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HERALD
Point-to-Point
Radio Link Design Sw
HERALD (HElp for
RAdio Link Design) is a PC program for Windows that assists the radio
engineer in the design of point-to-point (multi-hop) microwave links and
networks (frequency range 400 MHz to 58 GHz). Herald goal is to offer an easy-to-use
tool, at an affordable price, covering the gap between simple spreadsheet
computations and sophisticated (high cost) design suites.
Site/Hop Configuration; Link Budget;
Path Profile Analysis (clearance, reflections); Multipath Outage and Rain Unavailability
prediction; Interference analysis; Passive repeaters; One-click access to
Background Theory (context-sensitive links to HTML tutorial document "Point-to-Point Radio Link
Engineering").
What's New in HERALD Professional
 Ability to read NASA / SRTM terrain maps to import path
profiles: SRTM maps provide worldwide coverage with 1 or 3arcsecond
raster resolution. SRTM maps can be downloaded at no cost from several
websites.
Interface to Google Earth maps: export
of network topology defined in Herald to a Google map; import of radio site positions and names
to Herald site list.
Comparison of predicted radio section performance with performance objectives given by ITU-R or North America standards
Irregular terrain Model (ITM, Longley-Rice) for reliability prediction of radio links working below
about 3 GHz.
HERALD Professional Overview
HERALD is based on well-assessed procedures for radio link
design, implemented in an interactive, user-friendly PC program. Close
reference is made to design guidelines given by ITU-R Recs, with option for
additional models (Bell Labs, Barnett-Vigants, Crane, ITM Longley-Rice).
The main design functions performed by HERALD are :
 Topology definition (Radio Sites, including
Passive Repeater Sites, and Radio Hops)
Radio equipment and antenna configuration of
Radio Sites
Path profile analysis (clearance conditions,
obstruction loss, reflection geometry, and diversity)
Link Budget computation, with estimate of
unavailability time due to rain and of outage time due to multipath
propagation
Interference search and analysis, estimate
of receiver degradation
The DataBase and Output functions performed by HERALD are :
Customized Antenna, Radio Equipment, and
Feeder Libraries
Video and printed outputs with various
Reports, profile plots and other diagrams (multilanguage outputs: English,
Spanish, Italian)
Export of radio network topology to Google
Earth maps
Storing of Design data, for later revision
and updating.
For additional information, please select one of the following
sections:
 Detailed Functuion List: Configuration and Performance
Prediction
Video and Printed Outputs
Import / Export Functions
Related Services, Radio Link Engineering Background
Sw Features, Database Structure
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Detailed Function List : Configuration and Performance Prediction
Antenna, Equipment, and Feeder libraries
to be customized with user data
Radio network topology definition
(terminal sites, radio hops);
Site & Hop configuration ((Radio
Equipment, Antenna, and Feeder Data loaded from libraries; space and/or
frequency diversity, channel arrangement, passive repeaters, etc.)
Link Budget computation, based on the
user-defined configuration
Path profile analysis: display of Fresnel
Ellipsoids; check of Clearance Criteria and estimate of the
Obstruction Loss (one or multiple obstacles; knife-edge, spherical earth,
or rounded shape)
Reflection analysis: computation
of ray delay, angles, phase shift,
etc.; estimate of optimum Diversity Spacing and of threshold
degradation due to reflection
Prediction of Rain Unavailability time
(ITU-R rain intensity model or Crane model)
Prediction of Multipath Occurrence Factor
(Bell Labs or ITU-R multipath activity models)
Estimate of the Multipath Fading Outage
time (wide-band frequency selective models: ITU-R signature model or
Dispersive Fade Margin model); Space and Frequency Diversity; Same hop
interference (co-channel and adjacent channels)
Passive
repeaters (implemented with one or two
reflectors, or a back-to-back antenna configuration)
Interference
search and analysis in a P-P radio
network (options for evaluating received /
produced interference at any receiver site; search criteria: max distance,
max carrier spacing, max S/I ratio)
Rain correlation model to take account of rain attenuation on interfering and
interfered signals
Analysis of External
Interference, allowing to select a previous Herald project and to compute
interference produced by radio hops in that network to radio hops in the
network under design
Definition
of multi-hop Radio Sections: prediction of error rate and availability
performance and comparison with ITU objectives (Recs. G821 / G826) or
with North America reliability objectives
Longley-Rice
(Irregular Terrain) Model to estimate
reliability of radio links below about 3 GHz.
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Video and Printed Outputs
Video and printed Outputs (reports and
diagram labels) in English, Spanish, or Italian
Radio Site, Radio Hop, and Path Profile
Reports (site and hop lists, radio site configuration, link budget,
performance predictions)
Radio Equipment, Antenna, and Feeder
Reports
Path Profile diagram with Fresnel
Ellipsoids; same with Reflection geometry (if any)
Path Profile Report (results of Clearance
and Reflection analysis)
Diagram Received power level vs. k-factor
in presence of reflection (with / without diversity)
Diagram Multipath Attenuation vs.
time percentage
Diagram Rain Unavailability time vs.
fade margin.
Diagram Multipath Outage time vs.
fade margin: comparison with/without space and/or frequency diversity,
interference, and multipath selectivity
Diagram of Antenna radiation patterns
Interference Report: list of
significant interference sources, interference power and threshold
degradation, results transferred to the link budget
Radio Section Report (multipath
outage and rain availability predictions, comparison with ITU-R or North
America objectives)
Radio Network Report (radio site,
hop, and section list)
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Import/Export Functions
Import of path profile from table in ASCII format or from NASA/SRTM terrain maps (available for free downloading from NASA and other websites, raster resolution 1 or 3 arcseconds)
Import of site names and coordinates from table in ASCII format or from *.kml file produced by Google
Earth (or other compatible application)
Export of Radio Network topology (radio
sites and hops) to be displayed as a Google Earth map.
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Related Services, Radio Link Engineering
Background
CUSTOMIZATION - HERALD printed
outputs (reports and diagrams) can be customized with User Company's name and
logo.
ASSISTANCE - Support for any question
on HERALD Professional installation and use, through fax or e-mail
ENHANCED TUTORIALS - Registration for
the "Point-to-Point Radio Link Engineering (PPRLE)" tutoring
service with support for questions about propagation and link design theory
INFORMATION - Email newsletter about
HERALD Professional updates and revisions in ITU-R relevant Recommendations
MAINTENANCE - One-year service with
free HERALD Professional updates (subscription to a Maintenance &
Assistance contract after the first year use of Herald)
ON-REQUEST SERVICES - Customized routines
to import Path Profiles from a user-defined Terrain Data Base. Conversion of
already available Equipment and Antenna DataBase to HERALD format (radio
equipment and antenna manufacturers are assisted in formatting their
catalogues as HERALD compatible libraries).
Translation of HERALD output texts (reports and diagram labels) to
other languages (English, Spanish, and Italian now available)
HERALD licensed users are now provided
with the document on "Point-to-Point
Radio Link Engineering" (PPRLE), which includes Course Notes in HTML format, as well as radio
link design exercises ("HERALD Lab"). The course deals with
fundamental concepts in radio propagation, with application to the design of
point-to-point radio links and networks. It overviews background theory and
can be accessed during HERALD use with a mouse click in a context-sensitive
mode.
The Radio Link design process implemented in HERALD starts from
the fundamental radio propagation theory (free space propagation, link budget
under ideal conditions) and includes reliable models to deal with the
anomalous propagation effects (rain, multipath, obstructions, reflections). A
complete Interference analysis is performed by HERALD Professional.
To this end, specific reference is made to the ITU-R Recommendations; in
recent years, ITU-R Recommendations (in particular, Rec. P.530) have been
more specifically addressed to provide design guidelines and propagation
models, covering the main aspects in radio link engineering. As far as
multipath propagation is considered, the ITU-R model has been recently
updated and it is not yet familiar to most designer. For this reason, also
the well-known Bell Laboratories (Barnett-Vigants) model is available in
HERALD.
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Software Features, DataBase
Structure
HERALD is a single-user PC application for the Windows
environment. The most relevant software features are :
Windows 9x / Me / NT/ 2000 / XP operating
systems
User-friendly interface and data input
(drop-down menus, dialog boxes)
Access Data Base architecture
Context-sensitive on-line Help, one-click
access to HTML tutorial on Background Theory
Self-installing procedure (Windows 9x / Me /
NT / 2000 / XP).
The minimum PC configuration required to install HERALD is :
Personal Computer with Pentium-class
processor, 128Mb RAM and 42Mb free hard-disk space
Microsoft Windows 9x / Me / NT / 2000 / XP
Color monitor and graphic printer (laser,
inkjet or compatible).
The HERALD DataBase is configured
according to the Access structure. The use of a widely used format offers the
possibility of sharing HERALD Libraries with other applications, if desired.
HERALD Libraries are : Antenna Library; Radio Equipment Library;
Feeder Library.
The three Libraries are edited by using straightforward functions, enabling
the Radio Engineer to store design data of frequently used hardware. Updating
functions are used to modify or delete existing data or to include new items.
Items in the Antenna / Radio Equipment customized libraries can be associated
with few (always required) parameters, or with additional, optional
parameters. To ease the storing process, for each input parameter, help
messages answers to the questions "What is it?", "Is it
required or optional?", "When is it used?". In the radio hop
design process, the Radio Engineer just has to access the libraries and to
select the desired items; retrieval operations are supported by simple
filtering options.
The HERALD project is saved in a Database with Access format, as well.
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Copyright © Luigi Moreno 1998-2010, All rights reserved
Phone & Fax +39-011-8194575 - E-mail : info(at)radioengineering.it
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