1. NENA Next Generation 9-1-1 Architecture
Brian Rosen
Senior Director, NeuStar
Chair, NENA Long Term Definition WG

2. Background NENA = North American Emergency Number Association
Sets standards (among many other things) for emergency calls in U.S./Canada
Next Generation project
Complete overhaul of the entire system
Based on IP
Includes changes to processes, funding, training, etc, etc
The initial version of the technical standards part is known as “i3”

3. i3 is based on IETF Emergency Call Mechanisms
Endpoint (phone) “determines” its location by measurement (e.g. GPS) or from the access network via a “Location Configuration Protocol”
Endpoint “maps” the location to the URI of the PSAP with a new protocol, LoST
Endpoint learns LOCAL dialstring (9-1-1, 1-1-2) from LoST
Endpoint recognizes emergency call dialstring when dialed
Call is marked with service urn (urn:service:sos)
Call is sent to PSAP with mapped URI
Location is “conveyed” with the call
Call arrives at PSAP with location and call back info
Works for all media (voice, video, text, IM, …)

4. Location Determination
How location is actually figured out
Measurement (GPS) or wiretrace or manual configuration
Can be done by the endpoint or the access network
Can be civic (street address) or geo (lat/lon/altitude)

5. Location Configuration Protocols
How the access network provides location
Exchange an identifier of some kind, implicitly (e.g. what port on the switch) or explicitly (e.g. MAC address, IP address) for location
Location can be civic or geo
Current discussion on whether it can be a reference (e.g. URI) which must be dereferenced by some other protocol, or must be a value
DHCP is an example LCP
There is a “Layer 7” LCP in development
LLDP-MED is another example of an LCP

6. Marking an Emergency Call
Single global standard to denote an emergency call (does not rely on local dialstrings)
Uses a newly defined Service urn
Local dialstring is detected, and call is then marked with the service urn
Single number countries (9-1-1) use urn:service:sos
Number-per-service countries (1-1-6=police) use e.g. urn:service:sos.police
Extends to commercial location based routing, e.g. urn:service:restaurant.pizza.pizzahut)
Normally endpoint does dialstring to service URN translation, network can do it

7. Routing Emergency Calls
Location to Service Translation = LoST
Service URN + Location in, URI out
A “Mapping” function
Accepts civic/geo and service urn, returns URI, e.g. SIP and/or XMPP URI of where to route the call
Normal (SIP) routing of that URI
LoST is global, distributed, and replicated
Normally endpoint maps, network can do it
LoST will also supply the dialstring(s) for a location
LoST will also validate a civic location

8. Back to NENA i3 All calls answered as IP calls at PSAP
Implies gateways between older TDM switches and PSAPs
All calls routed with LoST
Implies TN to location lookup prior to routing
All calls arrive at PSAP with location and call back address (can be URI or e.164)

9. Emergency Services IP Network
An IP network FOR ALL OF PUBLIC SAFETY, not just 9-1-1
A regular routed IP network
DOES have (firewalled) connections to the Internet
Conceived as LOCAL networks (e.g. County level) interconnected with neighbors, perhaps a backbone for efficiency
Most local carriers will have private connections to the local ESInet
Option of using the Internet to introduce calls

10. Multi-Stage Routing
Emergency Services Routing Proxies at edge of ESInet onward route calls to PSAP
Uses LoST with authentication
User LoST query may return URI of ESRP
ESRP will foreward to PSAP
Could have more than one level of ESRP

11. More Data will be accepted
Additional Information about the call
Includes carrier contact info, subscriber class of service, etc
Call marked with URI of a datastructure to be retrieved by the PSAP
Also used for pointer to telematics data
Additional Information about the caller
Refers to the person, independent of home/office/mobile telephone
Could be medical info, “in emergency, please contact”, …)
Also a URI (anonymous), supplied by subscriber to carrier
Additional Information about the location
Comes from LoST
Two calls from same location will have same info, regardless of caller or carrier
Could be floor plans, hazardous materials, surveillance video, …

12. i3 PSAPs will be multimedia
Voice, Video, Text
Will support a variety of codecs (but not all of them, carriers don’t decide)
Will support both IM and interactive (character at a time codecs)
Full Offer/Answer negotiation
Will use codec choice to automatically engage relay operators if needed
Will use Language preference info to route calls to appropriate call takers, and automatically engage interpreters

13. 3rd Party Calls Used when user contacts a call center first
Text/Video/IP Relay
Telematics (OnStar)
Central Alarm Monitoring
Authorized 3rd parties can directly introduce calls, routed by location of user, with all 3 parties conferenced at the PSAP

14. PSAPs use LoST to route to responders
A PSAP will make LoST dips with caller’s location to determine the responding police, fire, ems, … services
A different service urn
Requires authentication
Same underlying database
This replaces the “ESN” of the current system

15. Notes to endpoint vendors
Read –phonebcp (will be draft-ietf-ecrit-phonebcp-00)
Implement ALL OF a short list of LCPs
Map location to PSAP URI and cache it
Recognize local (and maybe home) dialstrings as emergency calls
Mark emergency calls with service URN
Try to update location and LoST mapping at call time, use cached values if needed
Several other SIP things to support PSAP operations on calls
Support manual override of determined location, but make it possible, not easy to use

16. Notes to Access Network Providers
Need to choose one of the LCPs the phones will implement and deploy it
The only way to choose something not on the –phonebcp list is to force every endpoint to do something else
But watch out for Ethernet connected phones behind a router/switch with an uplink to your network; you may not be able to control them
Probably will be asked to supply a hint to a local LoST service
Validate (use LoST) civic locations when you put them in your location server

17. Notes to Communications (e.g. VoIP) Carriers
Prepare to route marked emergency calls to PSAP/ESRP
Prioritize marked emergency calls in softswitches
Deploy connections to local ESInets
Add the “Info about the call” URI with your contact data, etc.
Support Interactive Text & Video codecs all the way through the system for the disabled