Digital Radio Central - Sponsored by TSS Radio
  DRC Home Page DRC Forums Contact Us  
 
SIRIUS Backstage Forum
 
 
 
  Sirius Satellite Radio XM Satellite Radio iTunes/iPod Slacker Pandora  
 
 
FAQ Members List Calendar Search Today's Posts Mark Forums Read  
Go Back   SIRIUS Backstage Forum > >
Visit Digital Radio Central

Notices

Galaxy Nation Explore the other side of the universe. Discuss AM/FM, XM, DISH, DirecTV, HD Radio, and all mp3 players. Here you can also discuss the ins and outs of tomorrow's radio technology...where music and satellites collide. Who said it's not rocket science?!?

 
 
Thread Tools Display Modes
 
 
Old 11-11-2006, 12:07 PM   #1
masonspencer
Just Tuned In
 
Join Date: Jul 26, 2006
Posts: 7
masonspencer is on a distinguished road
Default A little help on repeater info

Can anyone give me the total repeaters for Sirius and XM individually?
Thank You
masonspencer is offline  
 
 
Old 11-11-2006, 12:14 PM   #2
HomieG
Sirius Star
 
HomieG's Avatar
 
Join Date: Feb 06, 2006
Location: Somewhere in the USA
Posts: 1,431
HomieG is on a distinguished road
Default

I don't have the exact numbers. I believe XM is something like in the 700's or 900's, and Sirius is something in the 100's.
__________________
- Homie
Lifetime Sirius Subscriber

Originally Posted by atlwxman: "I love Sirius...but in my car, not in my portfolio."

Originally Posted by Andrew-NYC: "...Just make a radio that gets both services, and there will be no need for the merger!"


Current Sirius radios:
Brix Streamer Replay
XACT "Visor"
XACT XTR8 Replay
HomieG is offline  
 
 
Old 11-11-2006, 12:42 PM   #3
masonspencer
Just Tuned In
 
Join Date: Jul 26, 2006
Posts: 7
masonspencer is on a distinguished road
Default

I have heard 1500 for XM and as high as 8000.. I know sirius has a low number in the hundreds. Anybody who knows it would be greatly appreciated
masonspencer is offline  
 
 
Old 11-11-2006, 02:57 PM   #4
HomieG
Sirius Star
 
HomieG's Avatar
 
Join Date: Feb 06, 2006
Location: Somewhere in the USA
Posts: 1,431
HomieG is on a distinguished road
Default

Quote:
Originally Posted by masonspencer
I have heard 1500 for XM and as high as 8000.. I know sirius has a low number in the hundreds. Anybody who knows it would be greatly appreciated
I can say it definitely is not 8,000 for XM. My post above is the correct magnitude for both XM and Sirius.

Here's some additional recent info on XM. Note that it says they operate about 800 repeaters (2nd paragraph) and a handful of low power repeaters:
http://svartifoss2.fcc.gov/servlet/i...nt_key=-117677

And some additional recent info on Sirius. Note that is says 130 currently operational, with some more coming:
http://svartifoss2.fcc.gov/servlet/i...nt_key=-117714

"Sirius timely filed for renewal of this satellite radio service consists of 240 transmit sites, of which approximately 130 currently are operational, with 16 additional sites sought but not yet granted."


The reason for the difference is due to the different methods that XM and Sirius use for their satellite orbits, and the resultant coverage.
__________________
- Homie
Lifetime Sirius Subscriber

Originally Posted by atlwxman: "I love Sirius...but in my car, not in my portfolio."

Originally Posted by Andrew-NYC: "...Just make a radio that gets both services, and there will be no need for the merger!"


Current Sirius radios:
Brix Streamer Replay
XACT "Visor"
XACT XTR8 Replay

Last edited by HomieG; 11-11-2006 at 04:41 PM..
HomieG is offline  
 
 
Old 11-11-2006, 10:47 PM   #5
realwx
Banned
 
realwx's Avatar
 
Join Date: Dec 26, 2005
Location: Elkridge, MD
Posts: 2,554
realwx is on a distinguished road
Send a message via AIM to realwx Send a message via MSN to realwx A little help on repeater info
Default

Last I heard, 857 repeaters for XM and 141 for Sirius. The numbers may have changed, though.
realwx is offline  
 
 
Old 11-13-2006, 09:09 AM   #6
RoadClosed
Sirius Star
 
RoadClosed's Avatar
 
Join Date: Jun 17, 2005
Location: Estimating the Airspeed Velocity of an Unladen Swallow
Posts: 5,758
RoadClosed will become famous soon enoughRoadClosed will become famous soon enough
Default

Quote:
Last I heard, 857 repeaters for XM and 141 for Sirius. The numbers may have changed, though.
I had no idea XM had that many. And all the XM peeps "think" its better to have the sats in a geostationary orbit over the equater. And Sirius wants to put one there.
__________________
West of House
You are standing in an open field west of a white house, with a boarded front door.
There is a small mailbox here.


God does not believe in Athiests. Therefore they do not exist.
RoadClosed is offline  
 
 
Old 11-13-2006, 02:46 PM   #7
vo1one
Mixologist
 
Join Date: Dec 27, 2003
Location: Mount Pearl, Newfoundland, Canada
Posts: 336
vo1one is on a distinguished road
Default

Quote:
Originally Posted by RoadClosed
I had no idea XM had that many. And all the XM peeps "think" its better to have the sats in a geostationary orbit over the equater. And Sirius wants to put one there.
I don't mind that Sirius wants to add a geostationary sat. There are some advantages by adding one to the mix. For example, we would no longer have to lease a Ku transponder to feed the terrestrial repeaters. However, that would mean every repeater site would have to lose the Ku setup and add an S band receive setup and that would be quite pricey, but it would make up for itself in the long run. Another advantage would be pointing an antenna at home would be easier. I just don't see how Sirius could keep 2 Molniya satellites transmitting at the same time and add a geostationary satellite to that with their existing bandwidth. ~4MHz for 2 sats and another ~4MHz for terrestrial and that uses it all. I hope they don't plan on transmitting with one Molniya sat at a time. If that was the case, they'd probably have the satellites turn on once they enter the northern loop of the figure 8, and once the one leaves another arrives and there's the handoff instead of over the equator. This would mean that the satellites would go from 2/3 duty cycle to 1/3 duty cycle thus extending their life expectancy and the geostationary satellite would be running 100% all the time like XM's. An interesting concept now that I think about it, but how that'll affect our reception in vehicles where the overwhelming majority of subbed radios use the service, I'm not sure. Time will tell!
__________________
news:alt.radio.satellite - Usenet's Home for everything Satellite Radio
Ask your news server to carry it today!
vo1one is offline  
 
 
Old 11-13-2006, 04:52 PM   #8
realwx
Banned
 
realwx's Avatar
 
Join Date: Dec 26, 2005
Location: Elkridge, MD
Posts: 2,554
realwx is on a distinguished road
Send a message via AIM to realwx Send a message via MSN to realwx A little help on repeater info
Default

Count how many repeaters XM vs. Sirius:

www.liquid-sun.info/SiriusRepeater.kml
realwx is offline  
 
 
Old 11-14-2006, 12:48 AM   #9
Scorpion
Mixologist
 
Join Date: Nov 23, 2003
Posts: 255
Scorpion is on a distinguished road
Default

Quote:
Originally Posted by vo1one
I just don't see how Sirius could keep 2 Molniya satellites transmitting at the same time and add a geostationary satellite to that with their existing bandwidth.
You're right, only 2 satellites can broadcast at any time. From their filing with the FCC, it appears the geostationary satellite will broadcast only when those in elliptical orbits are just north of the equator. This implies they plan on the continued use of the leased VSAT downlink.

Decreasing the transmit duty cycle won't extend their useful in-orbit life. It's the fuel used for station keeping that's the primary limiting factor. Makes no difference if the transponders are on or off, the same amount of fuel will be used to maintain their assigned orbits. If you haven't ever noticed, the Sirius satellites and XM's have the same rated life expectancy.
Scorpion is offline  
 
 
Old 11-14-2006, 08:42 AM   #10
vo1one
Mixologist
 
Join Date: Dec 27, 2003
Location: Mount Pearl, Newfoundland, Canada
Posts: 336
vo1one is on a distinguished road
Default

Quote:
Originally Posted by Scorpion
You're right, only 2 satellites can broadcast at any time. From their filing with the FCC, it appears the geostationary satellite will broadcast only when those in elliptical orbits are just north of the equator. This implies they plan on the continued use of the leased VSAT downlink.
Do you have the link to that filing handy? If not, I'll just search for it.

As it stands now, there are always 2 Sirius sats north of the Equator turned on for 16 hours a piece, staggered by 8 hours each so I don't see where you are getting the opportunity to use that geostationary satellite from your explanation.

Quote:
Originally Posted by Scorpion
Decreasing the transmit duty cycle won't extend their useful in-orbit life. It's the fuel used for station keeping that's the primary limiting factor. Makes no difference if the transponders are on or off, the same amount of fuel will be used to maintain their assigned orbits. If you haven't ever noticed, the Sirius satellites and XM's have the same rated life expectancy.
Actually, I had read at one time that the EOL for XM's sats were 10 years but I've searched again and do indeed see 15 years, the same as Sirius. In amateur radio satellites, we're used to having cycling of the batteries be the limiting factor in life. One of our satellites, AO-7, which is 32 years old came back to life a few years ago after being dormant for 20 years when its batteries would no longer charge. The short that these dead batteries places across the solar panels eventually cleared thus allowing for daylight ops again. I'd say satellite radio should be quite able to handle inclined orbit operation since directionality of the receiving antennas isn't as critical (especially with Sirius) as it is in other commercial satellite situations.
__________________
news:alt.radio.satellite - Usenet's Home for everything Satellite Radio
Ask your news server to carry it today!
vo1one is offline  
 
 
Old 11-14-2006, 10:54 AM   #11
limegrass69
Rocket Scientist
A little help on repeater info
 
limegrass69's Avatar
 
Join Date: Dec 28, 2005
Location: Westchester County, NY
Posts: 621
limegrass69 will become famous soon enough
Default

I am sure there will be several uses for the new sat.

As posted earlier, the eliptical sats will turn off earlier as they set. Given the nice parking slot, I am sure Sirius will have other uses and users for the sat. They may bounce the Ku signal off that bird instead of paying rent somewhere else. Plus I am sure they'll lease out transponders to others.
__________________
Looking for help on Sirius/XM??


A little help on repeater info
limegrass69 is offline  
 
 
Old 11-15-2006, 05:27 AM   #12
Scorpion
Mixologist
 
Join Date: Nov 23, 2003
Posts: 255
Scorpion is on a distinguished road
Default

Quote:
Originally Posted by vo1one
Do you have the link to that filing handy? If not, I'll just search for it.

As it stands now, there are always 2 Sirius sats north of the Equator turned on for 16 hours a piece, staggered by 8 hours each so I don't see where you are getting the opportunity to use that geostationary satellite from your explanation.
I don't have the link to the document, but I'll see if I can dig it up.

Again, there's only enough spectrum for 2 satellites to broadcast at any given time. Normally the southbound bird transmits until it's directly above the equator. With the new satellite in orbit, the handoff (to the geostationary bird) would occur while the southbound one is well north of the equator. The handoff (from the geostationary bird) to the northbound bird would be delayed until it's some distance north of the equator. So instead of the NGSO satellites transmitting 16 hours per orbit, that would be reduced to possibly something closer to 14. This helps correct the problem of low elevation angles while the current satellites are close to the equator.

The document doesn't exactly state what their transmit plans are. It could be the geostationary satellite is on 100% of the time. This would likely mean the NGSO birds would be on only while in the "northern loop", or only 8 hours per orbit.

The batteries aren't normally a limiting factor in the service life of a geostationary satellite. They usually are in relatively good condition when the bird is boosted into a graveyard orbit.
Scorpion is offline  
 
 
Old 11-15-2006, 04:53 PM   #13
vo1one
Mixologist
 
Join Date: Dec 27, 2003
Location: Mount Pearl, Newfoundland, Canada
Posts: 336
vo1one is on a distinguished road
Default

Quote:
Originally Posted by Scorpion
With the new satellite in orbit, the handoff (to the geostationary bird) would occur while the southbound one is well north of the equator. The handoff (from the geostationary bird) to the northbound bird would be delayed until it's some distance north of the equator. So instead of the NGSO satellites transmitting 16 hours per orbit, that would be reduced to possibly something closer to 14. This helps correct the problem of low elevation angles while the current satellites are close to the equator.
This seems to be to be a complete waste of a geostationary satellite. It would save a couple of degrees of elevation for some people for a couple hours a day. The advantage of a geostationary satellite for people living in North America is obviously not that of elevation above the horizon unless you're comparing it with LEO's. The advantage would be ditching the Ku repeater feed and ease of operation from fixed indoor locations outside of terrestrial repeater range. This proposed use of a geostationary satellite does not take advantage of either of those things.

Quote:
Originally Posted by Scorpion
The document doesn't exactly state what their transmit plans are. It could be the geostationary satellite is on 100% of the time. This would likely mean the NGSO birds would be on only while in the "northern loop", or only 8 hours per orbit.
This would seem to be to be the smartest/most effective solution if a geostationary sat had to be incorporated into the existing 3 molniya orbit satellite system. You have the advantages of both systems working for you. Always one satellite transmitting from a very high elevation above the horizon and always one satellite in a "fixed" position in the sky for repeater feeds and indoor antenna users.
__________________
news:alt.radio.satellite - Usenet's Home for everything Satellite Radio
Ask your news server to carry it today!
vo1one is offline  
 
 
Old 11-15-2006, 07:14 PM   #14
Scorpion
Mixologist
 
Join Date: Nov 23, 2003
Posts: 255
Scorpion is on a distinguished road
Default

Quote:
Originally Posted by vo1one
This seems to be to be a complete waste of a geostationary satellite. It would save a couple of degrees of elevation for some people for a couple hours a day. The advantage of a geostationary satellite for people living in North America is obviously not that of elevation above the horizon unless you're comparing it with LEO's. The advantage would be ditching the Ku repeater feed and ease of operation from fixed indoor locations outside of terrestrial repeater range. This proposed use of a geostationary satellite does not take advantage of either of those things.
Sirius doesn't agree with your opinion.
Quote:
The hybrid constellation provides several service improvements. Figure A.1-1 shows the elevation angle of the current NGSO constellation to a subscriber near Chicago over a day (subsequent days are identical except for a shift in time of all satellites by a few minutes). Note that the second diversity satellite goes to near 25 degrees elevation for less than an hour three times a day. Figure A.1-2 shows the same plot with the addition of FM-5 which is the constant elevation angle line at approximately 40 degrees. Operating FM-5 during these three periods will improve service to such subscribers and a near identical situation occurs for subscribers throughout most of the CONUS service area.
I also doubt they have any plans to eliminate the Ku feed to their repeaters. Problem 1 is they have no backup for FM-5. Their entire repeater network would be totally off-line if FM-5 failed. XM can feed their repeaters from either of their satellites. The next problem is Sirius doesn't have guard bands between the satellite downlinks and the repeater's output. XM divides their allocated frequency band across 4 satellite tansponders and 2 blocks for each terrestrial repeater. The output of each repeater is separated from its feed by the bandwidth of a transponder. In the crude diagram below, TRa is fed by transponder SAT2a and TRb by SAT2b. Sirius has no such guard bands. No cavity filter can provide sufficient rejection to allow the system to work.

| SAT2a | SAT1a | TRa | TRb | SAT1b | SAT2b |

Last edited by Scorpion; 11-15-2006 at 10:21 PM..
Scorpion is offline  
 
 
Old 11-21-2006, 04:25 PM   #15
realwx
Banned
 
realwx's Avatar
 
Join Date: Dec 26, 2005
Location: Elkridge, MD
Posts: 2,554
realwx is on a distinguished road
Send a message via AIM to realwx Send a message via MSN to realwx A little help on repeater info
Default

Someone posted on another thread that you could just take the 2332.450 MHz broadcast, rebroadcast it stronger on the same frequency and that would work, and stores already do this?
realwx is offline  
 
 
 

Go Back   SIRIUS Backstage Forum > >


Digitalradiocentral.com




Similar Threads
Thread Thread Starter Forum Replies Last Post
SIRIUS repeater & other technical stuff, courtesy FCC scb147 Galaxy Nation 69 11-09-2006 08:42 PM
List of SIRIUS Contact Info Chad SIRIUS Dogstar Cafe 20 06-01-2006 06:30 PM
Repeater placement: downtown v.s. suburbs yg17 Galaxy Nation 19 11-19-2005 12:08 AM
Land repeater locations and info? William Galaxy Nation 3 12-12-2004 11:15 AM
car sirius sid's retrieval info PaulCB Install Garage & Help Desk 2 11-09-2004 07:43 PM

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 12:19 AM.
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
Search Engine Optimisation provided by DragonByte SEO v2.0.39 (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
All Content Copyright SIRIUS Backstage. All Rights Reserved. SIRIUS and registered trademarks are the property of SIRIUS Satellite Radio, Inc. The opinions posted on SIRIUS Backstage website and forums are those of the individual posters and/or this website and are not necessarily the opinions or positions of SIRIUS Satellite Radio, Inc.