By DIONNE SEARCEY, SARMAD ALI and ALMAR LATOUR Staff Reporters of THE WALL STREET JOURNAL
Like many London residents, when Marianne Dunn heard about the bomb attacks, she immediately tried to call colleagues on their cellphones to see if they were all right. But all the computer trainer got were busy signals. Then Ms. Dunn heard on the radio that authorities advised people to use text messages via cellphones in lieu of calls. "I got the message through using text," she said.
A sudden surge of voice traffic following yesterday's attacks overloaded many British cellphone networks for at least three hours. The calling volume was so high that even parts of the landline networks were congested: The network of BT Group PLC, the largest U.K. landline operator, experienced disruption, as did that of Cable & Wireless PLC, another large phone company.
Several newer communication tools appeared to hold up better, including text messages sent via cellphone keypads, wireless email and instant messaging sent over computers. And some state-of-the-art, "third-generation" cellphone networks, which are equipped to send and receive video images and music as well as calls, also continued working. Some customers even recorded images of the bomb damage on their cellphone cameras and sent them to media outlets.
The communications problems indicate that, at least in Britain, cellphone-system operators may not have learned many lessons from the Sept. 11, 2001, terrorist attacks in the U.S. And landline networks, which previously were thought to be more robust, also face challenges. After the World Trade Center attacks, landline phones generally held up in New York, though there were some congestion problems, while cellphone networks were clogged.