AT&T, T-Mobile open networks, offer free roaming for Sandy relief

AT&T and T-Mobile USA are taking "extraordinary measures" by opening their networks in New York and New Jersey to each other to help customers' affected by the recent hurricane communicate.

The two major U.S. cellular networks said in a joint statement overnight that they have entered an agreement to enable roaming on their networks to customers of both networks impacted by the path of the storm. In doing so, it allows customers on T-Mobile USA to seamlessly use AT&T operational cell masts and vice-versa by whichever network is most operational in their area.

In the joint statement, the cellular networks said there will be "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."

AT&T, the second-largest U.S. network with around 105 million subscribers, and T-Mobile USA, the fourth-largest U.S. network with 33 million subscribers, both use GSM and UMTS network standards allowing the two networks to work seamlessly alongside each other. This means data and voice traffic can be shared across the two networks.

Meanwhile, cell mast recovery continues but could take weeks before the service is restored across the 10 states hit by Sandy on Monday night. 

The U.S. Federal Communications Commission said on Wednesday that around 25 percent of the U.S.' wireless companies' cell sites in the 10 states affected by Hurricane Sandy were downed by the 'superstorm,' and warned that things may get worse before they get better.

An AT&T spokesperson told ZDNet on Tuesday that it was "experiencing some issues in areas heavily impacted by the storm," and was in the "initial stages of performing an on-the-ground assessment of our network." 

T-Mobile USA said in a statement on its website that it was also "assessing the situation" as a result of "service disruptions" in some areas of the storm's path.