NENA Next Generation 9-1-1 Architecture

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NENA Next Generation 9-1-1 Architecture

• Brian Rosen
• Senior Director, NeuStar
• Chair, NENA Long Term Definition WG

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Background

• NENA North American Emergency Number
  Association
• Sets standards (among many other things) for
  emergency calls in U.S./Canada
• Next Generation 9-1-1 project
• Complete overhaul of the entire 9-1-1 system
• Based on IP
• Includes changes to processes, funding, training,
  etc, etc
• The initial version of the technical standards
  part is known as i3

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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 (urnservicesos)
• 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, )

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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)

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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

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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
  urnservicesos
• Number-per-service countries (1-1-6police) use
  e.g. urnservicesos.police
• Extends to commercial location based routing,
  e.g. urnservicerestaurant.pizza.pizzahut)
• Normally endpoint does dialstring to service URN
  translation, network can do it

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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

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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)

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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

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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

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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,

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i3 PSAPs will be multimedia

• Voice, Video, Text
• Will support a variety of codecs (but not all of
  them, carriers dont 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

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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

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PSAPs use LoST to route to responders

• A PSAP will make LoST dips with callers 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

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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

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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

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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