I used to sell cell phones, so I found this interesting
Katrina outages reveal phone system quirks
Some cell users can make calls, but not receive them
The storm also revealed some quirks of how the telephone system works: Some Gulf Coast residents who had fled far away before the storm hit were finding that their cell phones could make calls but not receive them.
The problem affected only those whose cell phone numbers came with area codes from the affected region such as 504 for New Orleans.
Gary Morgenstern has been unable to dial the cell phones of his daughter or her boyfriend, both students at Tulane University, since Monday even though they evacuated from New Orleans late Saturday and have been driving west through Texas and Arizona.
As a result, Morgenstern’s been sending text messages to her phone when he wants her to call so he can find out how they’re doing.
“My daughter could be sitting next to me in New Jersey and I could be having the same problem,” said Morgenstern, a public relations executive for AT&T Corp., noting that his daughter and boyfriend have different national providers.
Wireless industry experts said the problem revolves around basic network architecture.Usually, when cell users take their phones outside their local area code, the wireless network checks back with a network computer in the home market to verify account information and let the service provider know where to route calls.
With communications to the home switch in New Orleans and nearby area codes cut off by the storm, cellular operators quickly made arrangements on their networks and with one another to automatically connect any calls dialed from one of those phones.
Incoming calls, however, can present a problem because the phone network can’t determine where to route those calls without first checking in with the New Orleans switch to find out where the cell user is located.
http://www.msnbc.msn.com/id/9120503/
No comments:
Post a Comment