Wireless Growth & Wireless Interference

windowpain writes "An article in Monday's Washington Post says "The explosive growth of the mobile phone industry has crowded and tangled the nation's airwaves to such an extent that wireless company signals are increasingly interfering with emergency radio frequencies used by police and firefighters, public safety agencies said." Wifi is not a problem, evidently. Understandable, given its short range."

Comments

How can this happen?

[rokzy]

if the FCC (or whoever) made reasonable specs and if everyone's following the specs how can this mess happen.

=> fire people at FCC or sue mobile companies.

Police chatter in the classroom

[awtbfb]

This problem has been around for some time in the hearing impaired community.

Exactly how crowded?

[Faust7]

As organized, the spectrum, which is a limited resource, simply can't accommodate everyone...

There are several wireless companies operating in the 800 megahertz band...

How finely split can the spectrum be before there's danger of overlap? Is it possible for, say, one phone to send signals at 800.0001 MHz while another does so at 800.0002 MHz? Where is the precision cutoff for neighboring frequencies before things start to interfere?

Re:Exactly how crowded?

[mgs1000]

FYI

There are two sets of frequencies for cell phones in the U.S. The orginial band at 800 Mhz(actually uses 825-895Mhz, IIRC) and the "PCS" frequencies at 1900MHz(1850-1990Mhz, once again, IIRC)

You'll find CDMA and TDMA networks in both bands. GSM uses mostly just the PCS bands, and Analog uses the 800Mhz exclusively.

Short Range?

[Gaewyn L Knight]

*Laughs at /. editor as he types this over a 6.1mile 802.11b link*

Really... the main reason for the interference between cell and emergency is that they are all moving into the same spectrum space. 800mhz is a busy place these days.

True wireless (802.11a,b,g) are all in FAR different spectrums so other than cordless phones and some radar equipment interference is a moot point.

Open Spectrum

[schnarff]

Seems like we need to point the FCC towards Open Spectrum (mentioned in a previous Slashdot article). After all, why go to all the trouble of reshuffling the tiny spectrum we've got now when the proper devices and management can give us more bandwidth than we know what to do with yet?

NYC Wi-Fi

[TrippTDF]

I do some home and small business tech support in New York, and I've seen some interesting things happen with Wi-Fi.

The most interesting being the fact that I found 20 open and join-able networks on the corner of 20th and Broadway last week. I'd say some people need a lesson in security...

Also, I've seen people name their network things like "get the fuck off my shit" when neighbors try to join their network.

I'll also be interested to see if Wi-Fi networks effect piracy at all- what if the RIAA manages to crack down on piracy to a point that it cripples internet file trading (it wont happen, but come with me on this for a sec) and the only safe way to trade files is by sharing them on a local AirPort network. Then people can run around with their Wi-Fi PDAs with 1GB or greater flash cards, and download stuff from open networks they find on the street.

here's a thought ...

[dlasley]

> Meantime, Fisher said many colleagues on the Anne Arundel County police force have found their own solution: They carry cell phones in case their radios go dead.

so that being an option, why not have the cell companies take over administration of all the systems in these ranges, subcontracted thru local government offices? have the companies then manage (and be liable for) the need for non-overlapping frequencies separating critical traffic from the general public. especially the ones that shouldn't be driving and yapping on a cell phone as they hurtle through traffic (you know who you are!!!)

and yes, i know this puts a consumer-driven entity in charge of systems that are depended upon by lcoal/stage/regional entities, but hasn't private enterprise often proven its ability to manage complex systems a tad better than the government? could be a re-birth of telecom spending and contracts (which could mean jobs, more bottom-line investing, more attention on the nation's eroding infrastructure ...)

WiFi Is Not Near Public Safety Bands

[Goody]

Wifi is not a problem, evidently. Understandable, given its short range.

Ummm, no. Here's a frequency chart of the radio spectrum. People seem to think everyone uses all frequencies and it's one big radio spectrum blob. Radio spectrum resembles IP space, except in this case you can't create more of it. Print out the chart on a big plotter, hang it on the wall and impress your techie friends, and consult it when a wireless article is posted on Slashdot. :-)

K3NG

Good timing!

[Anml4ixoye]

How funny that this should come up. I was just in a meeting last week talking about this very thing.

I am the Assistant Chief of a volunteer department north of Tampa, Florida. We operate off of the 800mhz radio system, and for all of the money we spent on it, you would think it would work better. Instead, we have spots where we can hear but not transmit, or just plain not get reception at all.

While we were talking about this one of the Hillsborough County chiefs brought up the fact that when he is at headquarters (where our central towers and dispatch are) he can't use his little car-alarm-door-unlock-gadget-thingy unless he is almost touching his vehicle. When he is at home, he can activate it from 200-300 yards away.

We have always blamed it on the hardware and crappy company, but now I think I might have to look a little more into what other kinds of interference would cause transmission and reception problems in the areas where we are having difficuly.