Philly's Nightmare - dslreports.com

Author	All Replies
Voyager2K2 join:2001-10-04 Wayne, PA ·Verizon FIOS 1 edit	Philly's Nightmare Philadelphia's new digital emergency radio (police, fire, EMT) doesn't work because of cellular phone interference. »cms.firehouse.com/content/articl···id=34950 Philly's system is 800Mhz. So there HAMs. Put that in your pipe and smoke it. Should we ban cell phones that create a REAL (not imagined) problems? Oh wait a minute. HAMs don't use 800Mhz so I guess cell phones are OK.
	to forum · permalink · · 2004-09-13 11:04:24 ·
Steve I'm a PC, so shut up Consultant join:2001-03-10 Yorba Linda, CA	What's this got to do with hams?] If people are allocating two uses (public safety and cellphones) in the same band, then that sounds like a pretty bad idea, and it certainly ought to be fixed. But the radio amateurs have no dog in this fight. -- Stephen J. Friedl * Security Consultant * Tustin, California USA * my web site
	to forum · permalink · · 2004-09-13 11:10:26 ·
sabersaw Premium join:2001-08-21 Dayton, OH	reply to Voyager2K2 said by Voyager2K2 : Philadelphia's new digital emergency (police, fire, EMT) doesn't work because of cellular phone interference. »cms.firehouse.com/content/articl···id=34950 Philly's system is 800Mhz. So there HAMs. Put that in your pipe and smoke it. Should we ban cell phones that create a REAL (not imagined) problems? Oh wait a minute. HAMs don't use 800Mhz so I guess cell phones are OK. yeah, once again this problem is money talking, without thinking about science and existing services. Nextel has pushed there way into frequencies that pollute public service.
	to forum · permalink · · 2004-09-13 11:33:26 ·
pcscdma Chocobo Chocobo Random Battle Premium join:2004-01-14 Winterset, IA clubs:	reply to Voyager2K2 The problem is Nextel. They don't use the same A/B frequencies as the rest of the cellular carriers. Nextel uses the same SMR band as trunking systems. iDEN just seems to bleed a lot.
	to forum · permalink · · 2004-09-13 11:35:48 ·
ernie870654 join:2002-04-22 Cumming, GA	reply to Voyager2K2 Don't be silly! The Nextel & Public Safety communications problem is related to adjacent channel interference. The article you referenced identified this as...I quote "cell-phone signals are bumping up against public-safety channels" It was poor engineering analysis on the part of the FCC engineers that allowed this to happen. BPL and Ham radio is a co-channel problem which even a junior RF engineer can understand. ....and yes, I am a Ham and I work in the wireless industry. ernie870654
	to forum · permalink · · 2004-09-13 11:42:41 ·
pcscdma Chocobo Chocobo Random Battle Premium join:2004-01-14 Winterset, IA clubs:	reply to sabersaw When the FCC wanted to give Nextel some PCS spectrum, Verizon Wireless jumped in and cried foul and offered some cash for it. This put them in a unique position. Either Verizon Wireless doesn't care about public safety or they are spectrum whores and still don't care about public safety. Either way I thought it was kind of funny.;) -- I registered on DSLReports/BroadbandReports to talk about Broadband and DSL. Did you see GWReports or JKReports because I sure as hell didn't. Enough with the political bullshitting already.Free Kevin
	to forum · permalink · · 2004-09-13 11:43:15 ·
sabersaw Premium join:2001-08-21 Dayton, OH	yeah, I remember reading and responding to that topic on the news here. I can understand that Verizon doesn't care about public safety, that is not expected of them. What does surprise me is the FCC and their actions or lack of. I know little of cell phone modulation types, but my guess is your first response to the iDen signal being dirtier than tested is the true root of this disaster.
	to forum · permalink · · 2004-09-13 11:50:34 ·
cghh join:2001-01-15 Milpitas, CA 2 edits	reply to ernie870654 I read the reference articles, and they first talk about cellular interference, and then continue on talking about Nextel, which is a different beast. AFAIK, the interference between wireless phones and public safety radios involves only Nextel, since they share the same frequency band (SMR) as the 800MHz public safety radios. The cellular bands do not overlap with the SMR band.
	to forum · permalink · · 2004-09-13 12:24:56 ·
RayW Premium join:2001-09-01 Layton, UT clubs: ·XMission	reply to Voyager2K2 quote: As a result, a firefighter making a call at an 850-MHz frequency might unknowingly be standing under a cell-phone antenna transmitting at 851 MHz. One signal could block the other. GOOD GRIEF! Assuming that the article had the facts straight, what idiot put an emergency band one MHz away from a cell phone frequency? That is as bad as the idiots who want BPL (at least in my experience with RF interference). But all that aside, as of October 2003 the 849-851 MHz band was reserved for Aeronautical Mobile use, what is a land mobile public safety outfit doing there? 851-866 MHz is land mobile, which covers one set of cell phone frequencies, so they are where they belong (old analog phones?). Maybe they are splattering a bit considering the ineptitude of the phone company, but that is also a different story. FYI GSM cell freqs are : 850 MHz (824.2 - 848.8 MHz Tx; 869.2 - 893.8 MHz Rx) 900 MHz (880-2 - 914.8 MHz Tx; 925.2 - 959.8 MHz Rx) Which would explain why sometimes my weather station looses signal (around 915 MHz). -- I am not lost, I find myself every time.
	to forum · permalink · · 2004-09-13 12:34:48 ·
cghh join:2001-01-15 Milpitas, CA	said by RayW : FYI GSM cell freqs are : 850 MHz (824.2 - 848.8 MHz Tx; 869.2 - 893.8 MHz Rx) 900 MHz (880-2 - 914.8 MHz Tx; 925.2 - 959.8 MHz Rx) Which would explain why sometimes my weather station looses signal (around 915 MHz). The 850MHz band you list is the US cellular A/B band, in which various protocols are used, such as AMPS (analog), IS-136 (U.S. "TDMA"), CDMA, and (only recently) GSM. The SMR band, where Nextel and the public safety radios operate, is 806-824MHz for the uplink (from the mobile), and 851-869MHz for the downlink (to the mobile).
	to forum · permalink · · 2004-09-13 12:57:13 ·
pcscdma Chocobo Chocobo Random Battle Premium join:2004-01-14 Winterset, IA clubs:	reply to RayW The US doesn't use the 900MHz band for cellular. It's one of the unlicensed ISM bands and used mostly for cordless phones.
	to forum · permalink · · 2004-09-13 13:05:41 ·
richk_1957 If ..Then..Else Premium join:2001-04-11 Minas Tirith	reply to Steve I checked & you're right The radio amateurs have 420-450 Mhz and then 902-928Mhz, nothing around 800. So don't blame any interference on us. I can't find any recent radio frequency allocation lists, but it's getting more & more crowded, so the spectre of interference crops up.
	to forum · permalink · · 2004-09-13 13:10:22 ·
w2co join:2003-07-16 Longmont, CO	reply to Voyager2K2 I don't know what your problem is man. Hams share the 2.4 Ghz band with all the lousey 802.11b/g routers anyway. And the 2.4Ghz band is a weak signal satellite band to boot. The 800 Mhz band is only 100 Mhz away from the nearest ham band, and is hardly used at all. You should get more educated on this stuff before you make statements like that. This has nothing to do with BPL which also is a real pandora's box and uses entirely different frequency ranges, but you fail to seperate the two. What the heck are you smoking man?
	to forum · permalink · · 2004-09-13 13:13:59 ·
pcscdma Chocobo Chocobo Random Battle Premium join:2004-01-14 Winterset, IA clubs:	reply to richk_1957 said by richk_1957 : I can't find any recent radio frequency allocation lists, but it's getting more & more crowded, so the spectre of interference crops up. »www.ntia.doc.gov/osmhome/allochrt.html -- I registered on DSLReports/BroadbandReports to talk about Broadband and DSL. Did you see GWReports or JKReports because I sure as hell didn't. Enough with the political bullshitting already.Free Kevin
	to forum · permalink · · 2004-09-13 17:17:43 ·
pcscdma Chocobo Chocobo Random Battle Premium join:2004-01-14 Winterset, IA clubs:	I've lost the ability to post URLs
	to forum · permalink · · 2004-09-13 17:19:23 ·
RayW Premium join:2001-09-01 Layton, UT clubs:	reply to pcscdma True pcs, that was a cut and past for fullness. -- I am not lost, I find myself every time.
	to forum · permalink · · 2004-09-13 21:38:20 ·
RayW Premium join:2001-09-01 Layton, UT clubs: ·XMission	reply to cghh True cghh, but there is also the band from 851-866 MHz which I THINK is one of the old analog cell phone bands. I probably should not have included the 850 and 900 MHz GSM bands, but did so so someone who only looked at those would know I was not confused (more than I usually am that is). -- I am not lost, I find myself every time.
	to forum · permalink · · 2004-09-13 21:42:16 ·
pcscdma Chocobo Chocobo Random Battle Premium join:2004-01-14 Winterset, IA clubs:	»wireless.fcc.gov/services/cellul···lan.html Check this out - »www.fcc.gov/cgb/kidszone/ Broadband the cat!:p
	to forum · permalink · · 2004-09-13 22:06:41 ·
Eat Me join:2002-09-25 Sussex, NJ ·PenTeleData ·Future Nine Corpor.. ·VOIPo ·Vonage	reply to Voyager2K2 quote: Should we ban cell phones that create a REAL (not imagined) problems? Oh wait a minute. HAMs don't use 800Mhz so I guess cell phones are OK. Any and all interference is bad. But since we're not affected, it's really not our problem. I don't see the big complication here. It's not an issue of us being selfish, it's an issue of us not interfering where we don't need to interfere. If your neighbor is having domestic issues with his wife, does it affect you? Similarly, if cell phones are interfering with public safety comms, then the public safety agencies should go through the proper channels (i.e. the FCC) and get the cell phone carriers to resolve this interference.
	to forum · permalink · · 2004-09-15 03:09:43 ·
cghh join:2001-01-15 Milpitas, CA	reply to RayW said by RayW : True cghh, but there is also the band from 851-866 MHz which I THINK is one of the old analog cell phone bands. I probably should not have included the 850 and 900 MHz GSM bands, but did so so someone who only looked at those would know I was not confused (more than I usually am that is). The 851-866 band is the SMR (trunked radio, including Nextel) downlink band. AFAIK, the FCC does not specify the protocols to be used in the cellular and PCS bands (except that AMPS must currently be offered in the cellular band); that is, there is no such thing as a "GSM" band in the U.S. The 850MHz band mentioned is just the U.S. cellular band, in which GSM can be used, along with any other protocol (AMPS, CDMA, IS-136). The GSM Consortium specifies definitions for GSM channels, some of which fall in the 850MHz cellular band, which are meaningful only if GSM happens to be used in that band. In Europe and other places, of course, regulations require that only GSM can be used in certain bands, but that is not the case in the U.S.
	to forum · permalink · · 2004-09-15 17:35:00 ·


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