Continuing our discussion from last time about how to identify a user’s location when the caller’s mobile handset is connected to a wireless router or femtocell, we checked in with Sprint. Sprint uses a femtocell in the home to support the company’s Airave service.

According to Sprint, Airave provides full E-911 support in all markets where the service is offered. In a prepared statement, the company noted: “Customers should rest assured that a 911 call will be routed as required by law to the appropriate Public Safety Answering Point (PSAP) regardless of whether the call is made on Airave, or the macro network. The Airave calculates its location automatically every time it is powered up and provides location based 911 services where a PSAP is capable of receiving location-based information.”

T-Mobile relies on registering the Wi-Fi router’s stationary physical address with PSAP agencies so that when a call is placed using the wireless router, the user’s location can be reported appropriately.

In both cases, once the user leaves the wireless access point and returns to the transmission domain controlled by the public cellular network base station, the location is reported using the triangulation or Assisted GPS we discussed in our last newsletter.

However, a few sticking points remain about the geographic specificity and regulatory reporting requirements on the user’s location for a VoIP call vs. a mobile call. For clarification on this point, we turned again to Brian J. McNiff who leads the marketing, business development and product management teams at TechnoCom. TechnoCom supplies five of the nation’s largest mobile network service providers with location assurance management.

According to Brian, one aspect to resolve is the fact that regulations for VoIP and mobile caller location identity differ both in terms of pinpointing the user’s location and in reporting requirements. He anticipates that the location and reporting requirements for both will converge saying that “we’re not there yet, but we believe the requirements will be [the same] soon in terms of performance and reporting.” To bypass the inefficiency of manual processes that were used in the early days of location-based services, TechnoCom uses a mediation platform and server that can manage the required performance and reporting.

Steve Taylor is president of Distributed Networking Associates and publisher/editor-in-chief of Webtorials. Larry Hettick is a principal analyst at Current Analysis.