Reply
Thread Tools
Apoc's Avatar
Posts: 73 | Thanked: 79 times | Joined on May 2009 @ Virginia
#91
I see two possible options why this could very well be true.

1. AT&T *is* upgrading towers to support T-MO phones so they can make the big bucks off T-MO for data roaming at 3G.

OR

2. He was logged onto AT&T, but it was actually roaming and connected to a T-MO tower in the area, thusly getting 3G.

Just a thought.
 
Posts: 118 | Thanked: 26 times | Joined on Jun 2008
#92
Originally Posted by jomnoc View Post
Btw, the operator name changes if you travel outside the US. The only way in which this would not change here in the US is by an agreement with T-Mobile which I seriously doubt. In that way, the T-Mobile network would detect an IMSI that belongs to an AT&T SIM and then send back the AT&T operator name.
It's not a function of the network, it's a function of the SIM. It uses the same mechanism that causes network selection to be restricted when using a carrier's phone.

It does so happen that on current at&t SIMs that they only override networks in MCC 310, although several years back that wasn't the case, and no matter where in the world you went your phone would display "Cingular," and any time you scanned for networks they would all be named "Cingular."

I haven't investigated whether it's possible to disable that functionality on the N900.
 
Posts: 118 | Thanked: 26 times | Joined on Jun 2008
#93
Originally Posted by depu View Post
Odd that the speed test shows AT&T as the ISP though.

And i really dont think that TMo would show a different operators name *while* its their own network which is being used.
Of course it would have an at&t IP address. When roaming, your packets still transit your home network's GGSN. You're essentially tunneled back to your home network for data purposes.

The phone reading "AT&T" has nothing to do with T-Mobile. at&t's SIM forces the phone to say that no matter what network it's on. (As long as the mobile remains in the US, anyway)
 
Posts: 117 | Thanked: 44 times | Joined on Dec 2009
#94
Originally Posted by wierdo View Post
Of course it would have an at&t IP address. When roaming, your packets still transit your home network's GGSN. You're essentially tunneled back to your home network for data purposes.

The phone reading "AT&T" has nothing to do with T-Mobile. at&t's SIM forces the phone to say that no matter what network it's on. (As long as the mobile remains in the US, anyway)
Sorry i just dont get your meaning here in the first para. I was matching the 3G shown as network on the picture with the AT&T shown as the ISP. Tunneling is out of the question, you cant tunnel faster than your current network speeds. So *if* he is on ATT network, he should either not be shown 3G or by should be showing TMobile as the ISP.

Also if i remember right on network roaming, it will also show the name of the network which you are currently on, even if it is not your home network.
I was down at virginia around the new year and at some places it showed me ATT while i was using my Tmobile phone.
 
Posts: 118 | Thanked: 26 times | Joined on Jun 2008
#95
Originally Posted by Sheon View Post
can anyone else do a manual search and see AT&T 3G pop up?
Anyone who does this (using an at&t SIM) will only be determining whether T-Mobile has 3G at their location.

This is what I get in my area that has T-Mobile 3G. Since at&t doesn't allow in-market roaming here, I get "Access Denied" if I try to connect to it.

 
Posts: 117 | Thanked: 44 times | Joined on Dec 2009
#96
Originally Posted by jomnoc View Post
It is not possible that he is locking to LTE. N900 is not LTE capable. That is a fact. The radios are not made for that. Also, it cannot lock to the AT&T 3G network. It is not something about sw, it is about hw. Now, AT&T got some space in the 700 MHz spectrum back in 2008. This is most likely the freq they will use for their LTE deployment. (http://www.att.com/gen/press-room?pi...rticleid=25428). I would say that you are using the app to change the operator name. Btw, the operator name changes if you travel outside the US. The only way in which this would not change here in the US is by an agreement with T-Mobile which I seriously doubt. In that way, the T-Mobile network would detect an IMSI that belongs to an AT&T SIM and then send back the AT&T operator name. This does not sound logical but I have not tested this myself. One question, why the map that you are using to prove your speed shows that you connected to some server near Kansas if you say you are in Reno? Did I miss something?

@depu. 4G is a broad term. It can refer to more than one technology. LTE and Wi-Max are two examples of 4G technologies.
Yep. I know, Wi max really is not an option i consider for 4G on the n900 though .

And if ATT is running LTE on 700 band, then this should not be possible.

About the Kansas thing, i wouldnt think much of it, i live on the east coast and it shows the same for me. But come to think of it, i am on the Tmobile network not ATT like sheon, odd that we have the same end point for 3G.
 
Posts: 118 | Thanked: 26 times | Joined on Jun 2008
#97
Originally Posted by depu View Post
Sorry i just dont get your meaning here in the first para. I was matching the 3G shown as network on the picture with the AT&T shown as the ISP. Tunneling is out of the question, you cant tunnel faster than your current network speeds. So *if* he is on ATT network, he should either not be shown 3G or by should be showing TMobile as the ISP.

Also if i remember right on network roaming, it will also show the name of the network which you are currently on, even if it is not your home network.
I was down at virginia around the new year and at some places it showed me ATT while i was using my Tmobile phone.
T-Mobile doesn't program their SIMs to lie to you about the network you are using.

And yes, when you roam on at&t, you are using T-Mobile's Internet service. at&t (or other roaming carrier) only provides a backhaul from your present location back to your home carrier's network.

GPRS requests first go to the SGSN of the carrier you are connected to. Your phone then starts up a PDP context through the SGSN to a GGSN, which is identified by the access point. (epc.t-mobile.com, whatever) All your data traffic goes to the GGSN back on your home network. From then on, it's no different from you being on your home network.

As a T-Mobile user, if you found yourself roaming on at&t with an N900, you'd obviously only get EDGE speed, because that's all the network supports. Conversely, if an at&t user roamed on T-Mobile 3G, they would very possibly see 3G speeds, because at&t's GGSN is certainly capable of sustaining 3G transfer rates, given that they have a 3G network. As long as the interconnection between T-Mobile and at&t has the capacity available to sustain a high speed transfer, you'll get the faster speed.
 

The Following 2 Users Say Thank You to wierdo For This Useful Post:
Posts: 117 | Thanked: 44 times | Joined on Dec 2009
#98
Originally Posted by wierdo View Post
T-Mobile doesn't program their SIMs to lie to you about the network you are using.

And yes, when you roam on at&t, you are using T-Mobile's Internet service. at&t (or other roaming carrier) only provides a backhaul from your present location back to your home carrier's network.

GPRS requests first go to the SGSN of the carrier you are connected to. Your phone then starts up a PDP context through the SGSN to a GGSN, which is identified by the access point. (epc.t-mobile.com, whatever) All your data traffic goes to the GGSN back on your home network. From then on, it's no different from you being on your home network.

As a T-Mobile user, if you found yourself roaming on at&t with an N900, you'd obviously only get EDGE speed, because that's all the network supports. Conversely, if an at&t user roamed on T-Mobile 3G, they would very possibly see 3G speeds, because at&t's GGSN is certainly capable of sustaining 3G transfer rates, given that they have a 3G network. As long as the interconnection between T-Mobile and at&t has the capacity available to sustain a high speed transfer, you'll get the faster speed.
Ye, this makes sense. So basically it seems that he is doing a domestic roaming on the tmobile network while using an ATT sim.

So in a way it is possible to enjoy 3G on ATT network
Just have an ATT SIM and be in a place which has no ATT coverage and has Tmobile 3G coverage. Of course roaming charges and penalties apply.
 
Posts: 10 | Thanked: 1 time | Joined on Jan 2010
#99
I wanna roam off Tmo then too! =(
 
Posts: 118 | Thanked: 26 times | Joined on Jun 2008
#100
Originally Posted by alliswell View Post
I wanna roam off Tmo then too! =(
I wish I could also, but I have yet to encounter any T-Mo 3G I can roam on, and I was in several cities lit with T-Mo 3G last month.

There was one place I didn't try it, as I wasn't aware T-Mo had 3G there. When I'm back in Alabama next month, I'll definitely be checking it out. (There's a half-decent chance roaming is allowed there, as at&t's network isn't very good in SE Alabama, thanks to a severe lack of spectrum)
 
Reply


 
Forum Jump


All times are GMT. The time now is 05:15.