58881439 a Understanding MW Link

Training Module

on

MW radio engineering

Learning today……

Understanding Microwave link : applications, configuration, operating parameters, system calculations

Line of Sight requirements and Antenna Heights Antenna Installation alignment and its parameters,

safety and quality MW Link Installations and commissioning :

standard practices : NEC’s approach Concluding : General site issues: questions &

answers

1

excerpt from theScientific American

July 1892

In the specification to one of his recent patents, Thomas A. Edison says:

“I have discovered that if sufficient elevation be obtained to overcome the curvature of the earth’s surface

and to reduce to the minimum the earth’s absorption, electric signaling between distant points

can be carried on by inductionwithout the use of wires.”

MICROWAVE PATH ENGINEERING – OVER 110 YEARS AGO!

• Operates on a “Line-of-sight" principle

• Use Two antennas aimed directly at one another

• Transmit Digitally modulated Microwave Frequencies through free space from one terminal to another

• Typically transmit simultaneously in both directions (Full Duplex)

Basic characteristics

4 0 0

1 0 0

2 0 0

3 0 0

0 . 5 4 . 54 . 03 . 53 . 02 . 52 . 01 . 51 . 0 5 . 0

T y p i c a l P a t h P r o f i l eD i s t a n c e ( m i l e s )

Line of sight Point to Point MW link

FWS (Point-to-Point Transport) and FWA (BWA, Access) Hops

POP – Point of Presence

PBX

CPECPE

Nodal (Hub) Site

155 Mbit/s Sonet/SDH FWS (Fixed Wireless System) Hop

CPE

ClearBurst MB Point-to-Multipoint FWA (Fixed Wireless Access) Broadband

Links

CPE – Customer’s Premises Equipment:

- Frame Relay- Video Conference

- Sonet/SDH (PTP) - ATM Switch

- LAN/IP - Base Station - T1/E1 - POTS - Sonet/ SDH - ISDN

Deployment and applications

FWS and FWA (BWA) Radio Hops

Sonet/SDH NxOC-3 or NxSTM-1Backbone FWS (Radio-Relay) Hop

OC-12 or STM-4 Fiber Ring

Long Distance 2xT1/E1 Unlicensed Hop

Short Distance 4xT1/E1 HopsAccess Hops

Short Distance SONET/SDH Hop

X

X

Transport HopNMS system

GSM Network layout

Fiber and MW transmission media in GSM/CDMA Networks

23 GHz (OC-3)

38 GHz (N x DS1)

18 GHz (N x DS1) 18 GHz (DS3)

BTS

BSC

MTSO(MSC)

BSC

(DS3 or OC-3NxOC-3 ) or 155 (Nx0C-3) Self-Healing Ring

BTSBTS

BTS

FWS Microwave Applications

PCS/Cellular Site Interconnection MTSO (MSC) - Switching Office BTS - Base StationBSC - Base Station Controller

(North American Hierarchy)

Access and metro /transport networks

Core Network Topologies

Some Attributes of Digital Microwave Radios • Superior availability - route security (no cable cuts)• Rapidly expandable and upgradeable, in-service if protected

• High quality - no multihop “noise” addition

• Rapid deployment over difficult terrain and into urban areas

• Economical - no copper or fiberoptic cable deployment

• Robust to fading and interference

• Insensitive to antenna feeder system and long-delayed on-path echoes

• Highly efficient data and broadband transport

• Exacting in-service visibility of radio hop performance with NMS

• Seamless interconnectivity to an ever-expanding digital transport (fiberoptics and other), PABX/MSC switch, and LAN/IP world.

1 M H z 1 0 M H z 1 0 0 M H z 1 G H z 1 0 G H z 1 0 0 G H z 1 0 1 2 1 0 1 4

M i c r o w a v e s

A M B r o a d c a s t R a d i o U H F T e l e v i s i o n

F M B r o a d c a s t R a d i o

V H F T e l e v i s i o n

M o b i l e R a d i o

S h o r t w a v e R a d i oM o b i l e R a d i o

V i s i b l e L i g h t

F i b e r O p t i c s

1 0 0 0 m( 3 0 0 K H z )

1 m m( 3 0 0 G H z )

1 c m( 3 0 G H z )

1 0 c m( 3 G H z )

1 m( 3 0 0 M H z )

1 0 m( 3 0 M H z )

1 0 0 m( 3 M H z )

Typical Electromagnetic spectrum

3xDS3/OC-3/STS-34xDS3, 4xE3/STM-1

Capacity

GHz T1/E1

DS3 or 28 T1 E3 or 16 E1

Frequency Band: 2 86 1813 23

Backbone Transport

2 T1/E1

4 T1/E1

4211 37

16 T1

NxOC-3/STM-1

10

Network Management

Element Manager

SNMP Interface1:N

Backbone & Access

Unlicensed

1-5mi/2-8km 5-10mi/8-17km7-15mi/12-25km >15-60mi/25-100km

Access

Broadband Wireless Access (FWA)

26

8 E1

Typical Path Lengths:

Transport and Access Bands

Example of capacity and frequency bands

CEPT PDH Hierarchy

140 Mbit/s(1920 Ch)

1

2...

1

2...

2

3

1

30/31*

4E1

E2

E3

16

34 Mbit/s(480 Ch)

1234

E3

34.368 Mbit/s(480 Ch)

8.448 Mbit/s(120 Ch)

2.048 Mbit/s(30/31 Ch)

PCM ChannelBanks

M34-140Radio MUX

1stOrder

CEPT Hierarchy is the international TDM digital standard everywhere except North America (USA, Canada), Taiwan, Korea and Japan.

1234

M8-34

3rdOrder

E4

Skip Mux

M2-8

2ndOrder

M2-34

Skip mux

VF/data/LAN/IP andteleconferencing circuits

16 x 2.048 Mbit/s E1 Trunks

PDH -Plesiochronous(asynchronous) DigitalHierarchy

*30 VF Channels with signaling channel or 31x64 kbit/s Data Channels (no signaling)

TDM: CEPT PDH Hierarchy

Voice Channel

Equivalent

130120480

1920/1890*

Desig-nation

E0E1E2E3E4

No. of E1 Trunks

30/31 = 1E114

1664/63*

Bit Rate(kbit/s)

642,0488,448

34,368139,264

LineCode

AMIHDB3HDB3HDB3CMI

*63 E1 (1890 VF ch) are mapped in Synchronous Digital Hierarchy (SDH)

AMI, HDB3, & CMI codes are bipolar.

Cable types: 120Ω Twisted Pair, 75Ω Coax(Length/type assigned for 6 dB maximum loss)Ref: ITU-T G.703, G.704

CEPT PCM Analog-Digital PCM Quantizing Code is A-Law

PDH - Plesiochronous Digital Hierarchy

SDH Fundamentals: Rates

Line Rate(Mbit/s)

SDH Signal PDH Signal# E1 (2048 kbit/s)

VF Transport

2.048 VC - 12 1 30

34.368 VC - 3 16 480

51.84 Sub-STM-1* 21 630

139.264 VC - 4 64 1,920

155.52 STM - 1 63 1,890

622.08 STM - 4 252 7,560

2488.32 STM - 16 1,088 30,240

9953.28 STM - 64 4,032 120,960

SDH Synchronous Digital Hierarchy PDH Plesiochronous Digital Hierarchy*Sub-STM-1 RR-STM, STM-0 = 51 Mbit/s for Radio Relay)Ref.: ITU-R Rec. F.750-3 (1997)

Radio or Fibre

Fibre

1:N Radio or Fibre

SDH Fundamentals: Mux

Note: Bold indicates commonly available multiplexer interface

RRRP

NNI

SDH Synchronous Digital HierarchySTM Synchronous Transport ModuleVC Virtual ContainerTU Tributary UnitTUG Tributary Unit GroupAU Administration UnitAUG Administration Unit GroupATM Asynchronous Transport ModeRRRP Radio-Relay Reference PointNNI Network Node InterfaceSub-STM-1 = RR-STM (52 Mbit/s for radio) = STM-0

ATM

x4

Pointer Processing

MultiplexingAligningMapping

DS1 VC11 TU11

VC3

VC12

VC2 TUG-2

TUG-3

VC3

VC4 AU4

AUG STM-N

E1DS1

DS2

E3DS3

E4

x1

x1x1

x1

x3x3

x3

x7

x3

AU3

x1

TU12

TU-3x1

Sub-STM-1

TU-2

Basic Building blocks of MW Link

Basic Building blocks of MW Link

Circulator, Filter(CBN)

WaveguideRFRF

Circulator, Filter(CBN)

Waveguidef [GHz]

Channel

BB = Basebande.g. 155 Mbit/s

Classical Design

Channel

Demodulator16 - 128 QAM

Modulator16 - 128 QAM

IF = Intermediate frequencye.g. 140 MHz

RF = Radio frequencye.g. 7.5 GHz, 18.7 GHz

TXTransmitter

RXReceiver

Basic blocks of radio

IDU

Important to know…

IDU Functional blocks

ODU configuration

ODU Layout

• Outdoor Units (ODUs) are software configurable so that capacity upgrades can be made without climbing towers.

• Indoor Units (IDUs) support capacities of 2/4E1, 4/8E1, 16E1, E3, 4/8DS-1, or DS3 and are frequency independent so that they can be used with any ODU of like capacity.– Minimal Installation time– Single coaxial cable connection between IDU and ODU– Dual polarity DC input of (±21.6 to ±60 VDC)– Adjustable transmit output power– Frequency/channel setting via keypad or laptop PC– Diagnostic loopbacks accessible via laptop PC– Capacity to store 25 different channel plans

ODU functional modules

LineInterfac

e

MUX MOD

DEMUX DEMOD AGC N-plexor

LIU Input MUX PLL TX FPGA

TX IF PLL TX IF

RX FPGADEMUX FrameFrame SyncPrivate Link

DEMOD LockLow BER (>1e-9)High BER (>1e-3)

AGC

ODU Communication

N-plexor

ALC

≈

≈

PAIF LO RT 1848 PLL

Synth Up Conv. Osc UnlockSynth TX Offset VoltageSynth TX Main Loop UnlockSynth TX Offset Loop Unlock

Synth Rx Main Loop UnlockSynth Rx Offset Loop UnlockSynth Rx Offset Loop Voltage

TX Synth

RX Synth

LNA

PA

70MHz

310MHz

2158MHz

1778MHz

Line Interfac

e

MUX MOD

DEMUX DEMOD AGC N-plexor

LIU InputMUX PLLTX FPGA

TX IF PLL TX IF

RX FPGADEMUX FrameFrame SyncPrivate Link

DEMOD LockLow BER (>1e-9)High BER (>1e-3)

AGC

ODU Communication

N-plexor

ALC

≈

≈

PAIF LO RT 1848 PLL

Synth Up Conv. Osc UnlockSynth TX Offset VoltageSynth TX Main Loop UnlockSynth TX Offset Loop Unlock

Synth Rx Main Loop UnlockSynth Rx Offset Loop UnlockSynth Rx Offset Loop Voltage

TX Synth

RX Synth

LNA

PA

70MHz

310MHz

2158MHz

1778MHz

Far End SP Far End RF Plug-in

Near End RF Plug-inNear End SP

Link Block Diagram

Link Block Diagram

IDU-Indoor Unit

ODU Components

Signals on IF cable –IDU-ODU

Protection and Diversity

Protection Schemes and

Diversity Arrangements

Protection and Diversity

The Need for Protection and Diversity

In the past, short traffic interruptions without traffic disconnect in microwave links were often acceptable to many private users.

Expectations changed with the digital microwave transport of MSC-cell site data, ATM, high speed data transfer, teleconferencing, imaging (medical, etc.), and such technology as the new digital mobile trunking systems.

Excessive numbers of short fade hits (circuit interruptions) are now barely tolerable, except in LAN/IP transport and access (millimeterwave) hops impacted by rain cells, long-term outages (traffic disconnects) are usually unacceptable.

87

Protection Schemes

*Reverse Channel Switch command from far end receivers ** If FD is permitted

Equipment degradation, failure:– 1+1, hot-standby or on-line modules …HS– 1:N, one standby for >2 modules ……..HS

Antenna system misalignment, failure:– Split transmitters + RCS* ………….HS+ST– Two-dish hybrid diversity** ….HD, SD+ FD– Self-healing ring (loop) architecture …..SR

Protection Types

1+1 hot-standby protection …………………….HS

1+1 on-line (paralleled elements) protection ...HS

1:N module protection ………………………….HS

1:N multiline protection …………….HS or HS+FD

Split transmitters with RCS* ……….……...HS+ST

Self-healing ring (or loop) architecture …….….SR

*Reverse Channel Switch command triggered by the dual failure (outage) of both far-end receivers

Protected & Diversity - Dual Antenna

CBN

10dBCBN

1+0 Equipment Protection - "1+1 HSB" Configuration

RPS RPS

f1f1af1

f1af1`f1bf1`f1b

f1a

f1a

TX

TX

Station BStation A

Ch. 1(STM-1)

Ch. 1(STM-1)

DM RXf1b

DM RXf1b 10dBOP

PR f1b PR

TX MDf1b

TX MD

OP

OP

PR

MD

MD

RXf1a

RXf1a

DM

DM

PR

OP

1+0 Equipment Protection - Space Diversity

f1f1af1

f1af1`f1bf1`f1b

CBN

Station BStation A

Ch. 1(STM-1)

Ch. 1(STM-1)RPS RPS

f1b PR

TX MDf1b

TX MD

OP

OP

PR

MD

MDf1a

f1a

TX

TX

CBN

RXf1a

RXf1a

DM

DM

PR

OP

CBN

CBN

DM RXf1b

DM RXf1bOP

PR

Frequency (GHz)

Minimum Spacing (m)

Ideal Spacing (m)

6,8 4,5 10

7 4,5 10

13 2,5 5

15 2,0 5

Typical spacing for SD

∆ ∆

Microwave Radio Technology - Space Diversity

DMRX

TX MDCBNMain

+DMRX

TXMD CBNMain

+

STM-1 STM-1

CBNDiv

RX

Lengthcompensation

CBNDiv

RX

SD +HSB

TXMDCh. 1

(STM-1)

DM RX

horizontal f1a

f1b

Ch. 1(STM-1)

DMRX

TX MD

f1a

f1b horizontal

140MHz

140MHzCBN CBN

Ch. 2(STM-1)

DMRX

TX MD

f1a

f1b

TXMDCh. 2

(STM-1)

DM RXvertical

f1a

f1b vertical

140MHz

140MHz

PWPW

CBN CBN

OP2f1

OP2f1

V

f1OP1f1

OP1

f

H

Block Diagram - 2+0 Configuration with XPIC

Clock synchronizationData compensation

V VH H

2 Waveguidepro Station

Microwave Radio Technology - Frequency Diversity

f1a

f3a

f1b

RPS CBNChannel 1

MD TX

MD TX

DMf3b

RX

RXDM

f1 f3f

f3f3af3

f3af1

f1af1

f1af3’f3bf3’f3b

f1’f1bf1’f1b

Hot-Standby & Space Diversity

Hot Standby Terminal Hot Standby Terminal with Space Diversity Receivers

*

* Power splitters in digital radios are always asymmetrical, not 3/3 dB as in analog radios, as data are errorlessly switched - not combined as are analog radio basebands. A 3/3 dB RF receiver splitter provides no protection benefits over the 1/7 dB splitter, and will lower fade margins 2 dB for 58% more outage time.

Splitter/Combiners

Waveguide Coupler Primary Path Insertion Loss

Standby Pass Insertion Loss

6 dB unequal coupler 1.6 dB 6.4 dB

3 dB equal splitter 3.5 dB 3.5 dB

RFD Configurations

1+0 1+1 HH

2+0 1+1 HS

Hybrid module for NEC radios

Cost-effective method of providing T1/E1 trunk redundancy in mixed radio, fiberoptics, span lines.

Protects against Path, Site, and Equipment Failures with non-protected radio repeaters - lowers costs ~40%.

Only protection from long-term periods of unavailability due to fiber cuts, power fades such as heavy rain at higher frequencies, infrastructure failures, etc.

Operation, fault location, testing, and maintenance are simplified.

A ring-closure microwave hop (perhaps longer or with degraded performance) or other T1/E1 trunk for ring closure (fiber, leased line) is necessary.

Benefits of Ring Protection

Ring (Loop) Protection (SR)

Component mountings- IF Module

The IF Module (IFM) consists of the following items: TX IF assembly RX IF assembly DC-DC converter

dB

dB

dB

dB

2 *

Syn

2 * Syn

DC

DC CPU

dB

dB

High integratedRF Module RF Diplexer

Modulare ODU-Design

IF

Antenna

OP

f1

H

V

STM-1

DPU

EOW

Modulator

Demodulator

Power Supply

IDU

Broad Band Filter

ODUcoax.cable

Frequencies 7 up to 38 GHz

Operation mode 1+0 with integrated antenna In some cases of interest in an offer because of the lowest price

Some more configurations..

OP

f1

H

V

Frequencies 7 up to 38 GHz

STM-1

DPU

EOW

Modulator

Demodulator

Power Supply

Broad Band Filter

ODUcoax.cable

wave guide

IDU 155-16/128 LS

Operation mode 1+0 with separate antenna

Operation mode 1+1 HSB with integrated antenna

Frequencies 7 up to 38 GHz

f1

H

V

BK

DPU

EOWModulator

Demodulator

Power Supply

DPU

EOWModulator

Demodulator

Power Supply

ODU

ODU

Coupler

coax.cable

Slave-IDU

Master-IDU

1,3 dB

6,3 dB

Operation mode 1+1 HSB with integrated antenna

Frequencies 7 up to 38 GHz

f1

H

V

BK

DPU

EOWModulator

Demodulator

Power Supply

DPU

EOWModulator

Demodulator

Power Supply

ODU

ODU

Coupler

coax.cable

Slave-IDU

Master-IDU

1,3 dB

6,3 dB

Operation mode 4+0 or 2x(1+1) dual polarized CCDP with XPIC

STM-1 DPU

EOWModulator

Demodulator

Power Supply

DPU

EOWModulator

Demodulator

Power Supply

4 x IDU 155-16/128 LS

OMT

Waveguide

Wave-guide

STM-1

Frequencies 7 up to 38 GHz

f1

f1

H

V

f3

f3

OP1

OP3

OP2

OP4

ODU LX – Adjacent ChannelsODU S – 1 Ch. to be left

ODU

ODUCoupler

STM-1 DPU

EOWModulator

Demodulator

Power Supply

DPU

EOWModulator

Demodulator

Power Supply

STM-1

ODU

ODUCoupler

Operation mode 4+0, coupler version in dual polarized ACAP

STM-1 DPU

EOWModulator

Demodulator

Power Supply

DPU

EOWModulator

Demodulator

Power Supply

4 x IDU

OMT

Waveguide

Wave-guide

STM-1f2

f1

H

V

f4

f3

OP1

OP3

OP2

OP4

Frequencies 7 up to 38 GHz

ODU

ODUCoupler

STM-1 DPU

EOWModulator

Demodulator

Power Supply

DPU

EOWModulator

Demodulator

Power Supply

STM-1

ODU

ODUCoupler

90°

Hhorizontal

Frequency Patterns - Transmission via 2 Polarizations

1. Polarization

2. Polarization

V: vertical

Orthomode transducer(OMT)

V

TXMD

DM RX

f1a

f1b

CBNf1f1

TXMD

DM RX

f1a

f1b

CBN

f1f1

H

VH

Waveguide V

Waveguide H

Operational parameters and system planning

Microwave Frequency Required Necessary Antenna Gain Maximum Distance between terminals Receive Signal Level Margin Link availability

Understanding operating parameters

Understanding operating parameters

Understanding Threshold for receivers

TX

Terms of Microwave Radio Technology - System Overview

Max. powere.g. +31 dBm

[1.25 W]

Output power

min. powere.g. -73 dBm

[50 pW]

Fadingmargin

Free space attenuation e.g. 143.9 dB(Distance d = 50 km)

(Frequency: f = 7.5 GHz)

( )f[GHz]d[km]log2092.40

a ⋅⋅+=

CBNwaveguide

e.g.5.3 dB

CBNwaveguide

Antennagaine.g.

41.4 dB

Antennagaine.g.

41.4 dB

CBNwaveguide

CBNwaveguide

e.g.5.3 dB

System attenuation

(e.g. 71.7 dB)

Input power

RX

System gain

SYSTEM GAIN (to 10-3 BER or

LOF)Top of Bay Antenna Port

123

Transmitter Output Interface

Repeater Station

Top of Bay Antenna Port

RSL IN

1 2 3

ReceiverInput Interface

SYSTEM GAIN. dB

XMTR Power Out - RCVR RSL In (for 10-3 BER) at the Antenna

Ports. Typically 100 dB

NPL - NET PATH LOSS. dB

Waveguide In Site A to Waveguide Out at Site B. Typically 60 dB

(Excluding Fade Activity)

RECEIVER RSL INPUT. dB

RSL = XMTR Power Out - NPL

THERMAL FADE MARGIN. dB

TFM = System Gain - NPL

NET PATH LOSS (NPL)

FREE SPACE LOSS

(NO FADE)

Terminal Station

EIRP = P0 - Lf + Ga (FCC/ETSI Constraints)

Ga

Lf

P0

System Gain, Net Path Loss

Receive signal level calculation

RSL(dBm) = Tx power(dBm) + Tx antenna gain(dBi) - Free Space Loss(dB) – Branching Loss – Feeder cable loss + Rcv antenna gain (dBi) where Free Space Loss(dB) = 32.4 + 20logF +20logD where: D is Kms, F is MHzFor example:Given: Path Distance of 10 Kms, Radio Frequency is 7 GHz, Tx Power is 20 dBm, and Antenna Gain(both sides) is 38 dBi

•Free Space Loss = 32.4+20log(10)+20log(7000) = 32.4+20+76.90 = 129.30 dB

•RSL(dBm) = 20 dBm + 38 dBi – 129.3 dB + 38 dBi = - 33.3 dBm

Receive signal level margin

• Directly determines the availability of the link by providing threshold “cushion” against signal fade due to environmental conditions, i.e. rain, snow, hail, etc.

• Rain data for geographic location is needed to calculate availability once RSL margin is known.

System Gain, Net Path Loss RF Signal, Noise, and Interference Levels Static and Dynamic Thresholds Microwave Spectral Efficiency QAM, QPSK Modulation DSSS, OFDM/COFDM Signal Spreading Microwave Spectrum Calculations Co-Channel Dual Polarization (CCDP) Latency ATPC and DTPC Frequency Bands, Interference, Terrain Scatter Frequency Band Selection

Technical Topics that define Digital Radio Hops

Technology

ATPC and DTPC

DTPC – Dynamic Transmit Power Control (TRuepoint, Galaxy 23)ATPC – Automatic Transmit Power Control (all other radios)

ATPC or DTPC, features that reduce transmit powers except with far-end receiver alarms during deep fades, are occasionally assigned to some microwave links for one of the following reasons:

Prevents receiver front-end overload in higher frequency links assigned high rain fade margins

Complies with FCC (and other) EIRP constraints in short hops, <17 km in the 6 GHz bands and <5 km at 10 and 11 GHz,

Prevents receiver overload in shorter 6, 10, and 11 GHz paths requiring large antennas in frequency-congested areas

Reduces interference levels at hubbing sites and into adjacent links in frequency-congested areas.

ATPC

ATPC

DTPC/ATPC

-10

-20

-30

-40

-50

-60

-70

-80

Rec

eive

Sig

nal

Le v

el,

dB

m

+20

+10

0

-10

0 10 20 30 40 50 60 1-Hour of Rain Fade Activity, Minutes

Tran

smit ter O

utp

ut P

ow

er , dB

m

Fad

e D

epth

, d

B

0

-10

-20

-30

-40

-50

-60

-70

Transmit and Receive RF Levels During 1-Hour Fade Activity in a High Fade Margin (60dB) 23 GHz DTPC Link.

RSL follows fades below the “setting point”, -45 dBm in this example

RSLw/DTPC

Fade Depth,RSL w/o DTPC

Outage Threshold

NoOutage

DTPC RSL

Setting Point

-45 dBm

TransmitterOutput

10-6 BER Receiver Overload Error-free

Time

RSL

ATPC Off

ATPC On

Fading

Stopped Fading

7/10 dB

7/10 dB

15/18 dB BER = 10 -11

BER = 10 -6

10 –6 Th + 15/18 dB

Un-Fading

ATPC

Important to know…

Useful Formulas

For English (ft, mi, GHz, dB) Metric (m, km, GHz, dB)

Path Loss 96.6 + 20 log f + 20 log D 92.4 + 20 log f + 20 log D

Earth’s curvature 0.67 d1d2/k d1d2/12.7k

F1 radius 72.1 (d1d2/f D)0.5 17.3 (d1d2/f D)0.5

Fn radius F1 (n)0.5 F1 (n)0.5

Dish gain (55% efficiency) 7.5 + 20 log f + 20 log d 17.8 + 20 log f + 20 log d

Dish BW, degrees 66/fd 20/fd

Div. dish separation 1200 D/f h(t) 127D/f h(t)

Multipath delay, nsec Fn /2f Fn/2f

NOTATION: f = frequency, GHz D = path length

k = k-factor (4/3rds, etc.) d1, d2= distances (d1 + d2 = D)

h(t) = Tx dish height above n = Fresnel zone number

the reflection plane F1 = 1st Fresnel zone radius

d = dish diameter

Supplementing the Outage Model

Important to know…

Site Details Address, Lat-Long, Azimuth wrt North, equipment layout

Access /permission/approach road

Link Budget Expected Receive level/ Fade Margin

Tx Planner/Operator

Frequency of operations and Tx power;

Type of antenna, Height of antenna, Polarization

LOS cleared

Cabling details External alarm termination details/color code

NMS IP address/DCN planning /cabling/router/converter

Traffic E1/STM1 termination /Through

EOW, Auxiliary channels/Sideway E1

Frequency Sub Band [GHz]

Duplex [MHz]

10 350 10224

10574

350 10252

10602

Capacity BW [MHz] / Channel Raster

16 E1 28

8 E1 14

4 E1 7

2 E1 3.5

25 MHz Channel Filter Bandwidth

16 E1 CAPACITY

5.5 MHz 14 MHz 5.5 MHz

Understanding Frequency plan

Co- and adjacent-channel interference

Low fade margins

Antenna k-factor decoupling

Antenna misalignments

Dispersive (spectrum-distorting) fades

Ducting, defocusing, and obstruction fades

EMI and other environmental effects

Effective diversity arrangements lessen the impact of otherwise unacceptable conditions:

Fade Margin Degradations