The most discussed subject at the meeting was eventual spectrum usage in the 2.5 GHz band for the IMT-2000 satellite component. The question was whether, in that band, 2x20 MHz should be allocated to the terrestrial or satellite component. Although some countries wanted the decision postponed to the next meeting, it was agreed that it was necessary to decide the work pretexts in this meeting, in order to fulfil the 5th European Commission mandate (implying definition of the detailed frequency plan at the end of 2004).
Various presentations followed, from the UMTS Forum, Alcatel, Orange and ASMS-TF (Advanced Satellite Mobile Systems ? Task Force). The conclusions were contradictory, namely regarding projections for subscribers and traffic generated by the satellite component. The land mobile operators vociferously contested the ASMS-TF study, specifically regarding the aforementioned factors and the methodology used to determine the spectrum needed for the satellite component.
As a result of this debate, it was concluded that the working pretexts for the 2.5 GHz band are:
- To assign to the land component all identified spectrum in the 2.5 GHz band (2500-2690 MHz);
- The ECC Decision being prepared should recognise that mobile service by satellite needs all spectrum heretofore identified in the 1-3 GHz band, and that all administrations should support regulatory and standardisation actions that aim to foster the development of innovative services in the scope of that service.
Other aspects related to detailed planning of the 2.5 GHz band were debated in the group, such as traffic asymmetry (which is directly related to the introduction of FDD or TDD technology in this band and duplex direction of FDD), about which it was originally thought that duplex direction of the FDD component should follow the traditional frequency allocation mode; however, it was now concluded that there may be some advantages in inversion of the duplex direction. These issues should be studied further at upcoming meetings.
A report is nearing completion on the result of studies of IMT-2000 compatibility with other radiocommunication services operating in co-channel and adjacent frequencies. Among other aspects, it studies the co-existence of IMT-2000 with radio-astronomy, fixed service and satellite systems, identifying the spatial separation and guard bands needed to ensure compatibility.
