Howard WUSB Framework

8/13/2019 Howard WUSB Framework

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Wireless USB Framework

John S. HowardSenior Architect

Intel Corporation


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AgendaAgenda

Device States Basic Framework

New for Wireless USB Summary of Device Requests

Summary of Framework Descriptors Summary of WUSB Channel

Information Elements

Summary of Device Notifications


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Wireless USB Device StatesWireless USB Device States

USB 2.0 Device statemodel is preservedwithin WUSBFramework

Encapsulated withinthe SecureConnection

Additional states forestablishment and

re-establishment ofa Secure Connection

Un-

Authenticated

Default

Address

Configured

4-way Cmplt then

SetKey (groupKey)

then SetAddress (0)

Address

Assigned

Device

Configured

Device

Deconfigured

Un-

ConnectedConnect

ACK (UnAuthAddr)Explicit Disconnect or

Reconnect Failed or

ResetDev or

4-way Failed

SetAddress(0)

Connect Notification

Reconnecting

TrustTimeout

ReConnect

ACK (UnAuthAddr)

or

ACK (PrevAddr)

ReConnect

Notification

4-way Cmplt or

(4-way Cmplt then

SetAddress (PrevAddr))


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Basic FrameworkBasic Framework

USB 2.0 Standard Requests and Descriptors are

utilized in WUSB Restrictions on when requests are valid, based

on whether the secure connection is in place

No requests that modify device information/state areallowed (except for the requests to establish thesecure connection)

New requests and descriptors added to supportWUSB requirements

Extensions done in a way that enablesfuture extensibility


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Basic Framework

Summary

Basic Framework

Summary

Device States USB 2.0 Encapsulated in Secure Connection

ModifiedSet Address, Clear Feature, Set Feature, GetStatus

NewLoopback_data_read, Loopback_data_write,Security related requests, SetWSBData

NewSecurity, Key, Encryption Type, BOS, DeviceCapability, Wireless Endpoint Companion

MMC IEs All New

DeviceNotifications

All New

Modified Device, Configuration, Endpoint

Descriptors

Requests


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Extensions for Device Requests

Get Status

Extensions for Device RequestsGet Status

bmRequest10000000B

bRequestGet

Status

wValueZero

wIndexZero

wLengthTwo

DataStatus

USB

2.0

bmRequest10000000B

bRequestGetStatus

wValueZero

wIndexStatus Selector

wLengthVariable

DataSelector StatusData

WUSB

USB 2.0 Status USB 2.0 Status Information

WUSBFeatures

Current setting for WUSB featureselectors

Channel Info LQI with respect to last MMC

Received dataData from Capture/Count Packetoperation

MASAvailability

WiMedia MAS Availability bit map

CurrentTransmit Power

TPC settings for device-level managedpackets (Notifications & Beacons)

Get Status

Backward compatible with

USB 2.0 Isolates all WUSB-specific

Status Information

wIndex used to select

different status information


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New Device Requests

SetWUSBData

New Device Requests

SetWUSBData

bmRequest00000000B

bRequestSetWUSBData

wValueWUSB Data

Selector

wIndexZero

wLengthWUSB Data

Length

DataWUSB Data

SetWUSBData

Used to set/updateWUSB-specificdescriptors and controlparameters

wValue used forindividual WUSB dataselectors

DPRIE INFODRPIE to be used bySBDs for WUSBCluster

Transmit DataData packet to betransmitted by DBDfor TX Packet feature

Transmit ParamsDBD TX Packetcontrol parameters

Receive ParamsDBS RXcount/capture packetparameters

Transmit PowerHost directed controlfor TX power for

certain packet types


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Modifications for Descriptors

Device Level


Device Level

BOS DescriptorBOS DescriptorBOS Descriptor

WUSB Dev Cap.WUSB Dev Cap.WUSB Dev Cap.

Other Dev Cap.Other Dev Cap.Other Dev Cap.Length

includes

all

descriptorsin

set

Device Descriptor

bMaxPacketSize0 FFH

bcdUSB 0250H

New BOS Descriptor forDevice-level Extensions

Accessed via separaterequest

Extensible containermodel like Configurations

Set of descriptors

accessed as a set

WUSB Device Capabilities

P2P DRD Beacon Behavior

TX Rates Supported

TX Power Levels Supported

Band Groups Supported


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Configuration Level


Configuration Level

Configuration Descriptor

Required settings for WUSB devices

New Battery Powered attribute

Endpoint Changes to :

bmAttributes

wMaxPacketSize

bInterval

Backward compatible


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New Endpoint Companion


New Endpoint Companion

Interface DescriptorInterface Descriptor

Endpoint DescriptorEndpoint Descriptor

EP CompanionEP Companion

Endpoint DescriptorEndpoint DescriptorEP CompanionEP Companion

Configuration DescriptorConfiguration Descriptor Every Endpoint descr.

must have an EndpointCompanion descr. inevery configuration set

Endpoint companionsdescr. must follow theendpoint descr. they are

associated with Endpoint companions

carry new endpointcapabilities for WUSB

Length

includ

es

all

descriptors

in

set

Interface DescriptorInterface Descriptor

Endpoint DescriptorEndpoint DescriptorEP CompanionEP Companion

Endpoint DescriptorEndpoint Descriptor

EP CompanionEP Companion


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New Security Descriptors


New Security Descriptors

See Security Session for details


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MMC Information Elements

Basics


Basics

blength used to find the next IE

IE Identifierdetermines IE format (type)

IEs are always an even number of bytes in length

IEs addressable to multiple devices/endpoints are

organized as arrays Most are up to 4 elements (max)

Channel Time allocation IE is up to 32 elements (max)

May require host to add a pad byte to IE to get it to 2-byte alignment

blengthIE

Identifier IE Type SpecificIE

Identifier IE Type Specificblength


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Summary


Summary

Information in MMCs encapsulated in Information Elements

WCTA_IE Reports transaction group channel time allocations

WCONNECTACK_IE Host acknowledges connect requests

WHOSTINFO_IE Host-specific information to uniquely identify Host and the WUSB Channel

WCHCHANGEANNOUNCE_IE Information used to announce a channel change time and destination

WDEV_DISCONNECT_IE Host uses this to disconnect a specific device

WHOST_DISCONNECT_IE Host uses this to disconnect all devices

WRELEASE_CHANNEL_IE Host uses this to tell specific device to broadcast a UDR packet (not using channel)

WWORK_IE Host uses this to acknowledge Device sleep requests

WCHANNEL_STOP_IE Host uses this to announce the channel is stopping

WDEV_KEEPALIVE_IE Host uses this to force a device to check-in; usually prior to a TrustTimeout

WISOCH_DISCARD_IE Host uses this on an Isochronous OUT to communicate skips

WRESET_DEVICE_IE Host uses this as an analog to a USB 2.0 Port Reset signaling

WXMIT_PACKET_ADJUST_IE Host uses this to communicate xmit adjustments to all devs enabled for Packet Xmit


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Device Notifications

Basics

Device NotificationsBasics

Security

Header MIC

WUSB

Header bType

Notification

Specific

Most Notifications are encapsulated inSecure Packets

PID in WUSB Header set to DN designatesas Device Notification

May only be transmitted by devices during

Device Notification Time Slots (DNTS)bType field indicates format of notification-

specific payload

Max notification specific length is 32 bytes


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Device Notifications

Summary

Device NotificationsSummary

DN_ConnectConnect is transmitted without Secure Packet,Reconnect is

DN_Disconnect Device uses this to explicitly disconnect from Host

DN_EPRdyDevice uses this to report that flow-controlled endpointsare ready to resume data streaming

DN_MASAvailability

Self-beaconing Device uses this to notify that its MASavailability has changed

DN_RemoteWakeup

Device uses this to emulate USB 2.0 remote-wakesignaling

DN_SleepDevices uses this to inform the host that it intends to goto a Sleep state

DN_Alive

Device uses this in response to a

WDEV_KEEPALIVE_IE or to transition from a sleepstate (within a TrustTimeout period)


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SummarySummary

Extended the USB 2.0 Framework to supportWireless USB

New device states to support establishing andmaintaining a secure connection

Basic USB 2.0 defined device state preserved

New device level capabilities descriptor (extensible)

New endpoint companion descriptors

Modified existing endpoint and configuration descriptorfor applicability

Wireless USB device must use bcdUSB value of 0250H

MMC Information Elements and Device Notifications

added to framework


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