SUIRG's Uplink...Downlink - Second Quarter 2008

Letter from the President

Welcome to SUIRG's latest newsletter. The past few months have been very busy for us with WiMAX issues, especially for our web site where the number of hits per month has reached an all time high of 50,000, double our previous high, mostly due to the interest in the WiMAX/FSS compatibility testing SUIRG performed late last year and reported in the last newsletter. Even though the test report has been published and the WRC meeting has concluded, SUIRG is working closely with other organizations such as the Global VSAT Forum (GVF) to educate countries planning to implement WiMAX systems despite the ITU Recommendations and the potential impact to satellite operations.

This month, the newsletter addresses the huge cost of interference and how it affects the satellite industry's bottom line at multiple levels including lost revenue, additional labor and monitoring equipment which all ripples down to the end user where it manifests itself into higher tariffs, additional labor and lost service or poor quality of service.

Our organization continues to grow as more and more corporations recognize SUIRG's contribution to the satellite industry. In that regard, I am happy to add GASCOM, an operator from Russia to our organization. More on them later.

Finally, we're happy to announce the date for SUIRG's annual Interference Conference. Mark your calendar, clear your schedule and plan on joining the SUIRG management team and SUIRG members for an informative and enjoyable three days in Cairo, Egypt on 7-9 October. The 2008 conference is being co-hosted by SUIRG member NileSat.

Robert Ames, President

Interference: Its Affect on Satellite Capacity Availability — and on the Corporate Bottom Line

By R. James Budden
Chairman of the Board, SUIRG

Satellite radio interference events can generally be categorized into five main groups:

1. Interference caused by system users

2. Interference caused by adjacent satellites

3. Interference caused by terrestrial services

4. Deliberate interference into services

5. Interference caused by modulation types in cross polarized transponders

1. User Interference

This is usually accidental due to operator error, equipment malfunction or poor cable shielding. The more concerning aspect, though less prevalent, is deliberate interference, designed to upset either the system operator or a system user. While these interference types are usually relatively easy to find, it usually takes a disproportionate amount of the satellite operator's manpower and time to locate. Deliberate interference even, when identified as such, can be very problematic to remove.

2. Adjacent Satellite Interference

While generally accidental, interference by adjacent satellites is becoming more prevalent as two degree spacing between satellites in the geostationary arc becomes more common. The cause can usually be attributed to operator error or poor inter-system coordination with both parties seeking quick resolution. However, the time spent on locating and resolving the incident can result in the loss of useful spectrum and of revenue.

3. Terrestrial Interference

The problem of terrestrial interference spans existing terrestrial microwave systems, new microwave systems that have commenced service following deployment of the satellite, as well as civil or military radar systems. In general, terrestrial systems have priority resulting in dead capacity on the satellite. Terrestrial interference incidents are difficult to resolve. However experience shows that if proof of source can be indicated, the military is keen to remove the source if at all possible.

With recent attempts to open the lower portion of the C-band to Broadband Wireless Access (BWA) systems, terrestrial interference issues have received significant attention. Tests carried out by SUIRG in conjunction with other groups have demonstrated this to be a major issue in the near future for both satellite operators and ground system operators. Costs for this component of interference have not been accounted for in this model.

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