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BEST PRACTICES FOR BUILDING ULL NETWORKS

PROGRESSION LOW LATENCY NETWORKS

FIBER DATA NETWORKS (ANALOG/DIGITAL)

ON COPPER

MESSENGER SERVICES, PHYSICAL/HAND DELIVERY

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PRE-1970’S 70’-80’s 90’s-TODAY over $4B

market globally

NEXT STEP IN LOW LATENCY PROGRESSION: MICROWAVE

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MICROWAVE IS FASTER THAN FIBER AND IS QUICKLY BECOMING DEFACTO STANDARD FOR ULTRA LOW LATENCY TRANSPORT

microwave uses more direct routes (less distance)

propagation is 30% faster over air

Functional, viable, practical. ???

WHAT IS USABLE LATENCY?

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Weather (rain,

propagation)

Reliability Installation

Sites and Acquisition

Number Hops

Path Design and

Regulatory Issues

Network Management

Co-Existence with Fiber

Security

Latency

BUT MICROWAVE IS COMPLEX AND NEW TO FINANCIAL SERVICES…

3 ULL MICROWAVE QUESTIONS

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Full size image

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RELEVANT TECHNICAL CONSIDERATIONS

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Equipment Latency Payload Interface Serialization Delay Modem Technology

End-to-End Latency Repeaters RF and Modem Performance

Operational Considerations

WHERE DOES LATENCY GO? On a standard latency microwave link

0.39%

7.00%

19.26%

30.82%

38.52%

3.85%

0.15%

SHORT FRAMES (64)

Interface Speed

Switching &Serialization

Transfer Buffers

Interleaving

Encoding/Decoding

Mod/Demod

Analog Front End

5.13%

44.07%

10.57%

16.91%

21.13%

2.11% 0.08%

LONG FRAMES (1518)

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PAYLOAD INTERFACES AND SERIALIZATION DELAY

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Ethernet Interfaces L1 Interfaces (STM1/OC3) Proprietary L1 Interfaces (Clock and Data)

MODEM TECHNOLOGY

Forward Error Correction Modulations and Bandwidths Diversity Protection

Improves link availability and hence low latency availability Adaptive Modulation and Adaptive Coding Latency Increase

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FEC Method

Linear and Iterative

Convolutional Codes

Algorithm

LPDC, Turbo Codes

Viterbi

Latency

High

Medium

Block Codes

No FEC

Reed Solomon

- - -

Low*

Lowest

SG Imp.

High

Good*

None

Good

BW 30 MHz

40 MHz

Mod

16 Q

AM

32 Q

AM

50 MHz

128

QA

M

64 Q

AM

256

QA

M

QPS

K

LOW LATENCY… (OBVIOUSLY) SO HOW DO WE REDUCE THE LINK LATENCY?

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- High speed interfaces - Use small frame sizes - Early packet forwarding - Reduce buffering wherever possible - Eliminate Interleaving - Reduce or eliminate FEC

And equipment/box latency is easy to understand/measure, but…

~10-20 µs

BOX

THE REAL METRIC IS END-END LATENCY (THIS IS WHERE IT GETS COMPLICATED…)

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Exchange

And best ways to lower end-end MW latency…

BOX Exchange

BOX BOX

BOX BOX

REDUCE NUMBER AND COMPLEXITY OF THE HOPS INTRODUCTION OF THE REPEATER CONCEPT

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- Latency in Nx10 ns - RF Repeater

- Limited RF Options - Mask Limitations

- IF Repeater - Frequency Agile - Mask Limitations

- Digital Repeater - Frequency Agile - Usually No Mask Limitations

Regenerator Node

Regenerator Node

Repeater Node

Repeater Node

30% reduction

Regenerator Node

Repeater Node

Repeater Node

Regenerator Node

Repeater Node

Repeater Node

Regenerator Node

Repeater Node

Repeater Node

Regenerator Node

Repeater Node

Regenerator Node

ADAPTIVE REPEATER TECHNOLOGY

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Ultra Low End-End Latency

Low End-End Latency (still better than fiber)

99% of time

1% of time

RF AND MODEM PERFORMANCE WHERE DOES IT HELP?

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• Link Distance • Number of Hops • Link Availability

• Techniques include: - Tx Power - Rx Sensitivity - Diversity

• Antenna Size • Number of Repeaters

- FEC Coding - Rx Threshold - Higher Quality Oscillators

Ultimately all revolves around having better System Gain !!!

QUANTIFY RF / MODEM PERFORMANCE

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Example: Chicago rain zone, 99.999 Availability, 6 Ft Antenna, 64QAM

Frequency Band

6 GHz

11 GHz

Std System Gain

51.6 Miles

35.1 Miles

+3dB

55.8 Miles

38.5 Miles

AND MANAGING THE RELIABILITY / LATENCY TRADEOFF

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End-End Latency

Path Uptime

Low Latency

High Latency

99.999% 90%

Good News: with new innovations,

best of both worlds can be achieved…

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SO THAT’S LOW LATENCY…

Thus a full featured microwave solution will be required

BUT what good is low latency if your network is:

BEST PRACTICE FOR BUILDING LOW LATENCY MICROWAVE NETWORKS: FOCUS ON END-END LATENCY USING A FULL-FEATURED

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MICROWAVE PLATFORM

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ULL MICROWAVE LIFECYCLE

And path planning is more than just GPS Coordinates and Google Maps! AVIAT NETWORKS

VALIDATE THE ROUTE

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Phase 1 - Planning and Design • Regulatory • Site Selection • Frequency Coordination and Acquisition • Transmission and Network Engineering • Site & Path Survey Is the route viable?

SECURE THE SITES

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Site Acquisition and Construction • Site Acquisition and Leasing • Engineering and Drafting • Zoning • Utilities and Construction • System Engineering and Optimization

BUILD AND LAUNCH THE NETWORK

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Integration and Deployment • Configuration and Network Engineering • Factory Integration • Equipment Staging • Installation of Antennas, Lines & Ground

Equipment • Radio Installation and Path Alignment • Acceptance Testing & Commissioning • Commercial Launch

When the network is built…then what? Focus on what you do best and let Microwave experts keep the network running at optimal speed and efficiency

Peace of Mind! AVIAT NETWORKS

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Functional, viable, practical. ???

MAXIMIZE PROFITABILITY OF THE NETWORK

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THANK YOU

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