450-470 MHz band alignment
RA proposes to start a managed alignment process in 2005, although some alignment will take place prior to this date where opportunities allow. The aim is to complete the process within five years. In managing the process, RA will continue to plan in partnership with the radio industry. To this end, RA continues to engage industry and customers in dialogue about band alignment through regional customer focus panels, the Mobile Services Committee (MSC) and the Industry Working Group of the 450-470 MHz Band Alignment Project (IWG), as well as through mail- and web-based publicity.
2.2Proposed band plan and migration
It is possible to arrive at a band plan for the alignment process that complies with the CEPT Recommendation, by considering a phased transition process. This is based on moving spectrum blocks within the band over time into vacant spectrum slots to achieve the desired configuration, stimulated by the migration of Public Safety users out of the band. However, it is subject to a number of constraints (to do with existing services in and adjacent to the band, and also the technical characteristics of current equipment), which dictate where and when spectrum blocks can be moved. The constraints are described in Annex B; the transition process, endorsed by a majority of IWG representatives, is described fully in Annex C.
RA, in collaboration with its IT strategic partner Radio Spectrum International (RSI), is in the process of developing a software tool that will allow re-planning of the band to the most efficient configuration. This tool will be capable of combining licence-related information from RA’s databases with data taken from external frequency managers. Using advanced graphical functionality, the tool can visually move channel assignments in conformance to the CEPT plan. This system will also automate and verify the process of propagation modelling and interference analysis, to ensure accurate alignment and optimum use of the band. The feasibility of the software tool has been researched, and the first release of this application took place in August 2002. The full development of the application will be completed by June 2003 and it is expected that users will be notified of new assignments from summer 2003.
RA is able to draw upon the experience of a previous band re-planning project, which took place in the 1980s. Implementation of major frequency changes to police and fire services, resulting from changes agreed in the World Administrative Radio Conference 1979, was managed at this time by the Home Office Directorate of Telecommunications (DTels); this project was very similar to the current intention to align the 450-470 MHz band. The successful implementation of the DTels project relied upon precise project planning and accurate assignment data – RA is confident that, by following the same basic principles, the 450-470 MHz project will be equally successful. Some of the key points that RA will consider are:
users will be consulted and involved at each stage of planning and implementation;
accurate radio site engineering data (especially for the more complex sites) will need to be gathered, such as assessments of:
the spare capacity on masts/towers;
the space in equipment rooms;
the radio assignments at sites;
the likely EMC issues, blocking, desensitisation and the generation of intermodulation products;
the likely access problems if the site is remote, and the location of key holders;
the amount of recabling necessary; and
the standard of lightning protection.
All this site information will be documented in a ‘constraints database’, which will form part of RA’s band alignment IT system; and
the alignment scenario planning will go through several iterations before the most stable configuration can be agreed upon.
Page 8 of 24