Bridging the gap to i3

There are many advantages to implementing IP-based solutions within a public safety answering point (PSAP) or network of PSAPs today. While there will be additional benefits introduced with the implementation of a National Emergency Number Association (NENA) i3 Standard for delivery of Emergency Communication between the PSAP and the Service Provider or Network, interim solutions present challenges to the PSAP. Understanding the role of i3 in an NG9-1-1 System and the status of the i3 Standard development is critical in making informed choices for equipment and services selection.

The right choice will enable immediate integration with the existing ESInet functionality without additional investments in interfacing hardware, and will facilitate system support for the i3 standard when defined through a non-disruptive software upgrade.

The Challenges and Opportunities of Internet Protocol

The rapid adoption of advanced wireless and internet technologies is transforming the ways in which the public communicates, and therefore how it expects to request emergency assistance. While this has defined a significant challenge for PSAPs, the migration to internet protocol (IP)-based and connected solutions is promising richer, more ubiquitous communications between PSAPs and from PSAPs to first responders, as well as enabling increased flexibility in system deployment.

SMS texting from mobile phones is an excellent example of a well established new communication method that has not yet been effectively integrated into the E9-1-1 system. Obvious technical hurdles, such as lack of location information and best-efforts message delivery, as well as operational considerations such as the existence of a single, universal SMS address for 9-1-1 emergency services all combine to make any current efforts to support emergency, caller-initiated texting unacceptably limited for public safety applications.

Within the PSAP today, IP technology is well utilized. Several customer premise equipment (CPE) solutions available, including the following call processing solutions: Sentinel®, Patriot®, VESTA®, Pallas™, VESTA® CS, and Sentinel® CM, utilizing IP networks to support advanced deployment options, such as geo-diversity and direct session initiation protocol (SIP) trunking between PSAPs.

This technology provides PSAP directors with unprecedented flexibility in the operation of their systems, and protects PSAP operations from the effects of large scale natural or man-made disasters.

New IP-based solutions such as the PlantCML NG9-1-1 management information system (MIS) solution, Aurora™, provides flexible, comprehensive reporting to call center management. The application can integrate seamlessly with new media, such as email and text messages and provides the analytics necessary to enhance operational efficiency, all on an IP network and internet browser interface.

Other technologies, such as DataSync provide GIS and database updates distributed over the PSAP local area network (LAN). The PlantCML Managed Services offering utilizes remote monitoring of customer premise equipment (CPE) systems to ensure optimal function.

Development of Industry Standards

While the benefits of the IP-enabled PSAP are being realized today, the promise of direct IP connectivity between the ESInet and the PSAP CPE, utilizing SIP to deliver both voice and data, is yet to be fully realized.

Many elements of the overall communications system are changing during the migration to NG9-1-1, including the wireless service providers, networks, databases, call center equipment, and land mobile radio systems. The end goal, as depicted by NENA in Figure 1, is a system of systems:

Figure 1 - NENA NG9-1-1 Blueprint

The creation and adoption of industry standards for the specific communication linkages depicted above is a critical deliverable from the NG9-1-1 development process. Many industry leaders are actively working to establish those standards through bodies such as NENA, the Alliance for Telecommunications Industry Solutions (ATIS), and the Internet Engineering Task Force (IETF).

Not surprisingly perhaps, the elements of this system-of-systems that have evolved most slowly towards the NENA NG9-1-1 vision are those that require the creation of these new standards. The i3 specification, which defines the communication protocols between PSAPs and the ESInet, including the delivery of voice and data via SIP, is one of those elements.

Where are all the i3 solutions?

NENA has defined the structure of the NG9-1-1 system, including the Network Elements and Functions that will enable i3 (blue boxes, Figure 2 below), but stopped short of creating the communication protocols to be implemented over that network. The group that has the responsibility to fully define the i3 communications protocol is the Emergency Services Interconnection Forum (ESIF), a committee of ATIS members.

Figure 2 - Scope of NENA i3 Architecture

While good progress has been made, and a draft standard has been issued for review, the i3 standard is not yet ratified. As such, there are no i3 compliant solutions available today.

Deploying SIP-connected PSAP Solutions Today

Many public safety customers are deploying new PSAP equipment in order to take advantage of the myriad of benefits available today with an IP PSAP. Additionally, they desire immediate support of SIP trunking from the emergency services network provider (ESNP), while ensuring full and painless migration to comply with the i3 specification when it's ratified and released.

There are many different approaches to this challenge, often involving additional hardware (proxies, gateways, etc.) to connect prevalent legacy networks to the CPE. Typically, traditional automatic number identification/automatic location identification (ANI/ALI) delivery remains. None of this is difficult to implement or particularly advantageous for the customer, as it fails to provide consolidated information within a single SIP packet stream or significant cost savings.

PlantCML has recognized that many customers are looking to achieve more than enabling traditional network architecture over IP, and has defined an interim SIP Interface specification. This interface has been shared with the leading network and network appliance companies in the industry in order to enable broad support for this interface.

The PlantCML SIP Interface is well aligned with the existing elements of the draft i3 specification defined by ATIS, but remains flexible to support many of the remaining legacy characteristics of the available networks, for example traditional delivery of ALI. The draft i3 specification requires delivery imbedded in the SIP message with the voice information and the PlantCML specification fully aligns with this approach. Most Network Providers have not yet implemented delivery of ALI via IP, or imbedded in the SIP emergency message. As Network Providers transition from legacy ALI lookup, perhaps through IP ALI lookup based on imbedded Calling Party Number in the SIP message, to full delivery of Location Information within the SIP stream, PlantCML solutions will ensure ALI delivery to the PSAP.

Yet to be defined within the i3 specification development process is the content and protocol for communicating additional information within the SIP data stream. The PlantCML SIP Interface will evolve from the current capability of delivering caller identification and location information to include additional information when the ATIS i3 specification is better defined on this capability or when Service Providers deliver this additional data content.

Our goal is to provide the shortest path to full i3 support for existing users of PlantCML equipment and new customers alike while enabling immediate support for SIP interconnection. The migration from the SIP Interface to i3 will be a software upgrade once the i3 specification is ratified and released.

Looking Ahead

PlantCML is actively deploying advanced IP-enabled Networks and CPE systems for many customers today. We are ensuring that our customers have a direct and non-disruptive path to full support of the i3 Standard when it is ratified, and that they are not forced to accept proprietary and limiting interfaces to ESInets in the interim.

The full definition and ratification of the i3 communication protocol has several significant milestones remaining. Given the unknown timing, PlantCML is not advising our customers to wait on the specification's full development to realize the benefits available with existing NG9-1-1 capability.

During the transition, as Network Providers work to enable many of the advanced aspects of the Draft i3 specification, PlantCML will continue to support the spectrum of network capabilities, allowing our customers to achieve the greatest degree of NG9-1-1 connectivity available.