Like Voice over IP, (telephone calls over the internet) Videoconferencing over the Internet is rapidly replacing video calls that used to require digital (ISDN) phone lines. We have now accumulated several hundred hours of experience of IP videoconferencing, and have a couple of recommendations for trying things out.
For point-to-point connections between two sites, the D-Link DVC1000 at $185.00 from Amazon recommends itself. Quality control is still very much an issue for the hardware. When it works, however, it provides suprisingly good media quality, both with sound and video.
The D-Link can also be used for multi-point conferences.
The advantage of the D-Link is that it doesn’t require a personal computer to use, it interfaces with an ordinary TV and is operated using a simple remote control. If it is any consolation, they have a solid return program, so that if you do need to return a unit, the process is fairly straightforward.
For a PC-based system, the Polycom PVX software is $149.00 list, price. ($114 discounted) works with a web cam, like the Logitech Orbit. ($129.00). This unit is fully compatible with other Polycom equipment, and includes the ability to control remote cameras, and share data with other Polycom units.
For multi-point conferences, with n > 2 participants, you need to have an aggregator device, known as a multi-point control unit. The Polycom Viewstation EX with a multi-point add-on option allows for 3 simultaneous connections, and also serves as its own origination unit…bringing a theoretical number of simultanous connections to 4. We paid abou $7,000 for our unit.
We have been very impressed with a new MCU from Codian. We are using a 4200, with capacity for 12 participants. So far we’ve loaded it with 8 participants. This is a professional grade unit, with a professional price, around $30,000.
Connections require a broadband internet connection, such as DSL or cable. At the aggrator end, the connection needs to be able to accomodate the streams for all the simultaneous connections. We have our end points set at a low 256Kb inbound and outbound, which is well within the bandwidth of even a low-end home broadband connections. With 3 participants connecting to a Viewstation, a T-1 at the Viewstation end (1.5 megabits) seems to work well.
As soon as you get into multi-point, things sound expensive. There are, however, several applications which suggest themselves for this kind of hardware:
- Support groups
- Group therapy and exercise
- “Check-in” with home-bound patients
- Chronic disease management
- Family literacy
- Distance learning
Currently (June ‘05) we are running the second of two 15 week 3 times/week classes of exercise for seniors who have fallen or have a fear of falling. Our first group had six participants, and our second group now has 10.