 
TK Junk Mail
Go ahead, make my day
Premium
join:2002-03-03
Margate City, NJ
clubs:
 ·Comcast
edit:
March 16th, @12:49PM
|  Links to more details about the interference study
The results of the testing showed that the WiMAX transmit signal could cause significant problems to a satellite digital signal well in excess of 7.45mi distance. At the extreme measurement distance, the video program was fully operational with the WiMAX carrier centered on the video carrier. However, the data BER was degraded from a nominal 10-8 to a BER of 10-4. This is an unacceptable quality of service in the digital telecommunications industry.
Subsequent calculations based on the initial measured data, and scaling with ITU criteria for WiMAX output power along with additional path loss, resulted in a required separation distance of 172mi to reduce the level of interference to meet the -10dB specification. Combining the two analyses, from a flat nonblocking terrain to a wooded hilly terrain, results show that the criteria whereby FSS antennas cannot co-exist with WiMAX systems ranges from 31mi to more than 124.25mi depending on the local terrain and the WiMAX output levels. Parameters of the testing methods:
»www.suirg.org/pdf/SUIRG_WIMAXTes···ures.pdf
Full test report:
»www.suirg.org/pdf/SUIRG_WiMaxFie···port.pdf
Aside from the test study, there are already numerous anecdotal observations of earth based wireless systems having negative effects on C-Band systems around the world:
»talksatellite.com/blog/?p=6
»www.space.com/spacenews/archive0···226.html
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sporkme
drop the crantini and move it, sister
Premium,MVM
join:2000-07-01
Budd Lake, NJ | Re: Links to more details about the interference study Did the FCC not see this coming, or have they closed down all their engineering operations in favor of lawyering and disbursement of lobbying funds? | |
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TK Junk Mail
Go ahead, make my day
Premium
join:2002-03-03
Margate City, NJ
clubs:
·Comcast
edit:
March 16th, @01:17PM
| Re: Links to more details about the interference study said by sporkme  :Did the FCC not see this coming, or have they closed down all their engineering operations in favor of lawyering and disbursement of lobbying funds? In a small defense of the FCC, a working group of the ITU OK'd a compromise using Wimax and other terrestrial broadband frequencies after years of wrangling between the sat industry and ground based wireless firms. They split up frequencies to theoretically avoid interference. The latest studies seem to indicate that even though the C-Band and Wimax don't share the same frequencies, that interference is still taking place anyway from adjacent frequency bands. The ITU may need to revisit the brokered compromise if the latest study is accurate and no mitigations can avoid the interference.
»www.developingtelecoms.com/conte···1035/59/
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| | | cmaenginsb
Premium,MVM
join:2001-03-19
Palmdale, CA | No, they did regulate the new 3.65 band to prevent it's use near large concentrations of C-band usage such as los angeles. | |
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ureihcim
Freshly made
join:2007-12-16
Miami, FL
| After reading the report, it more than likely sounds as if they are also trying to include other forms of terrestrial based systems in the mix.
But also according to the report BWA is operating on the same frequency range as the CB for it's satellite downlinks.
On Wikipedia:
"The 5.4GHz band (5.15–5.35/5.47–5.725/5.725–5.875 GHz) is used for IEEE 802.11a WIFI and cordless phone applications, leading to occasional interference with C band weather radars."
So it's clearly a frequency issue in other countries, as C-band operates here in a lower frequency, and the current set frequencies for WiMAX are 2.5GHZ and not 3.4-5.4Ghz which is what C-band operates.
In short, the terrestrial signal from the WBA is overpowering the CB signal and is causing the receiver to go apeshit because they are both operating on the same frequency range. | |
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gaforces
United We Stand, Divided We Fall
join:2002-04-07
Santa Cruz, CA
 ·Cruzio Internet
| Re: Links to more details about the interference study From what I can gather, without paying for a new scientist subscription, the frequency that WiMax will be operating in the US will not interfere with C band satellite.
The interference was obtained when the WiMax radios were tested on the higher frequencys that C-Band uses, which they can run on but wont.
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ureihcim
Freshly made
join:2007-12-16
Miami, FL | Re: Links to more details about the interference study "The interference was obtained when the WiMax radios were tested on the higher frequencys that C-Band uses"
Exactly. | |
| | Kearnstd
Elf Wizard
join:2002-01-22
Mullica Hill, NJ
| well what we need to do is crank up a WiMAX network full wattage and see what happens.
what is C-Band still used for btw? i know that home owners no longer tune it as the big 1m dish is dead.
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TK Junk Mail
Go ahead, make my day
Premium
join:2002-03-03
Margate City, NJ
clubs:
·Comcast
| Re: Links to more details about the interference study said by Kearnstd :well what we need to do is crank up a WiMAX network full wattage and see what happens. what is C-Band still used for btw? i know that home owners no longer tune it as the big 1m dish is dead. Businesses; military; cable companies.
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wibpl
@shawcable.net | bpl>wimax I trust all the anti BPL people here also do not like wimax now? | |
| battleop
join:2005-09-28
00000 | The antennas? Wow. I always thought it was the radios that would cause the interference. | |
| cmaenginsb
Premium,MVM
join:2001-03-19
Palmdale, CA
| Flawed article Any article that starts out with Wi-Max is a long range version of WiFi is bound to have technical problems.
Here in the US the FCC has regulated the only frequency that interferes with C-band for sure by limiting it's use away from major centers of C-band earth stations.
WiMax uses a variety of frequencies from 2.4-2.7 Ghz and 3.4-3.7 Ghz and 5 Ghz in some places. As time goes on there will be more and more profiles for WiMax in a variety of other frequencies as well.
There are other wireless services that can use the same frequency bands and cause the same interference.
The satellite industry does not appear to be interested in change, just making everyone else change around them. Case in point was XM who wanted to outlaw wifi because they didn't build good enough filters to prevent wifi signal from interference with their near band equipment.
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Killer Max
@rr.com
| Re: You need to understand something... said by qworster :Part 1 of that statement means harmful interference to the primary user (telco microwave). Part 2 applies to the secondary users (satellite, WiMax and other secondary users). Sometimes this interference causes: "undesired operation"- meaning that the device doesn't work! In simple terms... In simple terms, your quote is for unlicensed spectrum and does not apply to licensed spectrum. Why-Max is currently available only in licensed frequencies. | |
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Boogeyman
Drive it like you stole it
Premium
join:2002-12-17
Huntsville, AL
·Comcast
| Re: You need to understand something... But you missed the first part of his post which stated:
said by qworster :Satellite use of this band is a SECONDARY SERVICE. The primary users of this spectrum are the microwave towers that used to be on top of every large telco central office. Most of these are gone (thanks to fiber) but the FCC has NOT re-allocated this spectrum because many towers still do exist, particularly in areas where installing fiber is not cost effective. I just went past a HUGE installation in the California high desert last week. Bold added by me. | |
| | | qworster
join:2001-11-25
Los Angeles, CA
·Brand X Internet
·RoadRunner Cable
 ·Vonage
·DSL EXTREME
·EarthLink
edit:
March 16th, @08:17PM
| said by Killer Max :said by qworster :Part 1 of that statement means harmful interference to the primary user (telco microwave). Part 2 applies to the secondary users (satellite, WiMax and other secondary users). Sometimes this interference causes: "undesired operation"- meaning that the device doesn't work! In simple terms... In simple terms, your quote is for unlicensed spectrum and does not apply to licensed spectrum. Why-Max is currently available only in licensed frequencies. I'm talking about licensed services. Again I say, Satellite and Wimax-while both licensed services are SECONDARY to the primary user of this band, which is telco microwave.
As secondary services, it it permitted for them to interfere with each other (but NEITHER can affect the telco microwave)-that is what SECONDARY means!
Also, though satellite transponders and uplinks are licensed, receive only dishes are NOT! You can FCC register them under certain cirsumstances, but that only applies to very LARGE dishes, and it still does not guarantee flawless operation.
By the way, this is why most newer satellites now operate on the Ku satellite band, because satellite is the PRIMARY user of that band. | |
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Killer Max
@rr.com
| Re: You need to understand something... said by qworster :I'm talking about licensed services. Again I say, Satellite and Wimax-while both licensed services are SECONDARY to the primary user of this band, which is telco microwave. As secondary services, it it permitted for them to interfere with each other (but NEITHER can affect the telco microwave)-that is what SECONDARY means! Your opinion sounds very logical, but it would be interesting to see an actual FCC regulation of the frequency band in question that confirms that satellite is primary and every other license issued in said band is secondary. The label on the bottom of a cordless phone is not relevant to the 3.x Ghz licensed band. | |
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Killer Max
@rr.com
| said by qworster :said by Killer Max :said by qworster :Part 1 of that statement means harmful interference to the primary user (telco microwave). Part 2 applies to the secondary users (satellite, WiMax and other secondary users). Sometimes this interference causes: "undesired operation"- meaning that the device doesn't work! In simple terms... In simple terms, your quote is for unlicensed spectrum and does not apply to licensed spectrum. Why-Max is currently available only in licensed frequencies. I'm talking about licensed services. Again I say, Satellite and Wimax-while both licensed services are SECONDARY to the primary user of this band, which is telco microwave. As secondary services, it it permitted for them to interfere with each other (but NEITHER can affect the telco microwave)-that is what SECONDARY means! By the way, this is why most newer satellites now operate on the Ku satellite band, because satellite is the PRIMARY user of that band. Your opinion sounds very illogical, and it would be interesting to see an actual FCC regulation of the frequency band in question that confirms that satellite is primary and every other license issued in said band is secondary. The label on the bottom of a cordless phone may indeed be relevant to the 3.x Ghz licensed band. | |
| 
Subaru
1-3-2-4
Premium
join:2001-05-31
Greenwich, CT
clubs: | man... Is Wimax ever going to start up?? every news story I've heard so far on this site is nothing but issues with something else or how they are doing testing but it's never "full deployed" yet | |
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ureihcim
Freshly made
join:2007-12-16
Miami, FL
| Re: man... The problem is damn money, its that simple.
Sprint-Nextel would of already be releasing XOHM in the wild if the had the money to back it up, it's not just about starting a network but also the cost to maintain it. Also how many WiMAX devices are out there? When Sprint releases XOHM best bet Intel will also be releasing WiMAX enabled laptops amongst other things.
Other manufacturers will announce their WiMAX products and you will be able to buy them not from Sprint but say Samsung, Zyxel, Nokia amongst others.
The reason why these companies have a interest in WiMAX is because Google can use Sprint's WiMAX network as a last mile to reach their Skype customers and release a WiMAX phone that runs Skype. This in return gives them a network to operate on without the added cost of maintaining it.
Nokia is interested because they can release web enabled content and games to their customers, and with the flexibility that intel has provided, they finally have a chipset where they are not regulated by a network telling them how to build their phones but rather they can do direct sales to customers and you will see much better phones than the N95 be out and available.
Ericsson is interested by expanding their mobile division also known as Sony Ericsson to provide access to Sony enabled content to their phones providing multimedia rich applications and things that they are not locked on too.
What makes XOHM so worth it for these companies that see the opportunity is that Sprint has labeled themselves as the dummy pipe in this network which they will sell you data connectivity without restriction. It's all up to the content providers, so if Apple wanted to have a WiMAX iPhone, they don't need to talk to Sprint for licensing and make contracts and agreements. No it does not work that way, instead Apple can do what they wish with their phone, provide access to the iTunes music store and provide high speed data services.
The customer can also choose a data network, so if XOHM is not his cup of tea or poor coverage in his area, but Clearwire provides excellent coverage, he can switch data providers and this has no effect on the content providers nor the network operators themselves because it's all IP.
The flexibility to do what you want and when you want it, THATS Sprintspeed, that's the yes you can BS they been giving on the advertisements. It's all based on this system, which is why I been so glued to anything Sprint-Nextel was saying about it.
I will say it again, Sprint is sitting on a goldmine, it must eliminate Nextel and move over the PTT capability over to the CDMA network. Once that's done, I say destroy Nextel & Boost and move these customers over to CDMA. If PTT is all they want then Qchat is in back order.
Sprint is also trying to merge the whole network into IP because it would save them billions in the long run. Also with Rev.A it's not done there yet at just 3.1Mbps, Rev.B according to sources is a software upgrade. So when that's out expect Sprint and Verizon to upgrade their networks in a heartbeat.
All Sprint-Nextel has to do is deploy this correctly, fix the BS at the customer service centers and that stock price will start going up the roof even in a time of recession.
VOIP markets will explode because of this and before you know it, you will have over 100 different providers to choose from offering voice services. Playing the dumb pipe brings in more money because Sprint can only focus on data and it's own network.
Intel will make a killing and that's why they don't mind pumping in 2 billion into XOHM. Because the return is enormous. | |
| | | jaminus
join:2004-10-14
Arlington, VA
| Re: man... Excellent post, sir. Xohm is an prime opportunity for Sprint to capitalize on the desire for mobile broadband. 3 Mbps sustained mobile throughput is a big deal considering the relatively meager offering of Evdo.
I yearn for a Sprint Wi-Max Smartphone; yet Sprint provide subpar service and inadequate phone pickings. Who wants a 320x240 HTC Touch when there's the iPhone? My dream is a high-res, Sprint Xohm smartphone with a touch-screen, good browser, removable battery, and micro SD-HC slot. When that happens Sprint will get some serious cash from me.
I am tired of slow mobile broadband but the only worthwhile Internet phone (iPhone) can't even do 3G let alone Wi-Max. Sprint has a golden opportunity to become the market leader if only it can figure out how to run a mobile network properly. | |
| russotto
join:2000-10-05
Collegeville, PA | SUIRG? The name "Satellite Users Interference Reduction Group" stinks of astroturf. But you'd thing they could come up with a better acronym. | |
| 
MadMANN
Premium
join:2005-08-19 | A club for everyone Man, there is a group for anything these days.
The Satellite Users Interference Reduction Group (SUIRG)??
I'm gonna start my own group called The Losing Socks in the Dryer Reduction Coalition (LSDRC). | |
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WiMax Antennas May Interfere with Satellites