Distinguished Minimum Latency Traffic Ludwig WINKEL Chair IEEE 8023 SG DMLT Siemens Presenter Marcel KIESSLING IEEE 8021 TSN WG Siemens Joint IEEESA and ITU Workshop on Ethernet 2 Geneva Switzerland 13 July 2013 ID: 321383
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IEEE 802.3 Distinguished Minimum Latency Traffic
Ludwig WINKEL,Chair IEEE 802.3 SG DMLT,SiemensPresenter: Marcel KIESSLINGIEEE 802.1 TSN WG,Siemens
Joint IEEE-SA and ITU Workshop on EthernetSlide2
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Geneva, Switzerland, 13 July 20132Reflector and Web site
Study Group reflector
stds-802-3-DMLT@listserv.ieee.org
To subscribe to the DMLT-reflector, send an email to:
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with the following in the body of the message (do not include “<>”):
subscribe stds-802-3-DMLT <yourfirstname> <yourlastname>
Study Group web page URL:
http://www.ieee802.org/3/DMLTSlide3
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Scope: The scope of this project is to specify additions to and appropriate modifications of IEEE Std 802.3 to add a support for interspersed express traffic.
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Draft PAR (P802.3br)
title & scope
Geneva, Switzerland, 13 July 2013Slide4
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4Draft PAR (P802.3br) title & scopeSG DMLT proposes a PAR title:
IEEE Standard for Ethernet
Amendment Specification and Management Parameters for
Interspersing Express Traffic
.
Geneva, Switzerland, 13 July 2013Slide5
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AbstractThere is a need for support of time sensitive traffic in a converged traffic environment in IEEE 802.3 networks that supports interspersed express traffic and the traditional normal traffic. This would help address the requirements in markets such as industrial and automotive control networking, where control data is time-sensitive and often requires minimum latency. This workshop presentation will examine the needs of time sensitive traffic in IEEE 802.3 networks, the support for interspersed express traffic and the ordinary traffic, and will provide background for the PAR proposed by the IEEE 802.3 Distinguished Minimum Latency Traffic (DMLT) Study Group.
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Geneva, Switzerland, 13 July 2013Slide6
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Market needs and market potentialSpecific to automotive environmentStreaming, Data, Control, over single LAN segment that supports, infotainment, driver assist and diagnostics within various functional LAN segments within a vehicular network. Control systems require lower-latency bridged networks for this convergence.
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Geneva, Switzerland, 13 July 2013Slide7
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Market needs and market potentialSpecific to Industrial automationLow Latency Sampling Data, (closed loop) Control, Image streaming (e.g. image processing) and data traffic, sampling data and closed loop control traffic have very demanding latency requirements.
Image streaming and associated processing as a part of a control loop has greater requirements than best effort could provide in a converged network. Best effort traffic is not time-critical, but provides a constant source for interference traffic.
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Geneva, Switzerland, 13 July 2013Slide8
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8Ethernet captures more and more Applications
Traditional Markets
Industrial Automation
Factory Automation
e.g. Material handling, Automotive Manufacturing, Transfer lines,
Process Automation
e.g. Oil, Gas, Chemical / Petrochemical, Food & Beverage
Energy Automation
Power Generation
e.g. Fossil Power Plants, Wind Turbines
Power Transmission and Distribution
e. g. Smart Grid Application
Building Automation
Climate Control
Fire Safety
New Markets
Avionics
Fly-by-Wire
Railway Systems
Train Control
Railway Traffic Management Systems
Medical
Patient Imaging,
Geneva, Switzerland, 13 July 2013Slide9
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A bit of History of Industrial Automation1990 to 2000: Non-ETHERNET Solutions dominated the marketPROFIBUS,
INTERbus
,
ControlNet
,
DeviceNet
, ..
Since 2000 Ethernet based solutions enter the industrial market
Up to now Ethernet offers not the required real time capabilities (
QoS
) therefore specific Ethernet solutions appeared on the market, like:
CiP
,
EtherCAT
, Ethernet
Powerlink
,
TCnet
, PROFINET, ...
All these solutions contain
specific
additions or adjustments to the "standard ETHERNET" in order to provide the required real time capabilities (
QoS
) for industrial applications.
C
ustomers
ask for
one
IEEE 802.1/.3 standard based
solution
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Geneva, Switzerland, 13 July 2013Slide10
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10Required: Converged Traffic Environment
Customers ask for a solution which:
guarantees minimum latency for
Scheduled Traffic
and
provides guaranteed bandwidth for
Reserved Traffic
and
still allows the transfer of
Best Effort Traffic
on one single network
Geneva, Switzerland, 13 July 2013Slide11
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11Overview of Industrial Communication Requirements
Best Effort Traffic
Configuration, Online Parameterization, Web Services, Events, IT-Communication
Reserved Traffic
Real Time Diagnostic like inspection, identification, tracking, counting and measurement
Scheduled Traffic
Cyclic exchange of process values
Profile specific data (Safety profile, Drive profile, ...)
Best Effort Traffic:
Reserved Traffic:
Scheduled Traffic:
Future: Only one Network:
No guaranteed bandwidth
Separate network
Dedicated solutions to guarantee minimum latency, resources and bandwidth and often a separate network for the Best Effort Traffic is necessary
Guaranteed bandwidth for Best Effort Traffic
Guaranteed QoS for Reserved Traffic
Standardized solution to guarantee minimum latency, resources and bandwidth for Scheduled Traffic
Today
Geneva, Switzerland, 13 July 2013Slide12
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Why one single Network for all Communication ServicesOnly one network means:
Reduced possibility of network failures
wire breaks, reduced confusion in case of maintenance
Reduced installation costs
less cables, less connectors, less installation efforts as in the industrial area "field preparation on site" is common sense
Enables smaller devices
reduced space for connectors, lower power consumption (only 1 or 2 PHYs instead of 2 respectively 4 PHYs)
Reduced maintenance costs
easier to understand and to maintain
Only one interface in the devices
only one MAC address, only one IP address, easier to understand and to maintain, easier coordination of the communication relations in the stack and application layer in the devices
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Geneva, Switzerland, 13 July 2013Slide13
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The 24 ruleIf express/interspersed traffic is used, the guard band gets much smaller.
margin
guard band
part 2
1
margin
whole frame
guard band
Geneva, Switzerland, 13 July 2013Slide14
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A Potential ArchitectureMAC Merge sublayer Provides lower latency for express trafficPreserves frame integrityMinimizes impact on throughputIs transparent to existing non-deprecated PHYs above 10 Mb/sDoesn’t change MAC operation
Queuing Frames
Transmission Selection
Transmission Selection
MAC Control
MAC Merge
Sublayer
PHY (unaware of preemption)
Express MAC
MAC
Geneva, Switzerland, 13 July 2013Slide15
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DMLT negotiation
Negotiation Initiator
Link Partner
Normal Mode
Normal Mode
DMLT Request
Request Mode
DMLT Request
DMLT Xmit Mode
DMLT Accept
DMLT Accept
DMLT Request
DMLT Accept
DMLT Accept
Operational Mode
Frame without DMLT encap
Frame with DMLT encap
DMLT Accept
DMLT Accept
Operational Mode
Geneva, Switzerland, 13 July 2013Slide16
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THANK YOU
for your attention
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Geneva, Switzerland, 13 July 2013