Everyone has heard Nextel to be the culpret of interference with Public Safety radio systems, no arguments there. As we are all aware of Nextels consensus plan/rebanding/major overhaul that will take place. This is the first I have heard of Cingular to also be a culprit, if true do they have a plan to remedy the problem. Is this something new?
Interesting find. Thanks for that. I've never heard of Cingular causing interference either. The paragraph which states that interference can be eliminated by changing angle of antennas, etc. is interesting. This might cause service to deteriorate in some places if power is reduced, angle of antennas are changed, etc. ~Andy
A Side carriers in the 800 Mhz band are adjacent to ESMR channels. Click Here to see the pre and post reconfiguration strategies from the FCC Website. In regards to the co-located systems, when you get a blend or "Mix" of frequencies, they can generate interference called "Harmonics". This is interference generated by mixing two signals that appears at an unintended frequency. This is quite common, especially at mountaintop locations where you have cellular, PCS, trunking phones, paging, radio stations, and television all in one 1 acre site. Normally antenna placement, as well as type of antenna with transmit filtering can prevent this.
Sprint is a PCS carrier and not in the cellular band. They operate in the 1900 mhz range, not 800.....yet The A and B side providers in the 800 cellular band differ by state (and county for that matter)! Depending on where you live, you see providers such as Verizon, Cingular, Alltel or other regional providers in the A and B slots.
Does the FCC have something on their site that details which carriers are on which band for each market (A, B, PCS, etc.)? I'd be interested in checking that out!! Anybody know for sure?
I haven't heard of any other carrier so far causing a problem other then Nextel, but anything is possible, of course it will be interesting to see what happens once Nextel moves most of there frequencies to another band & if Cingulars transmissions are causing a problem & how close they are in the frequencie range for Philly's PS frequencies & if any other carrier all of the sudden has a problem. It would also be nice to see if Philly's radio system is setup with enough repeaters to cover all the area's of the City, I know DC is having problems & it's attributed to not enough towers & repeaters put up (They wanted to save money).
Interesting, I thought only Nextel was causing the interference. Funny thing is here I notice is a lot of the police dept. uses Nextel to communicate with other cops rather than using their radio. I guess it's to be more private ... I dunno but anyhow this is nice find.
I know with my fire Investigation field, we like to use the Nextels for security reason's, even though we do have digital encripted radio's sometimes it just seems safer not to use them, as well as sometimes we can't talk on them due to lack of a repeater in the county. Also the County radio i use, I have never had any interference from Nextel or Cingular/AT&T & it's on the 800 band. My township radio is on 500Mhz so no worries about interference there.
Is your township broadcasting on TV? Just Kidding 470-512 is also used for TV channels 14-20 512-698 is used for TV channels 21-57. There are however 11 cities according to the FCC that use the 470-512 range for public safety, transportation, industrial and general access. I just thought it was funny that you happen to be in one of those areas...
Actually there are quite a few towns & cities by me that use the 500 band, My town is on an EDACS system using 501.6375, 501.9625, 502.1125, 502.7125 & 502.9125 and each frequency has 5 to 10 channels, almost like a trunking system that Moto use's only this is by Ericsson. And since I am only 10-15 Air miles from NYC & 2 miles from Newark NJ I guess we aren't having a reception problem from any TV stations around here.
Wow an Ericsson system huh! I know they are out there, but we don't see many of them around our parts down here in the Southwest!
Yeah, we have had them for a little over 5 years now & they work good. Of course Ericsson came out with lighter & smaller portables a year later so we have bricks for portables, which I have seen them run over by fire engines & survive and continue to work.