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Hmvaii Preliminary Technical Assessment (CTAP-HUHA-PREASSESS-001-RO FCC Part 90 frequencies with FCC Part 22 (paging and radio-telephone) frequencies and frequencies normally allocated for the exclusive use of federal agencies. The implementation of these large systems proves that VHF is a viable alternative for amulti-site system. Channel spacing: In the 800 MHz band, the channel spacing is 25 kHz except for the NPSPAC porfion1 of the band where the channel spacing is 12.5 kHz. In order to achieve this spacing, the permitted bandwidth of the voice modulation is less than in the other portions of the 800 MHz band. Geographic spacing is employed between adjacent channels to reduce the interterence from signals that are separated by only 12.5 kHz. Due to the decreased bandwidth of the modulation in the NPSPAC portion of the band, performance could be lower than in the other portions of the band, at least for analog voice modulation. In the VHF and 700 MHz bands, the channel spacing will ultimately (after 12/31/2014) be 6.25 kHz throughout the band. In the interim, two channels are usually aggregated to provide 12.5 kHz channel spacing. The P25 Phase 1 modulation is designed to work with 12.5 kHz channel spacing. P25 Phase 2, which is under development, will provide two voice paths in 12.5 kHz. 2.1.2 RF Coverage Comparison (CTAP conducted a study comparing coverage predictions of 3 frequencies, one each from the VHF, 700 MHz and 800 MHz bands. Two RF sites were used, one at Kahua Ranch and the other at Lulani Cone. This comparison is not intended to precisely show coverage from the different sites but to provide a relative comparison between the 3 different bands. For example, an average loss was applied to represent land use land clutter as opposed to using varying values mapped to a detailed land use database. Bounded Area Comparison To directly compare the results of the three coverage predictions, a bounded area must first be identified. For this case, the coastline of the Island of Hawaii was used to define the bounded area. The following images show a comparison between the covered areas (blue overlay) predicted for the three frequencies (Figure 1 - 861 MHz, Figure 2 - 769 MHz, Figure 3 - 155 MHz) using a receiver threshold of -110dBmW. This threshold estimates talk-out coverage to a mobile radio. ~ NPSPAC portion of the 800 MHz band: base transmitter frequencies from 866 to 869 MHz prior to reconfiguration and 851 to 854 MHz after reconfiguration. October 2008