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IEEE 802.21 WG Presentation Template

VIEWS: 4 PAGES: 13

  • pg 1
									IEEE 802.23 Emergency Services
DCN: 23-11-0007-00-0000
Title: 802.11 call flow for Layer 2 support for unauthenticated
  requests
Date Submitted: March, 2011
Presented at IEEE 802.23 session in Singapore
Authors or Source(s): G. Scott Henderson, Research In Motion


Abstract: This contribution proposes an 802.11 call flow for Layer
 2 support for unauthenticated ES requests. It also identifies
 some changes by component required to support this call flow.


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         802.23
    IEEE 802.21 presentation release statements
                                                      802.23
This document has been prepared to assist the IEEE 802.21 Working Group. It is
  offered as a basis for discussion and is not binding on the contributing
  individual(s) or organization(s). The material in this document is subject to
  change in form and content after further study. The contributor(s) reserve(s)
  the right to add, amend or withdraw material contained herein.
The contributor grants a free, irrevocable license to the IEEE to incorporate
  material contained in this contribution, and any modifications thereof, in the
  creation of an IEEE Standards publication; to copyright in the IEEE’s name
  any IEEE Standards publication even though it may include portions of this
  contribution; and at the IEEE’s sole discretion to permit others to reproduce in
  whole or in part the resulting IEEE Standards publication. The contributor also
  acknowledges and accepts that this contribution may be made public by IEEE
  802.23.
  802.21.
                                                        outlined Section 6 6.3 of
The contributor is familiar with IEEE patent policy, as stated in in Sectionof the
  the IEEE-SA Standards Board Operations Manual
  IEEE-SA Standards Board bylaws
  <http://standards.ieee.org/guides/bylaws/sect6-7.html#6> and in
  <http://standards.ieee.org/guides/opman/sect6.html#6.3> and in
  Understanding Patent Issues During IEEE Standards Development
  http://standards.ieee.org/board/pat/faq.pdf>
  http://standards.ieee.org/board/pat/guide.html>

 23-11-0007-00-0000
                  ES VoIP CALL
                                                      PSAP



                                                          PSTN




                                                     PSTN PROXY
                                        Internet
               802 x
      POA AP              PONA Router
EUT


                 DHCP Server                  Default SIP Server/ GW
                  Diagram Labels
A: End User Terminal (EUT)
B: Point of Attachment (POA)
   (e.g. 802.11 access point or 802.3 jack/switch port)
C: 802 infrastructure
   (intervening bridges, switches or wireless connections)
D: Point of Network Attachment (PONA) router
E: Default SIP Server / gateway
F: PSTN Proxy server
   (if the PSAP does not support IP directly)
G: PSAP Router (Direct IP support in the PSAP)
H: PSAP Station
                     Assumptions
• 802.11u and v conformance
• DHCP support
• 802.23 would define the ES VLAN and the ES call flow
  identifier (e.g. ES Ethertype, SNAP Headers or 11u UESA bit
  (clause 11.3.2.2) )
• Default GW/SIP proxy address would be provided by a DHCP
  server (RFC 3361)
• Default GW/SIP proxy is similar to a P-CSCF in functionality
• Higher layer development would be similar/equivalent to 3GPP
  IMS ES support (e.g. TS 24.229, TS 23.167) and would need to
  be developed by the IETF


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                     Layer 2 Call Flow (1)
• User initiates an emergency service call. EUT has no
  L2 association or authentication
• EUT scans for all SSIDs in range, for each SSID
  detected it listens to the beacon for the interworking IE
  (information element) and looks for ESR (emergency
  services reachable =1) and UESA (unauthenticated
  emergency services access = 1) bits in the
  interworking element advertising ES support (802.11u
  2011 clause X.1.5)
• EUT requests ES association (802.11u 2011 clause
  X.4.2)

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                     Layer 2 Call Flow (2)
• AP bridges to an ES VLAN to the PONA router and
  maps the VLAN to only support emergency service
  traffic from the EUT from the 802.11 air interface.
• EUT records location from AP (802.11u 2011)
  (Optional for the EUT: EUT can use its own location,
  uses the AP location, or ask the AP for the EUT’s
  location.) (802.11u 2011 clause X.4.2)*
• The layer 2 session is established.


*in regulatory domains that allow/require location

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                     Upper Layer Functions
• DHCP provides EUT with an IP address and the address to the
  Default GW/SIP Proxy
• The EUT signals to default SIP proxy/GW to open an
  ‘emergency context’ (comparable to an emergency bearer in
  3GPP) to/from the EUT. (3GPP 23.401)
• EUT sends an emergency SIP (unauthenticated) request (e.g.
  911 SIP invite) (using ES Ethertype) (Includes MAC id of EUT
  and AP (for callback) as well as location)
• Default SIP proxy/GW forwards call only to a PSAP/
  E(emergency)-CSCF
• PSAP responds with ‘2xx ok’
• During the call and/or shortly after ending, PSAP may request
  new/updated location information
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        EUT Applications Requirements
• EUT must be 802.11u and v compliant
• EUT must get location from the AP if needed
  (802.11u 2011 clause X.4.2)
• Request to AP to set up an ES call
• The call request must use an ES call flow identifier
  (ES Ethertype, SNAP Headers or 11u UESA bit)
• Upper layer requirements also need to be defined for
  the EUT



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                     AP Requirements
• The access point must be compliant to 802.11u
  and v
• The AP must provide LOC info (IEEE 802.11v
  2011)
• The AP must support access to the ES VLAN
  to the PONA based on incoming ES Ethertype
  (or UESA bit or SNAP Header)
• The AP must be able to bridge ES traffic to the
  ES VLAN

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     PONA Router Requirements
• The router must recognize traffic arriving on
  ES VLANs as emergency requests
• The router will routes signaling and bearer
  traffic arriving over the ES VLAN to only the
  default SIP proxy/GW.
• The router will signal the default SIP
  proxy/GW to set up an ‘emergency context’.




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   Default SIP Proxy/GW Requirements
• The gateway must support ‘SIP emergency
  services’ (e.g. 3GPP 24.229 clause 5.2.10)
• The SIP Proxy must forward ES call to the
  correct local PSAP
• In 3GPP terminology, this would be the P-
  CSCF (proxy call session control function)




23-11-0007-00-0000
                                          References
•     IEEE 802.11v Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications
      Amendment 8: IEEE 802.11 Wireless Network Management


•     IEEE 802.11u Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications
      Amendment 9: Interworking with External Network


•     IETF RFC 3690 IP Telephony Requirements for Emergency Telecommunication Service (ETS) Feb
      2004
•     IETF RFC 3361 (DHCP-for-IPv4) Option for Session Initiation Protocol (SIP) Servers Aug 2002
•     3GPP TS 23.167 IP Multimedia Subsystem (IMS) Emergency Sessions Release 11 January2011


•     3GPP TS 24.229 10.2.0 IP multimedia call control protocol based on Session Initiation Protocol (SIP)
      and Session Description Protocol (SDP) Dec 2010


•     3GPP TS 23.401 10.0.0 General Packet Radio Service (GPRS) enhancements for Evolved Universal
      Terrestrial Radio Access Network (E-UTRAN) access June 2010


•     Draft-ietf-sipcore-location-conveyance-04, Location Conveyance for Session Initiated Protocol


•     Draft-patel-ecrit-sos-parameter-11, SOS Uniform Resource Identifier (URI) Parameter for Marking of
      Session Initiation Protocol (SIP) Requests related to Emergency Services
    23-11-0007-00-0000

								
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