microwave planning procedure 2

Aircom Connect 6.0 Link Planner

BASIC EXPLANATIONBASIC EXPLANATION


Aircom Connect Link Planner is a graphical planning tool that provides support for microwave network .

Planning is divided into two different categories : Point-to-Point Point-to-Multipoint

Link Planner is using two project database for the data:1 Properties (sites)2 Link (connection between different properties)

and some other database relates to the equipment


Database windows MapConnect Module

In order to use Link planner, you have to select the Connect module. After that you can start using the map or writing the database.


Network Design

This 2D View is the same used from RF planner for 2G and 3G plan and also the site database is the same!

Interface command


Selection

INTERFACE COMMANDINTERFACE COMMAND

Map Map visualizationvisualization

Map Map managingmanaging

Zoom

Drag

Search

Open Legend

Control Data types

Favorite selection

Create Vector

Vector Manager

Quick parameter display


Add Network Element (MSC / BSC / Site )Move Network Element

Delete Network Element

Candidates Manager RF Part

Remove Connection

Point to Multipoint Hub manager

NE CreationNE Creation

PropertProperty y ManageManagerr

LinkLink ManagManagerer

NETWORK DESIGNNETWORK DESIGN

Add Property

Move PropertyDelete Property

Add new link


Height Data activation and definition

Clutter activation and definition

Filters activation and definition

DATA TYPE DATA TYPE

Aircom Connect 6.0 Link PlannerDATABASE SELECTIONDATABASE SELECTION

Inside the Database Menu you can select which Database you want (Sites and Link database) and filter manager (red ellipsoid)

Aircom Connect 6.0 Link PlannerEquipment SELECTIONEquipment SELECTION

In this Menu you can also define equipments and MW antennas (blue ellipsoid)

Aircom Connect 6.0 Link PlannerSITE DATABASESITE DATABASE

• General : Coordinates, Code and Name

• Status : flag selection

•Contacts : address , city

•Search Area : not used

In this field you can select which filter activate


LINK DATABASE LINK DATABASE

• General : Coordinates, Code and Name, Flags

• Linkend Setting : All planning parameters like Radio eq. Frequency, Channel, Antenna definition

•Calculation : Setting for Model calculation

•Performance : Calculation result

In this field you can select which filter activate


LINK DATABASE - GENERAL WINDOW -LINK DATABASE - GENERAL WINDOW -

• Info : Coordinates, Code, Name and Los Info

• Status : flag selection

•Attachments : not used


LINK DATABASE - LINKEND SETTING WINDOW / RADIO TAB -LINK DATABASE - LINKEND SETTING WINDOW / RADIO TAB -

In this Tab you have to define all equipment characteristics.


LINK DATABASE - LINKEND SETTING WINDOW / FREQUENCY TAB -LINK DATABASE - LINKEND SETTING WINDOW / FREQUENCY TAB -

In this Tab you have to define frequency channel and High / Low Selection

Please note that the tool doesn’t give any warning at this phase for H/L conflict


LINK DATABASE - LINKEND SETTING WINDOW / ANTENNA TAB -LINK DATABASE - LINKEND SETTING WINDOW / ANTENNA TAB -

You have to add an antenna, to select which one to use, fix the height and check the polarisation.

Please note that the tool doesn’t link between the antenna the polarisation!


LINK DATABASE - LINKEND SETTING WINDOW / FEEDERS TAB -LINK DATABASE - LINKEND SETTING WINDOW / FEEDERS TAB -

In this Tab you have to define the feeders (connectors or Wave guide)

Aircom Connect 6.0 Link PlannerLINK DATABASE - CALCULATION WINDOW / PROPAG. PREDICTION TAB -LINK DATABASE - CALCULATION WINDOW / PROPAG. PREDICTION TAB -

In this Tab you have to define which Method you use and relative parameters


LINK DATABASE - CALCULATION WINDOW / RAINFALL TAB -LINK DATABASE - CALCULATION WINDOW / RAINFALL TAB -

In this Tab you have to define the rain rate. You can select a rain zone or put manually the value.


LINK DATABASE - PERFORMANCE WINDOW / LINK BUDGET TAB -LINK DATABASE - PERFORMANCE WINDOW / LINK BUDGET TAB -

This tab shows the complete Link Budget.


LINK DATABASE - PERFORMANCE WINDOW / FADE MARGIN TAB -LINK DATABASE - PERFORMANCE WINDOW / FADE MARGIN TAB -

This tab shows the Fade margin study


LINK DATABASE - PERFORMANCE WINDOW / AVAILABILITY TAB -LINK DATABASE - PERFORMANCE WINDOW / AVAILABILITY TAB -

This tab shows the Reliability and Availability of the link

Aircom Connect 6.0 Link PlannerINTERFERENCE TOOLINTERFERENCE TOOL

If you want to have a level indication about the interference, you can use the wizard.Inside the Tools Menu you can select which tool you want use Select interference analysis -> Interference Wizard


INTERFERENCE TOOLINTERFERENCE TOOL

Calculate interference only for the link inside the 2D view

Calculate interference only for the link inside a filter

Calculate interference only for the link indicated



Carrier Level and Interference Level

Create an excel Report


Link ProfileLink Profile

To generate Link Profile


Link ProfileLink Profile

Show the Fresnel ellipsoid

Show Reflections

Give the antenna minimization height


LINK PROFILE – REPORTLINK PROFILE – REPORT

In this case we have also a Link Budget report.This Report give the principal info for the link.

Aircom Connect 6.0 Link PlannerREPORTINGREPORTING

With NAP Link Planner we are available a wizard reports tool in order to have reports for Link or site.

For that we have to active the “Reports” menu (red ellipsoid) and select which type of report we want realize [database selection] (blue block).


REPORTING - LINK REPORT -REPORTING - LINK REPORT -

General Filter Selection

Area Field Selection

Report Generation


REPORTING - NODE REPORT -REPORTING - NODE REPORT -

General Filter Selection

Area Field Selection

Report Generation

Choice of Radio Equipment Fresenel Zone Clearance Objective Availability / Reliability Objectives Interference degradation Objectives Tower Height & Loading Restrictions

Link Designing: Basis of Design Criterion

Basis of Design Criterion

Link Design: The design of microwave links, involves three sets of calculations.

Working out antenna heights for the link. K-factor is major dominant variable. Earth bulge. Fresnel zone radius. Actual obstructions on the route Path Loss Operating frequency. Path profile: it indicates the distance from one of the transmitter site

where obstructions to the line of sight radio link may occur. The object of this calculation is to arrange tower heights along the

entire route of the link, so that an obstruction in the path does not enter into the fresnel zone by a specified amount for a specified K-factor used.

To determine equipment and other parameters for each hop. Transmit power. Antenna type and gain. Transmission type. Other losses. (Absorption, Diffraction, Reflection or Scattering etc.) Maximum received power. Receiver threshold. This will decide the thermal fade margin, which we will be able to get for each

hop. To determine the reliability of each hop and overall reliability of the link. Climatic factor. Terrain roughness. Average annual temperature Annual rain. This will decide, what is total expected outage time per annum for each hop

as well as for the entire link.

Basis of Design Criterion

Link Power Budget Receiver Sensitivity: The lowest Possible signal which can be detected by

receiver is called as Receiver Sensitivity or Threshold. This threshold value is manufacturer specific.

Fading: Received Signal vary with time due to multipath fading and rain etc. Refractive index of atmosphere varies with Temp. humidity and pressure which in turn cause the electromagnetic waves to change direction. Another cause for Multipath fading is ground reflection. So a fade margin is built in Link Designing.

Fade Margin: The fade margin is the power level, that, the unfaded received signal can fall to until it reaches the receiver threshold. This margin will vary depending on geographic and climatic conditions of different geographic areas and desired reliability of the system. Higher Fade Margin provides better link reliability. Typically it is 35-40 dB.

Fade Margin dB=Prx-Pthresh

Signal to Noise Ratio: It’s the minimum power difference between the wanted received signal and received noise.

Signal/Noise Ratio (dB)=10 log10 (Signal Power/Noise Power) Typically it is > 50 dB, logically it should be more than the Fade

Margin, so that it is always below the threshold level.

Link Power Budget Formula

Received Signal Level = Rxl

RxlB = TxA – LA + GA – Fl + GB – LB Where

TXA = Trans Power Station A

LA = Losses at Station A (Misc.)

GA = Antenna Gain at Station A

Fl = Free Space Losses

GB = Antenna Gain at Station B

LB = Losses at Station B

RxlB = Rx. Level at Station B

RXL must be > Receiver Sensitivity always

Important Formula

Free space losses)log(2045.92 fdL fs

d = distance in kilometers f = frequency in GHz

Basic Loss Formula

Propagation Loss

d = distance between Tx and Rx antenna [meter]

PT = transmit power [mW] PR = receive power [mW] G = antennae gain

2)4

(d

GPP TR

Fading

Phenomenon of Attenuation of Signal Due to Atmospheric and Propagation Conditions is called Fading

Fading can occur due to Refractions Reflections Atmospheric Anomalies

Fading

Types of Fading Multipath Fading Frequency Selective Fading Rain Fading

Multipath Fading

Multipath fading is caused due to reflected / refracted signals arriving at receiver Reflected Signals arrive with

Delay Phase Shift

Result in degradation of intended Signal

Space Diversity Radio Configuration is used to Counter Multipath Fading

Frequency Selective Fading

Frequency Selective Fading Due to Atmospheric anomalies different frequencies undergo different

attenuation levels Frequency Diversity Radio Configuration is used to Counter Frequency

Selective Fading

Rain Fading

Frequency Band > 10 GHz are affected due to Rain as Droplet size is comparable to Wavelengths

Rain Fading Occur over and above Multipath and Frequency Selective Fading

Horizontal Polarization is more prone to Rain Fades Path Diversity / Route Diversity is the only counter measure for Rain Fade

Drop Shape and Polarization

As raindrops increase

in size, they get more

extended in the Horizontal

direction, and therefore

will attenuate horizontal

polarization more than

vertical polarization

1mm 1.5mm

2.0mm 2.5mm

Link Engineering – Interference

Counter Measures Avoid Hi-Lo violation in loop Frequency Discrimination Polarization Discrimination Angular Discrimination High Performance Antennae Lower Transmit Power , if possible

PtP Microwave Transmission - Issues

Link Performance is Seriously Affected due to Atmospheric Anomalies like Ducting Ground Reflections Selective Fading Excessive Rains Interferences Thunderstorms / High Winds causing Antenna Misalignment Earthing Equipment Failure

Thank You !

microwave planning procedure 2

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