Nokia MIH Proposal

Document Sample
Nokia MIH Proposal Powered By Docstoc
					•   IEEE 802.21 MEDIA INDEPENDENT HANDOVER
•   DCN: 21-04-0169-02-0000
•   Title: Nokia MIH Proposal
•   Date Submitted: January, 10, 2004
•   Presented at IEEE 802.21 session #06 in Monterey (CA)
•   Authors or Source(s):
•    Stefano M. Faccin, Michael Williams
•   Abstract: This presentation outlines a proposal for the 802.21
    Media Independent Handover, covering event/triggers, MIH
    model and information service.




    21-04-0169-02-0000                                        1
      IEEE 802.21 presentation release statements
•   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
    802.21.
•   The contributor is familiar with IEEE patent policy, as outlined in Section 6.3
    of      the      IEEE-SA       Standards     Board      Operations       Manual
    <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/guide.html>

    21-04-0169-02-0000                                                        2
                          Contents


• A revised version based on comments received
• Architectural framework for 802.21 MIH
• Model for MIH Functionality
• Triggers/Events model
• Information Service
• Transport Solutions for 802.21 services
• Conclusion




  21-04-0169-02-0000                             3
       MIH Architectural Framework:
          Terminal View (logical)
                                                             Applications
                                                              TCP/RTP


                          Policy                             IP/Mobile IP/
                         Manager                                IPSec




                                       Bearer Manager




                                      802.21 MIH Function




                        WLAN    Cellular    802.16      BT

                                   DEVICE DRIVERS


Architectural Framework depicted here for sake of discussion and introduction of proposal
21-04-0169-02-0000                                                                          4
       MIH Architectural Framework:
       Terminal View (Protocol Stack)
  MIHF: not a protocol layer!


           Policy Management

                                                             Apps


                                             SIP             ….

            Bearer
                          802.21                          TCP/UDP
           Manager
                           MIH
                                                              IP
                         Function
                                                    (Mobile IP, IPsec, etc.)



                                          802.11     802.16                     802.16
                                                                      …
            Management Plane             MAC/PHY    MAC/PHY                    MAC/PHY




Architectural Framework depicted here for sake of discussion and introduction of proposal
21-04-0169-02-0000                                                                          5
             MIH Functional Framework
• Framework depicts two main functions
    • Bearer Manager
    • MIH function
• Bearer Manager
    • represents an abstraction of connection management on terminal side
    • introduced in framework discussion to better identify functionality of
      MIH function wrt connection management
    • not specified in 802.21
    • indicates functionality that is in charge of connectivity decisions and
      handles L3 aspects




  21-04-0169-02-0000                                                            6
         MIH Architectural Framework:
              MIH Function (1)
• Collects information and relies event to Bearer Manager and
  other protocol layers or functions that subscribed to them
• MIHF maps requests and requirements from Bearer Manager
  and other functions/protocols to link layers
• Converts different link layer parameters to enable connection
  decision (e.g. mapping between different QoS
  characterizations)
• Does not make connection or handoff decisions:
• Bearer Manager (not specified in 802.21) makes decisions
  based on:
   • information available through 802.21 information service
     and from Layer 2 drivers
   • 802.21 events
   • application requirements and policies (user, equipment
     owner, operator, etc.)
  21-04-0169-02-0000                                              7
         MIH Architectural Framework:
              MIH Function (2)
• MIHF maintains state information
    • Currently available accesses, and corresponding discovered features/requirements (e.g.
      authentication/security requirements, cost, domain, etc.)
    • Current connections and respective status
    • Configuration information obtained by subscribing functions/protocols
• Triggers to upper layers delivered upon subscription but based on Bearer Manager
  decisions, e.g.
    • Mobile IP not informed of a “link up” if the link is not suitable based on application
      requirements and policies (e.g. level of security)
    • Bearer Manager initiates setup of VPN/IPSec secure tunnels based on need to setup
      connection over a specific access and information discovered regarding the access
      requirements
• MIHF may masks link layer details:
    • e.g. 802.11 signal strength not reported to Bearer Manager
          • For predictive handoff MIHF may implement two-thresholds mechanism based on strength
            reports from driver it triggers: when signal goes below first threshold, MIHF provides “Current
            link may go down” trigger to Bearer Manager, so that it can begin setting up an alternative
            connection. When signal goes below second threshold, MIHF provides “Current link down”
            trigger to Bearer Manager to trigger the actual handoff
    • e.g. Data throughput and QoS are reported based on events and information subscription
      and on requests
    • details of this should not be standardized, only triggers, trigger subscription (and MIHF
      “configuration” by other functions/protocols) and information service


  21-04-0169-02-0000                                                                                    8
         MIH Architectural Framework:
              MIH Function (3)
• What MIHF does not do?
    • Connection/handoff decision or any type of policing: MIHF supports such
      actions with triggers and information service
          • A must to be independent of specific implementation and OS
    • Admission control: MIHF supports decisions providing information service (e.g.
      terminal know up front if required QoS will be available on new access)
    • Security (e.g. authentication, VPN setup, etc.):
          • performed through access specific or L3 mechanisms
          • E.g. if VPN tunnel needed over access after handoff, bearer managers sets up tunnel
            before (preferred) or after handoff
• Backward compatibility
    • since 802.21 will be introduced gradually, backward compatibility must be
      ensured
    • impact on terminals: for accesses with no 802.21 information service and
      triggers, assumption is that handoff can be performed based on current unreliable
      solutions (i.e. basic information, e.g. “link up” with no additional details is
      provided)
    • impact on network: if a terminal is not 802.21-enabled, networks implementing
      NW-controlled handoff must discover this
    • 802.21 discovery is suggested in this proposal (in transport section)

  21-04-0169-02-0000                                                                        9
         MIH Architectural Framework:
              MIH Function (4)
• Location of handoff “control” versus MIHF
    • 802 technologies with loose coupling:
          • control is in terminal, MIHF in terminal plays key role to support decision
          • MIHF in network mainly for information service
    • 802 technologies with tight coupling:
          • Control can be in network, depending on network implementation
    • 802 and non-802 technologies (e.g. .11 and cellular)
          • Control can be both in network and terminal, depending on deployment scenario
          • Even when control is in terminal (e.g. on when to handoff), network can exercise
            control by providing specific information through MIH services




  21-04-0169-02-0000                                                                       10
                 MIH Architectural Framework:
                Example Interactions in Terminal
                                                                                     APPLICATIONS
                                                                                        TCP/RTP

                                                                    Application
                                                             requirements (e.g.        IP/
                                                 Policy                                                 Link/connection events (e.g.
                                                             QoS, security, etc.)    Mobile IP/         events related to link
                                                Manager
                                                             Application events       IPSec             quality, etc. for TCP/RTP
                                                                                                        optimizations)


                                                                  Bearer Manager
                                                                                                             Link/connection events filtered
                                                  Subscribes to 802.21                                       based on policy decisions (e.g.
                                                        event/triggers                                       link availability, link up)
             Event/triggers, e.g. report link
                     availability and status         Primitives toward                                       Link/connection events filtered
                                                  802.21 MIH function                                        based on policy decisions (e.g.
                                                                                                             link availability, link up)
                                                             802.21 MIH Function                             for connection selection when
     Event/triggers, e.g. report link                                                                        no mobility protocols are in use
             availability and status
                                                                                           Request data from 802.21
                  Report data from
                                                                                           information services
802.21 information services with L2
                           transport
                                           WLAN        Cellular      802.16         BT

                                                          DEVICE DRIVERS



         21-04-0169-02-0000                                                                                                     11
        MIH Functionality Primitives (1)
• A non exhaustive list is provided here
• Triggers are generic (independent on protocol/function
  subscribing for events)
    • Primitives parameters depend on subscribing protocol/function
    • Specific parameters may be required by subscribing different
      protocol/function
    • Subscribing protocol/function will indicate when and under which
      conditions event shall be reported




  21-04-0169-02-0000                                                     12
       MIH Functionality Primitives (1)
• Event Discovery Request / Response {[Event_Type]}
   • Used to discover the events available
   • The response contains a list of the events available
• Event Registration Request {[Event_Type,
  Event_Features]} / Response {[Result_Code]}
   • Upon discovery of events available, this is used by the requesting
     function/protocol to register for a particular set of event. The request indicates:
        • the type of event (Event_Type, representing the identity of the event)
        • the features for the specific type of event (different events have different
          features, to be specified separately). Features include:
               • Thresholds, used e.g. to specify a minimum or maximum threshold
                  value beyond which a Event must be sent by the destination
                  interface. This request may be generated after MIHL has initialised
                  depending on configuration. It may also be generated upon
                  receiving requests from upper layers.
               • Frequency: how often the event should be sent
               • Parameters: to describe what parameters should be reported in the
                  event (e.g. to provide link-layer parameters to upper layers for
                  RTP/TCP optimizations)


 21-04-0169-02-0000                                                                 13
          MIH Functionality Primitives
  • Event Registration Request is also used to modify previous registrations:
      • Register for a new event: if the request contains the Event_Type of an event
        the requesting function/protocol has not subscribed before, the MIF
        function registers the function/protocol for such event
      • Modify previous registration: if the request contains the Event_Type of an
        event the requesting function/protocol has subscribed before, the MIF
        function registers the function/protocol for such event with the new features
        provided (e.g. difference Frequency)




21-04-0169-02-0000                                                              14
            MIH Functionality Primitives
• Event De-Registration Request {[Event_Type]} / Response
  {[Result_Code]}
    • This request is used to cancel existing registration for the requesting
      function/protocol. Only the event indicated by the Event_Type list are
      deregistered (Event_Type = “all” is permitted to de-register all events).
    • An Event Registration Response is sent to the requesting function/protocol
      containing either indication of success or an error code
    • Upon receiving the request, the MIH function registers the requesting
      function/protocol for the events. An Event Registration Response is sent to the
      requesting function/protocol if successful, or an error message is sent otherwise.




  21-04-0169-02-0000                                                                15
            MIH Functionality Primitives
• Interface Status Request {[Interface_ID, [Interface_Feature]]} /
  Response {[Interface_ID, [Interface_Feature/Result_Code]]}
    • The request is used to obtain information regarding a certain interface that upper
      layers know to be available (e.g. thanks to 802.21 information services and
      events), e.g. when the terminal is exploring a potential new connection
    • Request are made on a specific interface (Interface_ID)
    • By specifying which Interface_Feature the requesting function/protocol is
      interested in, it can enquire about specific information relevant to carry out a
      decision:
         • Cost
         • QoS (theoretical QoS level)
         • Security mechanism supported/required by the interface
         • Etc. (see information services for type of information available)
    • The response contains the specific features or an error code in Result_Code in
      case the requested features are not available or the interface is not available




  21-04-0169-02-0000                                                                16
            MIH Functionality Primitives
• Interface Configuration Request {Interface_ID, [Interface_Feature]} / Response
  {Interface_ID, [Result_Code]}
    • used to configure the features of a specific interface
• Connection Setup Request {Interface_ID, Connection ID,
  [Interface_Parameter]} / Response {Interface_ID, Connection ID,
  [Result_Code]}
    • used to request a specific interface to setup a connection. The MIHF maps a request
      incoming from Bearer Manager with this primitive into a request to the interface driver to
      perform the sequence of actions required to setup the connection
          • MIHF involve in connectivity setup to allow MIHF to have updated and complete picture of terminal
            connectivity
    • Interface_Parameter is used to provide the necessary parameters for the connection
      (including e.g. the AP, the domain to connect to, etc.)
    • The Connection Setup Response is sent upon successful establishment of the connection or
      with an error code
    • Connection_ID will be used between the requesting protocol/function and the MIH
      function to identify the connection for future operations
• Connection Tear-Down Request {Connection ID} / Response {Connection ID,
  [Result_Code]}
    • Used to request tear-down of a specific connection




  21-04-0169-02-0000                                                                                            17
            MIH Functionality Primitives
• Connection Status Request {[Interface_ID, Connection ID,
  [Connection_Feature]]} / Response {[Interface_ID, Connection ID,
  [Connection_Feature/Result_Code]]}
    • The request is used to obtain information regarding a certain current connection
      (i.e. the terminal may be using actively such connection or exploring a potential
      connection)
    • Request are made on a specific connection basis (Connection ID) for specific
      interfaces (Interface_ID)
    • By specifying which Connection_Feature the requesting function/protocol is
      interested in, it can enquire about:
          • Cost
          • QoS (theoretical QoS level)
          • Data throughput (actual data throughput)
          • Security mechanism in use
          • Etc.
    • The response contains the specific features or an error code in Result_Code in
      case the requested features are not available or the connection does not exist




  21-04-0169-02-0000                                                               18
            MIH Functionality Primitives
• Handover Request {} / Response {}
    • used to request a handover between interfaces
    • Whether all connections are handed over or a subset of the connection only
      (indicated by the requesting function/protocol) is handed over is TBD




  21-04-0169-02-0000                                                               19
                       MIH Event/Triggers
• Two types of event/triggers:
    • Internal event/triggers
          • When lower layers send triggers to MIH function, triggers are propagated
            to upper layers based on subscription
    • Across an interface => 802.21 event signaling




  21-04-0169-02-0000                                                             20
   Internal Event/Triggers Description
Link_Available       Lower layers =>   used to indicate availability of a new link.
                     MIH               Generated from lower layers (PHY or MAC),
                                       propagated by MIH based on subscription. MIH
                                       function may use 802.21 information services
                                       upon receiving trigger to discover additional
                                       features of the link before reporting to upper
                                       layers.
Link_Going_Up        Lower layers =>   used to indicate that a specific link is being
                     MIH               connected (it may provide the estimated delay to
                                       link up)

Link_Up              Lower layers =>   used to indicate that a specific link has been
                     MIH               connected


Link_Down            Lower layers =>   used to indicate that a specific link is no longer
                     MIH               available




21-04-0169-02-0000                                                                      21
   Internal Event/Triggers Description
Link_Change          Lower layers =>   used to inform the upper layers that specific
{[Features]}         MIH               features of the link have changed (e.g. QoS, data
                                       throughput, etc.). All the features that have
                                       changed are reported (according to event
                                       subscription)
Connection_Availa    MIH => Upper      used to indicate availability of a new connection.
ble                  layers            Generated from lower layers (PHY or MAC),
                                       propagated by MIH based on subscription. MIH
                                       function may use 802.21 information services
                                       upon receiving trigger to discover additional
                                       features of the link before reporting to upper
                                       layers.
Connection_Going     MIH => Upper      used to indicate that a specific connection is being
_Up                  layers            connected (it may provide the estimated delay to
                                       link up)

Connection_Up        MIH => Upper      used to indicate that a specific connection has
                     layers            been connected



21-04-0169-02-0000                                                                       22
   Internal Event/Triggers Description
Connection_Down      MIH => Upper   used to indicate that a specific connection is no
                     layers         longer available


Connection_Chang     MIH => Upper   used to inform the upper layers that specific
e {[Features]}       layers         features of the connection have changed (e.g. QoS,
                                    data throughput, etc.). All the features that have
                                    changed are reported (according to event
                                    subscription)
Event_Discovery      MIH => Upper   Used to inform upper layers new event types are
                     layers         available (provide periodic updates)




21-04-0169-02-0000                                                                 23
   Additional Details on Events/Triggers
• Subscribers (example list)
    • Bearer manager
    • Mobile IP
    • Applications
          • E.g. for multi-access support by applications that do not use Mobile IP

• Interdependency of triggers:
    • Detailed definition of triggers includes detailed interdependency
    • Not all triggers treated sequentially (e.g. different levels of trigger
      priority are introduced)
          • E.g. MIH function my act different upon a Link_Available whether current
            link is stable or Link_Going_Down is received for current link, or on
            Link_Going_Down when an handover command is received from the
            network
    • Details in detailed text proposal




  21-04-0169-02-0000                                                                  24
                      802.21 Event Signaling
• Based on MIH Functionality Primitives:
   •   Event Discovery Request/Response
   •   Event Registration Request/Response
   •   Event De-Registration Request /Response
   •   Interface Status Request/Response
   •   Interface Configuration Request/Response
   •   Connection Setup Request/Response
   •   Connection Tear-Down Request/Response
   •   Connection Status Request/Response
   •   Handover Request/Response




 21-04-0169-02-0000                               25
                       Information Services
• Access to Information Services
• Discovery of 802.21 services
• Types of Information




  21-04-0169-02-0000                          26
 Access to 802.21 Information Service (1)
• Characteristics:
   • Accessible from any network
   • Primarily “static” information
   • Possible to access information about networks available on one interface
      type from a different interface (e.g. learn about .11 AP’s from the cellular
      link)
• Different dimensions specified in the solution:
   • How the information is carried (e.g. broadcasting versus probe/response)
   • “Where” to get such information
          • E.g. in proximity/p2p networking scenarios (e.g. getting such information from
            neighbors to avoid unnecessary traffic over currently used access, e.g. cellular)
    •   What information is carried
    •   When the information is obtained
    •   The scope/type of transport (L2 or L3)
    •   Security
• How the information is carried: proposal enables
    • information to be broadcasted
    • query/response access to information
• Transport: solution is defined to be transport independent
  21-04-0169-02-0000                                                                            27
   Access to 802.21 Information Service (2)
How • Two types of access
       • Distribution (advertisement)
                 • This means information are distributed e.g. in a “broadcast” fashion (e.g. part
                   of link layer beacon)
            • Query/response
                 • In several cases, plain distribution (e.g. broadcast) on Information Services data
                   is not practical (too much information) => a query/response mechanism is
                   proposed to enable access to such information
                 • Query/response needed for link layers that do not support any form of
                   broadcasting/advertisement of information
How • Two models are possible (not mutually exclusive)
       • Direct access: terminals access directly the information services
         provided by 802.21 functionality of a given network
       • Distributed access: networks have 802.21 network functions that
         talk to each other to:
                 • Advertise information availability: allows other 802.21 network functions and
                   terminals to be aware of what information a given 802.21 network functions
                   can provide, used to inform 802.21 network functions and terminal 802.21
                   function of what they may be interested in subscribing to
                 • Publish the information to subscribers

    21-04-0169-02-0000                                                                         28
    Access to 802.21 Information Service (3)
 How • Two relevant aspects for the access:
        • Advertisement/publishing of information
                  • More information in detailed text submission
            • Semantic:
                  • E.g. how query is performed, what type of information is provided
                  • based on more or less precise queries, 802.21 network function can decide if it
                    has info cached locally or needs to retrieve them (e.g. from the 802.21 network
                    function that advertised the availability of such information)
                  • current slide set does not contain such details: semantics to be presented at next
                    level of detail in discussion
Where • Where is Information Service accessed from:
         • Current access:
                  • Data for new link/network is obtained through current access
            • New access:
                  • Data for new link/network is obtained through current access
            • Closely related to transport of information services (see transport
              section)



     21-04-0169-02-0000                                                                         29
   Access to 802.21 Information Service (4)
When • Access of information:
        • Pro-actively:
                 • e.g. through broadcasting, before handoff/connectivity decision must be taken
                 • Corresponds to “bootstrapping” scenario
           • Reactively:
                 • just before handoff/connectivity decision must be taken (e.g. upon specific
                   request to MIHF from protocol/functions)
                 • Based on specific remote query/responses
           • 802.21 does not rely on any single one of these two options




    21-04-0169-02-0000                                                                           30
                       Types of Information
• Include:
    • Information available to MIH function on current links/connections
    • Information on potential links/connections
    • Constitutes dynamic information set to perform connectivity/handover
      decisions
• List is not exhaustive, provided as initial draft




  21-04-0169-02-0000                                                    31
                        Types of Information
Information     Current               Potential Link/        Link              Available or type of discovery
Type            Link/Connection       Connection             layer/interface   required
                                                             or network
                                                             layer

Link Features   parameters used by    interface capability   Link layer        Available for current
                current link          (e.g. available                          Advertised for potential
                status (e.g.          bandwidth) for                           link/connection
                powered down, in      potential links
                sleep mode, etc.)

Cost                                                         Both              Available for current
                                                                               Advertised for potential
                                                                               link/connection
QoS             levels of QoS         levels of QoS          Both              Available for current
                supported             supported                                Advertised/queried for
                                                                               potential link/connection
Power           Power levels in use   e.g. power levels      Link Layer        Available for current
                                      available for a                          Advertised for potential
                                      specific interface                       link/connection


   21-04-0169-02-0000                                                                                  32
                        Types of Information
Information     Current             Potential Link/         Link              Available or discovery
Type            Link/Connection     Connection              layer/interface   required
                                                            or network
                                                            layer
Security        security level,     security level,         Both              Available for current
                authentication      authentication                            Advertised/queried for
                method/algorithm,   method/algorithm,                         potential link/connection
                encryption          encryption
                algorithm in use    algorithm available
                and available       and/or required
                                    (indicate what the
                                    terminal needs to do
                                    to gain secure
                                    access, e.g. open
                                    authentication +
                                    VPN establishment,
                                    , 802.11i security
                                    establishment at
                                    WLAN only,
                                    802.11i security +
                                    VPN establishment,
                                    802.11i security +
                                    authentication with a
                                    FA, etc.)


   21-04-0169-02-0000                                                                                 33
                          Types of Information
Information       Current                Potential Link/          Link              Available or discovery
Type              Link/Connection        Connection               layer/interface   required
                                                                  or network
                                                                  layer
Roaming/          Security domains       Security domains         Both              Available for current
Security          accessible (e.g. for   accessible (e.g. for                       Queried for potential
Domain            authentication         authentication                             link/connection
                  credentials)           credentials).
                                         Terminal queries
                                         about accessibility
                                         to specific domains
                                         (can I use my
                                         credentials here?)
Accessible core   Core networks          Core networks            Connection        Available for current
networks          reachable (e.g.        reachable (e.g.          layer             Queried for potential
                  based on roaming       based on roaming                           link/connection
                  agreements and         agreements and
                  broker                 broker
                  interconnections)      interconnections):
                                         can I get to a given
                                         PLMN core network
                                         from here?
Accessible        Services accessible    Services accessible      Connection        Available for current
Services          (e.g. 3GPP IMS)        (e.g. 3GPP IMS):         layer             Queried for potential
                                         can I get this service                     link/connection
                                         here?
   21-04-0169-02-0000                                                                                       34
                       Transport Aspects
• Transport for:
   • Event/triggers
   • Information Services
• Local transport (i.e. inside terminal):
   • MIH-link layer:
          • use generic SAP at MIH side, media specific SAP at link layer side
    • MIH-upper layers:
          • use generic SAP both at MIH side and upper layer (e.g. bearer manager)
          • use generic SAP at MIH side, protocol specific SAP at upper layer




  21-04-0169-02-0000                                                             35
    Remote Transport Aspects for 802.21
     Triggers and Information Service
• Assumptions:
   • 802.21 does not define specific transports (L2 or L3)
   • Event notification/trigger service and information service defined to be
     transport independent  802.21 defines a set of IE and the logic on how
     they are exchanged (when and why)
   • IE are carried in different transports (L2 and L3)
   • The needed transport/encapsulation of 802.21 payload in L2 will be
     defined by each 802 family member, and added to their standard
   • L3 transport is defined in IETF
   • 802.21 defines a set of recommendations (e.g. requirements to be
     satisfied), and influences other groups (.11, .16, IETF, 3GPP, 3GPP2)
     through liaison and by submitting recommendations




 21-04-0169-02-0000                                                      36
    Remote Transport and Architecture
        Model for MIH Function
                                     Upper Layers/IP

                                           IP
               Access/MAC
                                       802.21 MIH           802.21 MIH
              Centric Model
                                        Function             Function
              => L2 transport
                                       MAC/PHY              MAC/PHY
                                        Terminal             AP/Base
                                                             Station


                   Upper Layers/IP

                           IP
                                                                             Can be distributed
                                                                802.21 MIH   function (e.g.
   Semi-                                                         Function    through broker for
                       802.21 MIH                                            inter-domain
Access/MAC              Function
Transparent
                                            802.21 MIH L2                    scenarios)
                                              Transport
Model => L2
 transport                                                       Access
                       MAC/PHY                  MAC/PHY         Controller
                       Terminal                  AP/Base         /802.21
                                                 Station          Server

  21-04-0169-02-0000                                                                 37
    Remote Transport and Architecture
        Model for MIH Function
                   Upper Layers/IP

                           IP
                                                                          Can be distributed
                       802.21 MIH            Logical view   802.21 MIH    function (e.g.
Access/MAC              Function                             Function     through broker for
Transparent                                                               inter-domain
                                                              Access      scenarios)
Model => L3            MAC/PHY                 MAC/PHY       Controller
 transport             Terminal      Transport  AP/Base       /802.21
                                       view     Station      “Server”




  21-04-0169-02-0000                                                              38
          L2 Remote Transport for 802.21
               Information Service
• E.g. over 802.11 MAC with extensions to MAC to enable
  transport of new Information Elements
• L2 transport can amount to potentially:
    • extending beacon (for broadcasting of Information Service data)
    • extending the current .11k probe request/response mechanism to enable
      carrying
    • as data traffic (to avoid slowness of management frames) at highest
      priority (11e assumed)
    • other solutions (e.g. new MAC specific signaling with high priority) to
      be studied in 802.11/.16/etc., however 802.21 must consider feasibility
      and should provide requirements and recommendations
• Bridged network with direct 802.21 communications between
  APs supported



  21-04-0169-02-0000                                                      39
          L2 Remote Transport for 802.21
               Information Service
• Where is the information accessed from:
    • Current access:
          • Very useful e.g. when accessing over cellular and not wanting to have to
            “scan” for all other technologies available
          • Useful when new access deploys an 802.21 “server” in network without
            upgrading “APs” to support 802.21: in such way terminals can still benefit
            of 802.21 to speed up handoff to new access
    • New access:
          • In most cases possible only with L2 transport (L3 would require actually
            accessing the media, thus requiring authentication, etc.)
          • Availability of 802.21 service over beacon should be provided
                • An important aspects is how the terminal chooses when service is
                   available both through current and new access. E.g. when two
                   accesses are in different (security) domains, it is more probable than
                   more information are available through new access (i.e. two
                   domains may not interchange 802.21 information). However,
                   terminal does not know whether new access is in new domain or not
                   without first receiving 802.21 information  e.g. access 802.21
                   information through new access by default when available

  21-04-0169-02-0000                                                                40
     L2 Remote Transport for 802.21 Information
                     Service
      External I/F to 802.21            External I/F to 802.21
          functionality                     functionality
                        (1)                              Enterprise Network
                                  (3)                                (1)
      External
                                 (4)
      Network
       (e.g.                       WLAN (2)                         WLAN
      cellular,
     other 802
                                    Sub-                             Sub-
     network)                        AP 1
                                  Domain(i)                           AP 2
                                                                   Domain(ii)
                                                                             802.21

                                                                       (3) (4)
                                                   Scenario: Intra-802 and Inter-802 Same Domain/ Network
                                                                     Technology 802.21 Information Service
•    Different possible implementations
      i.    802.21 functionality external to AP, AP with enhanced MAC to carry 802.21 information (for existing APs, AP requires
            only firmware upgrade to support new signaling, no additional function required)
      ii.   802.21 functionality internal to AP, interacting with other 802.21 functionality in network (APs or servers)
1.   Information are broadcasted/multicasted (not over media) to other 802.21 function on network side that
     subscribed for distribution of 802.21 information
      •     802.21 server that acts as interface to external networks filters/consolidates the information to be provided to external
            networks
2.   AP interfaces with external 802.21 functionality
      •     Information elements generated at external 802.21 server, AP carries signaling to/from STA, forwards query from STA to
            server, receives information (e.g. for broadcast) from 802.21 server. I/F between AP and 802.21 external functionality is
            outside the scope of 802.21
3.   Terminal subscribes to 802.21 services based on preferences
4.   Alternatively, no subscription but query/request by the terminal based on terminal policies (on when and what)
•    Access is over L2: Potentially extension of 802.11k (beacon for broadcast part, probe request/response for
     response/request)
     21-04-0169-02-0000                                                                                                         41
 L3 Remote Transport for 802.21 Information
                 Service
• This in reality is transport of L2-specific information over L3
    • L2 information comprises:
          • Connectivity information
          • Security information
    • e.g. similarly to what L2TP does for different purposes
• Both broadcast and request/response model can be supported
• A protocol must be specified to carry the IEs defined by 802.21
    • Could be specifying as an existing protocol can carry such information,
      or a new protocol
    • In both cases, a close liaison with IETF is needed since 802.21 does not
      specify L3 solutions
• For information services on cellular side, L3 seems to be only
  viable solution on short term
    • L2 requires changing L2 cellular protocols to enable carrying the new
      information

  21-04-0169-02-0000                                                       42
     L3 Remote Transport for 802.21 Information
                     Service
                                         Internet
                            (2)       External I/F to 802.21            802.21-enabled
                      (1)                 functionality                    VPN GW

                                                     WLAN                        Enterprise
           Cellular
                                                    Access                         WLAN
           Network
                                                    Network                       Network
         RAN                                              AP                             AP

                                        Scenario: Remote Access to 802.21 Information Service

1.    Terminal subscribes to 802.21 services based on preferences
2.    Information are broadcasted/multicasted (not over media) to other 802.21 function on network
      side that subscribed
3.    Alternatively, no subscription but query/request by the terminal based on terminal policies (on
      when and what)
•     Access is over IP (protocol TBD, re-use of existing protocols would be favorable)
•     How does terminal know where to send subscription request and queries:
       • based on 802.21 advertisement where available
       • based on information stored in the terminal (e.g. list of URLs or names translated
            through DNS to locate the source of 802.21 information for given networks) => requires
            pre-configuration of terminal by operator and/or owner (e.g. enterprise)

     21-04-0169-02-0000                                                                         43
     L3 Remote Transport for 802.21 Information
                     Service
                                           (1) (3)                  (1)
                                             (4) Internet                (3)
                       External I/F to 802.21 External I/F to 802.21 (4)                    802.21-enabled
                           functionality           functionality                               VPN GW
                       (2)
                 (4)      (3)                                    WLAN                                    Enterprise
            Cellular
                                                                Access                                     WLAN
            Network
                                                                Network                                   Network
           RAN                                                         AP                                        AP

                                             Scenario: Distributed Access to 802.21 Information Service

1.    802.21 “server” subscribes to 802.21 information services thanks to distributed 802.21
      advertisement/discovery
2.    Terminal subscribes to 802.21 services through local server based on preferences
3.    Information are broadcasted/multicasted (not over media) to other 802.21 function on network side that
      subscribed
4.    Alternatively, no subscription by terminal, but query/request by the terminal based on terminal policies (on
      when and what)
•     Access is over IP (protocol TBD, re-use of existing protocols would be favorable)
•     How does terminal know where to send subscription request and queries:
       •    based on 802.21 advertisement where available
       •    based on information stored in the terminal (e.g. list of URLs or names translated through DNS to locate the source of
            802.21 information for given networks) => requires pre-configuration of terminal by operator and/or owner (e.g.
            enterprise)


     21-04-0169-02-0000                                                                                                     44
     L3 Remote Transport for 802.21 Information
                     Service
       External I/F to 802.21              External I/F to 802.21
           functionality                       functionality
                         (2)                                     Enterprise Network
                                     (3)
       External
                                    (4)                                   (1)                          (1)
       Network
        (e.g.                   WLAN                                             WLAN                         Other 802
       cellular,                                           (1)
      other 802
                                 Sub-                                             Sub-                          Sub-
      network)                 Domain 1
                                   AP                                           Domain 2
                                                                                    AP                         Domain

                                                         Scenario: Intra-802 and Inter-802 Same Domain/ Network
                                                                           Technology 802.21 Information Service

1.     802.21 functionality can be centralized (e.g. in an AC) or distributed (in APs), various architecture shall be
       enabled by 802.21 mechanisms. 802.21 functionality is configured based on specific network mechanisms
       (manual, automatic, etc., not in scope of 802.21, more of a management issue)
2.     Information are broadcasted/multicasted (not over media) to other 802.21 function on network side that
       subscribed
3.     Terminal subscribes to 802.21 services through local server based on preferences
4.     Alternatively, no subscription by terminal, but query/request by the terminal based on terminal policies (on
       when and what)
•      Beside L2 transport described before, access can be also over IP (protocol TBD, re-use of existing
       protocols would be favorable)
•      How does terminal know where to send subscription request and queries:
        •      based on 802.21 advertisement where available (e.g. over MAC, e.g. 802.11 beacon indicating availability of 802.21 service)
        •      based on information stored in the terminal (e.g. list of URLs or names translated through DNS to locate the source of 802.21 information
               for given networks) => requires pre-configuration of terminal by operator and/or owner (e.g. enterprise)

     21-04-0169-02-0000                                                                                                                           45
   Access to 802.21 Information Service:
          Reliability and Security
• Reliability
    • Remote trigger delivery: essential for e.g. network controlled handoff
    • Information service: reliability important when service used to find out
      information in a reactive mode (e.g. just before handoff)
    • Reliability in terms of:
          • Ensure delivery
          • Timely delivery/response
    • How is reliability supported?
          • 802.21 does not specify transport
          • Specific L2 instantiations and L3 solution in charge of supporting reliability (depending on
            discussion in relevant groups/fora)
    • Assumption in this proposal:
          • Reliability is considered as possible when 802.21 is implemented (both L2 and L3)
          • Reliability delivered by specific instantiation (i.e. mapping to specific link)
          • 802.21 scenarios that need reliability defined as valid only when transport reliability can be
            provide  reliability not required for every 802.21 service, but scenarios based on transport
            reliability developed in 802.21 (i.e. not discarded just because reliability may not be achieved in
            every instantiation of 802.21)
• Security:
    • 802.21 information service and remote triggers must be protected at least for data
      integrity, possibly for authentication of source
    • Corrupted data may lead to wrong decisions
          • E.g. 802.11 hotspot advertised as free to lure terminals away from other access or hotspot
    • Security not defined in 802.21
    • Recommendations/requirements defined to ensure different instantiations (e.g.
      .11, .16. Etc.) support security
  21-04-0169-02-0000                                                                                       46
              Discovery of 802.21 services
• To enable 802.21 operations, discovery of 802.21 availability is
  required
    • E.g. terminal must know whether a certain access supports 802.21
• Terminal discovery
    • L2 is 802.21 enabled: discovery can happen through new access or
      current access
• L2 support for discovery
• Backward compatibility
    • 802.21 must work out scenarios (e.g. “terminal is 802.21-enabled, old
      access is not enabled, new access is enabled” versus “terminal is 802.21-
      enabled, old access is enabled, new access is not”)
    • define behavior/expectations of terminal and network in such scenarios
      to ensure interoperability
    • create recommendations for L2 and L3 solutions


  21-04-0169-02-0000                                                       47
 802.21 Triggers and Information Service
           vs. Type of Handoff
   Type of Handoff
                                 Terminal controlled                   Network Controlled (terminal supported)


 802.21
Service
 Triggers            Actual reason to begin handoff on              Network must know terminal can indeed move,
                     terminal side                                  plus terminal requirements  to enable this
                                                                    scenario, network MIHF must be aware of
                                                                    connection requirements and features (not only
                                                                    after one handoff, but from beginning of
                                                                    connection)  since network MIHF is
                                                                    currently not involved in connectivity setup, nor
                                                                    it is expected to be, MIHF in terminal must
                                                                    report connectivity setup event to MIHF in
                                                                    network when network required network-
                                                                    controlled handoff (this must be discovered by
                                                                    terminal, or explicitly requested by 802.21
                                                                    MIHF function)
 Information         Collected by MIHF in terminal locally and      Information generated in terminal reported to
 service             from network to enable decision of             network MIHF (upon subscription or specific
                     “where” to handoff                             request)
                     Can be part of trigger (e.g. a better access
                     becomes available based on information
                     service
    21-04-0169-02-0000                                                                                      48
                          Conclusion
• A proposal covering the various aspects of 802.21
• High level of detail to allow for introductory discussion
• Next level of details to be provided in draft text at January
  meeting




  21-04-0169-02-0000                                              49

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:4
posted:10/23/2012
language:Latin
pages:49