Satellite Space Segment
Orbital Media Networks has worked many years with satellite operators, like SES, to find the right mix of their fleet that will accommodate our customer base. We have committed to making sure your investment is protected with both satellite and transponder protected satellites, while providing the best possible price in the industry. We have strategically selected satellites that are located in prime locations that meet the needs of most end users.
Top 5 things you need to ask when looking for satellite space segment.
- What satellite band do you plan on using?
- C-Band. Requires a much larger antenna on both the Transmit and Receive side. It can range anywhere from 3 Meter on up. Rain fade is less likely, compared to the all other bands. Space segment is more available which translate to lower monthly reoccurring cost.
- Ku Band. You can use much smaller antennas on both Transmit and Receive. It can range from .75 Meter on up. Rain fade can occur in adverse weather. Space segment is in higher demand, which means slightly higher monthly reoccurring cost, compared to C-Band.
- What satellite location does your customer see?
- The middle of the arc is the prime location for end users since it can be seen from coast to coast. End users are sometimes limited on the number of antennas they can have at their facility or the look angle based on their location. You can determine look angle by clicking HERE.
- Does the satellite have transponder protection?
- If your service has this protection, your transponder can not be preempted to restore another transponder. If you don’t have this level of protection, you run the risk of being asked to move your service.
- Does the satellite have protection for the entire satellite?
- If your service has this protection, your satellite can not be preempted to restore another satellite. If you don’t have this level of protection, you run the risk of being asked to move your service.
- Is your service preemptible?
- Preemptible space segment usually has a lower monthly reoccurring cost; however it has a much higher risk of being taken over by clients that have fully protected services. This may be good for special events, not for long term obligations.
Glossary of Satellite Terms
Amplifier – A device used to boost the strength of an electronic signal.
Availability – The amount of time (generally expressed as a percentage) that a satellite signal is above threshold at a given downlink location, on overage. Also expressed as 99.9% (“three nine” availability) or as 99.99%(‘four nine” availability). Downtime is due to rain outage per site per year on average over 5 years. (99.9% = 8 hours and 53 minutes outage per year.)
Azimuth – The angle of rotation (horizontal) that a ground based parabolic antenna must be rotated through to point to a specific satellite in a geosynchronous orbit. The azimuth angle for any particular satellite can be determined for any point on the surface of the earth giver the latitude and longitude of that point. It is defined with respect to due north as a matter of easy convenience.
Backhaul – A terrestrial communications channel linking an earth station to a local switching network or population center.
Bandwidth – A measure of spectrum (frequency) use or capacity. For instance, a voice transmission by telephone requires a bandwidth of about 3000 cycles per second (3KHz). A TV channel occupies a bandwidth of 6 million cycles per second (6 MHz) in terrestrial Systems. In satellite based systems a larger bandwidth of 17.5 to 72 MHz is used to spread or “dither” the television signal in order to prevent interference.
Beacon – Low-power carrier transmitted by a satellite which supplies the controlling engineers on the ground with a means of monitoring telemetry data, tracking the satellite, or conducting propagation experiments. This tracking beacon is usually a horn or omni antenna.
Block Down Converter – A device used to convert the 3.7 to 4.2 KHz signal down to UHF or lower frequencies (1 GHz and lower).
Block up-converter (BUC) – Is used in the transmission (uplink) of satellite signals. It converts a band (or “block”) of frequencies from a lower frequency to a higher frequency. Modern BUCs convert from the L band to Ku band, C band and Ka band. Older BUCs convert from the 70 MHz band to Ku band or C band.
C Band – This is the band between 4 and 8 GHz with the 6 and 4 GHz band being used for satellite communications. Specifically, the 3.7 to 4.2 GHz satellite communication band is used as the down link frequencies in tandem with the 5.925 to 6,425 GHz band that serves as the uplink.
Carrier Frequency – The main frequency on which a voice, data, or video signal is sent. Microwave and satellite communications transmitters operate in the band from 1 to 14 GHz (a GHz is one billion cycles per second).
Conus – Contiguous United States. In short, all the states in the U.S. except Hawaii and Alaska.
DBS – Direct broadcast satellite. Refers to service that uses satellites to broadcast multiple channels of television programming directly to home mounted small-dish antennas.
dBW – The ratio of the power to one Watt expressed in decibels.
Down-Converter – That portion of the Fixed Satellite Service (FSS) television receiver that converts the signals from the 4-GHz microwave range to (typically) the more readily used baseband or intermediate frequency (IF) 70-MHz range.
EIRP – Effective Isotropic Radiated Power – This term describes the strength of the signal leaving the satellite antenna or the transmitting earth station antenna, and is used in determining the C/N and S/N. The transmit power value in units of dBW is expressed by the product of the transponder output power and the gain of the satellite transmit antenna.
Footprint – A map of the signal strength showing the EIRP contours of equal signal strengths as they cover the earth’s surface. Different satellite transponders on the same satellite will often have different footprints of the signal strength. The accuracy of EIRP footprints or contour data can improve with the operational age of the satellite. The actual EIRP levels of the satellite, however, tends to decrease slowly as the spacecraft ages.
Geostationary – Refers to a geosynchronous satellite angle with zero inclination. so the satellite appears to hover over one spot on the earth’s equator.
G/T – A figure of merit of an antenna and low noise amplifier combination expressed in dB. “G” is the net gain of the system and “T” is the noise temperature of the system. The higher the number, the better the system.
Ku Band – The frequency range from 10.9 to 17 GHz.
L-Band – The frequency range from 0.5 to 1.5 GHz. Also used to refer to the 950 to 1450MHz used for mobile communications.
Low Noise Block Downconverter (LNB) – A combination Low Noise Amplifier and downconverter built into one device attached to the feed.
Margin – The amount of signal in dB by which the satellite system exceeds the minimum levels required for operation.
MCPC – Multiple Channels Per Carrier
Noise – Any unwanted and unmodulated energy that is always present to some extent within any signal
Polarization – A technique used by the satellite designer to increase the capacity of the satellite transmission channels by reusing the satellite transponder frequencies. In linear cross polarization schemes, half of the transponders beam their signals to earth in a vertically polarized mode; the other half horizontally polarize their down links. Although the two sets of frequencies overlap, they are 90 degree out of phase, and will not interfere with each other. To successfully receive and decode these signals on earth, the earth station must be outfitted with a properly polarized feedhorn to select the vertically or horizontally polarized signals as desired.
In some installations, the feedhorn has the capability of receiving the vertical and horizontal transponder signals simultaneously, and routing them into separate LNAs for delivery to two or more satellite television receivers. Unlike most domestic satellites, the Intelsat series use a technique known as left-hand and right-hand circular polarization.
Protected-Use Transponder – A satellite transponder provided by the common carrier to a programmer with a built-in insurance policy. If the protected-use transponder fails, the common carrier guarantees the programmer that it will switch over to another transponder, sometimes pre-empting some other non-protected programmer from the other transponder.
QPSK – Quadrature Phase Shift Keying is a digital modulation technique in which the carrier phase can have one of four possible values of 0, 90, 180, 270 degrees on the equivalent of a 90 degrree rotation. There are even more advanced concepts based upon 8-phase (45 degree rotation), 16 phase (22.5 degree rotation) and so on to 32 phase, etc.
Rain Outage – Loss of signal at Ku or Ka Band frequencies due to absorption and increased sky-noise temperature caused by heavy rainfall.
Single-Channel-Per-Carrier (SCPC) – A method used to transmit a large number of signals over a single satellite transponder.
Solar Outage – Solar outages occur when an antenna is looking at a satellite, and the sun passes behind or near the satellite and within the field of view of the antenna. This field of view is usually wider than the beamwidth. Solar outages can be exactly predicted as to the timing for each site.
Spread Spectrum – The transmission of a signal using a much wider bandwidth and power than would normally be required. Spread spectrum also involves the use of narrower signals that are frequency hopped through various parts of the transponder. Both techniques produce low levels of interference Between the users. They also provide security in that the signals appear as though they were random noise to unauthorized earth stations. Both military and civil satellite applications have developed for spread spectrum transmissions.
SSPA – Solid state power amplifier. A VSLI solid state device that is gradually replacing Traveling Wave Tubes in satellite communications systems because they are lighter weight and are more reliable.
Transponder – A combination receiver, frequency converter, and transmitter package, physically part of a communications satellite. Transponders have a typical output of five to ten watts, operate over a frequency band with a 36 to 72 megahertz bandwidth in the L, C, Ku, and sometimes Ka Bands or in effect typically in the microwave spectrum, except for mobile satellite communications. Communications satellites typically have between 12 and 24 onboard transponders although the INTELSAT VI at the extreme end has 50.
VSAT – Very small aperture terminal. Refers to small earth stations, usually in the 1.2 to 2.4 meter range. Small aperture terminals under 0.5 meters are sometimes referred to Ultra Small Aperture Terminals (USAT’s)