Reliable operation can be a challenge when using wireless keyboards outside of the standard office environment.
In a conference room, classroom or auditorium, the desired distance between the wireless keyboard and the computer may be 30 - 100 feet, especially if the computer is located in a different room. For those using a wireless keyboard with a media center computer in a home theater or whole-house video system, the distance from the computer to the farthest viewing area often approaches 100 feet.
Problems and solutions
Several factors affect the performance and reliability of wireless keyboards used at greater operating ranges.
Obstructions such as walls or furniture may limit the effective range. If you mount the computer and receiver inside a lectern or in a different room from the keyboard, you will need a wireless keyboard with a range substantially greater than the actual distance due to the blocking effect of the lectern or wall.
Interference can interrupt wireless keyboard transmissions or shut them down completely. The effect is generally greater at greater distances, since wireless keyboard signals grow weaker with distance and a weakened signal is more likely to be overcome.
Bluetooth keyboards typically have a stated range of 10 - 15 feet, although a few manufacturers claim that you can use their keyboards at much greater distances. Bluetooth is not, however, an effective solution at longer distances, because the area of the wireless spectrum used by Bluetooth is also heavily used by mobile phone accessories, digital cameras, home appliances and many other wireless devices.
Wireless keyboards using 2.4 GHz wireless technology typically have a stated range of 20 - 30 feet. Interference, however, is also a major issue with these keyboards, especially from WiFi computer networks and 2.4 GHz telephone systems. Microwave ovens, which emit substantial levels of RF in the 2.4 GHz range, can bring many keyboard transmissions to a halt. Because of these issues, this type of keyboard will work reliably at no more than 15 - 20 feet from the computer.
Security can be an issue when a long-range keyboard does work reliably, since hackers in a different room or building may be able to intercept keystrokes containing passwords, credit card numbers and other important information.
The best long range wireless keyboards are carefully engineered devices using less-crowded areas of the radio spectrum. They include technologies that overcome problems caused by interference, and technologies to overcome any threats to security.
Keyboards from Wireless Computing, for example, operate at 916.5 megahertz, a frequency where there is little to no interference. They are rated to 100 feet and most often work at greater distances. They transmit using two-way communications, so that the keyboard and receiver work together to confirm that each keystroke is received at the computer.
Keyboards from Wireless Computing also include AES, an encryption algorithm that's so secure the US military uses it to protect top secret information.
Wireless Computing Keyboards
At this writing, Wireless Computing offers two long-range wireless keyboards: the full-sized RF-240 AES Secure Wireless Keyboard and the RF-222 Compact Wireless Keyboard with AES encryption and optical trackball. Both are capable of transmitting reliably for at least 100 feet. Each can be used in conference rooms, classrooms, auditoriums, offices and home theaters for government, corporate, educational and home applications.