124 lines
4.6 KiB
Elixir
124 lines
4.6 KiB
Elixir
defmodule Microwaveprop.Propagation.PathComputeTest do
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use ExUnit.Case, async: true
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use ExUnitProperties
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alias Microwaveprop.Propagation.BandConfig
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alias Microwaveprop.Propagation.PathCompute
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describe "compute_loss_budget/5" do
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test "fspl increases with distance" do
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band = BandConfig.get(10_000)
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near = PathCompute.compute_loss_budget(10.0, 10.0, band, nil, nil)
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far = PathCompute.compute_loss_budget(100.0, 10.0, band, nil, nil)
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assert near.fspl < far.fspl
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assert near.total < far.total
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end
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test "fspl increases with frequency" do
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band_10g = BandConfig.get(10_000)
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band_24g = BandConfig.get(24_000)
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low = PathCompute.compute_loss_budget(50.0, 10.0, band_10g, nil, nil)
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high = PathCompute.compute_loss_budget(50.0, 24.0, band_24g, nil, nil)
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assert low.fspl < high.fspl
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end
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test "gas absorption losses with default humidity when conditions absent" do
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band = BandConfig.get(10_000)
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result = PathCompute.compute_loss_budget(50.0, 10.0, band, nil, nil)
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assert result.o2 >= 0
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assert result.h2o >= 0
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end
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test "higher bands have more h2o absorption" do
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band_10g = BandConfig.get(10_000)
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band_75g = BandConfig.get(75_000)
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low = PathCompute.compute_loss_budget(50.0, 10.0, band_10g, nil, nil)
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high = PathCompute.compute_loss_budget(50.0, 75.0, band_75g, nil, nil)
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assert low.h2o <= high.h2o
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end
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test "rain loss is zero when there's no rain" do
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band = BandConfig.get(10_000)
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conditions = %{rain_rate_mmhr: 0.0, abs_humidity: 7.5}
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result = PathCompute.compute_loss_budget(50.0, 10.0, band, nil, conditions)
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assert result.rain == 0.0
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end
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test "rain loss is positive when it's raining" do
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band = BandConfig.get(10_000)
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conditions = %{rain_rate_mmhr: 5.0, abs_humidity: 7.5}
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result = PathCompute.compute_loss_budget(50.0, 10.0, band, nil, conditions)
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assert result.rain > 0
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end
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test "diffraction loss is included when terrain result is present" do
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band = BandConfig.get(10_000)
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terrain = %{analysis: %{diffraction_db: 15.0}}
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result = PathCompute.compute_loss_budget(50.0, 10.0, band, terrain, nil)
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assert result.diffraction == 15.0
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end
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test "diffraction loss is zero when no terrain result" do
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band = BandConfig.get(10_000)
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result = PathCompute.compute_loss_budget(50.0, 10.0, band, nil, nil)
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assert result.diffraction == 0.0
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end
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end
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describe "compute_loss_budget/5 property" do
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property "total is always >= fspl" do
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check all(
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dist_km <- float(min: 0.1, max: 500),
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band_config = BandConfig.get(10_000)
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) do
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result = PathCompute.compute_loss_budget(dist_km, 10.0, band_config, nil, nil)
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assert result.total >= result.fspl
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assert result.total > 0
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end
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end
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property "all loss components are non-negative across known bands" do
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bands = [50, 144, 222, 432, 902, 1_296, 2_304, 3_400, 5_760, 10_000, 24_000, 47_000, 75_000]
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check all(
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dist_km <- float(min: 0.1, max: 500),
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band_mhz <- member_of(bands)
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) do
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band_config = BandConfig.get(band_mhz)
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freq_ghz = band_mhz / 1000
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result = PathCompute.compute_loss_budget(dist_km, freq_ghz, band_config, nil, nil)
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assert result.fspl >= 0
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assert result.o2 >= 0
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assert result.h2o >= 0
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assert result.rain >= 0
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assert result.diffraction >= 0
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end
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end
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end
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describe "compute_power_budget/2" do
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test "computes rx power and margins" do
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loss = %{total: 140.0, fspl: 130.0, o2: 3.0, h2o: 5.0, rain: 0.0, diffraction: 2.0}
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params = %{tx_power_dbm: 30.0, src_gain_dbi: 20.0, dst_gain_dbi: 20.0}
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result = PathCompute.compute_power_budget(params, loss)
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# EIRP = tx_power + src_gain = 50 dBm
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assert_in_delta result.eirp_dbm, 50.0, 0.1
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# rx_power = eirp - loss + dst_gain
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assert_in_delta result.rx_power_dbm, -70.0, 0.1
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# margin_cw = rx_power - (-140)
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assert_in_delta result.margin_cw, 70.0, 0.1
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end
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test "higher tx power improves margins" do
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loss = %{total: 140.0, fspl: 130.0, o2: 3.0, h2o: 5.0, rain: 0.0, diffraction: 2.0}
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low = PathCompute.compute_power_budget(%{tx_power_dbm: 20.0, src_gain_dbi: 10.0, dst_gain_dbi: 10.0}, loss)
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high = PathCompute.compute_power_budget(%{tx_power_dbm: 30.0, src_gain_dbi: 20.0, dst_gain_dbi: 20.0}, loss)
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assert low.rx_power_dbm < high.rx_power_dbm
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assert low.margin_cw < high.margin_cw
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end
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end
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end
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