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The base for dependable NG9-1-1 calls: A resilient ESInet

According to a US Federal Communications Commission (FCC) report, a one-minute decrease in ambulance response times reduces the 90-day mortality rate of patients by 17 percent. This statistic highlights the crucial importance of 24 x 7 accessibility to emergency communications services to save lives and protect citizens.

The first emergency 9-1-1 service went live in 1968 in Haleyville, Alabama, heralding a dependable way for citizens to dial for emergency rescue services. Since then, society has relied on 9-1-1 to ensure public safety every day. With the introduction of automatic number identification and automatic location tracking as well as wireless communications service and voice over Internet Protocol (VoIP), the original 9-1-1 service has evolved to enhanced 9-1-1 (E9-1-1), wireless E9-1-1 and VoIP E9-1-1.

The advent of NG9-1-1

The 21st century has seen the rise of the World Wide Web and new multimedia communications technologies, including real-time text and video, instant messaging and social media — all available on smartphones and other wireless devices and all wildly popular with the public. In addition, innovative digital technologies such as unmanned aerial vehicles (UAVs), wearable devices (e.g., smart watches and fitness trackers) and CCTV are now so prevalent that they can be harnessed to widen situational awareness for public safety.

These innovations make it imperative that emergency call takers working in public safety answering points (PSAPs, also called emergency communications centers) have the capabilities to accept new digital information from any device and transfer the information to first responders as well as other PSAPs and public safety agencies. These capabilities will usher in “total conversation emergency calls” from citizens to PSAPs to first responders, resulting in more effective emergency response.

To support this new emergency call paradigm featuring multimedia communications, PSAPs need to upgrade to next generation 9-1-1 (NG9-1-1), which expands the current voice-based service with a data-centric service. At the same time, PSAPS need to maintain interoperability with legacy systems. Because NG9-1-1 employs new IP-based digital systems for call processing and dispatch, the network that connects NG9-1-1 PSAPs and NG9-1-1 core services (NGCS) is naturally an IP network called an Emergency Services IP network (ESInet).

IP technology was initially designed to offer non-critical, best-effort services that have no reliability requirements — and this is not acceptable for an ESInet. As a result, the National Emergency Number Association (NENA) has developed ESInet design considerations to help ensure reliable transport of emergency communications services, especially during major incidents or severe weather events.

Nokia ESInet architecture blueprint

Based on the ESInet design considerations, Nokia has developed an ESInet architecture blueprint that harnesses the resiliency and robustness of MPLS technology to build an IP/MPLS-based ESInet with the utmost reliability: one that delivers emergency communications services even when multiple network faults occur. The ESInet is shared by all public-safety agencies responding to an emergency. It connects PSAPs, NGCS systems and other applications such as CAD.

The ESInet also interconnects with communications service providers — wireline, wireless, VoIP and ISPs — to receive 9-1-1 calls. And the ESInet interconnects with public safety networks such as FirstNet that dispatch and support first responders.


An ESInet architecture blueprint

IP/MPLS for ESInet resiliency

Faults happen in any network. However, when an ESInet experiences network faults and cannot recover, PSAPs become unreachable and emergency communications services stop. The consequences could be dire.

To avoid this situation, utmost ESInet resiliency is necessary to withstand regular network failures and also multiple faults that commonly occur during disaster situations. The ESInet must be able to:

  • Detect network faults early
  • Rapidly restore service at the speed of SONET technology or faster
  • Recover from multi-fault scenarios

To capitalize on these capabilities, many networks carrying mission-critical applications — public safety land mobile radio (LMR) backhaul, teleprotection in high-voltage power grid, and railway signaling — have been built with IP/MPLS. ESInet can do the same to harness various protection schemes available on an IP/MPLS platform, including:

  • PSAP IP/MPLS access router redundancy protection
  • ESInet communication path redundancy protection
  • Host site georedundancy protection
  • Protection from adverse environmental conditions

To learn how to implement these protection mechanisms — and keep your emergency communications services up and running — read the application note “Providing highly dependable 9-1-1 emergency response services.”

Share your thoughts on this topic by joining the Twitter discussion with @nokiaindustries using #publicsafety #missioncritical #allwhere

Hansen Chan

About Hansen Chan

Hansen Chan is an IP Product Marketing Manager with a special focus on digital industries and government. He has worked with telecom service providers and critical infrastructure network operators worldwide for more than 25 years on protocol testing, network design and consulting, and product management. When he’s not talking networks, he’s reading up on history and religion, and listening to Baroque and 20th century classical music.

Tweet him @hchan888

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