Wired Projectors Made Wireless

David Colin, May 1, 2003

If you have an existing investment in cabled projectors and you'd like to take advantage of the benefits of wireless projection, you don't have to replace the equipment. A class of products has emerged that allows the once wired projector to become wireless without modification to your existing projectors.

We had a chance to test the Komatsu KJ-100B AirProjector, herein referred to as AirProjector, and we were pleased with what we found. This unit turns your cabled projector into a wireless projector giving you the multi-user benefits of integrated wireless. For those of you who are new to wireless check out Going Wireless.

Setup - Wireless operation is achieved by connecting the AirProjector wireless receiver to your projector using your projector RGB cable and installing the AirProjector Client software on each wireless computer that will have access to the projector. If your computer is not equipped for Wi-Fi (Wireless Fidelity), you will need to install a Wi-Fi 802.11b card and associated driver.

Komatsu KJ-100B AirProjector Setup
Komatsu KJ-100B AirProjector Setup

We tested AirProjector in the above configuration with the NEC VT460, Epson Powerlite 30c, and the Toshiba TDP-MT8U projectors. The unit performed well on all units.

Using a wireless Access Point, AirProjector can also communicate with wired local area network devices and as well as other wireless devices.

Komatsu KJ-100B AirProjector Infrastructure Communication Mode
Komatsu KJ-100B AirProjector Infrastructure Communication Mode

The first thing we noticed in testing the AirProjector is that the unit plugged and played as easily as anything we have worked with previously. Some software and firmware upgrades had been issued after we received the unit, so after getting the unit operational, we decided to do the upgrades online. We had no problem with the software upgrade, but we did have a minor problem with the firmware upgrade. A call to Katun support, the distributor for the product, resolved the problem.

Documentation - An 80 page User's Manual comes in electronic form on a CD; however, since we had no trouble getting the unit operational, we only scanned the manual for content. While the documentation seemed adequate, the truth comes when you have to troubleshoot a problem and we had only a minor issue. The technical support was excellent for the brief problem we did encounter.

Control - The AirProjector Client sends images to the projector either on request or in real time. The request mode turns the unit into a slide projector allowing the presenter to control what image is presented and when. When in real time mode images are sent continuously to the projector.

Overall Performance - All Wi-Fi 802.11b wireless projection seems to have the same set of issues that we discussed in prior articles including limitations on distance, some delays in transmission, some loss of color resolution when optimizing for speed, inability to handle video, and the potential for security violations. These issues are also true with the AirProjector.

Distance Performance - Mobility and multiple users are two of the strengths of Wi-Fi. Instead of one computer tethered to the projector, an individual, a room of students, or individuals in a meeting can actively access the projector from anywhere in the room. Transient use is the nature of wireless.

Generally speaking, with a clear line of sight to the projector, data can be transmitted up to 150 feet. Our test environment did not allow unobstructed transmission; however, we were able to transmit images to the Air Projector from 60 feet passing through 2 walls and a floor. While we could not monitor the actual signal strength, we did monitor the image transmission quality and time, and found no variation in performance over the tested distances. This performance was comparable to our experience with other integrated wireless solutions.

Speed Performance - Transmission time no doubt varies by some small percent among the various wireless solutions. Our experience with the AirProjector was not any different than our experience with the wireless projectors. Image transfer times ranged from nearly instantaneous to as much as 5 seconds. Entering text and moving a mouse had nearly imperceptible delays in transmission. Frame to frame image transitions with little content change take about a half a second. Changing from one graphic image to another typically takes 2 to 3 seconds, longer at higher resolutions or when there is interference. Slow image transfers build the image in a manner similar to a Powerpoint slide transition.

Color & Resolution - We were using an XGA notebook and transmitting text and full color graphic images. We ran a suite of images from the INFOCOMM 2000 Shootout and noticed the expected reduction in the color gradient as some color resolution is lost to improve transmission time. This color loss would be of concern if you were watching a movie, which is clearly not the intended use for Wi-Fi 802.11b technology; however it is not likely to be noticed in most computer applications. Graphic images with fine shaded detail are the places you would most likely notice a loss of some detail.

Security - An 802.11b Wi-Fi device is basically a digital radio broadcasting in the 2.4 GHz band. Outdoors Wi-Fi can transmit tens of miles and therein lies a security issue. If your data is not encrypted, then it is vulnerable. A security algorithm known as WEP (Wired Equivalent Privacy) is provided and is intended to overcome this vulnerability; however, the industry consensus seems to be that it can be violated by those skilled at hacking.

So beware, a passerby seeking free Internet access or someone with more fiendish intent can access an unsecured wireless network. This practice is known as war-driving and people who indulge in this include freeloaders, thieves, and some that are simply trying to create an awareness of security issues. War-drivers may also engage in war-chalking, which is a throwback to the communication technique used by hobos to alert other hobos with chalk markings identifying free places to sleep or eat. Like the hobos, these war-chalking symbols alert other war-drivers of free services, so if you unplug and go wireless, look for a war-chalking sign near you.

Limitations - AirProjector Client application does not support applications using DirectX, Microsoft Office Assistant, and DVD movie playback.

Where to Buy - The AirProjector is manufactured by Komatsu, a 96 year old Japanese manufacturer, and distributed in the United States, Canada, United Kingdom and Ireland by Katun, a major distributor of office equipment worldwide. The product retails for $999 and is sold through AV and IT dealers.

If you'd rather buy a wireless projector, there is a good selection of products in the market. Like the AirProjector, these units offer quick connects, multiple simultaneous users, collaborative meetings, and greater utilization of your investment.