RADWIN 2000 Technology Highlights Part 2

V1.5 Release 2.6.40 LA

Professional Services Manager Mexico & Central America

J.Manuel Surez N.

1. Scan & Display (Spectrum View)

2. Directional antennas

3. OFDM

4. Diversity VS. MIMO

5. Multi-Band (Combo) Product

6. Transmit Power Control (TPC)

7. Adaptive Modulation

8. ACS (Automatic Channel Selection)

9. Fast ARQ

10. MIMO OFDM based air-interface, enabling N-LOS deployments

11. Configurable jitter buffer

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Dealing with Air-Interferences

Spectrum View

Simplifying RF survey & installation by graphically displaying cleanest channel

Supports link installation before service activation

Activated by the installer

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Spectrum View Display Information

Helps selecting the best channel during installation

Spectral power measurements in 5MHz channel resolution

4 Receivers Display

Current, average and maximum power per channel

Channels free from radars, with radars and barred (for DFS bands)

Scanned and un-scanned channels

Channels selected for ACS

Current operational channel

Time stamp of the last spectrum scan

Zoom, selective view of antennas and sites and detail level

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Spectrum View Tool Capabilities

Save and Restore

save the spectral information and also view retrieved spectral information from historical spectrum scans

Diagnostics

The Spectrum View information is logged as part of the Diagnostics Information to improve link and

system diagnostics and remote support

It can be retrieved from the RADWIN Manager menu with Help Get Diagnostic Information

Management Integration

Spectrum view information is supported in RADWINs MIB and can be used by external Network

Management applications

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Spectrum View Tool Capabilities

Designed for Unlicensed Spectrum

Shows accurate information while accommodating with variances in frequency, temperature and

interference power

Overcoming anomalies that tend to occur in high interference environments

Scanning Time

~10 seconds for an entire band scan

We recommend that users perform a scan for a few minutes for accurate results

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Orthogonal Frequency Division Multiplexing

OFDM overcomes obstacles to direct line of site in Urban & Rural

Rural - water, jungles, mountains

Operate with up to 40% obstruction of Fresnel Zone

Urban - enables connectivity via reflections in radio path

The use of OFDM reduces the effects of multi-path and delay spread, which is

especially important for lower frequencies and near line of sight (NLOS) transmission

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Orthogonal Frequency Division Multiplexing

OFDM is a process of transmitting several high speed communication channels through a

single communication channel using separate sub-carriers ( frequencies) for each radio

channel

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Orthogonal Frequency Division Multiplexing

The subcarriers are small portions of the frequency spectrum

Hence, they are individually not harmed by inter-symbol interference (ISI - distortions

from adjacent symbols)

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If the data is coded across all

subcarriers, narrowband interference

can easily be handled by switching off

the subcarriers where the respective

narrowband interferer is persistent

OFDM: Data is coded across multiple channels

The following graph shows how a sequence of 8 QPSK symbols is represented in Frequency

and Time domains (OFDM):

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Data symbols occupy 15KHz for one OFDM symbol period

OFDM: High Spectral Efficiency

In the frequency domain, each sub-carriers spectrum is a sinc function with zero

crossing every f0

Since the sub-carrier spacing is identical f0 - there is no inter-sub-carrier interference

OFDM spectrum is overlapping - many sub-carriers can be placed every f0 frequency

interval. Then the total power spectrum shape is close to a square

This means OFDM has a very high frequency usage efficiency

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Diversity

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Diversity Mode uses two antennas to improve the quality and reliability of the link. Often, there is not a clear line-of-sight (LOS) between transmitter and receiver. Instead the signal is reflected along multiple paths before if-ally being received. Each such bounce can introduce phase shifts, time delays, attenuations, and even distortions that can destructively interfere with one another at the aperture of the receiving antenna. Antenna diversity is especially effective at mitigating these multi-path situations. This is because multiple antennas afford a receiver several recordings of the same signal. Each antenna will be exposed to a different interference envy-remnant. Thus, if one antenna is undergoing a deep fade, it is likely that another has a sufficient signal. Collectively such a system can provide a or-bust link. Antenna diversity requires antenna separation which is possible by using a dual-polarization antenna or by two spatially separated antennas.

MIMO

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With MIMO the system doubles the link capacity. At the same time, it keeps the same rate and modulation per radio as was used with single antenna, thus increasing capacity, range and availability. For example with a dual antenna RADWIN 2000 can transmit at modulation of 64QAM and FEC of 5/6 and get an air rate of 130 Mbps, compared to 65 Mbps with single antenna. To work in this mode, each antenna port must be connected to an antenna, the RSS level in both receivers should be balanced and a minimal separation between the antennas must be maintained. (For example, by using dual polarization antennas a cross polarization separation is attained). Upon selecting Antenna Type as Dual, RADWIN 2000 automatically selects MIMO mode and doubles the air rates. RADWIN Manager indicates a case of unbalanced RSS between the two antennas.

Diversity VS. MIMO

Diversity: Capacity 25 Mbps MIMO: Capacity 50 Mbps

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Diversity When to Use

Use MIMO

When highest capacity is required; up to 50 Mbps FD

When the air conditions are similar between the antennas

Use Diversity

When the system cannot operate in MIMO Mode due to link conditions

When you get higher capacity in Diversity Mode than in MIMO Mode

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Remember that the capacity in Diversity is than that of MIMO

Multi Band radios support multiple bands on same platform

From 2.4 GHz & 4.8-6.0 GHz

Enables installing multiple radios in same area and eliminates interference

Not all radios have to operate on same band

Ensure optimal transmission

If experiencing interference simply select another channel

Better stock control

Now ONE radio offers multiple bands

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Multi-Band (Combo) Product

What?

Enables control of ODU transmitted power level

Available in all products

Why?

Reduce co-location interference

Environmental issues

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TPC - Transmit Power Control

Automatic Adaptive Rate

RADWIN 2000 changes air interface rate and modulation dynamically, depending on radio link conditions

Benefits:

Maximization of ETH throughput while ensuring minimum Error rate

Enhanced robustness

Better performance in interference

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64QAM @ FEC 5/6

64QAM @ FEC 3/4

64QAM @ FEC 2/3

16QAM @ FEC 2/3

16QAM @FEC 1/2

QPSK @FEC3/4

QPSK @FEC1/2

BPSK@FEC1/2

Automatic Repeat Request (ARQ)

Patented mechanism

Ensures super-fast retransmission of errant data

Repeat Transmission is initiated without having to wait for a request from the

remote unit

Benefits:

Minimizing the end to end error rate while keeping the latency to minimum, to best support time constrained

services (e.g. TDM)

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Automatic Channel Selection (ACS)

Automatic selection of Best-Quality channel for transmission

Enhanced robustness and increase availability

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Configurable Jitter Buffer

By configuring the Jitter Buffer, the receiver jitter buffer for each site can be enlarged,

thereby increasing resistance to interference

Decreasing the Jitter Buffer decreases system delay

Jitter Buffer can be configured between 2.1 and 16.0 milliseconds

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Monitored Hot Standby (MHS) 1+1

Redundant/Backup to TDM services

Providing protection against:

Equipment failure (ODU and IDU)

Loss of air interface

Using a primary link and a secondary link can be done with:

2 RADWIN 2000 links

1 RADWIN 2000 link and 1 WinLink 1000 link

2 WinLink 1000 links

Provide redundancy and high reliability for carrier class operators

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Monitored Hot Standby (MHS) 1+1

Optimized for high capacity links operating in license-free bands

Additional values:

Each link can use a different band for

maximum protection to the air interface.

Affordable SLA can be offered by

protecting part of the RADWIN 2000 trunks

with WinLink 1000

Switching scenarios:

Failure in ODU or IDU (local or remote)

Loss of primary air interface (sync loss)

Loss of TDM data for 24msec (when TDM is

transmitted)

Automatic switching time < 50msec

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Secondary Link ON Hot Standby

nxE1

nxE1

HSS Cable

MHS Cable

Primary Link ON

Active

Solution Diagram 1+1 TDM (MHS)

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TDM Services

TDM Services

HSS Cable

MHS Cable

Secondary Link ON Hot Standby

nxE1

nxE1

HSS Cable

MHS Cable

Primary Link

DOWN

Link Failure

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TDM Services

TDM Services

HSS Cable

MHS Cable

Secondary Link ON

ACTIVE!

nxE1

nxE1

HSS Cable

MHS Cable

Primary Link

DOWN

Switchover!

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TDM Services

TDM Services

HSS Cable

MHS Cable

Thank You!