implementation of a "911" service

One of the stumbling blocks of Voice over IP (VOIP) has been the implementation of a "911" service. The following story appeared on the newswires on Tuesday:

AT&T Internet call service to require location
Tue Oct 11, 2005 2:52 PM ET
WASHINGTON, Oct 11 (Reuters) - AT&T Corp. <T.N> said on Tuesday it would suspend Internet phone service for subscribers who fail to keep their location up to date when they move around with the mobile service. Internet telephone service, known as Voice over Internet Protocol, can be used anywhere a subscriber has a high-speed Internet connection, which are becoming more common around the world.
That mobility has prompted concerns by U.S. communications regulators who worry that if a subscriber does not register his location in the United States, emergency authorities may not be able to find the person if he dials 911 for help. The Federal Communications Commission in May ordered VOIP carriers to provide 911 emergency services by Nov. 28, including connecting calls directly to dispatchers.
Carriers, like AT&T and the biggest U.S. VOIP provider, Vonage Holdings Corp., will also have to provide callers' numbers and addresses to dispatchers. There are about 3 million subscribers in the United States to VOIP, a cheaper alternative to traditional phone service. AT&T said it would use a telephone adapter to determine when a VOIP phone has been disconnected from the network and reconnected, prompting a query to the subscriber to confirm or update his or her location.The customer can either confirm the location has not changed or receive directions for updating it.
"If the customer confirms that she has moved her service from the existing registered location address, service will remain suspended until she registers a new primary location address," Robert Quinn, AT&T vice president for federal government affairs, said in an Oct. 7 letter to the FCC.
The subscriber still would be able to dial 911, according to Quinn. However, AT&T said there is not yet a way to confirm the customer's location. "This is the best technology has to offer at this time," AT&T spokeswoman Claudia Jones said. The FCC has said it eventually plans to require carriers to provide the customer's location on their own.
AT&T said it would not offer to new customers its VOIP service in areas after Nov. 28 where the company cannot provide 911 capabilities. The company, the No. 1 long-distance carrier, is being acquired by SBC Communications Inc. <SBC.N>, the No. 2 local telephone company. The FCC adopted the rules after several high-profile incidents in which people only reached an administrative or business line at a 911 emergency call center when they used a VOIP phone. The requirements only apply to those providers that connect calls to and from the public telephone network.
a.Why is it that traditional home telephone service does not suffer from this 911 problem, while an Internet-based telephony service does? What about cellular service?

b. As the next-to-last paragraph mentions, the FCC seems to be expecting the VOIP carriers in the future to be able to verify location automatically without a user's confirmation. Is this consistent with the perspective of identification as an emerging general purpose technology?