WISCOM Frequency Plan
Attachment K - WISCOM Statewide Interoperable Communications Network Trunking System
The WISCOM frequency plan is being developed and refined by the Wisconsin Dept. of Transportation (WisDOT). This plan spans the entire VHF high-band frequency band, meaning the frequencies utilized in WISCOM fall between 136 MHz and 174 MHz.
The goal is to secure 5 trunked channels at each radio site. For each channel, an input frequency (Mobile Transmit/Basr Receive) and an output frequency (Base Transmit/Mobile Receive) is required.
The frequencies at the sites can be described in three distinct categories.
1) Department of Defense (DOD) Frequencies
WISCOM, through the Army National Guard, has 20 frequency pairs for use throughout the State. These frequencies will be prudently reused as the trunked radio system's Control Channels. Table 1 is a summary of the available frequencies.
139.0125/141.5125
139.0875/141.6125
139.1125/141.6875
139.1625/141.8125
139.1875/141.9125
139.2125/142.1125
139.2625/142.1875
139.3125/142.2125
139.3625/142.2375
139.4125/142.3125
139.6125/142.3375
139.6625/142.3875
139.7375/142.4125
139.7625/142.4375
139.8125/142.4625
139.8625/142.4875
139.9125/142.8875
139.9625/142.9125
140.3625/142.9375
140.4125/142.9875
2) Part 22 Frequencies
WisDOT, for the benefit of WISCOM, has acquired many Part 22 frequencies pairs and continues to assess availability and acquire spectrum as it becomes available. The WISCOM Frequency Plan utilizes these licenses in a spectrally efficient manner. These 30 KHz channels provide ample bandwidth and the requisite guard band to allow for two P25 channels. Table 2 is a summary of the WISCOM Part 22 Frequency Plan.
152.0225/158.4825
152.0375/158.4975
152.0525/158.5125
152.0675/158.5275
152.0825/158.5425
152.0975/158.5575
152.1125/158.5725
152.1275/158.5875
152.1425/158.6025
152.1575/158.6175
152.1725/158.6325
152.1875/158.6475
152.2025/158.6625
152.2175/158.6775
152.5025/157.7625
152.5175/157.7775
152.5325/157.7925
152.5475/157.8075
152.5625/157.8225
152.5775/157.8375
152.5925/157.8525
152.6075/157.8675
152.6225/157.8825
152.6375/157.8975
152.6525/157.9125
152.6675/157.9275
152.6825/157.9425
152.6975/157.9575
152.7125/157.9725
152.7275/157.9875
152.7425/158.0025
152.7575/158.0175
152.7725/158.0325
152.7875/158.0475
152.8025/158.0625
152.8175/158.0775
3) Part 90 Frequencies
WisDOT has and continues to aggressively pursue Part 90 frequencies. The task is broken into two general areas. Public Safety Frequency Pool (90.20) and the Commercial Frequency Pool (90.35). Every effort to find available 90.20 frequencies is being made. In some areas where spectrum is constrained, review of the available 90.35 frequencies is being made.
In general, WISCOM's use of the Part 90 Frequencies can be summarized as:
Base Transmit/Mobile Receive Range: 150.000 to 156.000 MHz
Base Receive/Mobile Transmit Range: 156.000 to 161.000 MHz
The Part 90 frequencies will, in general, adhere to the ranges listed above, however, in an effort to evaluate all possible frequency opportunities, there may be some instances where a mobile transmit frequency may fall within the Base Transmit Frequency Range shown above.
4) Federal Frequencies
WISCOM has entered into a Memorandum of Understanding with the United States Department of Interior for cooperation and sharing of resources. The MOU sets the stage for discussions of the potential shared use of federal 162-174 MHz frequencies in the WISCOM system.
