One of the key components of the new Sirius FM-5 satellite, which was just recently put into service, is the satellite's massive advanced antenna reflector made by Harris.The concept of focusing the Sirius FM-5 signal on areas of peak population (like metropolitan areas on the east and west coast) is a significant departure from the satellite radio provider's satellite constellation. And it's the unfurlable antenna reflector (pictured above - click on the photo to see a big version) that makes this possible.
The Sirius FM-5 satellite featuress an S-band payload and the Harris antenna reflector makes it possible for the satellite to focus the 2 GHz S-band signals on the U.S.
The reflector features a Harris-patented, gold-plated mesh reflective surface coupled with a specific design used by Harris that maximizes antenna gain and provides the improved performance required for mobile, media services while reducing stowed volume and antenna mass.
During launch, the Harris reflector was stowed onboard the satellite - pretty much like an umbrella. Once on orbit, Space Systems/Loral controllers executed a series of maneuvers to deploy an articulating boom (also made by Harris) and then unfurl the reflector.
Harris actually has been in the mesh reflector business for over 30 years, and has over forty such reflectors already in orbit. They've worked with SS/L in the past, and this is yet another of a Harris reflector in a commercial application.
Please focus the reflector at Connecticut. My signal continues to clip out. FM-5 doesn't seem to improve much in Northeast.
Still no improvement in my car in the Washington, DC area. Sirius reception here is TERRIBLE relative to XM.
Also they still haven't told us how FM-5 fits into the system. What's the big secret?
Does that mean that Sirius will stop crapping out every time you go under an overpass or gas station/bank roof?
Highly effective for blocking out those annoying college interns on THE MORNING MASHUP show. God help me if I miss a moment of them laughing at each other's stale humor.
Nothing new on that front - when have they ever told us anything? There is virtually no communication between management and the subscribers, and everything they do is shrouded in secrecy. All this does is create uncertainty, which adversly affects the sub rate and the stock price. Is it any wonder why so many people are skeptical about Sirius/XM? The company does nothing to foster confidence and a positive image; in this country, image is everything. They need to reinvent themselves with three things: very good customer service, actually market the service, and program the music the way the subscribers want it - not how their lame programmers want it.
RP, I have to disagree with you. I'm in the Northeast (about 30 miles West of NYC) and I used to have constant signal loses when using my unit in my house. The antenna is on the Southern side of my house (only place I could easily locate it) and now I have no signal loses at all anymore. I have to think it's due to the new satellite.
Rumor has it, this antenna will be used to beam the Howard Stern show only, since the majority of subscribers only listen to that channel. It has also been rumored that it will block all attempts to listen to the Oprah channel, but nobody will really notice.
Can I have some dry oatmeal?
XM's platform is much more flexible. Each XM satellite has two dishes: one dish focused on the East Coast and one on the West Coast. Both dishes cover the entire USA, but each has a better signal for East and West coast.
Combined this with the two satellites you have an extremely robust signal for XM. Unfortunately for XM each bird is low in the sky for most customers. Since all the money is in the license, I'm hoping XM will eventually replace this Sirius bird with an XM bird, too, because the XM platform has twice the signal diversity of the Sirius platform and placing one of the XM birds at 95-degrees can only help and reduce the number of repeaters required for XM.
I have to say that reducing the number of signals broadast by the Molniya birds is going to hurt mobile users. They've reduced signal diversity significantly by deploying a low-in-the-sky Radiosat-5 and only using one of the "figure-8" Molniya satellites instead of two.
Keep making mistakes, Sirius.
It won't matter soon, anyway.
Aegrotatio: I agree with you about what they probably did. I really can't figure out any other reasonable plan. But I hope we are both wrong. As you note that really hurts (not helps) reception for many people.
Some have suggested that FM-5 is simply fired up on the repeater frequency. I have my doubts about that. In addition to interfering with the repeater signals, I believe they are using COFDOM for the repeaters while the sats are using straight QPSK. While COFDOM seems to me to be the natural choice for repeaters, I don't know of anyone else who ever tried it from a satellite and it seems to me like that would be a really expensive mess.
Is your post your own speculation or do you have some information to support it?
thanks
Pinball Wizard: I have based my speculation on my reading of annual reports, patent filings, FCC filings, white papers, and other sundry material about the satellites on both XM and Sirius and how they're designed and configured.
They are definitely not using the repeater frequencies for the new FM-5 bird and it's certainly not using COFDM for a satellite link.
I agree with you and will expand upon your comment: the Sirius platform as a whole has been a really expensive mess. It took over 8 months to get it to work at all which is what delayed the Sirius roll-out to Winter 2001-2002.
I agree with your comments about the quality of the XM signal. I'm in the Midwest, rarely in range of any terrestrial repeaters, and reception is almost always good enough to be a non-issue. I get XM in most rooms of my house without putting an antenna near a window, and in the car it works everywhere except in places where it never could, such as on a low level of a parking garage with no view to outside. Heavy tree cover virtually never causes a problem; occasionally it'll cut out for a few seconds if I'm driving between two tall buildings.
A friend who lives here had to change from XM to Sirius when he traded to a different make of car, and he says reception on Sirius is nowhere near as good.
Still very little change here in so calif riverside county, Corona Calif Still the same issues as before. Hell of alot of money for nothing. Thanks
Aegrotatio, your ignorance on the subject is substantial as evidenced by your unconvincing attempt to portray yourself as having a competent understanding of the RF engineering principals that determine the performance of the two different systems.
XM's supposed "superior" reception comes from the fact that it has inferior satellite coverage, and that in turn required them to deploy many times more terrestrial repeaters compared to Sirius. Based satellite reception alone, Sirius has a superior reception, but because of XM's inferior satellite coverage, they are essentially a huge very powerful terrestrial broadcaster, and when you combine XM's extensive terrestrial repeater coverage with it's inferior satellite coverage, overall it provides many XM customers better reception than what Sirius provides... which comes largely from their satellites alone.
PMcC's attempt to legitimize his own self by disparaging another is only eclipsed by his own total lack of understanding. Nothing in your post talks about anything except the look-angles of the satellites of both systems and the number of repeaters based on something you heard about on the internet.
If you had, and I doubt you ever, gone into areas with zero repeater coverage like rural New York you would not have posted your fallacious and inflammatory statement. The idea that XM is a terrestrial network with satellite spot-fillers and Sirius is the opposite flies in the face of user experience which has demonstrated that XM's platform is far superior.
In fact, the split 4 MHz ensemble broadcast from XM's satellites, compared to the large single 4 MHz ensemble of Sirius, allows for higher effective radiated power and tuner sensitivity that is much higher than Sirius simply based on RF theory and practice. Furthermore, the two-signal solution that XM uses allows the radios to use half the power while working more aggressively on forward error correction on only 2 MHz of signal as opposed to the massively wide 4 MHz of signal on Sirius.
PmCC, you are clueless, and nothing you have stated refutes any of my facts.