Statement from AT&T saying that cellphone service issues are linked to "congestion" contradict rumors that the service was shut down due to fears that cellphones were being used to activate explosive devices in the Boston area.
Cellphone congestion following the Boston Marathon bombings has led to many dropped calls, but according to wireless carriers, service has remained operational.
"There was no damage to the Verizon Wireless network, which is seeing elevated calling and data usage throughout the region since the explosions occurred," reads Verizon's statement, sent to NBC News.
Cell towers are like highway on-ramps — if too many people try to get on at once, things get slow. And the rise of smartphones means people are on their phones for many reasons, all competing moment-to-moment for access to precious cellular bandwidth.
Carriers anticipated increased call demand around Boston's Copley Square area because of the marathon. They boosted network capacity through technical means and by bringing in temporary mobile towers. Without the extra capacity, call drops and poor connectivity may have been even worse. Regardless, the events that transpired led to an unanticipated amount of cellphone use, hence the issues.
Sprint's Crystal Davis told NBC News that despite "above-normal call blockage," Boston's Sprint network is "still operating." AT&T's official Twitter account tweeted, "Boston customers may have issues w/wireless voice & data service due to spike in network activity," but reported no outage.
During emergency situations, many people reach for their cellphones to let loved ones know they are OK. Invariably, the phones are already ringing nonstop from people who are seeking them as well. In times like these, the best advice is to make fewer calls, and use other means of communication.
"Customers are advised to use text or email to free up voice capacity for public safety officials at the scene," said Verizon. AT&T gave similar advice, and has made its Wi-Fi network around the marathon finish line free to the public for the time being.
The Associated Press earlier cited an unnamed "law enforcement official" as saying that "cellphone service has been shut down in the Boston area to prevent any potential remote detonations of explosives." According to cellular carriers, this has not been the case.