CELLO

The objective of the IST " Cellular Network Optimisation based on Mobile Location" (CELLO) project is to utilize the mobile location information for various enhancements of the 2G/3G mobile networks. In particular, a Mobile Network Geographic Information System (MGIS) will be developed for collecting location-specific data from the cellular network and the mobile terminals. Based on the MGIS a new network planning and optimization concept will be developed. It will enable, for example, the observation of measurement-based coverage areas, location-specific handover performance data as well as variations in capacity demand. This information enables an Adaptive Coverage System (ACS), which will be implemented and tested in the project. Furthermore, the project also develops and validates location-aided handover algorithms and a mobility management function supporting multiple wireless systems including wireless LANs. In the framework of the CELLO project, the first trial measurements on a GSM1800 network have been carried out in Helsinki, Finland during summer 2002. The trial validated the new concept "Adaptive Coverage System" (ACS) with focus on switched base station antennas, providing capacity according to demand. A simple commercial antenna based solution is used for the system trials. For this stage a custom witch box (SW-BOX) system has been implemented. The antenna elements are connected to the Switch Box and they are switched on/off respectively in predefined and discrete positions. This switch box is remote controlled via a GSM data link. Figure 1 illustrates the switch box and adaptive coverage implementation during the trials. The CELLO system concept is shown in Figure 2, left. The 1st prototype SW-BOX has been completed. In this connection, the following document deliverables topics are completed with main CPK participation: "ACS Requirements and Specifications" Report: D6, CELLO-WP4-CPK-D07-007-Int [Eggers2001] , "Switch Control Module" Report: D11, CELLO-WP4-CPK-D011-002-Int [Krøyer2002a], "RF Switch Module" Report: D12, CELLO-WP4-CPK-D011-002-Int [Krøyer2002b]. The CELLO concept is also described in a paper to the IST summit 2002 "Diamitridis 2002, "Enhanced Cellular Network Performance with Adaptive Coverage based on Position Location of Mobile Terminals" submitted to IST Mobile & Wireless Telecommunications Summit 2002, 16-19, JUNE 2002, Thessaloniki - Greece. Towards this end, the design and development of a multiple beamformer based on a Butler matrix has been carried out. The beam former is interfaced with an antenna developed by NTUA, Athens, Greece (Figure 2, right). The novelty in this antenna lies in that it is based on a modular concept, something like a lego brick set. This implies that each element in the antenna, is essentially a detachable component. This enables configuration of the antenna on a site-specific basis. It has essentially two modes of transmission/reception, wide beam and narrow beam. In the widebeam mode a broad beam is developed comprising a sum of 6 adjacent beams. It has a beam width of 65°. In the narrow beam mode we switch to a set of four narrow beams each of beam width 13°. The CELLO results will be presented at the Mobile Location Workshop 2003 (MLW ?03), held in Aalborg, Denmark, on the 22nd and 23rd of May 2003. For a more detailed description (Figures, Tables, references) please visit http://cpk.auc.dk/antennas/research2003. (Patrick C.F. Eggers, Mohinder Jankiraman, Ben Krøyer)