Generic Radio Modelling Tool

Background
Transfinite has just completed a project to develop for Ofcom a prototype of a Generic Radio Modelling Tool (GRMT) for Spectrum Trading.

This figure shows the prototype software analysing a scenario involving Business Radio and low power GSM networks.

The GRMT is the result of a year long contract where Transfinite led a team with Rutherford Appleton Laboratories and University of Surrey as sub-contractors.

The objective of the GRMT was to be able to analyse proposals from licence holders for a Licence Variation or Change of Use (CoU). This could include applications for a new end user licence.

The ability to apply for CoU would give spectrum users increased flexibility, avoiding the restrictive allocation of certain bands to specific services.

However it is important that such flexibility does not cause unacceptable levels of interference into other services.

One method to assess whether a CoU application should be approved is to undertake interference analysis between the CoU licence and other licences that might be affected. These could be adjacent in either geography or frequency - requiring analysis of both in-band and out-of-band paths.

Key Stages
To achieve this objective requires the following stages:

  1. Definition of parameters to specify Spectrum Usage Right (SUR) in a generic, technology neutral manner that captures the essential features of radio services;
  2. Mapping existing licences into the new format to permit the creation of a database of licences to use when assessing the proposed CoU;
  3. Definition of an Algorithm that can calculate interference between any two licences contained with the database specified in generic SUR format;
  4. Implementation of the Algorithm in software with interfaces to the database and suitable user interface;
  5. Testing of the software including use of assignment databases.

These steps have been completed under this project.

Licence Parameters
We have defined a SUR format that can model a wide range of services. Emissions can be specified either:

  • Using EIRP, with the transmitters and receivers defined in detail - in particular their locations;
  • Using PFD on boundary, with the specific locations of transmitters and receivers not defined.

Given these two types of licence we have shown how we can map a wide range of services to our generic format - including FS P-P, FS P-MP, 2G, 3G, BR, T-DAB, DVB, DVB-H, Satellite ES, Radar, Tetra, Radio Astronomy.etc.

The software includes a database editing tool.

Analysis
The Algorithm specifies how to analyse interference between any two licences and has been defined in detail in a stand alone document.

A Monte Carlo approach is used to convolve all of the time varying parameters. The Algorithm takes account of SUR parameters including:

  • Locations;
  • Antenna gain patterns and pointing;
  • Propagation losses including terrain, clutter, indoor to outdoor losses etc;
  • Activity factors, TDD systems, frequency hoping systems etc;
  • Transmit and receive frequency dependency masks;
  • Statistical significance checks on the Monte Carlo process.

The result is a predicted interference level that can be compared against the Spectrum Quality Benchmark (SQB) of the victim licence.

This has been defined in the generic format:

Interference at a receiver should not exceed X dBW for more than Y% of time [at more than Z % of locations]

Software Status
We are continuing to develop and test the software, working with Ofcom and our consortium partners.

We aim to continue to develop this software so we can provide a tool to support Spectrum Trading in a way that is:

  • Flexible;
  • Powerful;
  • Transparent;
  • Vigorous.

It should be able to analyse a wide range of potential users of the spectrum, protecting existing licences and permitting innovative new entrants.

TNSUR Project
In parallel with the GRMT project, Transfinite has been working in a team led by Aegis Systems that also included Indepen to develop a framework of Technology Neutral Spectrum Usage Rights (TNSUR).

This project has recently delivered to Ofcom its Final Report which made recommendations about a flexible regime of rights to support spectrum trading and liberalisation while integrating legacy licences and providing controls on interference.

The conclusions of the study are consistent with the approach taken by the GRMT project.

Consultancy Support
We can provide our Consultancy services to support your goals relating to Spectrum Trading. Areas where our expertise could assist you includes:

  • Support to map existing licences onto new SUR parameters;
  • Analysing potential for licensees to apply for CoU;
  • Analysing impact of other licensees CoU on your network;
  • Optimisation of CoU while meeting regulatory requirements;
  • Estimation of quality of spectrum as part of valuation process;
  • Support for licence bidding process;
  • Developing responses to Ofcom Consultation Documents;
  • Negotiating with neighboring users of the radio spectrum;
  • Arbitration services to assist in dispute resolution;
  • Intermediary services to liaise between licensees;
  • Developing tools to assist in coordination of shared bands;
  • Representation at meetings;
  • Analysing the interference potential during the design of new radio services;
  • Training of staff in radio communications and interference related issues.

Contact us for more information about consultancy support and our product range:

  • Visualyse Professional
  • Visualyse Coordinate
  • Visualyse GSO.

 Spectrum Trading Tool for Ofcom