Technical Track 802.11n – Wireless Performance for Control? Paul Brooks, Rockwell Automation Paul Didier, Cisco

Technical Track

www.odva.org

802.11n – Wireless Performance for Control?

Paul Brooks, Rockwell AutomationPaul Didier, Cisco

Technical Track 2011 ODVA Industry Conference & 14th Annual Meeting page 2© 2011 ODVA, Inc. All rights reserved. www.odva.org

Agenda

• Wired – Wireless Factory Vision and Use Cases

• Deploying WiFi: Autonomous vs. Centralized management of Access Points

• 802.11N – Why its good for CIP and EtherNet/IP applications

• Interoperability: CCX – an industry best practice

• Cisco and Rockwell Automation Testing


Agenda







Wireless Factory Vision

(Confidential – For Internal Use Only) Copyright © 2008 Rockwell Automation, Inc. All rights reserved. 4

Long Haul (SCADA)Various IP based technologies

ISA-100.11a

WirelessHART

Wireless Infrastructure

Factory Server

Wireless IEEE 802.11n Access Point

Process Instrumentation 802.15.4 WirelessHART™ and/or ISA100.11a

Discrete SensorsTechnology: In Research

Ethernet Switch

Ethernet and EtherNet/IP are becoming dominant in processing and manufacturing – WiFi will follow

Process applications have needs better met by Wireless HART and ISA-100 than WiFi

Long distance comms will use satellite, GPRS, 3G, WiMAX etc technologies, Internet Protocols (IP) ensures interoperability

Wireless and Wired – 1 User Experience


(Confidential – For Internal Use Only) Copyright © 2008 Rockwell Automation, Inc. All rights reserved.

5

Application Considerations

Common usage todayApplication

restrictions not relevant to CIP

? Product available space ?

Latency biggest challenge

Fidelity biggest challenge


Drivers for Wireless ApplicationsMore points of visibility and control

Eliminating Wires and Cables Increase Reliability

• Replace cables (e.g., moving machinery) Reduce Installation Cost

• Wireless I/O, Wireless Sensor and mesh networks• Reach great distances (SCADA)

Enabling Portability and Mobility Mobile HMI (People) AGVs (Equipment) Communications (VoWLAN)

Tracking Assets RFID Real-Time Location Services

Remote Device Monitoring Troubleshooting / Maintenance Instrumenting existing machinery

Video Surveillance Security and process monitoring

Guest Access

802.11 Tag


Wireless Use Cases/Configurations

• Operator moves from zone to zone around a machine• Functions enabled and disabled according to location & user• Display changes according to location & context

• Mobile equipment full automated• Moves through a number of access points• Remote control maintained through cycle

• Rotating Equipment

• Fixed equipment in hard to reach location

• Wireless connection lower cost than wired

• Standalone or integrated

Wireless AP

http://images.google.com/imgres?imgurl=http://blog.loaz.com/media/blogs/timwang/mini-laptop-fujitsu-P7230.jpg&imgrefurl=http://blog.loaz.com/timwang/index.php?cat=61&h=449&w=500&sz=36&hl=en&start=2&tbnid=SVq8wDzMz9MHhM:&tbnh=117&tbnw=130&prev=/images?q=laptop&gbv=2&hl=en

http://images.google.com/imgres?imgurl=http://blog.loaz.com/media/blogs/timwang/mini-laptop-fujitsu-P7230.jpg&imgrefurl=http://blog.loaz.com/timwang/index.php?cat=61&h=449&w=500&sz=36&hl=en&start=2&tbnid=SVq8wDzMz9MHhM:&tbnh=117&tbnw=130&prev=/images?q=laptop&gbv=2&hl=en


Use Case – Anode Making

Moving Ramps:Hard to Reach83 Ramps, 350

locations

Cranes:Mobile

equipment1200m traverse

Workers:Asset

Management,Enterprise Planning

Voice

4 Networks Installed!


Images from a Smelter

On-machine Access Point

In-cabinet Client Gateway

In-cabinet Access Point


Agenda







WiFi DeploymentAutonomous vs. Centralized

Autonomous Solution Controller-Based Solution Flexible architecture for campus, branch, home, and

outdoor (Mesh)

Fast roaming

Centralized management and troubleshooting for lowest TCO

Mobility Services for voice over WLAN, guest access, context-aware and Adaptive wIPS

Industry leading scale for 802.11n

Small plant or factory

Base level Wi-Fi functionality

Limited Scalability

Upgrade Path to Controller-based

Access Points (autonomous)

Components Access Points

(lightweight)

WLAN Controller

Location Services

Components


CentralizedArchitecture Benefits

CentralizedManagement

Flexible/Scalable

Value-Added Services

Mobile/Secure

Reliable

Wired/Wireless Guest AccessVoice over WLANLocation ServiceMedia Ready (VideoStream)

RoamingSecurity Policy

Wireless IDS

CentralizedArchitecture

Buy as you grow licensingAppliance/Module

Ease of deployment/upgradeLoad Balancing to optimize per user performance

Dynamic RFSpectrum

Management


Agenda







What Painpoints Does 802.11n Solve?

• Throughput—Up to 6 times greater than existing networks

• Reliability—Fewer packet retries• Predictability—Consistent coverage and throughput• Compatibility—Backwards support for 802.11a/b/g

clients• Future-Proofing—Guaranteed Interoperability

–Tested/Validated

Better performance for data, voice, video, and control


Technical Elements of 802.11n

MIMO 40Mhz Channels

Packet Aggregation

Backward Compatibility

MIMO 40Mhz Channels Packet Aggregation



Aspects of 802.11n

Performance

Beam Forming Spatial MultiplexingMaximal Ratio Combining

MIMO (Multiple Input, Multiple Output)

MIMO 40Mhz Channels Packet Aggregation


Performed by Transmitter (Talk Better)

Ensures Signal Received in Phase

Increases Receive Sensitivity

Works with non-MIMO and MIMO Clients

MIMO AP

HALLWAY

Without Beam FormingTransmissions Arrive out of PhaseWith Beam FormingTransmissions Arrive in Phase, Increasing Signal Strength


Aspects of 802.11n



40Mhz Channels Packet AggregationBackward Compatibility

Performed by Receiver (Hear Better)

Combines Multiple Received Signals

Increases Receive Sensitivity

Works with non-MIMO and MIMO Clients

Performance

Multiple Signals Sent; One Signal Chosen

Without MRCMultiple Signals Sent and Combined at the Receiver IncreasingFidelity

With MRC

MIMO AP


Aspects of 802.11n



40Mhz Channels Packet AggregationBackward Compatibility

Transmitter and Receiver Participate

Concurrent Transmission on Same Channel

Increases Bandwidth

Requires MIMO Client

Performance

stream 1

stream 2

Information Is Split and Transmitted on Multiple Streams

MIMO AP


Aspects of 802.11n

40Mhz ChannelsPacket Aggregation

40Mhz Channels Packet AggregationMIMO Backward

Compatibility

Carpooling Is More Efficient Than Driving Alone

Without Packet Aggregation

Data Unit

Packet

802.11n Overhead

Data Unit

Packet

802.11n Overhead

Data Unit

Packet

802.11n Overhead

With Packet Aggregation

Data Unit

Packet

802.11n Overhead PacketPacket


Packet AggregationBackward Compatibility

Aspects of 802.11n

Packet AggregationBackward Compatibility

MIMO 40Mhz Channels

2.4GHz 5GHz

802.11ABG Clients Interoperate with 11n AND Experience Performance Improvements

11n Operates in Both

Frequencies


802.11nIt’s About a Whole Lot More Than Speed

Throughput Reliability Predictability

802.11a/g with AP1240802.11a/g with AP1250802.11n with AP1250

IDEAL6092130

2x

Predictability of ThroughputStandard Deviation of Packet Retries

Mbps Throughput

11a/g – AP1240

11a/g – AP1250

11n – AP1250

Average Packet Retries

2x

Enhanced file transfer and download speeds for large files

Lower latency More consistent coverage and throughput for mobile applications

>5x

5x more throughput 2x more reliable 2x more predictable


Agenda







Standards and Implementation Process

802.11 CiscoWiFi

Standards Group CompanyIndustry Group

The nature of engineers and the “design by committee” environment mean the IEEE often defines overly feature rich standards with many options

The industry bodies’ role is remove much of the “bloat” introduced as “features” into the IEEE standards, often by people not even selling equipment

Cisco adds differentiating features to the “minimal” set defined by WiFi. In the past, this has included better security. Features are licensed to RF chip vendors under “CCX” program

“Feature Bloat” “DifferentiatedFeatures”

“Minimal Features”

How are WLAN standards created? - Roles


CCX Overview

Open Mobility Services Architecture

Standard based innovation

Tested interoperability

Open Mobility Services Architecture

Standard based innovation


Innovative and reliable applications

Consistent delivery of services across access networks

Innovative and reliable applications

Consistent delivery of services across access networks

Industry Mobility Solutions

Application

Infrastructure

Secured and robust Mobile foundations


Platform for reliable and high value mobile applications

Secured and robust Mobile foundations


Platform for reliable and high value mobile applications

Silicon - DeviceAddressing

wave of devices

Managing disparate networks

Deployingapplications

Accelerating innovation while maintaining interoperability

A partnership program to drive accelerated innovation and deliver value to mobile users

Wireless Controller

Mesh APLightweight AP

Generic AP


Christophe Servais

CCX – Industry Standard

Over 120 vendors participants 70% of all features developed in the program have

since achieved standard 90% of WiFi silicon is CCX certified.

Foun

datio

n

Rob

ust a

nd

Secu

re c

onne

ctiv

ity

Col

labo

ratio

n

Voic

e an

d Vi

deo

Con

text

–

Awar

eLo

catio

n

Mob

ile

Dev

ice

Man

agem

ent

Services platform for reliable and high value mobility solutions

Fast addressing customer pain points through accelerated innovation

Flexible approach for optimum match of Service and Device function

Commitment to Standards

Delivering Mobile Services across transport layer

Tested interoperability (Network, Device, OS)

Supplementing Wi-Fi certification with innovative and tested capabilities


Christophe Servais

CCX Services

CCX services

Robust and secure

Connectivity

Seamless connectivity

802.11 Future Media Future media

Foundation

Location FutureServices

Context AwareVoice - Video Future

Services

Collaboration Management

Reliable and Accurate location

Voice ready devices

Voice quality monitoring

Congestion management

Remote diagnostic of mobile devices

Incr

easi

ng

bu

sin

ess

imp

act

Building robust and secured Mobile foundations


Christophe Servais

Making the RF link more secure

Cisco Unified Network and CCX Mobile devices encrypt all management packets exchanged

EAP-FAST natively provided on all CCX devices

Cisco Unified Network and CCX Mobile devices encrypt all management packets exchanged

EAP-FAST natively provided on all CCX devices

Radio interface is composed of Data and Management

traffic.

How to ensure both traffics are

secured?

802.11 Future Media

Future media

Foundation


Context AwareVoice Future

Services


MFP allows protection from

DOS attacks and quick detection of

“Man in the Middle” and other

Management Frame attacks

MFP allows protection from

DOS attacks and quick detection of

“Man in the Middle” and other

Management Frame attacks

Benefits : highest security made available at no additional cost


Christophe Servais

Ensuring fastest roaming with 802.1x

Cisco’s Centralized Key Management (CCKM) is a Key management protocol that enables fast 802.1x reauthentication.

CCKM allows active AP and CCX Mobile device to derive new encryption key before re-association to accelerate the secure roaming process.

Cisco’s Centralized Key Management (CCKM) is a Key management protocol that enables fast 802.1x reauthentication.

CCKM allows active AP and CCX Mobile device to derive new encryption key before re-association to accelerate the secure roaming process.

Encryption Keys are re-calculated at

every association and re-association,

delaying the roaming process.

How to accelerate securely the

management of keys when the mobile device

roams ?

802.11 Future Media

Future media

Foundation


Context AwareVoice Future

Services


Benefits : Ensures fastest secure roaming for optimum user experience


How CCX Works


Agenda







Unicast I/O Control Connections

V18

Enables a Logix controller to communicate to other EtherNet/IP devices via unicast

• Applies to standard I/O* and standard produced/consumed tags

• Unicast support for safety produced/consumed tags and safety I/O will be added at a later releaseEnhancements making Logix Wireless Ready


Enhanced Testing – Point to Multi-Point

CLX

Switch

AP

WGB

PIO1

WGB

PIO6

WGB

PIO7

Switch

ConsumerCLX

ProducerCLX

LatencyMeasurement

CLX Pair

Load GenerationCLX Using I/O w/PIO

CLX

Switch

AP

WGB

PIO1

WGB

PIO6

WGB

PIO7

Switch

ConsumerCLX

ProducerCLX

LatencyMeasurement

CLX Pair


Test Configuration

Load QTY ID

5.67k pps 3 2ms 1-3

4 3ms 4-7

(all) (in band)Total (index) (value) Average: 1075 1075

RPI (ms): 25 Counts First: 0 0 Minimum: 921 921Firmware: 4.700 100000 Last: 30 30 Maximum: 3797 3797

1756-ENBT

First and Last From Controller (us) Notesnon-zero values

Independent pulse generator

0

10000

20000

30000

40000

50000

60000

70000

80000

0 2 4 6 8 10 12

Time (ms)

0

10000

20000

30000

40000

50000

60000

70000

80000

0 10 20 30 40 50 60

Time (ms)

0

10000

20000

30000

40000

50000

60000

70000

80000

0 10 20 30 40 50 60

Time (ms)

0

10000

20000

30000

40000

50000

60000

70000

80000

0 10 20 30 40 50 60

Time (ms)

0

10000

20000

30000

40000

50000

60000

70000

80000

0 10 20 30 40 50 60

Time (ms)

0

10000

20000

30000

40000

50000

60000

70000

80000

0 10 20 30 40 50 60

Time (ms)

RPI QTY ms

20ms 7 Min Latency 0.921

Ave Latency 1.075

Max. Latency 3.797

1756-ENBT Maximum recommended 4,000 pps

Wireless Performance Matches Wired for I/O Control with 1 Scanner


Enhanced Testing – Packet Aggregation

CLX

Switch

AP

WGB1

PIO101 PIO119

WGB7Switch

ProducerCLX

ConsumerCLX

LatencyMeasurement

CLX Pair


24-port switch

EN2T ENBT ENBTCLX

Switch

AP

WGB1

PIO101 PIO119

WGB7Switch

ProducerCLX

ConsumerCLX

LatencyMeasurement

CLX Pair


24-port switch

EN2T ENBT ENBT

Test ConfigurationInterface Load QTY

ENBT #1 5000 pps 5 2msENBT #2 5000 pps 5 2ms

EN2T 9000 pps 9 2msDevice limits are more significant than network limits


Wireless-N A Step Change in Technology

(Confidential – For Internal Use Only) Copyright © 2008 Rockwell Automation, Inc. All rights reserved.

The step from Wireless-G to Wireless-N

is as dramatic as the step from10MBps Ethernet with Hubs

to100MBps Ethernet with Switches

Making Mainstream Control Possible


Summary – Key Takeaways

802.11n is right technology Ratified Already in use in process critical applications

Unicast for control over wirelessActive spectrum management is critical And it is a human responsibility

Architecture options – Autonomous / controller based

Autonomous – small localized point applications Controller based – scalable, multi-application, lower TCO

Technology proven and deployed for Human mobility in the plant Mobile equipment

Documents

Technical Track 802.11n – Wireless Performance for Control? Paul Brooks, Rockwell Automation Paul Didier, Cisco