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Location-Based Routing For Wireless 911 Calls


1. This Notice of Inquiry (NOI) seeks to determine the best way to avoid delay in the response to some wireless 911 calls that results from the manner in which such calls are routed in the current 911 system. When someone seeking aid initiates a wireless 911 call, the expectation is that the call will be directed to and answered by the public safety answering point (PSAP) that has the ability to promptly dispatch aid to the caller’s location. However, this may not always happen, because the current 911 system is configured to route wireless 911 calls to PSAPs based on the location of the cell tower that handles the call, which may be some distance (varying from a few hundred feet to several miles) from the caller’s location. In such circumstances, particularly in the case of wireless 911 calls made near jurisdictional borders, the call may be answered by a different PSAP from the one that serves the caller’s location. For example, a wireless 911 call originating in Washington, D.C. may be received by a cell tower in nearby Northern Virginia, causing the call to be routed to a Virginia PSAP. In such situations, the PSAP to which the call is initially routed must transfer the call to the PSAP that is responsible for call-handling and dispatch of emergency response to the caller’s location.

2. Each time a wireless 911 call is “misrouted” and transferred in this manner, the call transfer process consumes time and resources in both the PSAP that initially receives the call and the PSAP to which the call is transferred, and the process ultimately delays dispatch and the ability of first responders to render aid. We have reason to believe that 911 misroutes are not occasional or isolated and in fact occur frequently, on occasion with deadly consequences. The importance of addressing this issue is escalating as the public is increasingly dependent on wireless networks and devices for access to 911.

3. This Notice of Inquiry explores how the delays that arise from misrouting of wireless 911 calls can be avoided, possibly resulting in faster response times, via the implementation of location-based routing solutions. Historically, legacy approaches to wireless 911 call routing have relied on the location of the cell tower that handles the call rather than on information pinpointing the caller’s location because technology used by wireless carriers to generate caller location information took too long to be useful for initial call routing. However, as discussed in greater detail below, recent advances in location technology suggest that in many situations it is now feasible to pinpoint the 911 caller’s location quickly and accurately enough to support the initial call routing determination.

4. We believe transitioning from tower-based routing to location-based routing would significantly reduce the number of wireless 911 calls that must be transferred from one PSAP to another and, therefore, have determined that location based routing would be in the public interest and should be encouraged and actively facilitated. Moreover, adoption of location-based routing could provide an incentive for PSAPs and wireless providers to transition to Next Generation 911 (NG911) because NG911 systems are designed to route calls using caller location information obtained in real time. However, while many location-based routing methods are promising, uncertainty remains regarding their reliability, the time required to develop necessary standards, and the potential transition costs of implementing location-based routing on current wireless 911 systems.

5. We believe this Notice of Inquiry is the most appropriate initial step in evaluating this transition. This will allow for the development of a more complete record regarding the technical and operational implications, limitations, deployments, and best common practices of location-based routing and the costs and benefits of different location-based routing methods.

READ MORE HERE: Location-Based Routing For Wireless 911 Calls 

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