Frequency Coordination
Minimise intermodulation in existing radio plans through precision channel shifts. No hardware changes, no full redesign, just a cleaner plan within your installed constraints.
Most radio sites do not start dirty. They grow dirty. A network is deployed clean, then a contractor adds two channels, an operations team adds a data channel, an emergency channel is squeezed in for a one off project, and over the course of years the plan accumulates intermodulation products that mask weak signals, shorten range, and trigger intermittent interference that nobody can quite reproduce on demand. By the time the operator notices, the radios are already on the wall, the licences are already issued, and a full redesign would mean recoordinating the whole site.
The noIM₃ Frequency Plan Optimiser solves the problem differently. Instead of redesigning from scratch, the engine takes the existing frequency plan and applies small precision shifts to each channel within hardware tunable steps (typically 6.25, 12.5, or 25 kHz) to find the combination that minimises total intermodulation while preserving channel assignments, splits, and operational intent. The radios stay where they are. The licence holder keeps the same channel set. The technicians get a CSV reprogramming table and a single field visit to retune. The site comes back online materially cleaner.
Inputs include the existing frequency plan, allowed shift steps, per channel maximum shift limits, guard band requirements, intermodulation separation constraints, a list of channels to avoid, and optional priority weighting so the most critical channels (safety, dispatch, emergency) are constrained to the smallest shifts while less critical channels absorb larger adjustments. Output is a full before and after comparison table, headline reduction metrics, side by side spectrum views, and an exportable CSV ready to hand to the radio technician.
Define allowed shift steps (for example 6.25, 12.5, or 25 kHz) and a per channel maximum shift limit. The engine searches shift combinations across all channels simultaneously, scoring each candidate plan against total intermodulation product count, critical hit frequency, and average separation. Hardware constraints are respected at search time, not as an afterthought filter.
Each frequency pair gets a priority from 1 to 10. High priority channels (safety, control, emergency) are constrained to zero or minimal shift, so the optimiser will not move them unless absolutely necessary. Lower priority channels (operations, maintenance, data) absorb the larger adjustments. Per channel maximum shift limits can also be set in addition to the global default.
The primary output is a per channel comparison showing original transmit and receive frequencies, optimised transmit and receive frequencies, the shift delta in kHz, and the intermodulation product count before and after. Changed channels are highlighted. Unchanged channels confirm which pairs were already optimally placed.
Two spectrum analyser views render side by side, before and after, so you can see exactly how channel positions move and how intermodulation products shift relative to active carriers. The before view shows products clustering on or near active channels. The after view shows those products pushed into guard band or inactive spectrum.
Four metrics are surfaced at the top of every result: total intermodulation products before and after with percentage reduction, critical hits eliminated (products that fell within one channel step of an active channel), average spacing improvement in kHz, and worst case intermodulation level in dBc before and after. These are the headline numbers for a client report or internal justification.
Surface mode evaluates 2nd, 3rd, and 5th order products typical of open air systems. Underground mode focuses on 3rd order dominance, which reflects the confined environment behaviour observed in mining and tunnelling installations where higher orders are heavily attenuated by structure loss.
Export the optimised plan as a CSV reprogramming table that maps directly to your radio fleet. The CSV contains the original frequency, the new frequency, and the delta for each channel, ready to hand to a radio technician for a single coordinated retune visit.
Channels to avoid (incumbent licences, broadcast bands, exclusion zones) and guard band requirements are enforced at search time. The optimiser will never propose a shift that violates an exclusion or breaches a guard band, so the output is deployable as is, not subject to a post hoc compliance scrub.
Reach for the Frequency Plan Optimiser in any of the following situations.
The Frequency Coordination Tool selects fresh frequency pairs from scratch, which is the right choice for a greenfield deployment. The Frequency Plan Optimiser starts from an existing plan and applies small precision shifts within hardware tunable steps to clean it up without forcing a redesign. Use coordination for new networks. Use the optimiser when the radios are already on the wall.
Configurable. Typical inputs are 6.25, 12.5, or 25 kHz, matching the tuning resolution of common UHF and VHF radios. You can also enter custom shift steps. The optimiser will only propose shifts that are achievable on your installed hardware.
Each frequency pair gets a priority from 1 to 10. High priority (closer to 10) means the optimiser is constrained to zero or minimal shift on that channel. Lower priority channels absorb the larger adjustments. The intent is that safety, dispatch, and emergency channels stay put while operations, maintenance, and data channels do most of the moving.
Yes. Four headline metrics are reported at the top of every result. Total intermodulation product count before and after with percentage reduction, critical hits eliminated, average spacing improvement in kHz, and worst case intermodulation level in dBc before and after. Together they give you the numbers you need for a client report or an internal justification.
Yes. Underground mode focuses on 3rd order intermodulation dominance, which reflects the confined environment behaviour observed in mining and tunnelling installations where higher order products are heavily attenuated by structure loss. This avoids the false positives that a full surface mode analysis would produce in tunnels and stopes.
The CSV contains one row per channel, with the original transmit and receive frequencies, the optimised transmit and receive frequencies, and the shift delta in kHz for each. It is structured so a radio technician can program the new values directly into the fleet without further interpretation.
Yes. The avoid list accepts individual frequencies and ranges. Incumbent licences, broadcast bands, exclusion zones, and any channel you simply do not want the optimiser to consider can be added. Exclusions are enforced at search time, so the output is always deployable as is.
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