diff --git a/examples/simple_repeater/main.cpp b/examples/simple_repeater/main.cpp
index 12c843b7..5db62ff1 100644
--- a/examples/simple_repeater/main.cpp
+++ b/examples/simple_repeater/main.cpp
@@ -79,7 +79,7 @@
 struct RepeaterStats {
   uint16_t batt_milli_volts;
   uint16_t curr_tx_queue_len;
-  uint16_t curr_free_queue_len;
+  int16_t  noise_floor;
   int16_t  last_rssi;
   uint32_t n_packets_recv;
   uint32_t n_packets_sent;
@@ -183,7 +183,7 @@ class MyMesh : public mesh::Mesh, public CommonCLICallbacks {
         RepeaterStats stats;
         stats.batt_milli_volts = board.getBattMilliVolts();
         stats.curr_tx_queue_len = _mgr->getOutboundCount(0xFFFFFFFF);
-        stats.curr_free_queue_len = _mgr->getFreeCount();
+        stats.noise_floor = (int16_t)_radio->getNoiseFloor();
         stats.last_rssi = (int16_t) radio_driver.getLastRSSI();
         stats.n_packets_recv = radio_driver.getPacketsRecv();
         stats.n_packets_sent = radio_driver.getPacketsSent();
@@ -327,6 +327,9 @@ protected:
     uint32_t t = (_radio->getEstAirtimeFor(packet->path_len + packet->payload_len + 2) * _prefs.direct_tx_delay_factor);
     return getRNG()->nextInt(0, 6)*t;
   }
+  int getInterferenceThreshold() const override {
+    return _prefs.interference_threshold;
+  }
 
   void onAnonDataRecv(mesh::Packet* packet, uint8_t type, const mesh::Identity& sender, uint8_t* data, size_t len) override {
     if (type == PAYLOAD_TYPE_ANON_REQ) {  // received an initial request by a possible admin client (unknown at this stage)
@@ -565,6 +568,7 @@ public:
     _prefs.advert_interval = 1;  // default to 2 minutes for NEW installs
     _prefs.flood_advert_interval = 3;   // 3 hours
     _prefs.flood_max = 64;
+    _prefs.interference_threshold = 14;  // DB
   }
 
   CommonCLI* getCLI() { return &_cli; }
diff --git a/examples/simple_room_server/main.cpp b/examples/simple_room_server/main.cpp
index dad7ce78..d46270ac 100644
--- a/examples/simple_room_server/main.cpp
+++ b/examples/simple_room_server/main.cpp
@@ -406,6 +406,9 @@ protected:
     uint32_t t = (_radio->getEstAirtimeFor(packet->path_len + packet->payload_len + 2) * _prefs.direct_tx_delay_factor);
     return getRNG()->nextInt(0, 6)*t;
   }
+  int getInterferenceThreshold() const override {
+    return _prefs.interference_threshold;
+  }
 
   bool allowPacketForward(const mesh::Packet* packet) override {
     if (_prefs.disable_fwd) return false;
@@ -711,6 +714,7 @@ public:
     _prefs.advert_interval = 1;  // default to 2 minutes for NEW installs
     _prefs.flood_advert_interval = 3;   // 3 hours
     _prefs.flood_max = 64;
+    _prefs.interference_threshold = 14;  // DB
   #ifdef ROOM_PASSWORD
     StrHelper::strncpy(_prefs.guest_password, ROOM_PASSWORD, sizeof(_prefs.guest_password));
   #endif
diff --git a/src/Dispatcher.cpp b/src/Dispatcher.cpp
index 3d5b04fc..7ac5cbe3 100644
--- a/src/Dispatcher.cpp
+++ b/src/Dispatcher.cpp
@@ -10,6 +10,10 @@ namespace mesh {
 
 #define MAX_RX_DELAY_MILLIS   32000  // 32 seconds
 
+#ifndef NOISE_FLOOR_CALIB_INTERVAL
+  #define NOISE_FLOOR_CALIB_INTERVAL   2000     // 2 seconds
+#endif
+
 void Dispatcher::begin() {
   n_sent_flood = n_sent_direct = 0;
   n_recv_flood = n_recv_direct = 0;
@@ -36,6 +40,12 @@ uint32_t Dispatcher::getCADFailMaxDuration() const {
 }
 
 void Dispatcher::loop() {
+  if (millisHasNowPassed(next_floor_calib_time)) {
+    _radio->triggerNoiseFloorCalibrate(getInterferenceThreshold());
+    next_floor_calib_time = futureMillis(NOISE_FLOOR_CALIB_INTERVAL);
+  }
+  _radio->loop();
+
   // check for radio 'stuck' in mode other than Rx
   bool is_recv = _radio->isInRecvMode();
   if (is_recv != prev_isrecv_mode) {
diff --git a/src/Dispatcher.h b/src/Dispatcher.h
index d03c9f73..bce13b6b 100644
--- a/src/Dispatcher.h
+++ b/src/Dispatcher.h
@@ -56,6 +56,15 @@ public:
   */
   virtual void onSendFinished() = 0;
 
+  /**
+   * \brief  do any processing needed on each loop cycle
+   */
+  virtual void loop() { }
+
+  virtual int getNoiseFloor() const { return 0; }
+
+  virtual void triggerNoiseFloorCalibrate(int threshold) { }
+
   virtual bool isInRecvMode() const = 0;
 
   /**
@@ -107,6 +116,7 @@ class Dispatcher {
   unsigned long next_tx_time;
   unsigned long cad_busy_start;
   unsigned long radio_nonrx_start;
+  unsigned long next_floor_calib_time;
   bool  prev_isrecv_mode;
   uint32_t n_sent_flood, n_sent_direct;
   uint32_t n_recv_flood, n_recv_direct;
@@ -124,6 +134,7 @@ protected:
   {
     outbound = NULL; total_air_time = 0; next_tx_time = 0;
     cad_busy_start = 0;
+    next_floor_calib_time = 0;
     _err_flags = 0;
     radio_nonrx_start = 0;
     prev_isrecv_mode = true;
@@ -142,6 +153,7 @@ protected:
   virtual int calcRxDelay(float score, uint32_t air_time) const;
   virtual uint32_t getCADFailRetryDelay() const;
   virtual uint32_t getCADFailMaxDuration() const;
+  virtual int getInterferenceThreshold() const { return 0; }    // disabled by default
 
 public:
   void begin();
diff --git a/src/helpers/CommonCLI.cpp b/src/helpers/CommonCLI.cpp
index 8b8296f5..baad8f40 100644
--- a/src/helpers/CommonCLI.cpp
+++ b/src/helpers/CommonCLI.cpp
@@ -56,6 +56,7 @@ void CommonCLI::loadPrefsInt(FILESYSTEM* fs, const char* filename) {
     file.read(pad, 4);   // 120
     file.read((uint8_t *) &_prefs->flood_max, sizeof(_prefs->flood_max));   // 124
     file.read((uint8_t *) &_prefs->flood_advert_interval, sizeof(_prefs->flood_advert_interval));  // 125
+    file.read((uint8_t *) &_prefs->interference_threshold, sizeof(_prefs->interference_threshold));  // 126
 
     // sanitise bad pref values
     _prefs->rx_delay_base = constrain(_prefs->rx_delay_base, 0, 20.0f);
@@ -109,6 +110,7 @@ void CommonCLI::savePrefs(FILESYSTEM* fs) {
     file.write(pad, 4);   // 120
     file.write((uint8_t *) &_prefs->flood_max, sizeof(_prefs->flood_max));   // 124
     file.write((uint8_t *) &_prefs->flood_advert_interval, sizeof(_prefs->flood_advert_interval));  // 125
+    file.write((uint8_t *) &_prefs->interference_threshold, sizeof(_prefs->interference_threshold));  // 126
 
     file.close();
   }
@@ -176,6 +178,8 @@ void CommonCLI::handleCommand(uint32_t sender_timestamp, const char* command, ch
       const char* config = &command[4];
       if (memcmp(config, "af", 2) == 0) {
         sprintf(reply, "> %s", StrHelper::ftoa(_prefs->airtime_factor));
+      } else if (memcmp(config, "int.thresh", 10) == 0) {
+        sprintf(reply, "> %d", (uint32_t) _prefs->interference_threshold);
       } else if (memcmp(config, "allow.read.only", 15) == 0) {
         sprintf(reply, "> %s", _prefs->allow_read_only ? "on" : "off");
       } else if (memcmp(config, "flood.advert.interval", 21) == 0) {
@@ -223,6 +227,10 @@ void CommonCLI::handleCommand(uint32_t sender_timestamp, const char* command, ch
         _prefs->airtime_factor = atof(&config[3]);
         savePrefs();
         strcpy(reply, "OK");
+      } else if (memcmp(config, "int.thresh ", 11) == 0) {
+        _prefs->interference_threshold = atoi(&config[11]);
+        savePrefs();
+        strcpy(reply, "OK");
       } else if (memcmp(config, "allow.read.only ", 16) == 0) {
         _prefs->allow_read_only = memcmp(&config[16], "on", 2) == 0;
         savePrefs();
diff --git a/src/helpers/CommonCLI.h b/src/helpers/CommonCLI.h
index 0e88c266..37402c09 100644
--- a/src/helpers/CommonCLI.h
+++ b/src/helpers/CommonCLI.h
@@ -24,6 +24,7 @@ struct NodePrefs {  // persisted to file
     uint8_t reserved2;
     float bw;
     uint8_t flood_max;
+    uint8_t interference_threshold;
 };
 
 class CommonCLICallbacks {
diff --git a/src/helpers/CustomLLCC68Wrapper.h b/src/helpers/CustomLLCC68Wrapper.h
index c7d95c41..f7dd7a9f 100644
--- a/src/helpers/CustomLLCC68Wrapper.h
+++ b/src/helpers/CustomLLCC68Wrapper.h
@@ -6,18 +6,11 @@
 class CustomLLCC68Wrapper : public RadioLibWrapper {
 public:
   CustomLLCC68Wrapper(CustomLLCC68& radio, mesh::MainBoard& board) : RadioLibWrapper(radio, board) { }
-  bool isReceiving() override { 
-    if (((CustomLLCC68 *)_radio)->isReceiving()) return true;
-
-    idle();  // put sx126x into standby
-    // do some basic CAD (blocks for ~12780 micros (on SF 10)!)
-    bool activity = (((CustomLLCC68 *)_radio)->scanChannel() == RADIOLIB_LORA_DETECTED);
-    if (activity) {
-      startRecv();
-    } else {
-      idle();
-    }
-    return activity;
+  bool isReceivingPacket() override { 
+    return ((CustomLLCC68 *)_radio)->isReceiving();
+  }
+  float getCurrentRSSI() override {
+    return ((CustomLLCC68 *)_radio)->getRSSI(false);
   }
   float getLastRSSI() const override { return ((CustomLLCC68 *)_radio)->getRSSI(); }
   float getLastSNR() const override { return ((CustomLLCC68 *)_radio)->getSNR(); }
diff --git a/src/helpers/CustomLR1110Wrapper.h b/src/helpers/CustomLR1110Wrapper.h
index 3a96d3c2..7e2ffa2d 100644
--- a/src/helpers/CustomLR1110Wrapper.h
+++ b/src/helpers/CustomLR1110Wrapper.h
@@ -6,18 +6,13 @@
 class CustomLR1110Wrapper : public RadioLibWrapper {
 public:
   CustomLR1110Wrapper(CustomLR1110& radio, mesh::MainBoard& board) : RadioLibWrapper(radio, board) { }
-  bool isReceiving() override { 
-    if (((CustomLR1110 *)_radio)->isReceiving()) return true;
-
-    idle();  // put sx126x into standby
-    // do some basic CAD (blocks for ~12780 micros (on SF 10)!)
-    bool activity = (((CustomLR1110 *)_radio)->scanChannel() == RADIOLIB_LORA_DETECTED);
-    if (activity) {
-      startRecv();
-    } else {
-      idle();
-    }
-    return activity;
+  bool isReceivingPacket() override { 
+    return ((CustomLR1110 *)_radio)->isReceiving();
+  }
+  float getCurrentRSSI() override {
+    float rssi = -110;
+    ((CustomLR1110 *)_radio)->getRssiInst(&rssi);
+    return rssi;
   }
 
   void onSendFinished() override {
diff --git a/src/helpers/CustomSTM32WLxWrapper.h b/src/helpers/CustomSTM32WLxWrapper.h
index 84f78376..9e2d0441 100644
--- a/src/helpers/CustomSTM32WLxWrapper.h
+++ b/src/helpers/CustomSTM32WLxWrapper.h
@@ -7,18 +7,11 @@
 class CustomSTM32WLxWrapper : public RadioLibWrapper {
 public:
   CustomSTM32WLxWrapper(CustomSTM32WLx& radio, mesh::MainBoard& board) : RadioLibWrapper(radio, board) { }
-  bool isReceiving() override { 
-    if (((CustomSTM32WLx *)_radio)->isReceiving()) return true;
-
-    idle();  // put sx126x into standby
-    // do some basic CAD (blocks for ~12780 micros (on SF 10)!)
-    bool activity = (((CustomSTM32WLx *)_radio)->scanChannel() == RADIOLIB_LORA_DETECTED);
-    if (activity) {
-      startRecv();
-    } else {
-      idle();
-    }
-    return activity;
+  bool isReceivingPacket() override { 
+    return ((CustomSTM32WLx *)_radio)->isReceiving();
+  }
+  float getCurrentRSSI() override {
+    return ((CustomSTM32WLx *)_radio)->getRSSI(false);
   }
   float getLastRSSI() const override { return ((CustomSTM32WLx *)_radio)->getRSSI(); }
   float getLastSNR() const override { return ((CustomSTM32WLx *)_radio)->getSNR(); }
diff --git a/src/helpers/CustomSX1262Wrapper.h b/src/helpers/CustomSX1262Wrapper.h
index ea2da5fe..119f6dce 100644
--- a/src/helpers/CustomSX1262Wrapper.h
+++ b/src/helpers/CustomSX1262Wrapper.h
@@ -2,23 +2,15 @@
 
 #include "CustomSX1262.h"
 #include "RadioLibWrappers.h"
-#include <math.h>
 
 class CustomSX1262Wrapper : public RadioLibWrapper {
 public:
   CustomSX1262Wrapper(CustomSX1262& radio, mesh::MainBoard& board) : RadioLibWrapper(radio, board) { }
-  bool isReceiving() override { 
-    if (((CustomSX1262 *)_radio)->isReceiving()) return true;
-
-    idle();  // put sx126x into standby
-    // do some basic CAD (blocks for ~12780 micros (on SF 10)!)
-    bool activity = (((CustomSX1262 *)_radio)->scanChannel() == RADIOLIB_LORA_DETECTED);
-    if (activity) {
-      startRecv();
-    } else {
-      idle();
-    }
-    return activity;
+  bool isReceivingPacket() override { 
+    return ((CustomSX1262 *)_radio)->isReceiving();
+  }
+  float getCurrentRSSI() override {
+    return ((CustomSX1262 *)_radio)->getRSSI(false);
   }
   float getLastRSSI() const override { return ((CustomSX1262 *)_radio)->getRSSI(); }
   float getLastSNR() const override { return ((CustomSX1262 *)_radio)->getSNR(); }
diff --git a/src/helpers/CustomSX1268Wrapper.h b/src/helpers/CustomSX1268Wrapper.h
index f9eee447..5d7106b4 100644
--- a/src/helpers/CustomSX1268Wrapper.h
+++ b/src/helpers/CustomSX1268Wrapper.h
@@ -6,18 +6,11 @@
 class CustomSX1268Wrapper : public RadioLibWrapper {
 public:
   CustomSX1268Wrapper(CustomSX1268& radio, mesh::MainBoard& board) : RadioLibWrapper(radio, board) { }
-  bool isReceiving() override { 
-    if (((CustomSX1268 *)_radio)->isReceiving()) return true;
-
-    idle();  // put sx126x into standby
-    // do some basic CAD (blocks for ~12780 micros (on SF 10)!)
-    bool activity = (((CustomSX1268 *)_radio)->scanChannel() == RADIOLIB_LORA_DETECTED);
-    if (activity) {
-      startRecv();
-    } else {
-      idle();
-    }
-    return activity;
+  bool isReceivingPacket() override { 
+    return ((CustomSX1268 *)_radio)->isReceiving();
+  }
+  float getCurrentRSSI() override {
+    return ((CustomSX1268 *)_radio)->getRSSI(false);
   }
   float getLastRSSI() const override { return ((CustomSX1268 *)_radio)->getRSSI(); }
   float getLastSNR() const override { return ((CustomSX1268 *)_radio)->getSNR(); }
diff --git a/src/helpers/CustomSX1276Wrapper.h b/src/helpers/CustomSX1276Wrapper.h
index f9900705..28257990 100644
--- a/src/helpers/CustomSX1276Wrapper.h
+++ b/src/helpers/CustomSX1276Wrapper.h
@@ -6,18 +6,11 @@
 class CustomSX1276Wrapper : public RadioLibWrapper {
 public:
   CustomSX1276Wrapper(CustomSX1276& radio, mesh::MainBoard& board) : RadioLibWrapper(radio, board) { }
-  bool isReceiving() override { 
-    if (((CustomSX1276 *)_radio)->isReceiving()) return true;
-
-    idle();  // put into standby
-    // do some basic CAD (blocks for ~12780 micros (on SF 10)!)
-    bool activity = (((CustomSX1276 *)_radio)->tryScanChannel() == RADIOLIB_PREAMBLE_DETECTED);
-    if (activity) {
-      startRecv();
-    } else {
-      idle();
-    }
-    return activity;
+  bool isReceivingPacket() override { 
+    return ((CustomSX1276 *)_radio)->isReceiving();
+  }
+  float getCurrentRSSI() override {
+    return ((CustomSX1276 *)_radio)->getRSSI(false);
   }
   float getLastRSSI() const override { return ((CustomSX1276 *)_radio)->getRSSI(); }
   float getLastSNR() const override { return ((CustomSX1276 *)_radio)->getSNR(); }
diff --git a/src/helpers/RadioLibWrappers.cpp b/src/helpers/RadioLibWrappers.cpp
index 39fb340e..d37bc498 100644
--- a/src/helpers/RadioLibWrappers.cpp
+++ b/src/helpers/RadioLibWrappers.cpp
@@ -8,6 +8,8 @@
 #define STATE_TX_DONE    4
 #define STATE_INT_READY 16
 
+#define NUM_NOISE_FLOOR_SAMPLES  64
+
 static volatile uint8_t state = STATE_IDLE;
 
 // this function is called when a complete packet
@@ -28,6 +30,13 @@ void RadioLibWrapper::begin() {
   if (_board->getStartupReason() == BD_STARTUP_RX_PACKET) {  // received a LoRa packet (while in deep sleep)
     setFlag(); // LoRa packet is already received
   }
+
+  _noise_floor = 0;
+  _threshold = 0;
+
+  // start average out some samples
+  _num_floor_samples = 0;
+  _floor_sample_sum = 0;
 }
 
 void RadioLibWrapper::idle() {
@@ -35,6 +44,31 @@ void RadioLibWrapper::idle() {
   state = STATE_IDLE;   // need another startReceive()
 }
 
+void RadioLibWrapper::triggerNoiseFloorCalibrate(int threshold) {
+  _threshold = threshold;
+  if (threshold > 0 && _num_floor_samples >= NUM_NOISE_FLOOR_SAMPLES) {  // ignore trigger if currently sampling
+    _num_floor_samples = 0;
+    _floor_sample_sum = 0;
+  }
+}
+
+void RadioLibWrapper::loop() {
+  if (state == STATE_RX && _num_floor_samples < NUM_NOISE_FLOOR_SAMPLES) {
+    if (!isReceivingPacket()) {
+      int rssi = getCurrentRSSI();
+      if (rssi < _noise_floor + _threshold) {  // only consider samples below current floor+THRESHOLD
+        _num_floor_samples++;
+        _floor_sample_sum += rssi;
+      }
+    }
+  } else if (_num_floor_samples >= NUM_NOISE_FLOOR_SAMPLES && _floor_sample_sum != 0) {
+    _noise_floor = _floor_sample_sum / NUM_NOISE_FLOOR_SAMPLES;
+    _floor_sample_sum = 0;
+
+    MESH_DEBUG_PRINTLN("RadioLibWrapper: noise_floor = %d", (int)_noise_floor);
+  }
+}
+
 void RadioLibWrapper::startRecv() {
   int err = _radio->startReceive();
   if (err == RADIOLIB_ERR_NONE) {
@@ -108,6 +142,12 @@ void RadioLibWrapper::onSendFinished() {
   state = STATE_IDLE;
 }
 
+bool RadioLibWrapper::isChannelActive() {
+  return _threshold == 0 
+          ? false    // interference check is disabled
+          : getCurrentRSSI() > _noise_floor + _threshold;
+}
+
 float RadioLibWrapper::getLastRSSI() const {
   return _radio->getRSSI();
 }
diff --git a/src/helpers/RadioLibWrappers.h b/src/helpers/RadioLibWrappers.h
index bdbadb19..bb308071 100644
--- a/src/helpers/RadioLibWrappers.h
+++ b/src/helpers/RadioLibWrappers.h
@@ -8,10 +8,14 @@ protected:
   PhysicalLayer* _radio;
   mesh::MainBoard* _board;
   uint32_t n_recv, n_sent;
+  int16_t _noise_floor, _threshold;
+  uint16_t _num_floor_samples;
+  int32_t _floor_sample_sum;
 
   void idle();
   void startRecv();
   float packetScoreInt(float snr, int sf, int packet_len);
+  virtual bool isReceivingPacket() =0;
 
 public:
   RadioLibWrapper(PhysicalLayer& radio, mesh::MainBoard& board) : _radio(&radio), _board(&board) { n_recv = n_sent = 0; }
@@ -23,6 +27,20 @@ public:
   bool isSendComplete() override;
   void onSendFinished() override;
   bool isInRecvMode() const override;
+  bool isChannelActive();
+
+  bool isReceiving() override { 
+    if (isReceivingPacket()) return true;
+
+    return isChannelActive();
+  }
+
+  virtual float getCurrentRSSI() =0;
+
+  int getNoiseFloor() const override { return _noise_floor; }
+  void triggerNoiseFloorCalibrate(int threshold) override;
+
+  void loop() override;
 
   uint32_t getPacketsRecv() const { return n_recv; }
   uint32_t getPacketsSent() const { return n_sent; }