Bellew, Gerald P., The FBI Law Enforcement Bulletin
The Future of Law Enforcement Communications
As law enforcement prepares to enter the 21st century, it faces unprecedented emerging technology. While such developments as automated fingerprint identification systems, computer-aided dispatch systems, DNA typing, advanced surveillance capabilities, and computer-enhanced techniques assist today's police officers, the future holds even more promise for advancing technologies.
For example, imaging having the capability to see, hear, and converse with a peer in a police department across the country, or being able to interview a protected witness safely with no travel involved. Indeed, improvements in telecommunications make these and other scenarios a reality. In fact, telecommunications provides police officers with high quality, two-way audio and video teleconferencing, from both near and far distances, at the speed of light and at a fraction of the cost of travel.
Although the means for simultaneously transmitting both audio and video have long existed, the use of high-capacity, digital telephone lines has expanded the applications of two-way teleconferencing, while keeping costs relatively low. This new technology, called signal compression, provides exceptionally high-quality sound and pictures and can easily involve many participants at each site.
Compressed digital video works like this. First, a video camera shoots a scene. Then, special digital signal processing chips convert up to 15 frames per second into millions of individual pixels, or picture elements. Other chips select key pixels, such as the features of the speaker's face and clothing, while ignoring static background and redundant pixels, which do not change. Finally, the compressed image and sound are sent over a telephone line to the receiving videophone, which reassembles the pixels.
When using two-way teleconferencing equipment, a digital telephone line service must send the data. Although several types of digital service are available, the most popular is dial-up, public-switched service, because of its cost-effectiveness and growing availability.
Two-way videoconferencing systems come with a variety of features. The most basic system consists of a video camera, a monitor, and a keypad. Monitors range in size from 10 to 53 inches. Keypads dial the call, adjust the audio volume, select video sources--such as a camera, slide, or document--and position the camera.
One of the most practical teleconferencing units is completely mobile and compact and can be rolled from room to room like an audio/video cart. This particular system has a single microphone that can pick up anyone speaking in a standard conference-sized room. A built-in filtering system removes distortions, providing high-quality audio.
Perhaps teleconferencing's best feature is its versatility. It allows several participants to move freely within their conference sites and still be seen and heard by everyone. Because participants in one room can control the camera in the other room, they can focus on or even zoom in for a closeup of any individual. In addition, a "smart" window on the monitor allows callers to determine how their image appears to the receiver. Furthermore, the camera can be set to focus on predetermined locations, such as flip charts or white boards, during the conference. Thus, the meeting flows almost as if all the participants were in the same conference room.
Another capability of video teleconferencing is its adaptibility to much of the equipment already in wide use, such as FAX machines, VCRs, computers, and instant video disk cameras. In addition, many teleconferencing systems have encryption accessibility, making them secure for both domestic and international communications.
Applications for Law Enforcement
Compressed digital teleconferencing offers many applications for law enforcement, and some were demonstrated at the FBI National Academy in Quantico, Virginia. …