diff --git a/src/protocols/PhysicalLayer/PhysicalLayer.cpp b/src/protocols/PhysicalLayer/PhysicalLayer.cpp
index 5c9b697c..b244b856 100644
--- a/src/protocols/PhysicalLayer/PhysicalLayer.cpp
+++ b/src/protocols/PhysicalLayer/PhysicalLayer.cpp
@@ -289,6 +289,19 @@ float PhysicalLayer::getSNR() {
   return(RADIOLIB_ERR_UNSUPPORTED);
 }
 
+uint32_t PhysicalLayer::getTimeOnAir(size_t len) {
+  (void)len;
+  return(0);
+}
+    
+int16_t PhysicalLayer::startChannelScan() {
+  return(RADIOLIB_ERR_UNSUPPORTED); 
+}
+
+int16_t PhysicalLayer::getChannelScanResult() {
+  return(RADIOLIB_ERR_UNSUPPORTED);
+}
+
 int16_t PhysicalLayer::scanChannel() {
   return(RADIOLIB_ERR_UNSUPPORTED); 
 }
@@ -441,6 +454,14 @@ void PhysicalLayer::clearPacketSentAction() {
   
 }
 
+void PhysicalLayer::setChannelScanAction(void (*func)(void)) {
+  (void)func;
+}
+
+void PhysicalLayer::clearChannelScanAction() {
+  
+}
+
 #if defined(RADIOLIB_INTERRUPT_TIMING)
 void PhysicalLayer::setInterruptSetup(void (*func)(uint32_t)) {
   Module* mod = getMod();
diff --git a/src/protocols/PhysicalLayer/PhysicalLayer.h b/src/protocols/PhysicalLayer/PhysicalLayer.h
index ef5dd93e..ba7df212 100644
--- a/src/protocols/PhysicalLayer/PhysicalLayer.h
+++ b/src/protocols/PhysicalLayer/PhysicalLayer.h
@@ -302,6 +302,26 @@ class PhysicalLayer {
     */
     virtual float getSNR();
 
+    /*!
+      \brief Get expected time-on-air for a given size of payload
+      \param len Payload length in bytes.
+      \returns Expected time-on-air in microseconds.
+    */
+    virtual uint32_t getTimeOnAir(size_t len);
+    
+    /*!
+      \brief Interrupt-driven channel activity detection method. interrupt will be activated
+      when packet is detected. Must be implemented in module class.
+      \returns \ref status_codes
+    */
+    virtual int16_t startChannelScan();
+
+    /*!
+      \brief Read the channel scan result
+      \returns \ref status_codes
+    */
+    virtual int16_t getChannelScanResult();
+
     /*!
       \brief Check whether the current communication channel is free or occupied. Performs CAD for LoRa modules,
       or RSSI measurement for FSK modules.
@@ -409,6 +429,17 @@ class PhysicalLayer {
       \brief Clears interrupt service routine to call when a packet is sent.
     */
     virtual void clearPacketSentAction();
+    
+    /*!
+      \brief Sets interrupt service routine to call when a channel scan is finished.
+      \param func ISR to call.
+    */
+    virtual void setChannelScanAction(void (*func)(void));
+
+    /*!
+      \brief Clears interrupt service routine to call when a channel scan is finished.
+    */
+    virtual void clearChannelScanAction();
 
     #if defined(RADIOLIB_INTERRUPT_TIMING)