Shocked Londoners had a hard time getting in touch with their families and friends today as a sharp surge in calls overloaded both the wireless and landline networks in the first few hours following explosions that rocked the city.
At U.K. wireless carrier Orange, there was roughly double the amount of traffic that would usually be expected on a normal business day, according to Stuart Jackson, a company spokesman. Vodafone Group Plc, T-Mobile, and BT Group Plc also reported high levels of calls.
At 02, call volumes were more than double normal levels, according to spokesman David Nicholas. But 02 bolstered capacity by putting twice the traffic on the same bandwidth. The sound quality suffered, but more calls got through, Mr. Nicholas said.
"For some customers, they may have experienced difficulties in getting through, but on the whole the network has coped," said Adam Liversage, a spokesman for BT Group, Britain's biggest phone company. Congestion problems eased during the day, he added.
The problems people encountered when trying to make calls were due to the great volume of traffic, not because the networks were damaged by the attacks, according to the companies. Customers in London may have had to try a few times before they were able to successfully place a call, and some people trying to contact phones located in the London area reported difficulty getting through. The carriers suggested people try sending text messages instead.
"Understandably we are experiencing significant network congestion but we are working closely with the emergency services," Vodafone said on its Web page Thursday. "In these circumstances, we would ask all of our customers in Central London to avoid making unnecessary or lengthy phone calls."
Orange, Vodaphone and O2 confirmed that they did not purposely shut down their networks after the explosions in London's underground railway system and a double-decker bus. When people started having trouble making cellular calls, there was speculation that the networks might have been disabled by the carriers because of fears about explosives being set off by cellphones, as was suspected in the Madrid train bombings in 2004.
The police did ask phone companies like wireless carrier O2 for priority access for emergency services.
Ilana Levin, a London-based research executive originally from Toronto, Ont., uses a cellphone from Orange, one of the major mobile service providers in England. When she heard about the bombings Thursday morning, she called her parents in Toronto on a landline and was able to immediately reassure them that she was alright. However, she said cellphone reception was intermittent at best throughout the day. Ms. Levine said she was able to send text messages mobile-to-mobile, but getting reception on actual voice calls was difficult.
"You just had to keep hanging up and trying again," Ms. Levin said.
Each time she tried to use her cellphone, she would either get a busy signal or a message saying there was no network coverage, she said.
Eventually, she started using e-mail to get through to her friends and family to let them know she was alright.
"I think people just became aware that there would be difficulties using their cellphones, so they started using email," she said.
High-speed Internet services and voice-over-IP (VoIP) phones weren't affected by the increased network traffic volumes, British carriers said.
