Tomorrow is again time for a new Buyer's Review live event here at Kolabora. Spotlights are on Screen Sharing technologies, and on the podium I will have some of the most interesting tools out there to show your screen to other people online.

Since most Web conferencing solutions worth of this name, integrate a screen sharing or even an application sharing/remote control facility, I have opted, as in the past, to focus exclusively on those technologies that specifically focused on this communication ability: showing your computer screen live to other people connected on the Internet.

My selection tomorrow is limited to screen sharing/desktop sharing tools and to a few extra ones who have outgrown their simple screen sharing abilities to add a number of more traditional conferencing features.

My focus remains strongly bound to those companies and tools that have made around screen sharing their market reputation.

This industry niche is still in its early infancy, and very few players have fully understood and leveraged the potential of this sector. A general increase in the overall bandwidth available to many Internet users has also made it more practicable to hold effective screen sharing meetings.

Screen sharing is a bandwidth hungry activity, as the image of your screen has to be sent multiple times per minute to all other attendees. Since a full screen image in full color occupies on our large resolution screens over 1MB (one megabyte) uncompressed, you can imagine what kind of a hassle it is for the software doing this and the computer hosting it. Each image has to be captured, compressed, and sent over, at times in an encrypted way to all other attendees.

"Traffic tends to burst up to several hundred kilobits-per-second for several seconds whenever the screen being shown changes. As soon as the updates are sent, traffic returns back to near zero. Most Glance sessions average about 15 to 25 kbit/s, comparable to active web surfing. " (Glance FAQ)

The faster this can take place, the more in synch the attendees will be with what the presenter is actually seeing. When the Internet connection is slow (below 56Kbps), attendees will have to wait a long time before their screen is refreshed and may miss part of the "action", if the presenter is pointing to different objects or drawing live on the screen.

To counter some of the issues, the best solution providers in this area, have adopted, developed or refined advanced image compression techniques that would reduce to the smallest possible size the screen image to be sent over to each attendee.

To achieve this, most have been reducing screen images to 256 colors bitmaps which occupy only a fraction of the original image, with little loss in quality when the screen contains mostly text or simple graphics.

The other technique often implemented in higher end screen sharing solutions is the ability to control the frequency of the refresh, that is the frequency with which new screen shots are taken and sent over to the attendees. Being online events very different in nature, content and structure, it is a good idea to leave in the end of the final user the control of this fine options, rather than standardizing in one standard compromised solution that should fit all.

The ability for the presenter to control such settings (color depth and refresh rate) is a valuable addition to anyone such tool. Arguments resisting this in favour of simplicity have little ground to stand on as this is a feature that can be easily tucked away inside the Preferences menu or in any other "not-in-the-face" area of the interface.

Due to the long delays typical of screen sharing sessions done on poor quality Internet lines, presenters are further frustrated by the fact that they can't tell when the other attendees have effectively finished receiving a page.

Though not part of our event tomorrow, a special mention must go to Polycom which has long pioneered in its rich WebOffice conferencing solution, a visual system that informs the presenter of when each attendee has in fact finished receiving a certain content screen. The Polycom WebOffice is also capable of reporting to the presenter which attendees do not have their "focus" on the presenter window, but have wondered off into some of their local documents or applications.

"A useful colored light indicator next to each participant's name allows to monitor whether participants have been able to sync up with the application to be shared. When the light is red, the user has not yet synched up and cannot see what the presenter is showing. A yellow light means that the participant is about to synch up. A green light indicates the ideal situation: the participant can perfectly see everything the presenter is doing with the shared application."

(from Robin Good's Official Guide To Web Conferencing)

Outstanding.

Another issue when doing screen sharing can be sometimes the incompatibility between the presenter screen size and the attendees one. If for example the presenter has a her monitor set at 1024x768 resolution, but one of the attendees has his monitor set at 800x600, this last person will not see the full screen being shared, but will have to use his scroll bars to access the outmost right and bottom parts of the screens being shown.

To compensate for this possible problem the best thing a presenter can do is to set her screen resolution to a moderate resolution (800x600 or 1024x768 at the most) to ensure that 99% of the participants will be able to see in full each screen being shared).

Important factors in the selection of a screen sharing solution maybe security and the ability to encrypt sessions. Though this will not be an area we will be specifically reviewing tomorrow, there are sharp differences between the tools showcased in terms of security features.

Remote control / full application sharing is another feature that many of the screen sharing systems integrate. This functionality allows one or more people to work live on the same document or for one person to take full remote control of another person keyboard and mouse.

The complement of text chat, VoIP, and annotation tools remain the most useful optional additions to this type of facility.

Though many vendors still tout screen sharing as a presentation or web touring facility, this is really not the case at all. Screen sharing is essential for demonstrating software and online systems to remote people, for remote assistance, troubleshooting, technical assistance, marketing and training of software products.

For presentations other solutions are significantly more effective both in terms of quality, performance and ability to sync-in participants.

For Web touring or co-browsing, a basic system that broadcasts URLs instead of full pages is much more efficient and capable to support many different types of systems. Though co-browsing as such does not allow co-scrolling of the visited Web pages, it is more than sufficient for most applications.

To find out more, pose all of your live questions, and to see which ones I think are the most interesting and technologies in this area, sign-up now for tomorrow live event at Kolabora Live!.

Registration is here:
http://www.kolabora.com/events/buyersreview/registration.htm

The event is sponsored by:

iVocalize - http://www.iVocalize.com

Thinkofit - http://www.thinkofit.com/

Voxwire - http://www.voxwire.com/