MAC State Convergence Function

MAC State Convergence Function
September 2007 doc.: IEEE /2488r1 September 2007 MAC State Convergence Function Date: Authors: Matthew Gast, Trapeze Networks Matthew Gast, Trapeze Networks

September 2007 doc.: IEEE /2488r1 September 2007 Abstract This presentation provides one potential approach for providing MIH support in : Discussion of required support of primitive operations in terms of existing primitives and potential new additions, and Discussion of a “convergence function” that would supply MAC state information to higher layer applications such as MIH Matthew Gast, Trapeze Networks Matthew Gast, Trapeze Networks

The Problem, In Brief The 802.11 MAC does not have much state
September 2007 doc.: IEEE /2488r1 September 2007 The Problem, In Brief The MAC does not have much state Example: MIH Link_Up event is the “first” time that a wireless LAN is available Existing MLME operations are like the “lower” MAC – there is no high-level state, such as the ESSID a STA is associated with Many higher layer protocols (e.g MIH) need context Proposal: A “MAC state convergence function” Snoops on MAC management (MLME) and PHY management (PLME) events, and can retrieve state from station management (SME) Synthesizes events and state to create new logical operations/indications Inputs: MLME and PLME events, state information retrieved from SME Output: Operations and events useful to higher level protocols Matthew Gast, Trapeze Networks Matthew Gast, Trapeze Networks

Architectural Overview
September 2007 doc.: IEEE /2488r1 September 2007 Architectural Overview MIH Other higher layers using MAC state information MAC_STATE_CONVERGENCE_SAP MAC State Convergence Function MAC_SAP MSCF-SME_SAP MAC MLME SME Mobility Management MLME_SAP PHY_SAP Interworking Service Management PHY PLME PLME_SAP Note: The base standard version of this diagram is Figure 5-10 on page 42 of Matthew Gast, Trapeze Networks Matthew Gast, Trapeze Networks

Analysis of 802.21 Primitive Operations
September 2007 doc.: IEEE /2488r1 September 2007 Analysis of Primitive Operations Matthew Gast, Trapeze Networks Matthew Gast, Trapeze Networks

Primitives Required by 802.21
September 2007 doc.: IEEE /2488r1 September 2007 Primitives Required by From D7.1, Table L2: Link_Event_Subscribe Link_Event_Unsubscribe Link_Configure_Thresholds Link_Up Link_Down Link_Going_Down Link_Event_Rollback Link_Detected Link_Parameters_Report Link_PDU_Transmit_Status Link_Handover_Imminent Link_Handover_Complete Link_Capability_Discover Link_Get_Parameters Link_Action Matthew Gast, Trapeze Networks Matthew Gast, Trapeze Networks

Classification of 802.21 Primitives
September 2007 doc.: IEEE /2488r1 September 2007 Classification of Primitives Link Operations Link_Up Link_Down Link_Going_Down Link_Event_Rollback Link_Detected Link_Parameters_Report Link_PDU_Transmit_Status Mobility Operations Link_Handover_Imminent Link_Handover_Complete MAC “API” Link_Event_Subscribe Link_Event_Unsubscribe Link_Configure_Thresholds Link_Capability_Discover Link_Get_Parameters Link_Action Link_Parameters_Report Link Parameter operations Matthew Gast, Trapeze Networks Matthew Gast, Trapeze Networks

Link Operations September 2007 September 2007
doc.: IEEE /2488r1 September 2007 Link Operations Link_Up Link_Down Link_Going_Down Link_Event_Rollback Link_Detected Link_Parameters_Report Link_PDU_Transmit_Status Matthew Gast, Trapeze Networks Matthew Gast, Trapeze Networks

Link_Up English meaning for 802.11: A network is now up at layer 2
September 2007 doc.: IEEE /2488r1 September 2007 Link_Up English meaning for : A network is now up at layer 2 Technical meaning in terms of (1) the MLME-Associate.confirm with a result code of success for unencrypted networks, or… (2) the first MLME-Associate.confirm along with an MLME-SetKeys.confirm, both with result codes of success, for encrypted networks Implications for u draft MLME-Reassociate primitives are unimportant because they cannot be “first” MLME-Associate.confirm primitives may need to be filtered, based on whether associations occur within a “small enough” time window to be considered “first” – perhaps this should be tied to whether a full 802.1X authentication was required? Matthew Gast, Trapeze Networks Matthew Gast, Trapeze Networks

September 2007 doc.: IEEE /2488r1 September 2007 Link_Down English meaning: The link has gone down and can no longer send packets Technical meaning in terms of (1) the STA has received an MLME-Disassociate.indication (2) the STA has received an MLME-Deauthenticate.indication (3) frames to the STA are not acknowledged for a “long enough” period of time Implications for u draft The convergence function must access the state of Protected Management Frame MIB entry (dot11RSNAProtectedManagementFramesEnabled) Need to investigate whether TGw authentication will suppress Disassociate and Deauthenticate primitives. If not, then unauthenticated disconnection attempts or disconnects that fail authentication must be filtered by the convergence function Different applications may require different link performance metrics for #3, so the convergence function should store the state of metrics that are required to declare a link dead. Defaults may be vendor-specific. Matthew Gast, Trapeze Networks Matthew Gast, Trapeze Networks

September 2007 doc.: IEEE /2488r1 September 2007 Link_Going_Down English meaning: The link seems to be getting weaker, and might go down soon. This requires some form of prediction for future link quality. It may also mean an administrative shutdown Technical meaning in terms of (1) According to indications received with frames, it is possible to predict the link will fail “soon” (2) This may be received Data frames, or received Beacon frames Implications for u draft This is a new event that will be synthesized by the convergence function No “best” prediction algorithm can be specified in the standard, and must be vendor-specific logic in the SME There may be a need to provide configurable thresholds for the predictive algorithm through the SAP with between the CF and SME An identifier and sequence number are required to support rollback (the next primitive) RSSI is available for all of the radio PHYs (clauses 14, 15, 17, 18, and 19), but not the IR PHY (clause 16) Matthew Gast, Trapeze Networks Matthew Gast, Trapeze Networks

September 2007 doc.: IEEE /2488r1 September 2007 Link_Event_Rollback English meaning: “Oops! We were wrong about that impending link failure, so never mind.” Technical meaning The Link_Going_Down event no longer applies, so it needs to be cancelled No tie to existing primitive operations Implications for u draft: If the previous event is supported, this must also be supported This event needs a tie to the previous event -- they operate as two sides of the same operation Matthew Gast, Trapeze Networks Matthew Gast, Trapeze Networks

September 2007 doc.: IEEE /2488r1 September 2007 Link_Detected English meaning: A new type of is available for potential use; e.g., we have powered on the interface Implication for u draft No other IEEE 802 PHY supports this, so no support is required Matthew Gast, Trapeze Networks Matthew Gast, Trapeze Networks

Link_PDU_Transmit_Status
September 2007 doc.: IEEE /2488r1 September 2007 Link_PDU_Transmit_Status English meaning: Gets the status of a protocol data unit transmission Technical meaning in terms of Maps to existing MA-UNITDATA.confirm primitive Implication for u draft MA-UNITDATA.confirm results are received by the convergence function and passed up as this event Matthew Gast, Trapeze Networks Matthew Gast, Trapeze Networks

Mobility Operations September 2007 September 2007
doc.: IEEE /2488r1 September 2007 Mobility Operations Link_Handover_Imminent Link_Handover_Complete Matthew Gast, Trapeze Networks Matthew Gast, Trapeze Networks

Note on MIH “Handover” operations
September 2007 doc.: IEEE /2488r1 September 2007 Note on MIH “Handover” operations According to D7.1, clause : “Link_Handover_Imminent is generated when a native link layer handover or switch decision has been made and its execution is imminent …” Similar definition for handover complete operation in This is an L2 event, indicating intra-ESS transitions in This may be an extremely frequent report for link layers Question for WG: why is it necessary to report intra-L2 handover, since access networks are built with L2 mobility in mind These events probably do not need support in Matthew Gast, Trapeze Networks Matthew Gast, Trapeze Networks

Link_Handover_Imminent
September 2007 doc.: IEEE /2488r1 September 2007 Link_Handover_Imminent English meaning: The non-AP STA is about to try to move to another AP, but has not completed the process Technical meaning in terms of (1) The non-AP STA has authenticated (not 802.1X-authenticated) to a new AP, but has not moved its association. The mobility manager intends to move (2) The non-AP STA has initiated an r fast transition; in r-D7.0, this means that the MLME-RESOURCE_REQUEST.request has been sent, or that the MLME-(RE)ASSOCIATE.request containing the Fast Transition IE has been sent Implications for u draft The “intention to move” can only be determined by the SME. Therefore, this event must be reported by the SME and passed to the convergence function Or, TGu may choose not to support this, since intra-ESS handover is not an interesting or valuable event from the perspective of L3 mobility Matthew Gast, Trapeze Networks Matthew Gast, Trapeze Networks

Link_Handover_Complete
September 2007 doc.: IEEE /2488r1 September 2007 Link_Handover_Complete English meaning: The non-AP STA has completed its move to a new AP Technical meaning in terms of (1) On an unencrypted network, the MLME has received the MLME-ASSOCIATE.confirm primitive (2) On an encrypted network, the MLME-(RE)ASSOCIATE.confirm primitive has been followed by an MLME-SetKeys.confirm primitive in a “short” period of time Implications for u draft TGu may choose not to support this, since intra-ESS handover is not an interesting or valuable event from the perspective of L3 mobility Matthew Gast, Trapeze Networks Matthew Gast, Trapeze Networks

MAC API Operations September 2007 September 2007
doc.: IEEE /2488r1 September 2007 MAC API Operations Link_Event_Subscribe Link_Event_Unsubscribe Link_Capability_Discover Link_Action Matthew Gast, Trapeze Networks Matthew Gast, Trapeze Networks

Link_Event_Subscribe
September 2007 doc.: IEEE /2488r1 September 2007 Link_Event_Subscribe English meaning: MIH has requested to receive events from the lower level that will assist in its own operation Technical meaning Not relevant to the proposed convergence function. The convergence function would always be available, and thus, there is no need to define a subscription model. These functions are not defined for other IEEE 802 networks in D7.1 Table L2. Implications for u draft None; does not need to be incorporated Matthew Gast, Trapeze Networks Matthew Gast, Trapeze Networks

Link_Event_Unsubscribe
September 2007 doc.: IEEE /2488r1 September 2007 Link_Event_Unsubscribe English meaning: MIH no longer needs lower level events Technical meaning Not relevant to the proposed convergence function. The convergence function would always be available, and thus, there is no need to define a subscription model. These functions are not defined for other IEEE 802 networks in D7.1 Table L2. Implications for u draft None; does not need to be incorporated Matthew Gast, Trapeze Networks Matthew Gast, Trapeze Networks

Link_Capability_Discover
September 2007 doc.: IEEE /2488r1 September 2007 Link_Capability_Discover English meaning: MIH requests a list of supported events Technical meaning in terms of No primitive currently exists Implications for u Need to define two primitives in the convergence function: a request that comes in from higher layers, and a result that returns supported events Matthew Gast, Trapeze Networks Matthew Gast, Trapeze Networks

Link_Action September 2007
doc.: IEEE /2488r1 September 2007 Link_Action English meaning: Requests action on a link. Valid actions are listed in Table B4 on D7.1, p. 178. Technical meaning for Disconnect: Deauthenticate/Disassociate peer MAC address (MLME-Deauthentate.request or MLME-Diassociate.request) Low power: change power save status; in , this translates to MLME-POWERMGT.request Power down and power up link: no primitives exist Scan: issue MLME-SCAN.request LINK_RESOURCE_RETAIN attribute is defined in Table B5 (p 184). It is used to reserve resources for future reconnection, which is not a concept that exists in DATA_FORWARDING_REQUEST attribute asks that buffered data be sent to new point, which is already required by Implications for u draft Convergence function would need to map disconnect and low power actions to respective primitives Matthew Gast, Trapeze Networks Matthew Gast, Trapeze Networks

Link Parameter Operations
September 2007 doc.: IEEE /2488r1 September 2007 Link Parameter Operations Link_Configure_Thresholds Link_Get_Parameters Link_Parameters_Report Matthew Gast, Trapeze Networks Matthew Gast, Trapeze Networks

What are Link Parameters?
September 2007 doc.: IEEE /2488r1 September 2007 What are Link Parameters? For links, defines only 2 parameters in Table B2, page 181: RSSI of the beacon channel Flag to indicate that no QoS resources are available (i.e., request for capacity denied) Implications for u The MAC has no state. The state is stored in the SME, and the convergence function provides a “window” on to that new state that higher layers can access The parameter set is not as rich as the k framework, which includes noise, received power, signal/noise, antenna indication TGu may wish to assist in incorporating new k measurement parameters into the draft, along with additional parameters such as frame- or bit-error rates Matthew Gast, Trapeze Networks Matthew Gast, Trapeze Networks

Link_Configure_Thresholds
September 2007 doc.: IEEE /2488r1 September 2007 Link_Configure_Thresholds Meaning in English: Sets thresholds for MIH operations so that events will be reported only when they exceed thresholds Technical meaning for This operation sets a trigger threshold. Even though k-D8.0 defines triggered reporting, its MLME primitives do not define primitives Implications for TGu draft Need to define operations of the converge function to store parameter values (from the SME) Need to indicate normative behavior of events that are triggered when thresholds are passed; k revises clause to create triggered measurement reports, and TGu will need to define something similar in its functional description Matthew Gast, Trapeze Networks Matthew Gast, Trapeze Networks

September 2007 doc.: IEEE /2488r1 September 2007 Link_Get_Parameters English meaning: Retrieve the parameters set by the previous operation so that a higher layer protocol can determine when events will be triggered Technical meaning This operation retrieves a trigger threshold set by the previous operation Implication for u Need to define operations of the converge function to retrieve parameter values (from the SME) Matthew Gast, Trapeze Networks Matthew Gast, Trapeze Networks

Link_Parameters_Report
September 2007 doc.: IEEE /2488r1 September 2007 Link_Parameters_Report English meaning: Link parameters have crossed a specified threshold Technical meaning in terms of The MLME is stateless, so there is no existing primitive. This type of event would have be generated by the SME and passed to the convergence function so it can be made available to higher layers Implications for TGu draft Generation of an event triggered by crossing a parameter threshold needs to be defined, perhaps in a similar fashion to k Matthew Gast, Trapeze Networks Matthew Gast, Trapeze Networks

Way Forward September 2007 September 2007 doc.: IEEE 802.11-07/2488r1
Matthew Gast, Trapeze Networks Matthew Gast, Trapeze Networks

Next Steps TGu investigation required
September 2007 doc.: IEEE /2488r1 September 2007 Next Steps TGu investigation required Do MLME events for Deauthentication and Disassociation incorporate TGw protection, or do we need to filter them? Joint TGu technical investigation Do the intra-L2 handover events need to be supported with an link layer? Is the current parameter list sufficient for , or should more types of parameters be defined? Define convergence function for inclusion within TGu draft Call for ad hoc meeting! Matthew Gast, Trapeze Networks Matthew Gast, Trapeze Networks

September 2007 doc.: IEEE /2488r1 September 2007 References D7.1 802.11k-D8.0 802.11w-D2.3 802.11u-D1.0 Matthew Gast, Trapeze Networks Matthew Gast, Trapeze Networks

MAC State Convergence Function

Similar presentations

Presentation on theme: "MAC State Convergence Function"— Presentation transcript:

Similar presentations

About project

Feedback

Log in

Auth with social network:

MAC State Convergence Function

Similar presentations

Presentation on theme: "MAC State Convergence Function"— Presentation transcript:

Similar presentations

About project

Feedback