WIRELESS PROJECTORS: ADDING FLEXIBILITY FOR PRESENTERS
If you have been looking for a new LCD projector or DLP projector lately, you may have noticed that in recent years there has been a large increase in the number of technical features available on newer model multimedia projectors. While many of these technological innovations have been specifically designed to increase the quality of the projected image or to reduce common problems such as keystoning and image artifacts like the "rainbow effect" in DLP projectors, one of the technical advances with the most impact for presenter and operator flexibility is wireless projector connectivity.
Wireless projector connectivity is a feature that will have huge benefits, not only for users with many projectors such as schools and universities, but also for the individual user, such as sales people on the road.
This Projector Source Canada article will explain wireless projector connectivity and how it works, and will compare the advantages and disadvantages of the two main types of wireless projectors: "real time" wireless projectors and "upload" wireless projectors.
What are wireless projectors?
In the past, projectors were isolated machines which needed to be connected to the source where the image was coming from -- for example, a laptop. Then network projectors came along, which allowed users operating many projectors (such as schools, universities and large corporations) to connect their projectors to a network and download powerpoint presentations and other media from a central computer.
This allowed remote maintenance of all projectors on the network, which saves organizations using lots of projectors large amounts of time and money. Traditionally, network projectors were wired, meaning that a network cable had to be connected to the projector in order for the projector to connect to the network.
Today with the advent of wireless internet and Local Area Networks, a number of projectors are advertised as having "wireless" capabilities..
What is the difference between a wireless projector and a non-wireless projector?
When the term ''wireless'' is used in conjunction with a projector, it refers to the way the projector accepts images from a source. Wireless projectors are different to non-wireless projectors because they use 802.11b (11 megabits per second) or 802.11g (54 megabits per second) wireless protocols to receive data from a computer or other source that has the same wireless capabilities.
Although these projectors are called "wireless" projectors, they do still need at least one wire. No projector is capable of ever being entirely wireless as all projectors need to be powered by a mains cable plugged into a power source. Still, removing the wires needed for connections to the network or to image sources has many benefits which are described in more detail below.
Wireless projector capabilities
- 802.11b wireless connectivity, meaning a standard 11 megabits per second transfer rate, or:
- 802.11g or 802.11a wireless connectivity, meaning a faster 54 megabits per second transfer rate
- Using MPEG2 files, movies can be projected at up to 30 frames per second from a PC.
- Power Point presentations with animation can be displayed.
- Wireless projectors are usually compatible with both Macintosh computers and PCs networks
- Multiple computer sources can be switched between with a single click.
- Real time edits to document such as an Excel spreadsheets and Word documents can be displayed.
- Presenters can present from a computer placed anywhere in the room.
- Presenters can give presentations from distance -- usually up to 150 to 200 feet from the computer source.
The advantages of wireless projectors
The capabilities of wireless projectors give them several advantages over non wireless projectors. These advantages are mostly in the form of increased flexibility for those giving presentations, and reductions in time and cost for those responsible for maintaining the projectors on a daily basis:
- Projectors with wireless capabilities only need to be connected to a mains source, and not directly to a device like a laptop to receive an image. This means that presentations are much simpler to set up, and because there are less cables used, the projector set-up has a much cleaner look.
- AV cables are actually reasonably expensive, so wireless projectors can offset the fact that they are slightly more expensive by making savings on cables.
- Having no cables means that wireless projectors do not incur signal loss over longer distances.
- All that is required to alternate between different sources on a wireless projector is a few mouse clicks instead of the wired alternative that involves having to physically move devices and switch around cabling. This can be very useful if more than one person is presenting.
- Presenters can be much more mobile and flexible in their positioning since their source devices do not need to be directly next to the projector. This means that the presenter can give a far more interactive presentation, which can be very useful in school classrooms.
Types of wireless projectors
There are the two types of wireless projectors available: "real time" wireless projectors and "upload" wireless projectors, each with their own advantages and disadvantages.
"Real time" projectors
"Real time" projectors display images in real time by maintaining a permanent wireless link to the computer source.
The advantages of real time projectors
The main advantage of having a permanent wireless link to the image source is in that it allows for presentations to be quickly set up and delivered.
The disadvantages of real time wireless projectors
The fact that a wireless connection must be maintained in real time projectors can be a problem, since this depends on a continuous stream of data. Should the wireless link falter or disconnect then the presenter will be unable to continue the presentation. Also, even when the signal for a real time wireless link is strong, the projector still needs time to read the signal, meaning that there will always be a small delay between the source and what is projected. Real time projectors also have a bandwidth limit. While this does not affect the projection of static images such as spreadsheets, it does prevent these projectors from running full motion videos in real time due to their large file size.
Wireless "upload" projectors
Upload projectors have files uploaded to them over a wireless connection, and then store these files on the projector itself.
The advantages of wireless upload projectors
The main advantage of upload projectors is that they enable the presenter to project files stored on the projector without the need for the source to be connected to it.
The disadvantages of wireless upload projectors
Although having files stored on the projector is useful, this is only a significant benefit if the same file is to shown repeatedly without changes. If changes need to made frequently, the amount of preparation time needed prior to the presentation with an upload projector would probably mean that a real time wireless projector would be preferable.
Security of wireless projectors
If you are projecting highly sensitive or private data then it is extremely important to encrypt the wireless signal from the source to the projector. If you do not, anyone within range could have access to what you are projecting, meaning employees or even competitors could see data that you would rather be kept private.
Luckily wireless projectors have built in software encryption available, usually 64 bit or 128 bit. This keeps your data secure. The trade-off for encrypting your data is that the delay between the projector and source is increased slightly because the source needs to encrypt the signal before it sends it, and then the projector needs to decrypt the signal before the image can be displayed. Most people consider this a small price to pay for data security.
General Price differences between wireless projectors and non-wireless projectors
The only real trade off with a wireless projector over a non-wireless projector is that benefits of wireless technology come with a price tag attached. Given equal specifications such as contrast ratio and throw distance, wireless projectors often cost double the amount of their non-wireless counterparts. As innovations in projector and wireless technology continue, this difference in price will come down.
We hope you enjoyed this article by Projector Source Canada. For more information, or to purchase a display and projector for your business or home, visit us online at http://www.projectorsourcecanada.ca
or contact us at 1-800-821-3021.
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