IS-21 will shortly replace IS-9. GEONETCast is broadcast on IS-9 over a C-band transponder. This transition is not expected to affect operations, nor will users need to alter station equipment or re-point dish antenna. In day-to-day operations, this transition is likely to go unnoticed by most users, and it will likely occur sometime in the 4th quarter of 2012 or early 2013.
IS-21 brings some exciting benefits to GEONETCast Americas. First, as depicted in the C-band coverage map, the signal strength is better than with IS-9 in existing coverage areas. In comparison to IS-9, the coverage area of IS-21 also extends somewhat. For existing ground stations this could mean a better quality signal. For stations that were planned in the more eastern reaches of the Caribbean or South America, the likelihood of getting a signal lock is improved.
The improved signal strength may allow some GEONETCast Americas users to setup ground stations with 1.8 meter receive dishes, as opposed to the 2.4 meter dishes currently in use. This may not seem like a huge improvement in dish size, but a 1.8 meter dish is significantly more manageable and easier to deal with logistically than a 2.4 meter dish.
IEPAS plans to test a 1.8 meter dish on IS-9, and then once the switch over to IS-21 occurs, it will conduct a comparison test. Results and a prospectus on the use of 1.8 meter dishes for GEONETCast Americas will be posted later this year.