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4.3 ENHANCEMENT VERSUS REPLACEMENT OF PUBLIC SAFETY LAND MOBILE RADIO SYSTEMS IN ANOKA COUNTY 4.3.1 Base Alternative Directions There are two basic directions to be considered for improving public safety land mobile radio communications in Anoka County. One alternative is to enhance the existing systems, and the other alternative involves total replacement of the existing public safety land mobile radio systems. 4.3.2 Evaluation of Base Alternative Directions The project workgroup of Anoka County Central Communications used a matrix form to provide an evaluation scoring of the relative performance of the two basic alternatives. That evaluation form is included as the next page in this report. The project workgroup used a scale of 1-5 to evaluate the performance of various enhancements and new replacement systems that might be considered to improve the performance of land mobile radio systems in Anoka County. The scoring system was 1-5 with "1" meaning the system is performing exceptionally well in meeting the needs and "5" was a score given to systems that do not meet the needs at all. Scores of"2", "3", or "4" were given with "3" meaning barely acceptable, "2" meaning fairly good but not completely meeting the needs and "4" meaning the system does do something in the area but is essentially unacceptable. The first column in the form is entitled, "System As Is". The project workgroup evaluated that system as shown with four ofthe categories receiving a score of "2", one "3", one "4", and two "5's". Of even more importance, the three parameters considered most important by the project workgroup; congestion, coverage, and reliability; were scored "3", "4", and "5". This is an indication that the system, as is, must be improved or replaced as it is simply not performing in an acceptable manner in the most important parameter areas. In regard to system enhancement, the "Refarming" and "Frequency Turn Backs" columns indicate that improvements in the congestion area may be made by using those possibilities for enhancement. More improvement can occur with refarming than with frequency turn backs as the possibility of obtaining substantial relief from congestion through obtaining frequencies turned back by entities migrating to the Mn/DOT 800 MHz system is considered to be minimal. Adding frequencies by splitting channels with the refarming possibility will mean use of digital modulation mobile and portable radios which will result in a somewhat higher cost for those radios. Adding sites and simulcast does not improve congestion but can result in a very acceptable level of coverage and an improvement in reliability due to overlapping coverage from multiple sites. This discussion indicates that there are subalternatives within the overall basic enhancement alternative direction. However, obtaining more radio channels through refarming and the addition of substantially more fixed location radio transmitter sites is essential if improvement in the most important parameters is to result. From the discussion of costs in Section III of this report, it can be seen that adding simulcast capability will add a substantial amount to the cost of enhancements. It is possible to select individual transmitter sites rather Ronald Vegemast Engineering, Inc, -34- Report: Anoka County