define maximum used bandwidth during transmission

gui/src/components/settings_modem.vue

@@ -165,20 +165,20 @@ const audioStore = useAudioStore();
   </div>
 
   <div class="input-group input-group-sm mb-1">
-    <label class="input-group-text w-50">Enable 250Hz bandwidth mode</label>
-    <label class="input-group-text w-50">
-      <div class="form-check form-switch form-check-inline">
-        <input
-          class="form-check-input"
-          type="checkbox"
-          id="250HzModeSwitch"
-          v-model="settings.remote.MODEM.enable_low_bandwidth_mode"
-          @change="onChange"
-        />
-        <label class="form-check-label" for="250HzModeSwitch">250Hz</label>
-      </div>
-    </label>
+    <label class="input-group-text w-50">Maximum used bandwidth</label>
+    <select
+      class="form-select form-select-sm"
+      id="maximum_bandwidth"
+      @change="onChange"
+      v-model.number="settings.remote.MODEM.maximum_bandwidth"
+    >
+      <option value="250">250 Hz</option>
+      <option value="563">563 Hz</option>
+      <option value="1700">1700 Hz</option>
+    </select>
   </div>
+
+
   <div class="input-group input-group-sm mb-1">
     <label class="input-group-text w-50">Respond to CQ</label>
     <label class="input-group-text w-50">

gui/src/store/settingsStore.js

@@ -54,11 +54,11 @@ const defaultConfig = {
       enable_protocol: false,
     },
     MODEM: {
-      enable_low_bandwidth_mode: false,
       respond_to_cq: false,
       tx_delay: 0,
       enable_hamc: false,
       enable_morse_identifier: false,
+      maximum_bandwidth: 3000,
     },
     RADIO: {
       control: "disabled",

modem/arq_session.py

@@ -16,16 +16,19 @@ class ARQSession:
             'mode': codec2.FREEDV_MODE.datac4,
             'min_snr': -10,
             'duration_per_frame': 5.17,
+            'bandwidth': 250,
         },
         1: {
             'mode': codec2.FREEDV_MODE.datac3,
             'min_snr': 0,
             'duration_per_frame': 3.19,
+            'bandwidth': 563,
         },
         2: {
             'mode': codec2.FREEDV_MODE.datac1,
             'min_snr': 3,
             'duration_per_frame': 4.18,
+            'bandwidth': 1700,
         },
     }
 
@@ -162,10 +165,20 @@ class ARQSession:
         return stats
 
     def get_appropriate_speed_level(self, snr):
-        # Start with the lowest speed level as default
-        # In case of a not fitting SNR, we return the lowest speed level
+        maximum_bandwidth = self.config['MODEM']['maximum_bandwidth']
+
+        # Adjust maximum_bandwidth based on special conditions or invalid configurations
+        if maximum_bandwidth == 0:
+            # Use the maximum available bandwidth from the speed level dictionary
+            maximum_bandwidth = max(details['bandwidth'] for details in self.SPEED_LEVEL_DICT.values())
+
+        # Initialize appropriate_speed_level to the lowest level that meets the minimum criteria
         appropriate_speed_level = min(self.SPEED_LEVEL_DICT.keys())
+
         for level, details in self.SPEED_LEVEL_DICT.items():
-            if snr >= details['min_snr'] and level > appropriate_speed_level:
-                appropriate_speed_level = level
+            if snr >= details['min_snr'] and details['bandwidth'] <= maximum_bandwidth:
+                # Update appropriate_speed_level to the current level if it meets both SNR and bandwidth criteria
+                if level > appropriate_speed_level:
+                    appropriate_speed_level = level
+
         return appropriate_speed_level

modem/config.ini.example

@@ -45,10 +45,10 @@ enable_protocol = False
 
 [MODEM]
 enable_hmac = False
-enable_low_bandwidth_mode = False
 enable_morse_identifier = False
 respond_to_cq = True
-tx_delay = 200
+tx_delay = 50
+maximum_bandwidth = 1700
 
 [MESSAGES]
 enable_auto_repeat = False

modem/config.py

@@ -57,7 +57,7 @@ class CONFIG:
         'MODEM': {
             'enable_hmac': bool,
             'enable_morse_identifier': bool,
-            'enable_low_bandwidth_mode': bool,
+            'maximum_bandwidth': int,
             'respond_to_cq': bool,
             'tx_delay': int
         },