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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").



HERALD Professional Significant Features


*   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

*   Reliable design guidelines and propagation models (ITU-R, Bell Labs, Crane, ITM Longley-Rice)

*   Choice of video and printed Report language (English, Spanish, Portuguese, or Italian)



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, Portuguese, 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




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.





Video and Printed Outputs


*  Video and printed Outputs (reports and diagram labels) in English, Spanish, Portuguese, and 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)





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.






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, Portuguese, 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.







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