This section contains information to help you sort out local roles and responsibilities and help you plan in more detail. As time passes, you may find yourself hosting more complex meetings which require re more information; hopefully, you'll find it here.
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Copyright 1996, Dr. Albert E. Powell, Jr.
Assistant Director, Distance Learning Development
Colorado State University, Fort Collins, CO 80523-1040
Video teleconference downlink site costs - possible items:
Event Coordinator:
This person has overall responsibility for the receive site. They
make sure the physical arrangements are correct and the teleconference
works technically. This also means making sure any handouts are ready and
equipment for local speakers or activities (slide projectors, tables, flip
charts) are in place. They decide what additional jobs are involved in
a specific teleconference and make arrangements for additional staff, speakers
and support people to make the event work.
The event coordinator works with people at the local and national level. Locally, they handle the viewing audience, the facilitator (if any) and the meeting setup. Nationally, they are the contact to the teleconference producers.
Site Host/Facilitator:
This person is in charge of getting people settled in, running the
meeting, directing traffic, and either handling the content or introducing
those who will. This position is the official "greeter" and point person
for the event itself. If the Event Coordinator doesn't confirm the speakers
and handle the contacts with them, the Site Host does it.
Satellite & Video Equipment Operator:
This person sets up, runs the equipment, and handles any equipment
problems. This should not be taken on by the site coordinator, since they
can't handle the audience and solve technical problems at the same time.
Make sure there is a competent operator present to handle any last-minute
satellite tuning, record the program, or handle problems with the PA system,
video monitors or projector.
Local Speaker/Subject Matter Expert:
The Site Host may do this or there may be additional speakers, depending
on the event. The Site Host makes the arrangements, confirms time and date,
and makes sure any speakers are there. Local speakers often serve as facilitators;
otherwise, the Site Host usually facilitates the meeting. Local speakers
should be asked well ahead of time whether they need any support equipment
or special room arrangements!
Activity Leader(s):
These people may be required if you break into groups, have workshops,
etc. It depends on the event.
Caterer - Janitor - Security - Parking:
These are all obvious; just don't forget to arrange for them if
you need them.
Don't forget that people need to make business calls before, during and after a conference. Have at least one phone available for this if it's at all possible; if not, know where the closest phone is, even if it's next door, and tell your audience where to find it.
Many teleconferences use fax machines to handle Q&A or to send in reports or evaluations. Find out if you need a fax machine in order to participate, and remember that you can often borrow them or rent them on a short-term basis.
Fifty people can easily view two well-positioned 25 inch TV sets. TV monitors have advantages: they're easy to borrow or rent, they're portable, and they tolerate reasonably high light levels in the room. However, large monitors are heavy to elevate high enough for good sight lines, and you have to string cables to each monitor. (Obviously, to avoid accidents, all cables must be taped down and the monitors must be secured against falling over if they're bumped.)
Smart site hosts use video projectors when they have more than 50 people attending. Most projectors provide a viewing area of 100-plus diagonal inches, which is impressive to the viewers and gives you a safety factor if extra people show up. However, if you don't own a projector, they're expensive to rent and take time to set up. They also require good light control in the room, because high light levels wash out their image. If it's too bright in the room for slides, it's too bright for a video projector.
Remember that monitors and video projectors have tiny little speakers, if any. If you have more than 50 people attending, always test the audio to see if you need a separate room PA system. It's very common for built-in speakers not to generate enough volume for the larger audiences.
Viewing Distance:
The best distance for viewing is no closer than twice the screen size, and no farther away than eight times the screen size. Video projectors really look terrible if you get too close; the scan lines or pixels in their picture become too visible and distracting. Test your seating setup with a videotape and look for scan lines which are too visible from the front seats.
Viewing problems with monitors are just the opposite; people usually can't get too close to monitors, but they may be too far away. Play a videotape and sit in the back row of seats to make sure viewers aren't too far away from your monitors.
You must maintain good lines of sight from all seats to your TV or projector screen. After you're set up, walk around the room and check it out. You may have to elevate the monitors or projector screen.
Monitor and Screen Placement:
Most people automatically put video display equipment front and center in the room. This can be OK, as long as you have a large screen and it's high enough to provide a clear line of sight to all viewers. But if you have pillars in the room or an unusual room layout, it may not work.
Alternative screen placements:
If you're using a video projector, try placing the screen off-center to one side, or diagonally across a front corner of the room. You can then do your introductions and run the event from the center of the room or from the opposite corner.
If you're using two monitors, position them in the front (left and right) corners of the room at slight angles, and put your site host in the center of the room. This diagonal screen placement gives the audience two options for viewing and avoids limiting viewers to a single line of sight.
If you have a long, narrow room, if you must seat people in numerous short rows, try placing one monitor in front, and another about half-way toward the back of the room, along one wall. You can also set up the seats with rows running the wide direction, and put one monitor in front of each half of the room (left and right).
Pictures and Sound:
Adjust your TV monitors or video projector so they look good under the actual lighting conditions (bright or dark) you will have during the program. If there's no other reference, play a videotape and adjust the color so skin tones look natural.
Preset the audio levels on your monitors or the PA system. Remember, it takes more volume for the sounds to be audible when the room is full of people. Once people are seated, walk to the back of the room to make sure the audio is loud enough and adjust as needed.
If you plan to videotape the program, make a quick (30 seconds or so) test recording during the test signal and play it back to make sure the recorder works and is recording the correct signal and sound.
Have telephones available for handling any technical problems and for call-in Q&A, and check your telephone to make sure it works! If the participants can call in questions, make sure you can dial the necessary long distance or toll free number from your telephone.
Now, the good news: after the downlink has been installed and used at a given site, you can be pretty sure that basic problems have already been dealt with. Just to give you something to worry about, here are things which can still go wrong:
Outdated Receiver Programming:
Every now and then, some satellites are actually moved in the sky,
new satellites also go up every year, while some satellites go out of service.
Downlink receivers must be re-programmed at least once a year to keep up.
If the receiver's program is outdated, it may not be able to locate a new
satellite, or may think one is still in the sky when it has gone out of
service. Nothing can compensate for this except making sure you have seen
a program coming from the actual satellite which will be used.
Terrestrial Interference:
Powerful electrical or microwave systems near a downlink can interfere
with C-band satellite signals, creating lots of "sparklies" in the video.
The highest potential for problems exists if you have to bring in a portable
downlink for a meeting. Don't just assume the site is OK; test it, especially
in urban areas. There may be a source of electrical or microwave interference
nearby. In most cases, local satellite installers have reference charts
which can tell you if there's a problem with neighborhood X or at hotel
Y. If not, before you spend the money to bring in a downlink, have a satellite
installer do a site survey in which the receive site is checked for possible
interference.
Rain Attenuation:
Heavy local rains can sometimes interfere with receiving a Ku-band
signal. The result will be similar to that of terrestrial interference
problems on C band, creating lots of "sparklies" in the picture. A heavy
downpour or thunderstorm can wipe out the signal completely. The good news
is that this much interference requires a real gully-washer, and such intense
rain rarely lasts longer than a few minutes.
Snow on the Downlink:
A build up of snow or ice on your dish can interfere with signal
reception. Remove snow with a soft broom. Since accurate curvature of the
dish is vital for a good signal, don't bang or hit the dish! If you need
a ladder to brush the snow off, don't lean it on the dish, because this
may warp the dish or move it off the satellite. Be gentle as you brush,
and try not to move the dish. If ice builds up, do not bang on it to break
it off. About your only option is to melt it off with warm water or some
other heat source, depending on your creativity. Use some common sense
and don't damage anything!
High Winds:
A downlink dish makes a big target, and it may move in high winds.
If the dish has a good, solid mount you should be able to set it and leave
it during a program. If the mount flexes and the wind stays high, you may
have to live with varying reception and re-tune during the program.
Origination Problems:
If the problem seems to be in the incoming program, first look at
other transponders on the same satellite. If you are not receiving a clear
signal on your channel but others are OK, call the trouble number you should
have for the event. If the other channels are bad too, re-tune your downlink,
because it has probably shifted position slightly.
Equipment Gremlins:
These are wee folk who creep into equipment and cause problems for
those of us who don't plan ahead. Unfortunately, they also play jokes on
those who do plan ahead! They like to do things like cause power outages
at the program's origination point, or make circuit breakers trip. Try
to maintain your sense of humor and perspective at all times, because sooner
or later, you'll be tested.
ARC - Satellites orbit the earth so that they are motionless as perceived from the ground. All satellites are positioned left-to-right in a continuous arc which stretches between horizons. This arc positioning is the reason that changing satellites only requires moving the dish antenna left to right, not up and down. (Also see AZIMUTH, below.)
AUDIO BRIDGE - An audio bridge connects telephones at multiple remote sites, for a live audio teleconference. Sometimes used to have multiple callers on-line during a satellite teleconference.
AUDIO SUBCARRIER - A signal with audio which accompanies the video signal.
AUDIO TELECONFERENCING - Two-way voice-only communication between people in separate locations.
AZIMUTH - The east-west arc in the sky where satellites are located. Satellite positions are actually expressed in degrees east or west, but this information is usually only helpful to technicians. (Also see ARC, above.)
DECODER - Device that reconstructs or "unscrambles" an encrypted signal.
DISH - The parabolic antenna that is the largest and most recognizable element of a satellite earth station or downlink.
DOWNLINK - A satellite receiving station, also referred to as a TVRO (television receive only).
ECHO - A common effect noticed by people calling into a satellite teleconference. Their voice will be heard in the satellite program about one-half second after they speak, making it hard for them to concentrate. The cause is delay occurring when the uplink signal travels over 22,000 miles up to a satellite, and returns the same distance to the earth. The best solution is turn the program audio down slightly so the caller is less distracted.
ELEVATION - A satellite's altitude above the horizon, measured in degrees.
ENCODER - A device that electronically modifies (encrypts) a signal so that it can be clearly seen only by viewers using a decoder set to reverse the encryption process.
ENCRYPTION - The process of electronically altering or "scrambling" a signal. Encryption is usually used as a security method for commercial satellite transmissions; not generally used in educational programs.
FEEDBACK - Squeal caused by a microphone being too close to an operating loudspeaker. Feedback can occur when calling in to a satellite conference using a telephone inside a room containing a TV or PA system with the volume turned up high. Solution: turn down the TV or PA, or move the phone farther away from the speakers.
FOOTPRINT - Area of the earth covered by a satellite transmission beam. Inside this footprint, the satellite transmission can be viewed.
FREQUENCY - Each satellite signal is uplinked at a specific radio frequency, hits a satellite which then send it back to earth at a slightly different frequency. In many cases, you need to tune in the program by downlink frequency in case the channels in your receiver are set at different frequencies than the ones in use on the satellite you're watching.
GEOSTATIONARY ORBIT - An orbit roughly 22,300 miles above the earth. A satellite in geostationary orbit revolves around the Earth at the same speed the earth rotates, once every 24 hours. In practical terms, this keeps the satellite in one fixed location relative to the ground.
MICROWAVE - A band of radio frequencies used to relay telephone, radio or TV signals across the earth's surface. Microwave transmissions passing near a downlink can create interference in C-band satellite programs.
MODULATOR - A device which converts the video signal and audio signal onto a viewable TV channel. Its correct name is "RF Modulator", meaning "Radio Frequency Modulator".
POLARIZATION or POLARITY - Many satellite transponders can carry two channels at once; some are vertically and some are horizontally polarized. On C-band satellites, channels alternate horizontal and vertical polatiry; if 1 is horizontal, 2 will be vertical, etc. Ku-band satellites are not as predictable. If you are having a problem receiving a feed, try changing your receiver's polarity!
RADIO FREQUENCY - All radio, TV, satellite and similar signals occupy positions on the radio frequency band. The term Radio Freqency is often abbreviated as "RF".
RAIN ATTENUATION - When extremely heavy rains take place over a receiving site, Ku-band signals can be partially blocked by the raindrops. This results in a poor or unviewable signal until the rain abates.
RF MODULATOR - See MODULATOR, above.
SATELLITE - An electronic device which orbits the earth at such a speed that it is stationary relative to the ground. It receives date, video and audio signals broadcast upwards from the earth, re-amplifies the signal(s), and transmits them back downward to cover a large area on the earth. Using it requires an earth uplink to transmit signals and downlinks to receive the signals at ground locations. Often called a "bird." (See also: GEOSTATIONARY ORBIT, above.)
SCRAMBLING - See ENCRYPTION, above.
SUBCARRIER - A signal which is transmitted along with the main video signal carrier. Subcarriers can transmit data, color picture information or audio.
TERRESTRIAL INTERFERENCE (TI) - Microwave or electrical interference from a terrestrial (earth) source which creates problems in receiving a clear program signal at the downlink. Persistent TI problems at a site indicate a need to identify the source of the problem and find a permanent solution.
TRANSPONDER - There are from 12 or more transponders on each satellite. Some carry only one signal, some can carry two or more. A transponder receives a signal coming from an uplink, converts it to a new frequency, amplifies it and sends the signal back to earth.
UPLINK - A large dish- shaped antenna fed by high-power amplifiers. The uplink is like the transmitter of a radio or television station, but it concentrates its signal in one direction using a parabolic dish antenna. This delivers a strong signal to a specific satellite in space.
VIDEO PROJECTOR - Device which takes the signal from a satellite receiver, video tape deck or other source, and projects the video image onto a screen or wall. Similar in function to a slide or film projector. Recommended when displaying video images to more than 50 people.
WRAP AROUND - Local activities before, during or after a video teleconference. These help focus viewers on the intended outcomes and ideas, or provide additional information or hands-on training.