E9-1-1 Location: What's the Big Deal?

Picture of Todd Piett By Todd Piett


Recently, issues with E911 location accuracy have been all over the news, even hitting the mainstream press like the Wall Street Journal and USAToday.  FCC Commissioner Jessica Rosenworcel, recently stated at the APCO Emerging Technology Conference “ you call 9-1-1 from a wireless phone indoors, cross your fingers”. 

Clearly, location is the most valuable single piece of information needed by 9-1-1.  It determines to where the call is routed, and is the basis of dispatching resources.  With over 70% of calls now coming from wireless, we are increasing dependent on E911 technology to determine the location of callers (see a brief primer on the different types of technologies in this post).  With that in mind, the FCC created location accuracy standards.  The infographic below gives a hint at the root of the issue for wireless location callers:


There are two separate standards based on the technology used by the wireless carrier to provide caller location.  Increasingly, carriers have moved off the network-based methods to GPS technology.  GPS chips have become standard in most phones and are heavily utilized by commercial applications.  While the standards for the different technologies are scheduled to merge into one standard by 2019, it’s important to note that whether a carrier utilizes Network-based technologies (essentially trilateralization – or using the signal strength from cell towers to determine a users position) or GPS technology, there are pretty significant gaps in how often an “accurate” location must be provided.

Recent reports from a number of public safety entities have highlighted that these accuracy standards are not being met, particularly for indoor callers.  The network-based approach has a distinct advantage over straight GPS approaches in indoor location where satellite signals have difficulty penetrating (it is important to note that many carriers today use a hybrid of GPS and network technology called A-GPS).  Interestingly, according a recent CTIA report titled “Setting the Record Straight”, a founding organization of the http://findme911.org/  coalition is a technology provider that has significant intellectual property around the network based approach and suffers financially as other technologies are used.  The report also claims that the accuracy reports being circulated are not completely factual, highlighting that many of the results were prior to re-bids being performed to get better location data.

Leaving the spat around E9-1-1 location technologies aside, and the accuracy or lack thereof of various reports, I’d like to look at some of the core issues around location being delivered to 9-1-1 that we’ve run into in deploying Smart911 and some of the cool solutions being developed by Rave and others to address those challenges:

Multiline VOIP PBX Calls – If you work in a PSAP with any large campus in the area you’ve probably struggled with the accuracy of PS-ALI data.  Callers often display as being at the main IT office even though they may be several buildings (or more) away.  Existing solutions are expensive, and many communities are reluctant or unable to enforce expensive PBX upgrades, or unwilling to place penalties, on businesses in their area even where legislation exists.  One approach we’ve been working on with several partners, is to leverage the existing network capabilities for routing calls but reaching “over the top” or around the network directly to the PBX switch itself to get accurate caller location.  The advantage being that there is no lag or expense in provisioning new lines or changes as well as the ability to provide much richer data than can be pushed natively through the 9-1-1 network (e.g. floor plans, on-site security personnel contact information, etc.).

Accuracy of indoor location – As highlighted in the reports on location accuracy issue put forth by California, parts of Texas and others, indoor location is particularly problematic.  As we near 40% of the U.S. population being “wireless only”, more and more 9-1-1 calls are being made from home over wireless networks.  Not only does this mean the x-y (or lat/long) coordinates are less accurate, but there is no z-coordinate on callers.  In other words, you may see that a caller came from the general area of a tall apartment complex when a call comes in with 50m location accuracy, but will not really be sure of which building and will have no indication of which floor the caller is on.  There are a couple of interesting solutions here.  At it’s very simplest, Smart911 provides the callers registered address or addresses. Telecommunicators simply match the ALI data with the nearby Smart911 addresses for a good starting point on where the caller may be in the event they cannot provide their location themselves. There is also an increasing amount of work on indoor locations using wifi, Bluetooth, magnetic fields, and even light spectrum.  In our testing, if properly configured some of these can provide a good augmentation to existing 9-1-1 location data when delivered in an “over the top” method such as Smart911 and matched with existing floor plans.

Remote Areas – as you can see in the infographic above, significant gaps are built into the standards for rural areas.  In fact, up to 40% of counties EXEMPT from any form of location accuracy standard the network based approach (this is primarily due to the fact that there tend to not be enough towers from which to triangulate, or they are all in a straight line along a main road).  Clearly, a hybrid approach of technology is necessary to get as much coverage as possible in remote areas. Similarly to the indoor location model, a pre-registered address can often be very helpful in identifying a wireless callers location.  In a recent incident, this simple address data was credited with saving the life of an epileptic caller in a rural community who dialed 9-1-1 from her cell phone while at home.

While there are lots of options from a technology perspective, I want to emphasize the most important aspect of caller location – a well trained telecommunicator.  Effective use of available technology coupled with proper interrogation techniques is key.  As the tools available to our call takers evolve, so too must the training and procedures.  As the vendor community continues to iterate and work with our clients on new features, it’s important to always couple technology and process.  One without the other is a recipe for disaster.

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Written by Todd Piett

Todd Piett joined Rave in 2005 and today runs the global organization that has its technology deployed at thousands of colleges, universities, businesses and communities. Prior to joining Rave, Todd was responsible for launching new products for Unica Corporation where he helped drive their successful IPO. Previously, Todd was VP of Product and Marketing for iBelong, a portal provider targeting affinity organizations and a Program Manager at Dell Computer where he launched Dell’s branded ISP. Todd graduated with honors from the United States Military Academy at West Point and holds an MBA from Harvard Business School. After graduation from West Point he served 7 years in the US Army as an aviation officer.


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