TABLE OF CONTENTS EXECUTIVE SUMMARY 3
INTROdUCTION/BACkgROUNd 4
PSAP ChALLENgES/CONCERNS 4
hOw dOES TEXT-TO-9-1-1 wORk? 5
TRAFFIC VOLUMES - SERVICE TRIAL RESULTS 7
RELIABILITY OF TEXT 7
PSAP dISPLAY ANd dELIVERY 9
CPE/TELEPhONE SYSTEM INTEgRATION 10
wEB VIEwER 10
TTY 11
SERVICE PROVIdER INTEROPERABILITY 12
EXECUTIVE SUMMARY
TEXT-TO-9-1-1 SAVES LIVES
The ability to send a text-to-9-1-1 is a reality. Text-to-9-1-1 can save lives in many scenarios; natural disasters, when wireless networks are heavily congested, in remote locations with weak radio signals or in unsafe situations when a voice call to 9-1-1 could put someone in greater danger.
This white paper describes:
• The potential impacts of text-to-9-1-1 on a public safety answering point (PSAP)
• How text emergency requests can be delivered from multiple wireless carriers into a single stream
• Delivery and display options that meet the requirements of the NENA i3 reference architecture and the joint Alliance for Telecommunications Industry Standards (ATIS) /Telecommunications Industry Association (TIA) Native SMS to 9-1-1 J-STD-110
Introduction / Background
Currently, there are only a few places in the United States where citizens are able to text-to-9-1-1. However, in December of 2012 Verizon, ATT, Sprint and T-Mobile joined with the National Emergency Number Association (NENA) and the Association of Public-Safety Communications Officers (APCO) and made a voluntary commitment to provide text-to-9-1-1 services by May 15, 2014, and support automatic “bounce back” notifications to consumers attempting to reach 9-1-1 via text message, when service is not available in their area, by June 30, 2013. A further mandate by the FCC in May 2013 requires all Commercial Mobile Radio Service (CMRS) and interconnected text messaging service providers to provide automatic “bounce back” capabilities by September 30, 2013.
During 2012, ATIS and TIA developed a joint Native SMS-to-9-1-1 Requirements and Architecture Specification standard for delivery of text messages to PSAPs. This standard, J-STD-110, describes the three SMS-to-9-1-1 delivery interface types which are further described later in this paper. Future enhancements to the standard will include delivery of MMS-to-9-1-1 and interfacing to OTT solutions.
PSAP Challenges / Concerns
There are some concerns PSAPs have in expanding their means of communications with the public seeking emergency assistance via text-to-9-1-1:
• How are individual text messages transferred into a dialog between the texter and call taker?
• Will there be an overwhelming influx of text traffic? • Will text interfere with handling voice calls? • How reliable is text messaging?
• How can I get all text to 9-1-1 from every carrier without having to interact with each carrier separately?
how does Text-to-9-1-1 work?
When making a text call to 9-1-1, the caller requesting emergency assistance sends a text to 9 1 1 as they would to any text short code. The text is routed by the wireless Carrier to an emergency text service provider’s Text Control Center (TCC).
How doeS SMS work?
Commercial Location Server Short Message Center (SMSC) WEB Gateway Multimedia Message Center (MMSC) ECRF ECRF TTY Gateway ECRF Existing 9-1-1 Voice Circuit i3/Pre i3 i3/Pre i3 Internet LBS/MSC/HLR SMPP MM3, 4, 7
WIRELESS CARRIER RESPONSIBILITY PSAP RESPONSIBILITY
The TCC queries the wireless carrier for the location of the caller: routing of the text is similar to routing Phase 1 accuracy voice calls and is based on which PSAP jurisdiction the caller is located. This is implemented by the Emergency Services Routing Proxy (ESRP) querying a PSAP jurisdiction database with the caller location that, in i3 terms, is referred to as the Emergency Call Routing Function (ECRF). In this regard, the TCC acts in an equivalent way to a selective router or 9-1-1 tandem in a voice network. As in the case of the selective router, the TCC delivers texts from all wireless carriers over a common interface to the PSAP. If the PSAP is not text equipped or busy (as represented by full text message queues) a bounce-back message is sent to the caller instructing them to make a voice call to 9-1-1. All PSAP positions will be notified that a new text has arrived via flashing button on the text user interface (UI) and/or an audio tone is played. Text distribution across PSAP positions could be an automatic call distribution (ACD) method, or an all position notification (as in a key system), and the first to accept the message can establish a dialog with the text initiator. What this means is that the operator will be able to send a message to the texter and their response will be displayed back on that operator’s UI. A typical user interface is shown below.
It Is estImated that 1 In 10 calls wIll be text-to-9-1-1 calls.
Thereafter, messages can be sent between the operator and texter until the operator terminates the session. Technically, the dialog is accomplished by the TCC forming a temporary association between the texter’s telephone number and operator’s workstation via a SIP session, thus ensuring all subsequent messages are sent to the same operator.
With the exception of the TTY solution described in this document, text takes a different path to the PSAP and does not interfere with the delivery of voice calls. Trial evidence shows that call takers can handle multiple text sessions at the same time, or voice and text at the same time due to the time between messages. The transcript of the dialog is laid out on the text UI so the operator can skip between conversations while waiting for the next message to arrive. PSAP policy will determine how
operators handle text and voice calls, but note that the solution technically supports this approach if the PSAP chooses to go this route.
Traffic Volumes – Service Trial Results
Intrado has undertaken three extensive text trials over the last four years in Iowa, North Carolina, and Vermont. Each of these trials displayed the text dialog on the PSAP call processing equipment (CPE) workstation.
To date, we have seen low traffic volumes during these trials even though there was visibility and advertising in the local communities that text-to-9-1-1 was available. The messages received weekly have been minimal amounts. We expect significant traffic growth as additional wireless carriers bring their services online and the service becomes more accepted by the public. Long term, it is estimated that 1 in 10 calls will be text-to-9-1-1 calls; currently we see approximately 1 in 1,000.
Reliability of Text
There are practical situations where text can work more effectively than voice, although we are not suggesting that text will be a universal substitute for voice calls: • For the 36 million deaf and hard of hearing in the U.S.
• Real life situations where callers do not wish to be overheard requesting emergency assistance; a domestic abuse situation, for example.
• When a voice network gets overloaded, such as during a natural or man-made disaster (Hurricane Sandy or East Coast power outage).
• When radio signal strength is marginal, for example at a mountain resort where someone is injured skiing, callers can often text when voice communication may not be possible due to wireless radio signal strength.
Below, we show three alternative methods of delivering text messages to a PSAP; all three options interact with the wireless carrier networks to establish the terminating PSAP in the same way. Depending on the choices of the PSAP, text can be delivered in one of the following three ways:
• CPE Telephone System Integration: Uses an i3 IP protocol (SIP based) that terminates on the PSAP CPE (and, in the future, the CAD) and is displayed on the workstation.
• Web Viewer: This option provides PSAPs with a transition path without the need to upgrade their CPE.
• Teleprinting device TTY: This option uses the current TTY capabilities of the CPE and can be delivered without the PSAP changing their CPE configuration or TTY procedures.
aLTernaTIve TexT deLIvery and dISpLay opTIonS
Commercial Location Server Short Message Center (SMSC) WEB Gateway Multimedia Message Center (MMSC) ECRF ECRF TTY Gateway ECRF Existing 9-1-1 Voice Circuit i3/Pre i3 i3/Pre i3 Internet LBS/MSC/HLR SMPP MM3, 4, 7
WIRELESS CARRIER RESPONSIBILITY PSAP RESPONSIBILITY
CPE/Telephone System Integration
A PSAP can receive and display text-to-9-1-1 calls in the same manner that they receive voice calls. Text to-9-1-1 messages from all wireless carriers are managed on the same user interface and workstation as voice calls. The user interface typically provides the operator with the caller location coordinates as well as the originating wireless carrier. This solution is least disruptive to the call taker workflow but may require upgrades to the CPE equipment and private secure IP (ESInet) connections to the text service provider’s TCC.
While voice and text calls arrive at the same console, voice capacity is not limited by text messages since voice and text travel across different facilities to the PSAP – text messages are carried over separate or partitioned IP circuits or ESInet facilities where these are available.
Integration also enables expansion of the internal management information systems (MIS) to capture text transcripts in the same way as voice call records; vendors are also in the mode of building interfaces to computer aided dispatch (CAD) systems to enable text to be displayed on CAD workstations.
web Viewer
For PSAPs or CPE vendor who is not yet ready, to support text directly on the CPE workstation, the Web Viewer solution provides a short-term alternative to the CPE integration option.
There are two options for how text is displayed:
• On an existing CPE or CAD workstation. While it is displayed on the CPE workstation screen, it is not integrated to those existing systems nor integrated into the MIS or CAD systems; it is simply a window in the display.
• On a separate standalone workstation. This creates a “swivel chair” mode of operations where a call handler must manage between two different systems and screens for answering voice and text calls.
Text delivery to TTY works by setting up a voice call, using existing voice circuits, from a TTY gateway to the PSAP and transmitting the text messages to and from the emergency texter using BAUDOT tones into a PSAP’s existing TTY equipment. While this option does not require a PSAP to upgrade their equipment, it does have significant usability issues both for texters and PSAP operators. Specifically, texter/ call taker interactions will be very slow and the average text message could take several minutes to deliver, and is prone to errors that could lead to confusion for the texter. During this time, the operator is using a voice trunk that could far exceed normal voice call interactions and prevent other calls to the PSAP from getting through.
Service Provider Interoperability
One essential attribute of any text service provider is the ability to consolidate text messages from all wireless carriers in their jurisdiction into a single stream where they can be displayed at the PSAP CPE, regardless of the delivery method chosen by the PSAP.
Carriers choose service partners to provide the routing functionality. There are two main vendors in the market and there is a high probability that both will be selected by some of the carriers. Similarly, regional entities and individual PSAPs will choose a text service provider to collect, route and consolidate all wireless carriers’ text messages within their jurisdiction.
Carriers choose service partners to provide the routing functionality. There are two main vendors in the market and there is a high probability that both will be selected by some of the carriers. Similarly, States, PSAP entities (e.g., MEB, NCTCOG) and individual PSAPs will choose a text service provider to collect, route and consolidate all wireless carriers text messages within their jurisdiction. The carriers also have noted that only the one service provider they have chosen should be able to query the carrier network for location. As a consequence, the two leading service providers agreed to exchange text messages destined for delivery by the other service provider as shown in Figure 4, via the service provider TCC/ESRP chosen by the destination PSAP. The interface between the two TCCs is the i3 defined MSRP with location PIDF-LO included in the SIP invite message.
i3 Full i3 PSAP CARRIER A Commercial Location Server Short Message Center (SMSC) Multimedia Message Center (MMSC) Text Control Center (TCC) Emergency Services Routing Proxy (ESRP) SMPP i3/Pre-i3 i3/Pre-i3/WEB CARRIER B Commercial Location Server Short Message Center (SMSC) Multimedia Message Center (MMSC) Text Control Center (TCC) Emergency Services Routing Proxy (ESRP) Served PSAPs (Integrated, WEB, TTY)
Served PSAPs (Integrated, WEB, TTY) i3 Network
i3
i3
SMPP i3/Pre-i3 i3/Pre-i3/WEB
We see the expansion of text services to include the ability to transfer pictures, sound and video clips taken from cell phones to the PSAP as part of an incident or related to the incident. NENA i3 reference architecture and the ATIS/TIA Native SMS to 9-1-1 J- STD-110 are looking forward to supporting these additional capabilities using common infrastructure with text. Callers requesting emergency assistance in the future, particularly those using a smartphone, are unlikely to differentiate a text-to-9-1-1 from an MMS-text-to-9-1-1 and these services should work in the same way. Future messaging capabilities will also address OTT text applications. OTT content refers to content that is generated by a third party and transported via the Internet. Well known examples of OTT applications are Skype, Hulu and Netflix.
CARRIER A Commercial Location Server Short Message Center (SMSC) Multimedia Message Center (MMSC) Text Control Center (TCC) Emergency Services Routing Proxy (ESRP) SMPP i3/Pre-i3 i3/Pre-i3/WEB MMES Gateway OTT Text
Applications Emergency Services
Routing Proxy (ESRP)
i3/Pre-i3/WEB
Served PSAPs (Integrated, WEB, TTY)
Full i3 PSAP
Conclusion
Text-to-9-1-1 is a reality and will become a viable alternative to making a voice call when voice calls are not possible. We have also concluded that text-to-9-1-1 is a reliable service and can work effectively as a means to communicate with a PSAP call taker. Once it becomes a mature service, we anticipate the rate of text calls to be 1 in 10 calls that arrive at the PSAP. In the meantime, as the service develops, text calls will be much less frequent.
The PSAP’s choice of delivery and display can have a profound effect on the operations at the PSAP. There are three alternative delivery and display mechanisms being offered by Text Service and CPE Vendors;
• Integrated with the CPE – this has the least impact on PSAP operations but may require an upgrade to the CPE and IP connectivity;
• Web Viewer- offers an interim step to full CPE integration but will potentially have larger operational impacts and will not interfere with voice calls;
• TTY - while it affords universal coverage without any form of PSAP
enhancements, has severe limitations for the texterand PSAP call taker and is not recommended.
The important function of consolidating text from all wireless carriers into a single stream is being performed by two service providers initially and possibly more in the future. To enable all text messages to be delivered from all carriers regardless of which service provider is chosen, there is a need to exchange messages. There is an agreement in place to support this exchange through standard i3 interfaces.
Finally, looking to the future, we see additional services being added to text-to-9-1-1 to include OTT access from smartphone providers and multimedia to the PSAP made available across the United States in the same manner as voice.
About Intrado
In business for more than 30 years, Intrado, a subsidiary of West Corporation, has maintained a focus and passion for saving lives and supporting the needs of public safety. Agencies and telecommunication services providers throughout the world depend on Intrado for emergency communication services and technology. Intrado’s dedicated focus on emergency communications technology allows the company to continue pioneering network innovations that improve emergency response.
Intrado TXT29-1-1 is an end-to-end platform for wireless carriers and PSAPs providing a wireless subscriber the ability to text-to-9-1-1 directly in cases where verbal
communication is not possible or desirable. The PSAP has the ability to communicate with the citizen through either an integrated solution via integration with the CPE , a web viewer or TTY. The network infrastructure includes connectivity between Intrado and the wireless service provider’s network, and Intrado and the PSAP. With the recent agreement by the four major wireless carriers to provide text-to-9-1-1 service and others coming onboard, PSAPs now have options and decisions to make as to how they will deploy text-to-9-1-1 in their centers.
www.Intrado.com
