I have an 8260 with AT&T service and I recently moved from Austin, TX to Houston. In my apartment I get almost no signal, but from time to time (very rarely), the phone goes into "Extended Area" mode (using a Cingular tower) and my signal jumps to 4 bars. The problem that I am facing is that the signal from the AT&T tower is normally just strong enough for the phone to lock onto that tower, but not strong enough to receive/make phone calls. I did a little bit of experimenting and found that if I change the Home System ID for NAM1 from the AT&T ID to the Cingular ID, I get a better signal (the same as if my phone was in "Extended Area" mode. My question is: 1. Is it illegal to do this?? AT&T has a reciprocation agreement with Cingular, so I don't incur any roaming charges when I jump to the Cingular network. 2. Can either of the carriers detect that I have done this or will it appear to them as if an AT&T tower wasn't present, so it used a Cingular tower (normal behavior for the phone)? Thanks, Marc
You are going to run into problems....your phone an AT&T run an authentication loop on you every time you power up and whenever your phone registers on the tower. By changing the Home SID, your phones information is not consistent with what is in AT&Ts billing system and you will be unable to make and receive calls. You may get one or two through..but ultimately the system will shut you down.
Interesting. I've had the phone on for the past 24 hours using the Cingular Home System ID, but I have only made a couple of calls from it. When you say "the system will shut you down", does that mean that my phone will not work until I reset the Home System ID to AT&T's or will my entire account be shut down? Thanks, Marc
You can change the sid without any problems...it wont cause you any billing problems or any problems otherwise but it will be a problem for ATT. Whenever you leave your house you definatly want to change the phone back to home sid though!
When my phone goes into 'Extended Area', I can go to the System->Manual option and select the "Extended Network". My phone will show 'Extended Area' for a couple of days (or until I turn my phone off/on) with a great signal and then it will flip back to the AT&T display and back to a single or no bars of signal strength. If I try to do a System->Manual when the phone is not in 'Extended Area', the only network that I can pick up is the AT&T network. When I change the Home SID to Cingular's SID, I get a great signal, but you guys have warned me that this is only a temporary fix and won't work long term. My question is, is there a way that I can modify the programming of the phone so I can select the Cingular tower (automatically or via System->Manual) even when I get the marginal (good enough to register, but not good enough to talk on) signal from the AT&T tower? Thanks, Marc
WirelessTech is right. I keep changing my SID all the time and it's never a problem even when I travel. Actually, I have my SID changed most of the time. If it works for you, go for it! There's no such thing as it being illegal or the system shutting you down. There's no way they will know about it and even if they do, it really doesn't matter because since both carriers have agreements with each other, billing works the same way and won't make any difference. The SID setting in your phone affects how the phone searches for towers only, but it WILL NOT make any difference on how the system bills you. The only difference you will see is probably on the display, but who cares about what the display says if you know what you're doing. As far as changing the tower preference, this is only mandated by the IRDB and only AT&T can change this. IRDB is the list of SIDs your phone is allowed to use. There's no way for you to change the IRDB. By the behavior you described the phone has, it appears that your IRDB has Cingular listed as a preferred carrier, while AT&T is the home carrier. Again, whatever SID you use on the phone will not make any difference, but if it makes your phone lock to Cingular first then leave it like that.
How does a person go about checking which SIDs are available in his local area? I am in a 'no man's zone' about 1.5 miles north of Vicksburg, MI 49097 and I can watch my phone flip back and forth from analog to digital. There is a new tower about three miles from me but I don't know what services are available on it. Does anyone have any ideas?
I thought that there was a way to do it via the Field Test, but I haven't had any luck with it. I knew that AT&T had a reciprocation agreement with Cingular, so I went to this web page: http://www.the-mobile.net/psid/index.asp and found the Home SID for Cingular and changed my phone accordingly. -Marc
In some cases changing the SID can make a difference in some areas and depending on how the IRDB is programmed. However, the IRDB (Intelligent Roaming Database) will have the last word as to which carrier the phone will prefer.
AZO, You can try changing the SID, but I tried to do the same thing and had no effect on my Alltel V60i.....Are you in an area that was formerly CenturyTel? If so, the upgrades are on the way...i know here, Alltel plans to turn on 5 towers next Monday (17th of Feb)......I assume that they are probably doing that in other places as well. BTW...The SID that I entered into my phone was the SID for the old CenturyTel TDMA network....The only reason I entered it was so that the phone would quit switching back and forth between roam and home at my house.....didn't work.....Still shows 1038 to be a roaming SID even though it is entered into NAM 2 Good luck, Brad
DemoMan, you're right. I am on an old Centurytel area. Alltel took over around September 02. We're about 11 miles south of I94 and 7 miles east of US 131, the two major highways in this area. I'm not sure how far a tower will transmit under normal conditions, but I've got the feeling we're right on the verge of out of range. I'll keep my fingers crossed for some new towers around here, too. Thanks for the info. AZO (airport designation for Kalamazoo International Airport)
My understanding is...if conditions are right and the signal is not directed to go a certain way, a digital CDMA tower's signal reaches about 15 miles from the center (tower) in all directions. Since the tower is along a major highway, the signal is probably directed to follow highway....that would explain why this signal is so weak near where you are......
How does one go about changing the SID? I'm a Sprint customer and don't really think I do/should have had a need for it, but nonetheless, I am curious about how one goes aboout changing the SID that one's phone connects too.
TDMA and GSM towers transmit as far as CDMA or further (depending on the network load that the CDMA tower is accommodating. As more people join a CDMA tower, the covered area shrinks). It is illegal to change the SID on your phone. Most contracts also state that they can terminate your account or impose extra charges if x% of your calls aren't on towers that they own. If they decide to terminate your account for using others towers too often, you do have to pay the termination fee.
I guess it depends on your provider....some providers must not forbid you from changing the SID.....an Alltel agent told me how to change the SID......Funny that an agent of the company would tell me how to do it if it is so bad. As for the distance that the signal travels, I cannot find the page that had the information that I read....but I can promise it wasn't a page hosted by Qualcomm or cdg.org.....this page was str8 forward....told the advantages and disadvantages of CDMA, TDMA, and GSM. I'll keep looking
There's a bit too much misinformation floating around this thread... - It is NOT illegal to change the SID in a phone. (ESNs/IMEIs/IMSIs, yes, but everything else is basically fair game.) - SIDs are NOT part of authentication/registration data exchanges. - In many cases, changing a phone's home SID will not change roaming behavior in any way -- all it will do is change the roaming indicator for a given area. -SC
And to continue roamer 1's excellent insight.... Changing the SID in a phone would only have one possible adverse effect. Your phone possibly preferring the other carriers system while in the home coverage area. And if the carriers do not have reciprocating agreements, this could lead to possible billing (in-home roaming) issues. Cell phones look for a match on programmed SID's first, then programmed SOC. If there is a match with what it sees broadcast, it stops and locks onto that carrier. If no match is found, then IRDB's for TDMA scan (in order)... Partnered SOC, Partnered SID, Preferred SOC, Preferred SID. If no matches are still found, then the phone looks at what is scanned and make sure the SID/SOC is not on the forbidden list before using what it finds.
And to continue Viceduke and Roamer1's excellent insight.... If no Home, Preferred or Favored SID is found on the air scan, then whatever SID found is used as long as it is not Forbidden by the IRDB. This SID will be considered Neutral by the IRDB. If no Neutral SID is found and a Forbidden SID is found, or in some cases, no signal at all, then of course "No Service" is displayed on the screen. Finally, I would like Northform to inform us where did he see the movie showing that changing the SID is illegal. In the midst of misinformation, the information rich providers appear
