Ieee 802.11 standard

transcript

IEEE 802.11 Standard10. Layer Management

Department of Computer Science Konkuk University, Seoul, Korea

seryvuth-tan@nida.gov.kh

Mr. Tan Seryvuth

Professor: Keecheon Kim

MBC Laboratory

Date: 04-06-2012

Contents

1. Overview of management model

2. Generic management primitives

3. MLME SAP interface

MLME(MAC Layer Management Entity) and PLME(Physical Layer Management

Entity) are management entities including into MAC sublayer and PHY respectively

Station Management Entity (SME)

is the independent entity – can be viewed as residing in a separation

management plane.

SME-MLME SAPMLME-PLME SAP

SME-PLME SAP

SME-MLME SAP = SME MLME Service Access Point

SME-PLME SAP = SME MLME Service Access Point

MLME-PLME SAP = MLME PLME Service Access Point

2. Generic management primitives

Management Information Base(MIB) –

manage specific information of each layer (MLME, PLME)

manage primitives exchanged across the management SAP (SET/GET)

Depicts these generic primitives

XX-GET.request

XX-GET.confirm

XX-SET.request

XX-SET.confirm

XX-RESET.request

XX-RESET.confirmused to initialize the management entity.

XX denotes MLME or PLME

SET values of a MIB attribute

GET values of a MIB attribute

Communicate between MLME-SME

The general form:

MLME-ACTION.request

MLME-ACTION.confirm

MLME-ACTION.............

SME-MLME SAP

MLME SAP = MAC Layer Entity Management Entity – Service Access PointSME-MLME SAP = Service Management Entity - MAC Layer Management Entity - Service Access Point

3. MLME SAP interfaceNo Management Service No Management Service

1 Power Management 16 TPC request

2 Scan 17 SetKeys

3 Synchronization 18 DeleteKeys

4 Authenticate 19 MIC (Michael) failure event

5 Deauthenticate 20 EAPOL

6 Associate 21 MLME-PeerKeySTART

7 Reassociate 22 SetProtection

8 Disassociate 23 MLME-PROTECTED FRAMED ROPPED

9 Reset 24 TS management interface

10 Start 25 Management of direct links

11 Spectrum management protocol layer model

26 Higher layer synchronization support

12 Measurement request 27 Block Ack

13 Measurement Report 28 Schedule element management

14 Channel measurement 29 Vendor-specific action

15 Channel switch

3.1 Power Management

This mechanism supports the process of establishment and maintenance of the

power management mode of a STA.

Basic idea

Mobile sleeps, AP buffers downlink data, and sends the data when the mobile

device is awakened.

Using Timing Sync Function (TSF) all mobiles are synchronized and they

will wake up at the same time to listen to the beacon.

3.1 Power Management

Power management modes:

Active Mode (AM)

• STA may receive frames at any time

Power Save Mode (PS)

• STA listens to selected Beacon frames

Power Management Request

PowerManagementMode, WankUp, ReceiveDTIMs

Power Management Confirm

ResultCode

DTIM = Delivery Traffic Indication Message

3.2 Scan

This mechanism support the process of determining the characteristics of

the available BSSs.

3.2 Scan

MLME-SCAN Request

BSSType, BSSID, SSID, ScanType, ProbeDelay, ChannelList, MinChannelTime, MaxChannelTime,

VendorSpecificInfo

MLME-SCAN Confirm

BBSDescriptionSet, ResultCode, VendorSpecificInfo

3.3 Synchronization

Timing synchronization function (TSF)

Used for power management

• Beacons sent at well known intervals

• All station timers in BSS are synchronized

3.3 Synchronization

MLME-JOIN Request

SelectedBSS, JoinFailureTimeout, ProbeDelay, OperationalRateSet, VendorSpecificInfo

MLME-JOIN Confirm

ResultCode, VendorSpecificInfo

3.4 Authenticate

Provides a mechanism for one station to prove its identity to anther station in

the WLAN

Can be used between any 2 stations

More useful when used between a mobile station and a AP in an infrastructure

There are two authentication algorithm:

- Open System authentication

- Share key authentication algorithm STA APAuthentication

3.4 Authenticate

Open System example:

(a) Assertion : I’m station 4

(b)Challenge : Null

(c) Response : Null

(d)Result : Station becomes Authenticated

Share key authentication algorithm

A password based example :

(b) Challenge : Prove your identity

(c) Response : Here is my password

(d) Result : if password OK, station becomes Authenticated

STA4 APAuthentication

3.4 Authenticate

A Cryptographic based example :

(b) Challenge : Here is some information (X). I encrypted with your public key,

what is it?

(c) Response : The contents of the information is (X) (only station4’s private

key could have recovered the challenge contents).

(d) Result : OK, I believer that you are station 4

STA4 APAuthentication

3.4 Authenticate

MLME-AUTHENTICATE Request

PeerSTAAddress, AuthenticationType, AuthenticateFailureTimeout, VendorSpecificInfo

MLME-AUTHENTICATE Confirm

PeerSTAAddress, ResultCode, VendorSpecificInfo

MLME-AUTHENTICATE Indication

PeerSTAAddress, AuthenticationType, VendorSpecificInfo

MLME-AUTHENTICATE Response

3. 5 Deauthenticate

It is invoked when an existing Open System or Shared key authentication is to

be terminated.

The act of deauthentication shall cause the station to be disassociated –

authentication is a prerequisite for association.

MLME-DEAUTHENTICATE Request

PeerSTAAdress, ReasonCode, VendorSpecificInfo

MLME-DEAUTHENTICATE Confirm

MLME-DEAUTHENTICATE Indication

PeerSTAAddress, ReasonCode, VendorSpecificInfo

3.6 Associate

Used to establish relationship with AP. STA scan (active / passive) frequency

band to select AP with best communication quality.

Accomplished after a successful authentication has been completed

3.6 Associate

MLME-ASSOCIATE Request

PeerSTAAddress, AssociationFailureTimeout, CapabilityInformation, ListenInterval,

Supported Channels, RSN, QoSCapability, VendorSpeciticInfo

MLME-ASSOCIATE Confirm

PeerSTAAddress, CapabilityInformation, AssociationID, SupportedRates, EDCAParameterSet,

VendorSpeciticInfo

MLME-ASSOCIATE Indication

PeerSTAAddress, CapabilityInformation, ListenInterval, SSID, SupportRates, RSN, QoSCapability,

VendorSpeciticInfo

MLME-ASSOCIATE Response

PeerSTAAddress, ResultCode, CapabilityInformation, AssociationID, EDCAParameterSet,

VendorSpeciticInfo

3.7 Re-associate

MLME-REASSOCIATE Request

NewAPAddress, ReassociationFailureTimeout, CapabilityInformation, ListenInterval,

Supported Channels, RSN, QoSCapability, VendorSpeciticInfo

MLME-REASSOCIATE Confirm

ResultCode, CapabilityInformation, AssociationID, SupportedRates, EDCAParameterSet,

VendorSpeciticInfo

MLME-REASSOCIATE Indication

PeerSTAAddress, CurrentAPAddress, CapabilityInformation, ListenInterval, SSID, SupportRates,

RSN, QoSCapability, VendorSpeciticInfo

MLME-REASSOCIATE Response

PeerSTAAddress, ResultCode, CapabilityInformation, AssociationID, EDCAParameterSet,

VendorSpeciticInfo

3.8 Disassociate

This mechanism is the termination of existing association.

It is invoked whenever an existing Association must be terminated, and can be

invoked by either party to an Association (Mobile STA or AP).

It is a notification that cannot be refused.

STAs are encouraged to Disassociate whenever they leave a network

3.8 Disassociate

MLME-Disassociate Request

PeerSTAAddress, ReasonCode, VendorSpecifinInfo

MLME-Disassociate Confirm

Resultcode, VendorSpecificInfo

MLEW-Disassociate Indication

PeerSTAAddress, ReasonCode, Vendorspeecity

3.9 Reset

This mechanism supports the process of resetting the MAC.

used to initialize the management entity.

Clear all internal variables to the default values (MIB)

MLME-RESET Request

STAAddress, SetDefaultMIB

MLME-RESET Confirm

ResultCode

3.10 Start

This mechanism supports the process of creating a new BSS.

MLME-START Request

SSID, BSSType, BeaconPeriod, CF parameter set, PHY parameter set, IBSS parameter set,

ProbeDelay, CapabilityInformation, BSSBasicRateSet, OperationalRateSet, Country,

IBSS DFS Recovery Interval, EDCAParameterSet, VendorSpecificInfo

MLME-START Confirm

3.11 Spectrum management protocol layer model

- The layer management extensions formeasurement and channel switchingassume a certain partition of spectrummanagement functionality between theMLME and SME.

Category Action ValueDialog Token

Measurement Request elements

Category Action ValueDialog Token

Measurement Report elements

Category Action ValueChannel Switch

Announcement element

3.12 Measurement request

This set of primitive supports the signaling of measurement requests between peer

MLME-MREQUEST Request

Peer MAC Address, Dialog Token, Measurement Request Set, VendorSpecificInfo

MLME-MREQUEST Confirm

MLME-MREQUEST Indication

Peer MAC Address, Dialog Token, Measurement Request Set, VendorSpecificInfo

3.13 Measurement Report

This set of primitives supports the signaling of measurement reports.

MLME-MREPORT Request

Peer MAC Address, Dialog Token, Measurement Report Set, VendorSpecificInfo

MLME-MREPORT Confirm

MLEM-MREPORT Indication

Peer MAC Address, Dialog Token, Measurement Report Set, VendorSpecificInfo

3.14 Channel measurement

This set of primitives supports the requesting and reporting of measurement data.

MLME-MEASURE Request

Dialog Token, Measurement Request Set, VendorSpecificInfo

MLME-MEASURE Confirm

ResultCode, Dialog Token, Measurement Report Set, VendorSpecificInfo

3.15 Channel Switch

This primitive requests switch to a new operating channel.

MLME-CHANNELSWITCH Request

Mode, Channel Number, Channel Switch Count, VendorSpecificInfo

MLME-CHANNELSWITCH Confirm

MLME-CHANNELSWITCH Indication

Peer MAC Address, Mode, Channel Number, Channel Switch Count, VendorSpecificInfo

MLME-CHANNELSWITCH Response

Mode, Channel Number, Channel Switch Count, VendorSpecificInfo

Thank You !!!

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