Over the past 30 years, more and more satellites have been launched into orbit, primarily for television and telephone service. But in the 1970s, the U.S. Department of Defense created a military system of NAVSTAR (Navigation Signal Training and Ranging) satellites built by Rockwell International, each the size of a car and weighing close to 2,000 pounds. Called the Global Positioning System (GPS), the satellite network would revolutionize how we communicate.
The GPS network, completed in 1995, initially helped soldiers communicate with each other and their bases, and was a military navigational system. In 1996, recognizing the importance of GPS applications to civilian society, President Bill Clinton issued a directive that made the GPS network available as a national asset.
The original GPS was made up of 18 satellites, six in each of three orbital planes, and their ground stations. Today’s system consists of 24 satellites, each orbiting the Earth every 12 hours in a formation that ensures that every point on the planet will always be in radio contact with at least four satellites.
In the past 10 years, the GPS has improved the effectiveness and security of our military forces, and has changed the way we communicate with each other, our cars, airplanes, computers, and anyone or anything else equipped with a GPS receiver.
One of the fastest-growing civilian uses of GPS is the automotive market. In 1996, General Motors introduced OnStar, a hands-free in-vehicle communications system using GPS and cell phone technologies. Today, most major automakers offer in-vehicle navigation and communications capabilities based on GPS. These systems enable the transmission of data communications between the car and a central server location, giving drivers the ability to communicate with a live person 24 hours a day in the event of an accident, breakdown, or other type of emergency.
Virtual Reality & Interactive Training
While many people think of virtual reality (VR) as video games and movie special effects, the technologies that form the basis of virtual reality are rooted in scientific visualization. Before the 1980s these technology elements existed, but once high-performance computers became more commonplace, virtual reality became a popular form of interactive communication. Today’s applications of VR technologies include immersive training and simulation, and scientific visualization in areas such as telesurgery and tele-robotics.
Immersive VR training and simulation employs a number of technologies that, when combined, enable the users to communicate in a three-dimensional environment. Head-mounted displays (HMDs), high-resolution video screens, audio, and data input devices such as data gloves and other tracking devices can all be used to communicate a particular environment. The HMD presents a stereoscopic view of the computer-generated environment, and is used extensively in military flight training simulators and in VR surgical systems. The military also incorporates HMDs as part of advanced soldiers’ helmets, providing night-vision capabilities, two-way communications, and intercoms.
The most basic form of communication is speech, but for those who are unable to speak, effective communication is anything but basic. Augmentative and alternative communication (AAC) refers to ways in which people communication other than through speech.
Prior to the popularity of the PC, augmentative communication tools featured symbols that conveyed general concepts, and were combined to form words. With the introduction of the PC, software and electronic devices became available that could speak in response to entries on a keyboard or via other input such as the push of a button or a puff of air.
Today, computer-based AAC devices and equipment take advantage of technology advances in graphics, speech synthesis, and software. A number of handheld communication devices are available that act as speech-generating devices. These allow the speech-impaired user to communicate by selecting words or phrases from prerecorded buttons, and combining them to create a single message that is output in a clear voice.
Radio Frequency IDentification (RFID)
Gaining popularity in recent years is RFID, an automatic method of communicating location and identifying products — or even people and animals. An RFID tag is attached to or put into a product and a transponder receives data from the tag using radio waves. Passive RFID tags do not have an internal power supply; they signal by backscattering the carrier signal from the reader. Because they require no power supply, passive tags can be very small — small enough to be embedded under the skin of a person or animal.
Active RFID tags do have a power source to power the circuits that generate an outgoing signal. Active tags can be used in challenging environments such as within metal containers or in water. Active tags can communicate information on products such as temperature of perishable goods, humidity, light, and radiation exposure.
RFID tags are used today on everything from library books to passports. They are used for automatic toll collection on highways, airline baggage tracking, ID badges, and even credit cards. Implanted RFID tags are used for pet identification and location. Toyota has introduced a key using an active RFID circuit that enables the car to acknowledge the key’s presence within about three feet. The driver then opens the door and starts the car while the key remains in the driver’s pocket.