Can they do "This" or is it just a ruse??
 

My wife works for a large Chicago distribution firm. We currently have Cingular cellular service (actually ATT "blue" - but I suspect that doesn't matter), and I'm contemplating a switch to T-Mobile in order to change phones.

Here's the rub: My wife's company has told her that in their "new" building, the only cell signals that can get through are Cingular, so she doesn't want to switch. Fair enough. But how can someone put up "shielding" that will filter out Cingular from T-Mo??

As I understand it, cellphones are simply radios, and the wavelength broadcast by both Cingular and T-Mo should be identical. If I'm right, isn't what she's being told similar to someone saying you can listen to a radio at work made by Sony, but if you own a Panasonic radio- you're outta luck??

What's the straight skinny??? Thanks in advance for any help!
Best, Dave

Cellphones are radios that work in various microwave bands. Shorter wavelengths have more trouble penetrating steel-reinforced concrete buildings. I don't know whether T-Mobile and Cingular are on the same band, but if they're not, the one with the longer wavelength will do better. Both are GSM phones, which use shorter wavelengths than the TDMA and CDMA systems employed by Sprint and Verizon, which is one of the reasons why Verizon will give better coverage than a GSM carrier.

Each carrier has their own network of cell towers. Cingular may be the only one with good coverage of that area. I have that problem, my carrier has very weak signals in my office building but colleagues with other carriers get better signals.

I read something about coverage once. I think it said that even the same tower can have transmitters belonging to different companies, but the equipment can be calibrated/aimed differently resulting in different coverage between two carriers using the same tower.

This I think I understand. Both of them should be operating on the same wavelength, but perhaps the towers in the area of the building are set such that only one of them gets thru.
I had thought of that as well....but since we are going to stay with GSM under any circumstances (International travel) - I was hoping that there'd be no difference between GSM carriers.

In any event, thanks much for the help so far!!
Best , Dave

This may be the answer - in the sense that the tech people at her company are not "claiming" they've blocked anyone else's signal "out", but rather are telling her that only Cingular is in a position (due to tower location) to get "in".

Many thanks!
Dave

Some building landlords have deals with one or more cellphone companies to operate repeaters within a building that provide better within-building signal coverage than the outside cell towers can provide.

I used to work in a building in downtown chicago where Verizon users had great signals and Cingular (me) users barely had 1 bar.

It's most likely a coverage issue, where Cingular has good coverage there (either because they are under a tower or because they have a repeater installed) and the other companies don't.

Type of phone and position in the building could make a world of difference.

T-mobile (and probably others) have street level coverage maps that at least around my house are quite accurate

http://www.t-mobile.com/coverage/

Toss in the address and see what they say they have for coverage.

Says they have 2-3 bars, which means that "should" be recv'b indoors. I appreciate about the repeaters, tho, and perhaps that's the issue.

Best, Dave

There are three major things that determine reception. All have been mentioned but to reiterate they are tower position relative to you (and what is between you and the tower), the phone, and wavelength. I dont know as much about the wavelength issue but others have commented on it.

In my experience it is impossible to separate having good reception from what phone you are using. There are ENORMOUS differences. I was told once that a site (a cell phone store) didnt have TMobile coverage, only ATT and shown a Sony Ericcson phone (T68) with no TMobile signal. I pulled out my Nokia 6310 (a known very high end phone re reception) and had 4 bars and could easily make and receive calls. Another anectdote, my wife works in big office building near Rockefeller Center. She had very intermittent reception on her Verizon phone (a Samsung). I did some research and got her a particular model of Nokia that had a strong positive buzz about its reception on Howards Forums and she gets solid reception now. None of her coworkers on any carrier in that area of the building get any reception.

So if you want to switch you should probably consider the phone aspect. It can make a very big difference. Generally Nokias probably have the best reception. A look around the Howard Forums TMobile Forum will probably get you the name of some likely candidates among Nokia and other brands. Double check on the following but I think that if you buy your phone and sign up at a TMoble corporate store (ie, not some guy in a mall but a TMobile owned store) you get a 2 week money back guarantee. If so, pick a phone and try it and see if she gets reception there. Good luck.

Note that they may not operate on the same frequency. T-Mobile's coverage is exclusively 1900MHz. However, Cingular operates in many areas on the 850MHz band. As far as I can tell, Chicago is one of those areas.

850 tends to have better building penetration.

The 850 band goes back to the original analog wireless system, where there were two carriers licensed, the "A" and "B" sides. Through various mergers, Cingular has some of those original licenses.

The 1900MHz band was added later, and was opened to new entrants to the market.

Everything else being equal, I'd suspect a repeater. My company's headquarters had no reception inside for anything. They installed repeaters for Cingular and, boom, we had Cingular reception. The others still don't work well.

You can find repeaters on the web, I think they're about $1000US and you don't need permission from the cellular carrier to install them. I recall each repeater was company specific.

Search for "cellular repeaters" and you'll get a load of ads and other information.

Thanks for your help on that - seems as though this too (along with many other suggestions :) could be the situation.

Best, Dave

You can check the TMO reception with your existing Cingular phone. Just go to the Networks option and choose, "manual." You'll see whatever networks are available. You should be able to select TMO (if there) and see how many bars you get. Put it back to automatic when done, or you'll only be able to make emergency calls.