompasses various types of fixed, mobile, and portable two way radios, cellular telephones, personal digital assistants (PDAs), and wireless networking. Other examples of wireless technology include GPS units, garage door openers and or garage doors, wireless computer mice and keyboards, satellite television and cordless telephones.When viewed as a method of data transport, wireless technology appears very similar to wired technology. You have a piece of hardware, a method of transmission, and connections on both ends that transform data from human-intelligible to transportable and back. For both wired and wireless technology, the range of transmission is an issue. You can’t move your laptop 15 feet from the wall jack when depending on a 10-foot cable. Similarly, you can’t go out for a jog and expect your in-home cordless phone to keep a connection five miles away from its receiver. But if you get either a 20-foot cable or a wireless connector of sufficient power, you can move your laptop 15 feet away from the wall jack; and if you get a cellular phone, you can go jogging five miles away from your house and still take calls (as long as your service provider has a reasonable antenna set up).The methods of connection and ranges of service available vary in wireless technology just as they do in wired technology. Home telephones with a wireless handset have a more limited range than cellular phones; infrared transmissions have a more limited range than radio-wave (including microwave) transmissions. Different types of wireless solutions can communicate ten feet, ten miles, or with a satellite in orbit.

Applications of Wireless Technology

• Professional LMR (Land Mobile Radio) and SMR (Specialized Mobile Radio) typically used by business, industrial and Public Safety entities

• Consumer Two Way Radio including FRS (Family Radio Service), GMRS (General Mobile Radio Service)

• Amateur (“Ham”) and Citizens band (“CB”) radios

• Consumer and professional Marine VHF radios

• Cellular telphones and pagers: provide connectivity for portable and mobile applications, both personal and business.

• Global Positioning System (GPS): allows drivers of cars and trucks, captains of boats and ships, and pilots of aircraft to ascertain their location anywhere on earth.

• Cordless computer peripherals: the cordless mouse is a common example; keyboards and printers can also be linked to a computer via wireless.

• Cordless telephone sets: these are limited-range devices, not to be confused with cell phones.

• Satellite television: allows viewers in almost any location to select from hundreds of channels.

• Security Systems: Now a days , wireless technology is broadly used in security related applications using some other technologies in parallel with it.

Missiles : A major strength of Indian Defence

Indian defence scientists are developing a new medium-range, multi-platform missile, called the Nirbhay or the dauntless, that will add more teeth to its armory and is slated to be tested by end-2009.The missile, with a range of 1,000 km, is being developed at the Advanced Systems Laboratory -, a unit of the Defence Research and Development Organisation. They have done the design and begun hardware planning for its latest missile, Nirbhay, or the dauntless, with the technology demonstrator flight planned for end-2009, top officials at the state-run Advanced Systems Laboratory – here said.The latest in the series of India’s missile development programme, the Nirbhay follows the Agni and the Prithvi.There are many more missiles recently tested and fired successfully, which are given below -

Brahmos Cruise Missile:

Brahmos is a Supersonic Cruise Missile that can be launched from submarine, ship, aircraft and land based Mobile Autonomous Launchers (MAL). The missile is launched from a Transport-Launch Canister (TLC), which also acts as storage and transportation container.

The missile met all mission parameters and the test has established the sea to land capability of the formidable weapon system. A ship-to-shore version of the supersonic Brahmos missile was successfully test fired in the Andamans recently. Defence Ministry announced that the missile with a range of more than 290 kms was launched from the deck of the Russian acquired missile destroyer INS Rajput and precisely hit a land target in one of the islands. This was the 15th test of the missile jointly developed by Russia and India. Scientists have already carried out successful tests of the ship-to-ship version as well as Surface-to-surface version of the multi-role missiles.

The induction of Brahmos has already begun in the Navy as well as Army. Defence Research and Development Organisation is now developing air-to-ground and submarine-launched version of the missile.

Trishul Missile:

The Trishul (Trident) is a short range, quick reaction, all weather surface-to-air missile designed to counter a low-level attack. It has been flight tested in the sea-skimming role and also against moving targets. It has a range of 9 km and is fitted with a 5.5 kg HE-fragmented warhead. It’s detection of target to missile launch is around 6 seconds. The missile can engage targets like aircraft and helicopters, flying between 300 m/s and 500 m/s by using its radar command-to-line-of-sight guidance. Development of Trishul missile system has been completed recently as technology demonstrator. Till January this year, around three billion rupees had been incurred on the development of the system.

Submarine Based K-15 Ballistic Missile :

India will soon conduct its first test of a submarine-based ballistic missile which can be tipped with a nuclear warhead, an official announced on Monday. According to DRDO, the experimental missile will be fired from a submerged pontoon and the missile, has a top range of 700 kilometres (438 miles), and is ready for testing and waiting for the approval of Indian Government. If the test is successful, India will be capable of launching missiles from air, land, ships and submarines, and it will join an elite group that includes the United States, Russia, France and China.

Major products and Technologies through Defence

Technologies through Electronics Department

• 3D-Car : A 3D Central Acquisition Radar (3D CAR) has been developed as medium range Early Warning Sensor. This state-of-the-art radar is capable of detecting & tracking multiple targets in a hostile electronic warfare environment. The radar was demonstrated to the Services with live sorties provided by Air Force. The radar has gone through extensive in house evaluation and field exploitation by the Air Force for three months.

• Weapon Locating Radar : Weapon Locating Radar is developed based on the proven Rajendra radar technology. Its primary roles are location of enemy guns, mortars and rocket launchers and own fire direction. The system is developed as a joint collaboration between DRDO and Bharat Electronics Limited.

• Sangraha : An indigenous EW programme for Navy, development of all five types of electronic warfare (EW) systems have been completed under the project SANGRAHA.

• Antenna Systems : Antenna technology has gone through several changes commensurate with the evolution of the complex systems for various applications. Defence has developed the capability in designing antennas for various ground-based and airborne radar systems, communication systems, electronic warfare, and underwater scenarios.

• Laser Warning Sensor : Defence has developed a compact sector-sensing laser warning sensor capable of giving warning against existence of a laser threat in the form of an audio beep as well as a visual display when exposed to radiation from typical existing and emerging battlefield solid-state lasers.

• Passive Q-Switching : Defence has developed passively Q-switched continuously pumped Nd:YVO4 generating ~16 ns wide pulses at ~70 kHz repetition rate by end pumping an Nd:YVO4 crystal of 1 mm thickness and 3 mm x 3 mm cross-section employing a CW laser diode with maximum output power of 700 mW at 808 nm.

• Threshold Detector : The gadget has selectable energy density threshold level and gives an audio/visual indication when the energy density actually available at the target plane is above the set value. It can be used with both free running as well as Q-switched lasers. The gadget can handle free running lasers with pulse width in the range of 100 µs to 600 µs

• Multi-Detector Temography System : A gamma ray transmission-based multi-detector computed tomography (CT) system which is based on Ir-192 radio-isotope source and uses four discrete detectors thereby reducing the data acquisition time by one-fourth as compared to the single-detector first generation CT systems. The technology is unique and first of its kind in the country.