The bid to create a top-level domain for mobile devices, announced on Wednesday, will have even more support behind it by its official unveiling on Monday, according to a Microsoft spokesman.

The group of big companies behind the plan - Microsoft, Nokia, Vodafone, Hewlett-Packard, Hutchinson 3G, Samsung, Sun, Orange and the GSM Association - hope to defuse criticism with a period of consultation. It has also started to explain what exactly will be so different about a domain for mobiles.

"We expect other companies to join us before Monday when the bid will be submitted to ICANN," said Annemarie Duffy, Microsoft's PR and marketing manager for mobile devices in EMEA. "We've had a lot of interest from other companies in both the PC and mobile world."

She would make no comment on whether negotiations are going on with potential rival bids, choosing to put more flesh on the benefits that a mobile TLD would offer.

The group's nine major players have already signed an agreement to set up a registry if ICANN will allow it. "We want to make sure that the top-level domains represent the best interests of the community," said Duffy. "And we are demonstrating broad industry support."

The domain would provide a "clean environment" for mobile users and content, said Duffy. One advantage would be to offer less confusion: "At the moment, do I go to techworld.com/mobile, techworld.mobile.com, or mobile.techworld.com?" [our name inserted - Ed] It would be much easier to go to sites ending ".mob" or ".mobile", she said.

More importantly, the domain could let content providers offer better quality of service, says Duffy: "Today, if a user wants to stream music or video from the Internet to a mobile phone, the experience is not predictable."

A new top level domain could be set up to encourage the use of IP version 6, and SIP, improvements to the Internet's basic protocol intended to improve services. "It is still early days, but our plan is that the domain will support IPv4 and IPv6, but will encourage any company that registers a second-level domain, to move towards IPv6, and to use the new features of IPv6," she said. It's not likely to be possible to make it an all-IPv6 domain at this stage, she added.

The final benefit she mentioned, is to allow mobile devices to be IP-addressable. Mobile devices themselves will offer services to the Internet, she said: "If I get off a plane in a different country, my family will want to access photos stored on my device."

To have the device addressable in a simple way, it has to have an IP address. If it pops up in a different part of the network, the DNS service needs to be updated very quickly, she said. She would not be drawn, however, on the actual technology involved here.

In fact, pretty much all aspects of the proposed mTLD are under wraps for now, though Duffy reckons the fairness of the proposal will be pretty well defined by ICANN's guidelines for any TLD. If not, end users will have plenty of opportunity to comment, apparently, since "we are going to have a number of policy formation groups, representing users and business leaders, to make sure the joint venture addresses the need of the broader community at large," she said.

The least important part of the new domain, and the part everyone wants to know, of course, is still unknown. The actual name is up to ICANN - though ".mob" and ".mobile" are being bandied around.

However, there is one incidental detail that we do know. The Irish Times has reported that the proposed registration authority, if it is granted, would be located in Ireland, like the .info domain.