The Real Story about Microwave Capacity

June 2013

Capacity Innovation

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Capacity Innovation

2

• It is hard to compare capacity claims from different vendors

• Capacity innovations are split between

• Radio throughput (“committed” capacity) - without any optimization

• Capacity-boosting techniques - e.g., “accelerators”

• In this presentation we will explain the pros and cons and

considerations about each innovative capacity technique

• There is no “silver bullet” in capacity innovation. Each technique is

additive to other capacity innovation techniques offered by Ceragon

• Beware of microwave vendors who “warn” and advise you not to

adopt a specific capacity innovation – it usually means they don’t

support it…

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Can You Get More Capacity from Your Backhaul?

3 Increased capacity in microwave links: 5 Steps

Network Utilization

Spectrum

Spectral Efficiency

Spatial Efficiency

Traffic Boosting

Payload Deduplication

4x4 LoS MIMO

2048QAM

Wide Channels

Asymmetrical

Header Deduplication

Radio Throughput without any optimization

Capacity Boosting Techniques

WRED

HQoS

TCP Buffers

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Radio Throughput - “Committed” Capacity

4 Increased capacity in microwave links: 5 Steps

Network Utilization

Spectrum

Spectral Efficiency

Spatial Efficiency

Traffic Boosting

Payload Deduplication

4x4 LoS MIMO

2048QAM

Wide Channels

Asymmetrical

Header Deduplication

Radio Throughput without any optimization

Capacity Boosting Techniques

WRED

HQoS

TCP Buffers

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Radio Throughput without any optimization

5

Spectral Efficiency Spectrum

Use more spectrum efficiently

Spatial Efficiency

Pros

• Wider channel bandwidth

• New spectrum (V/E-band)

Cons

• V/E-band radios with high frequencies are

suitable for short distance, high capacity

backhaul

Considerations

• Continuous 112MHz bands are rarely

available in traditional microwave

frequencies

• Other techniques like Channel

Aggregation or Multi-Carrier Bonding are

also available

• Vendors claiming to have up to 10Gbps

microwave (MW) actually provide high

frequency millimeter wave radio in

E-Band (70-90GHz) or V-Band (60GHz)

for short distance wireless links Recommendation ITU-R F.746-10 (03/2012) - Radio-frequency arrangements for fixed service systems

Wireless frequency bands (by ITU-R )

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Radio Throughput without any optimization

6

Spectral Efficiency Spectrum

More Bits per Symbol

Spatial Efficiency

Pros

• More capacity per given spectrum

• 2048QAM offers 35% more radio throughput

than 256QAM (without any optimization)

• In 28MHz + 66Mbps

• In 56MHz +130Mbps

Cons

• System Gain (signal strength) decreases as

modulation increases

• Higher sensitivity to interference

Considerations

• System gain decrease can be offset using multi-

core radios or LoS MIMO technologies

• Enhanced algorithms allow high Tx power even

with high modulation

• Apply ACM with higher modulation offset lower

system gain and increase link availability

2048QAM

Use Spectrum Where Needed

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Radio Throughput without any optimization

7

Spectral Efficiency Spectrum Spatial Efficiency

Pros

• 50% more downlink capacity at no

extra cost!

• Spectrum saving

Cons

• Requires block-allocated spectrum

• Requires regulation approval

• Spectrum coordination complexity

Considerations

• Asymmetrical network planning

requires a backhaul specialist –

contact Ceragon’s representative for

more information

Symmetrical

Asymmetrical

Click for - Asymmetric Transport - Technical Brief

More Bits per Symbol Use Spectrum Where Needed

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Radio Throughput without any optimization

8

Spectral Efficiency Spectrum Spatial Efficiency

Re-Use (...and re-use again)

Pros

• 4x4 LoS MIMO – Quadruple capacity over

single channel bandwidth

• MIMO – increase system gain and immunity to

dispersive fading (similar to space diversity)

• XPIC – Double the capacity over single channel

bandwidth

Cons

• While XPIC is implemented with one antenna,

LoS MIMO requires two antennas at each site.

Installation is based on calculated antenna

separation.

Considerations

• Ceragon’s IP-20C MultiCore radio offers 2+0

XPIC and 2x2 MIMO in a single outdoor unit

• Ceragon MIMO innovation is designed to cope

with non-optimal antenna separation installations

XPIC

4x4 LoS MIMO

Capacity Boosting Techniques

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Capacity Boosting Techniques

10 Increased capacity in microwave links: 5 Steps

Network Utilization

Spectrum

Spectral Efficiency

Spatial Efficiency

Traffic Boosting

Payload Deduplication

4x4 LoS MIMO

2048QAM

Wide Channels

Asymmetrical

Header Deduplication

Radio Throughput without any optimization

Capacity Boosting Techniques

WRED

HQoS

TCP Buffers

Proprietary and Confidential

Capacity Boosting Techniques

11

Traffic Boosting Network Utilization

Header Deduplication Payload Deduplication

Pros

• Typically 30% More Capacity

Cons

• Capacity improvement dependent on

average Ethernet packet size

Considerations

• Does not impact or alter traffic

• Does not affect latency

• Operates between two ends of the same link

• Few vendors offer “accelerators” with

capacity gain dependent on traffic types.

Ceragon’s Header Deduplication is effective

for all types of services

Header Deduplication Typically 30% extra capacity

Loss-less compression of duplicated

frames headers

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Capacity Boosting Techniques

12

Traffic Boosting Network Utilization

Header Deduplication Payload Deduplication

Pros

• 35-40% improvements were measured in

live networks worldwide

• Content in mobile data is highly repetitive

especially in peak hours (users access

the same content – news, youtube, …)

Cons

• Capacity improvement depends on traffic

patterns

• Not suitable for encrypted data

Considerations

• Additive to other traffic acceleration

techniques offered by Ceragon

• Content, application & protocol agnostic

• Does not affect network functionality

Payload Deduplication Typically 40% extra capacity

Compressor

De-compressor

Innovative bit stream indexing technology

that exploits repetitive bit patterns in

traffic

Virtual capacity is generated by eliminating repetitions

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Capacity Boosting Techniques

13

Traffic Boosting Network Utilization

Pros

• Deep priority queues with configurable

buffer length allows network planners to

handle bursty TCP-oriented traffic in

order to maximize network utilization

Cons

• Buffer size can be configured as a

tradeoff between the latency and

immunity to bursts according application

requirements

Considerations

• Ceragon offers priority queues with

configurable buffer length and ultra deep

buffers (click for more information)

Radio capacity is not enough… the end-user experiences the TCP throughput

Most services and applications runs over TCP protocol.

Instantaneous congestion over the TCP protocol

resulting in instantaneous, large bursts that contribute to

application throughput reduction and poor quality of

experience for the user

HQoS WRED TCP Buffers

Network speed benchmark measurements are done

with Single TCP Flow

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Capacity Boosting Techniques

14

Traffic Boosting Network Utilization

Pros

• improve radio link utilization by up to 25%

Cons

• Requires traffic engineering

implementations

Considerations

• TCP uses packet loss as indication of

congestion

• Radio link congestion causes

synchronized packet loss on all the flows

• WRED randomness breaks the rate

synchronization

WRED can improve radio link utilization by up to 25%

WRED tracks length of queue. When queue

starts to fill up, begins dropping packets

randomly with increased probability

Without WRED

With WRED

HQoS WRED TCP Buffers

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Capacity Boosting Techniques

15

Traffic Boosting Network Utilization

HQoS

Pros

• Higher QoS granularity - per service,

policy-based capacity allocation

• Increased level of over-subscription and

congestion management - better link

usage, fewer spares

• When congestion occurs, only low priority

traffic are effected (e.g. low revenue SLAs)

Cons

• Requires traffic engineering

implementations

Considerations

• Capacity improvement depends on

effective network dimensioning

Hierarchical QoS

Enabler for efficient use of available capacity

WRED TCP Buffers

Summary

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Can You Get More Capacity from Your Backhaul?

17 Increased capacity in microwave links: 5 Steps

Network Utilization

Spectrum

Spectral Efficiency

Spatial Efficiency

Traffic Boosting

Payload Deduplication

4x4 LoS MIMO

2048QAM

Wide Channels

Asymmetrical

Header Deduplication

Radio Throughput without any optimization

Capacity Boosting Techniques

WRED

HQoS

TCP Buffers

Proprietary and Confidential

Show Me The Numbers Capacity innovations over a single 28MHz channel in licensed bands

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• Ceragon specializes in capacity

innovations that can be used together

• Over a single 28MHz channel we offer:

• Radio Throughput – 1Gbps without

optimization in licensed bands

• Capacity boosting – extra 700Mbps

260Mbps (2048 QAM)

195Mbps (256 QAM)

240Mbps (1024QAM)

28MHz

Radio

Throughput

without any

optimization

Header

Deduplication

30%

Payload

Deduplication

30-40%

1.3Gbps (2048 QAM)

1.7Gbps (2048 QAM)

520Mbps (2048 QAM)

1Gbps (2048 QAM)

XPIC

4x4 LoS

MIMO

+65Mbps

+260Mbps

+520Mbps

+300Mbps

+400Mbps

Ceragon offers 1Gbps radio throughput over a

single 28MHz channel in licensed bands

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Key takeaways

19

• Capacity innovations are split between

• Radio throughput (“committed” capacity) - without any optimization

• Capacity-boosting techniques - e.g., “accelerators”

• Each capacity innovation technique has pros and cons

• Beware of microwave vendors who “warn” and advise you not to adopt

a specific capacity innovation – it usually means they don’t support it…

• There is no “silver bullet” in capacity innovation - the proper capacity

schemes should be optimized for each network according to its specific

requirements and constraints

• Contact Ceragon’s representative for more information about the best ways

to adopt capacity innovation in your network

Ceragon – The #1 Wireless Backhaul Specialist

Thank You