The National Emergency Number Association (NENA) today announced the publication of its i2 standard, which is designed to let voice-over-IP (VoIP) providers route emergency calls through the legacy E-911 system.

NENA officials described i2 as an “interim solution” that lets VoIP providers offer E-911 without requiring changes by the public-safety answering point (PSAP). As a result, i2 calls for VoIP providers to secure access to the selective router—typically owned by an incumbent phone carrier—as the FCC’s E-911 order dictates.

To date, VoIP providers typically have been able to provide PSAPs with caller-location information for users that are fixed, or remain in one place. VoIP providers with nomadic and mobile users have had difficulty meeting the FCC regulations.

NENA Technical Issues Director Roger Hixson said full implementation of i2 would let a VoIP provider offer location information for nomadic users but not mobile users.

Publication of the i2 standard is a precursor to NENA’s next-generation standard, or i3, Hixson said. The much-anticipated i3 standard—built on an IP platform to receive emergency “calls” from all communications devices without requiring access to a selective router—could be completed by April, he said.

“We expect in January to release a technical requirements document [and publish the i3 standard] in the latter part of the first quarter,” Hixson said.