Sprint, T-Mobile respond to the femtocell E-911 caller location problem

The femtocell E-911 caller location problem, Part 2

VoIP, unified messaging, products and services

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.

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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.

Brian believes that the best approach to the problem will be found in using IP-Multimedia Subsystem (IMS) as the common factor between Wi-Fi, WiMAX, and cellular location services and he further believes “the solution will probably happen in Europe first because the (American) wireline companies are reluctant to give up their wireline revenues” associated with FMC technology. He concludes (and we agree) that “users expect to be found whether on a mobile or fixed [E-911] connection.”

CORRECTION: A reader correctly noticed in our last newsletter that we had an incorrect range for locating wireless callers who contact E-911. Here's the FCC text taken from page 7 of the 1999 FCC ruling found here. The FCC said: "We adopt the following revised standards for Phase II location accuracy and reliability: For network-based solutions: 100 meters for 67% of calls, 300 meters for 95% of calls; For handset-based solutions: 50 meters for 67% of calls, 150 meters for 95% of calls." Requirements on both Mobile and VoIP E-911 notification are being reviewed by the commission and are likely to change based on new technology.

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