• AT&T and T-Mobile temporarily share networks in New York City and New Jersey


    Just got the release. Both AT&T and T-Mobile are allowing their users to roam on each other's networks in areas that have been hit by Hurricane Sandy.

    Good job T-Mobile and AT&T!
    Today in the wake of destruction caused by Hurricane Sandy, T-Mobile and AT&T are taking extraordinary measures to make sure our customers can stay in touch. AT&T and T-Mobile have entered into an agreement to enable roaming on their networks to customers of both companies in the heavily impacted areas and where capacity is available and for subscribers with a compatible device.

    T-Mobile and AT&T have taken steps to help our customers in the following ways:
    · Customers will be able to place calls just as they normally would, but their calls will be carried by whichever network is most operational in their area.
    · This will be seamless for AT&T and T-Mobile customers with no change to their current rate plans or service agreements even if the phone indicates the device is attached to the other carrier’s network.
    · T-Mobile and AT&T both utilize network technology based on GSM and UMTS standards, which allows for this sharing of voice and data traffic.
    This article was originally published in forum thread: AT&T and T-Mobile temporarily share networks in New York City and New Jersey started by Scottish Skyedance View original post
    Comments 30 Comments
    1. GSMinCT's Avatar
      GSMinCT -
      Good for them. Although most people in that area have Verizon, and even the mighty Verizon seems to be a mess.
    1. sprke81's Avatar
      sprke81 -
      So it would be interesting to know what it takes to implement this...couple guys on a computer playing with roaming settings? Do they have to play with every towers software in that area or can they choose a "block" of towers and do a mass update? How would they make the phones not have a network preference and choose whatever's available? I have a lot of questions lol...
    1. howard's Avatar
      howard -
      Quote Originally Posted by sprke81 View Post
      So it would be interesting to know what it takes to implement this...couple guys on a computer playing with roaming settings? Do they have to play with every towers software in that area or can they choose a "block" of towers and do a mass update? How would they make the phones not have a network preference and choose whatever's available? I have a lot of questions lol...
      Maybe they already have this all set up from when AT&T tried to buy T-Mobile.

      They went to the computer's recycling bin, undeleted the AT&T-Mobile program and then ran it.
    1. lordkaosu's Avatar
      lordkaosu -
      Now we can all hold hands.
    1. zephxiii's Avatar
      zephxiii -
      and sing Kumbaya!!!!!!!!!!!!!!!!
    1. Barry ATL's Avatar
      Barry ATL -
      Quote Originally Posted by sprke81 View Post
      So it would be interesting to know what it takes to implement this...couple guys on a computer playing with roaming settings? Do they have to play with every towers software in that area or can they choose a "block" of towers and do a mass update? How would they make the phones not have a network preference and choose whatever's available? I have a lot of questions lol...
      This is very fuzzy memory: With CDMA and TDMA, a database in the phone had to be updated. It was a very un-exact science. With GSM the blocking is done at the tower. It has to do with the background communications that goes on between GSM towers worldwide.

      With GSM all of the towers world wide are assigned a numbering system of some sort. They are organized by carrier, then regions, and so on until it gets to the individual tower. Back from the days when AT&T and T-Mobile shared a network in CA, I seem to remember that they can block or unblock a region with a few keystrokes.

      Probably as things are gotten more advance, they have a map graphic interface to work with.
    1. Nucleartx's Avatar
      Nucleartx -
      Gsm roaming is changed from the back end. Att or T-Mobile just have to "allow" Sim cards from another carrier to register on their network. It can be even set to individual towers. Cdma phones have to have its prl updated in many cases to allow roaming as the provider gets to pick whose network they are allowed on.

      Sent from my SGH-I747 using Tapatalk
    1. GSMinCT's Avatar
      GSMinCT -
      Did T-Mobile have their PCS 3G up before the storm? I guess EDGE would be better than nothing, but I feel like GSM/EDGE would overload very quickly compared to UMTS.
    1. Barry ATL's Avatar
      Barry ATL -
      The two companies did the same thing in MS and LA during Katrina. Basically, this is for places where a tower or two is down. Maybe the other company has a tower closer that is working.
    1. Squid7085's Avatar
      Squid7085 -
      I wonder if it connects to the closest and highest signal tower, AT&T or T-Mobile first, or tries to connect to an AT&T tower first, even if there is a working T-Mobile site next door. I would have to assume the later.
    1. Jordan T's Avatar
      Jordan T -
      Quote Originally Posted by Squid7085 View Post
      I wonder if it connects to the closest and highest signal tower, AT&T or T-Mobile first, or tries to connect to an AT&T tower first, even if there is a working T-Mobile site next door. I would have to assume the later.
      Almost certainly the latter, to do the former requires more network integration and SIM card programming - I'm not sure what's involved but it HAS been done (during the AT&T/Cingular integration and presently during the ongoing T-Mobile/Orange integration in the UK)
    1. i0wnj00's Avatar
      i0wnj00 -
      Quote Originally Posted by Scottish Skyedance View Post
      T-Mobile USA users should have lots of fun with roaming on AT&T.
      Once the data limit has been reached, all data stops until the billing cycle ends or when connected back to a working T-Mobile USA site.

      Quote Originally Posted by Barry ATL View Post
      With GSM all of the towers world wide are assigned a numbering system of some sort. They are organized by carrier, then regions, and so on until it gets to the individual tower. Back from the days when AT&T and T-Mobile shared a network in CA, I seem to remember that they can block or unblock a region with a few keystrokes.

      Probably as things are gotten more advance, they have a map graphic interface to work with.
      That's pretty much it. You really haven't forgotten much.

      Quote Originally Posted by sprke81 View Post
      So it would be interesting to know what it takes to implement this...couple guys on a computer playing with roaming settings? Do they have to play with every towers software in that area or can they choose a "block" of towers and do a mass update? How would they make the phones not have a network preference and choose whatever's available? I have a lot of questions lol...
      The "block" you're referring to is called the Location Area Code (LAC) so both AT&T and T-Mobile know which ones they will allow access to. At least, from my observations both GSM/EDGE and HSPA+ use unique LACs so the carriers actually know two things 1). Is it GSM or HSPA+? and 2.) The given boundaries.

      Your device already knows what networks it can "see", it's just a matter of allowing access to it.
      If I do manual network select with my T-Mobile SIM card any device it will do a scan and present me with a list of available networks...
    1. brad15's Avatar
      brad15 -
      Quote Originally Posted by i0wnj00 View Post
      T-Mobile USA users should have lots of fun with roaming on AT&T.
      Once the data limit has been reached, all data stops until the billing cycle ends or when connected back to a working T-Mobile USA site.
      What i read is implying neither one will be imposing the limits of roaming, so im assuming T-Mobile will not be doing any 3G throttling nor data caps in those areas, as that would make the most sense
    1. Shizam76's Avatar
      Shizam76 -
      I thought because of the break up, there was a new 7 year roaming agreement between the two carriers? That hasn't been mentioned since the breakup.
    1. Jordan T's Avatar
      Jordan T -
      There is a roaming agreement, yes.
    1. buckspaul's Avatar
      buckspaul -
      this seems to benefit tmobile customers since the option to manually select networks is still available. this option is long vanished on att years ago you dont know your roaming tmobile anyway the network is masked to say att when using any non att us network.
    1. Shizam76's Avatar
      Shizam76 -
      Quote Originally Posted by buckspaul View Post
      this seems to benefit tmobile customers since the option to manually select networks is still available. this option is long vanished on att years ago you dont know your roaming tmobile anyway the network is masked to say att when using any non att us network.
      I can tell when I am off the AT&T network, because the few times that I've lost signal, my phone camps on a tmobile tower and my data icon goes away because I have my phone set to not allow data roaming. That's how I know I'm off AT&T's network. I will show signal bars on T Mobile but when I try to make a call it says emergency calls only. Sucks. I thought the roaming agreement went both ways.
    1. silentjudge's Avatar
      silentjudge -
      Perhaps that wasn't one of the areas where the roaming agreement included?

      Sent from my LG Nitro HD
    1. i0wnj00's Avatar
      i0wnj00 -
      Quote Originally Posted by brad15 View Post
      What i read is implying neither one will be imposing the limits of roaming, so im assuming T-Mobile will not be doing any 3G throttling nor data caps in those areas, as that would make the most sense
      Quote Originally Posted by http://www.engadget.com View Post
      ...the two have struck a deal to share their GSM and 3G networks in the area with no roaming fees or plan changes while the networks come back
      Since the article mentions no plan changes it means that the existing terms of the plan apply, whatever they may be. That's unless somebody can vouch otherwise.
      I think this is more for people who are worried about being charged for off network roaming more than for anything else.
    1. Shizam76's Avatar
      Shizam76 -
      Quote Originally Posted by silentjudge View Post
      Perhaps that wasn't one of the areas where the roaming agreement included?

      Sent from my LG Nitro HD
      Shame on me for thinking there was a lot of areas of open roaming now. I just assumed that covered both systems nationwide.