In a recent post I wrote called Dial SIP in an Emergency, I talked about new I3 standards emerging from the National Emergency Number Association (NENA) which will change the way that we interact with emergency services personnel and which may offer several more communications options.

In this post, I'll dig into more of the details of what NENA is proposing and examine the implications for vendors and consumers.  The overall telecom voice network has been moving aggressively toward adoption of Voice over IP during the last couple of years and NENA has been devising specifications which are designed to run over IP networks.  The Session Initiation Protocol (SIP) is a lynchpin for the efforts.  One of the key benefits of SIP is that is can support multiple types of media.  So in addition to voice for emergency services, many consumers would like options to make emergency calls using SMS (texting) or video.  In principle, SIP is well suited for this, but the communications won't work unless they are supported by the consumer, the network and the Public Safety Answering Points (PSAPs).  As I noted in the last post, automatic incorporation of location information is also important, so there are efforts afoot to make sure the IP-based standards will capture location information, even if the user is on a mobile phone or Voice over IP device. 

At the heart of NENA's new approach is the adoption of communications over an IP network.  NENA has dubbed these next generation IP networks ESInets (Emergency Services IP Networks).  An ESInet is essentially a kind of intranet for use by the emergency services community for a particular state or region.  Today there are over 6000 PSAPs in the United States.  Each PSAP acts as a tiny call center, supporting both inbound calls and dispatching of services.  In the new IP connected world, geographic limitations are less critical, so it's anticipated that a regional ESInet could service the equivalent of many PSAPs and allow for efficiencies such as consolidation of agent resources.  Another important goal of the NG 9-1-1 work is to enable much better communication between different PSAPs, so that if an emergency call comes into the "wrong service location," it can quickly be re-routed to a better location which has more local knowledge and access to applicable emergency resources such as police, fire trucks and EMTs. 

The NENA I3 architecture will have a familiar look for those who are acquainted with the IP Multimedia Subsystem (IMS) where an IP core connects to other access networks at the network edge.  Before IP callers are granted access to the ESInet, a Border Control Function (BCF) will execute various security functions, such as examining the IP call characteristics and authenticating the incoming call.  The BCF acts as a specialized Session Border Controller which will execute the policy rules for a particular ESInet.  Since NENA anticipates a long network transition where IP and circuit-switched emergency services will co-exist, I3 includes another network element known as a Legacy Network Gateway (LNG). The LNG is a specialized integrated media gateway solution which connects existing circuit switches, also known as Selective Routers, with the ESInets.  The ESInet provides an IP-enabled bridge between network resources (circuit-based or IP) and the various types of PSAPs.   PSAPs currently connect directly to Selective Routers via a variety of circuit-switched protocols, but an ESInet will enable PSAPs to invest in IP and accept calls from both IP and circuit-switched subscribers.  The PSInet acts as a kind of vetting and routing service to ensure that emergency calls get to the right place.  As ESInets get implemented, they will be able to accept calls from either IP or circuit-based switches, look up geographic information as needed and then rout the call to either traditional circuit-based PSAPs or the newer IP varieties.  So the ESInet concept is at the heart of the movement to support next generation emergency services over IP networks. 

Let's suppose a consumer wants to make an emergency call and use a new technique such as text or video to pass on the information.  What will it take for this to become available?  Let's use text as an example.  First, the consumer will need a communications device which can support text messaging.  Next, the network will need to support these types of messages.  In practice, this means the carrier of the voice and text services will need to agree to pass on these types of messages in the context of emergency services.  As in the case of a voice call, the call will work best if it can be sent forward along with geographic information stating where the call is coming in from.  This likely entails a database lookup to retrieve the location associated with the consumer's device. The call gets authenticated, then passed into the ESInet, where it will be routed to a PSAP associated with the geographic location.  Assuming the PSAP also supports incoming text messages, the text message and its geographical information can be passed to a PSAP agent, who can then communicate with the consumer, determine the problem and arrange for an emergency service response.  Voila, we have an example of emergency services that can be triggered by text messaging.  But this scenario won't become reality until the network standards are in place, and both carriers and PSAPs invest in equipment and software that implements the new standards.  

Dialogic has been following the NENA I3 standards work and has several partners who are actively involved in producing the standards and solutions which will bring I3 architecture and ESInets to life.  There is also similar standards work ongoing in other world regions such as within the European Union.  The early benefits of IP-based emergency services are likely to be in areas such as support for more accurate location information, new capabilities to cross connect emergency calls between regions and potential efficiencies through consolidation of PSAPs.  For vendors, this is an opportunity to participate in the build out of a much more robust class of emergency services networks.   As consumers, we can continue to encourage all of the stakeholders involved to make this important investment in our public safety and request support for additional types of media such as text and video on emergency calls.  Keep your eye out for new types of IP-based emergency services - coming soon to a community near you.