(CNN) -- Getting cell phone reception in waterlogged New York and New Jersey could get a bit easier.
In a rare moment of collaboration, wireless providers AT&T and T-Mobile have agreed to share networks in the challenging days following Superstorm Sandy, allowing customers to use whichever network gets coverage in their areas.
The combining of networks will happen entirely behind the scenes, so all customers need to do is dial out. They'll automatically be routed over whatever network is currently the strongest in their location.
There will be no roaming charges for customers of either company, and no need to change any settings, rate plan or service agreements.
Making calls across the Northeast has been difficult following Sandy, and New York and New Jersey seem to be the hardest hit. According to the Federal Communication Commission, about a quarter of cell phone towers in the 10 states were knocked out by the storm.
Repairing these towers will take several days or longer, and continued inclement weather could cause additional issues and repair delays. Some transmission sites that are still working are currently running on backup generators, which carriers hope will last until power is restored.
"Our assumption is that communications outages could get worse before they get better, particularly for mobile," FCC chairman Julius Genachowski said on a call with reporters Tuesday.
Only a very small number of 911 call centers had lost power, and those calls were being rerouted to working centers, according to the FCC.
The major cellphone carriers have shared varying amounts of information on their service outages following Sandy. Sprint said it was experiencing "service impacts," but that it could not provide a specific number for the amount of people without service. T-Mobile said that in New York CIty, 20% of its network was down. In Washington that number was 10%.
Verizon's New York City facilities were severely flooded, and the damages were still being assessed. The carrier said its networks were mostly doing well, but there were serious problems in lower Manhattan and general problems throughout New York City. The company did not give exact numbers for outages.
Verizon officials also cautioned that some customers in the Northeast might receive "all circuits are busy" messages when trying to make calls because of an unusually large volume of post-Sandy demand on the network.
AT&T was the most vague, only saying that it was monitoring its land line and wireless networks and working to restore service.
T-Mobile and AT&T did not give a timeline for how long this cross-company cooperation would last.
In a related act of corporate generosity, Comcast said it will offer free Wi-Fi to users in areas affected by Sandy, according to CNET.