* new RX delays based on SNR

examples/companion_radio/main.cpp

@@ -46,8 +46,8 @@
 
 #define SEND_TIMEOUT_BASE_MILLIS          300
 #define FLOOD_SEND_TIMEOUT_FACTOR         16.0f
-#define DIRECT_SEND_PERHOP_FACTOR         4.0f
-#define DIRECT_SEND_PERHOP_EXTRA_MILLIS   200
+#define DIRECT_SEND_PERHOP_FACTOR         5.0f
+#define DIRECT_SEND_PERHOP_EXTRA_MILLIS   250
 
 #define  PUBLIC_GROUP_PSK  "izOH6cXN6mrJ5e26oRXNcg=="
 

examples/simple_repeater/main.cpp

@@ -121,6 +121,7 @@ struct NodePrefs {  // persisted to file
   float freq;
   uint8_t tx_power_dbm;
   uint8_t unused[3];
+  float rx_delay_base;
 };
 
 class MyMesh : public mesh::Mesh {
@@ -193,6 +194,10 @@ protected:
     return true;   // Yes, allow packet to be forwarded
   }
 
+  int calcRxDelay(float score, uint32_t air_time) const override {
+    return (int) ((pow(_prefs.rx_delay_base, 0.85f - score) - 1.0) * air_time);
+  }
+
   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)
       uint32_t timestamp;
@@ -371,6 +376,7 @@ public:
 
     // defaults
     _prefs.airtime_factor = 1.0;    // one half
+    _prefs.rx_delay_base = 10.0;
     strncpy(_prefs.node_name, ADVERT_NAME, sizeof(_prefs.node_name)-1);
     _prefs.node_name[sizeof(_prefs.node_name)-1] = 0;  // truncate if necessary
     _prefs.node_lat = ADVERT_LAT;

examples/simple_room_server/main.cpp

@@ -138,6 +138,7 @@ struct NodePrefs {  // persisted to file
   float freq;
   uint8_t tx_power_dbm;
   uint8_t unused[3];
+  float rx_delay_base;
 };
 
 class MyMesh : public mesh::Mesh {
@@ -246,6 +247,10 @@ protected:
     return _prefs.airtime_factor;
   }
 
+  int calcRxDelay(float score, uint32_t air_time) const override {
+    return (int) ((pow(_prefs.rx_delay_base, 0.85f - score) - 1.0) * air_time);
+  }
+
 #if ROOM_IS_ALSO_REPEATER
   bool allowPacketForward(const mesh::Packet* packet) override {
     return true;   // Yes, allow packet to be forwarded
@@ -484,6 +489,7 @@ public:
 
     // defaults
     _prefs.airtime_factor = 1.0;    // one half
+    _prefs.rx_delay_base = 10.0;
     strncpy(_prefs.node_name, ADVERT_NAME, sizeof(_prefs.node_name)-1);
     _prefs.node_name[sizeof(_prefs.node_name)-1] = 0;  // truncate if necessary
     _prefs.node_lat = ADVERT_LAT;

examples/simple_secure_chat/main.cpp

@@ -44,8 +44,8 @@
 
 #define SEND_TIMEOUT_BASE_MILLIS          300
 #define FLOOD_SEND_TIMEOUT_FACTOR         16.0f
-#define DIRECT_SEND_PERHOP_FACTOR         4.0f
-#define DIRECT_SEND_PERHOP_EXTRA_MILLIS   200
+#define DIRECT_SEND_PERHOP_FACTOR         5.0f
+#define DIRECT_SEND_PERHOP_EXTRA_MILLIS   250
 
 #define  PUBLIC_GROUP_PSK  "izOH6cXN6mrJ5e26oRXNcg=="
 

platformio.ini

@@ -16,7 +16,7 @@ lib_deps =
   Wire
   jgromes/RadioLib @ ^6.3.0
   rweather/Crypto @ ^0.4.0
-build_flags = -w -DNDEBUG -DRADIOLIB_STATIC_ONLY=1
+build_flags = -w -DNDEBUG -DRADIOLIB_STATIC_ONLY=1 -DRADIOLIB_GODMODE=1
   -D LORA_FREQ=867.5
   -D LORA_BW=250
   -D LORA_SF=10
@@ -69,7 +69,7 @@ build_flags =
   -D ADVERT_LAT=-37.0
   -D ADVERT_LON=145.0
   -D ADMIN_PASSWORD="\"password\""
-;  -D MESH_PACKET_LOGGING=1
+  -D MESH_PACKET_LOGGING=1
 ;  -D MESH_DEBUG=1
 build_src_filter = ${Heltec_lora32_v3.build_src_filter} +<../examples/simple_repeater/main.cpp>
 lib_deps =

src/Dispatcher.cpp

@@ -4,6 +4,8 @@
   #include <Arduino.h>
 #endif
 
+#include <math.h>
+
 namespace mesh {
 
 void Dispatcher::begin() {
@@ -18,6 +20,10 @@ float Dispatcher::getAirtimeBudgetFactor() const {
   return 2.0;   // default, 33.3%  (1/3rd)
 }
 
+int Dispatcher::calcRxDelay(float score, uint32_t air_time) const {
+  return (int) ((pow(10, 0.85f - score) - 1.0) * air_time);
+}
+
 void Dispatcher::loop() {
   if (outbound) {  // waiting for outbound send to be completed
     if (_radio->isSendComplete()) {
@@ -47,6 +53,13 @@ void Dispatcher::loop() {
     }
   }
 
+  // check inbound (delayed) queue
+  {
+    Packet* pkt = _mgr->getNextInbound(_ms->getMillis());
+    if (pkt) {
+      processRecvPacket(pkt);
+    }
+  }
   checkRecv();
   checkSend();
 }
@@ -57,6 +70,8 @@ void Dispatcher::onPacketSent(Packet* packet) {
 
 void Dispatcher::checkRecv() {
   Packet* pkt;
+  float score;
+  uint32_t air_time;
   {
     uint8_t raw[MAX_TRANS_UNIT];
     int len = _radio->recvRaw(raw, MAX_TRANS_UNIT);
@@ -87,6 +102,9 @@ void Dispatcher::checkRecv() {
 
           pkt->payload_len = len - i;  // payload is remainder
           memcpy(pkt->payload, &raw[i], pkt->payload_len);
+
+          score = _radio->packetScore(_radio->getLastSNR(), len);
+          air_time = _radio->getEstAirtimeFor(len);
         }
       }
     } else {
@@ -94,27 +112,41 @@ void Dispatcher::checkRecv() {
     }
   }
   if (pkt) {
+    #if MESH_PACKET_LOGGING      
+      Serial.printf("PACKET: recv, len=%d (type=%d, route=%s, payload_len=%d) SNR=%d RSSI=%d score=%d\n", 
+            2 + pkt->path_len + pkt->payload_len, pkt->getPayloadType(), pkt->isRouteDirect() ? "D" : "F", pkt->payload_len,
+            (int)_radio->getLastSNR(), (int)_radio->getLastRSSI(), (int)(score*1000));
+    #endif
+
     if (pkt->isRouteFlood()) {
       n_recv_flood++;
+
+      int _delay = calcRxDelay(score, air_time);
+      if (_delay < 50) {
+        MESH_DEBUG_PRINTLN("Dispatcher::checkRecv(), score delay below threshold (%d)", _delay);
+        processRecvPacket(pkt);   // is below the score delay threshold, so process immediately
+      } else {
+        MESH_DEBUG_PRINTLN("Dispatcher::checkRecv(), score delay is: %d millis", _delay);
+        _mgr->queueInbound(pkt, futureMillis(_delay)); // add to delayed inbound queue
+      }
     } else {
       n_recv_direct++;
+      processRecvPacket(pkt);
     }
-    #if MESH_PACKET_LOGGING
-      Serial.printf("PACKET: recv, len=%d (type=%d, route=%s, payload_len=%d) SNR=%d RSSI=%d\n", 
-            2 + pkt->path_len + pkt->payload_len, pkt->getPayloadType(), pkt->isRouteDirect() ? "D" : "F", pkt->payload_len,
-            (int)_radio->getLastSNR(), (int)_radio->getLastRSSI());
-    #endif
-    DispatcherAction action = onRecvPacket(pkt);
-    if (action == ACTION_RELEASE) {
-      _mgr->free(pkt);
-    } else if (action == ACTION_MANUAL_HOLD) {
-      // sub-class is wanting to manually hold Packet instance, and call releasePacket() at appropriate time
-    } else {   // ACTION_RETRANSMIT*
-      uint8_t priority = (action >> 24) - 1;
-      uint32_t _delay = action & 0xFFFFFF;
-
-      _mgr->queueOutbound(pkt, priority, futureMillis(_delay));
-    }
+  }
+}
+
+void Dispatcher::processRecvPacket(Packet* pkt) {
+  DispatcherAction action = onRecvPacket(pkt);
+  if (action == ACTION_RELEASE) {
+    _mgr->free(pkt);
+  } else if (action == ACTION_MANUAL_HOLD) {
+    // sub-class is wanting to manually hold Packet instance, and call releasePacket() at appropriate time
+  } else {   // ACTION_RETRANSMIT*
+    uint8_t priority = (action >> 24) - 1;
+    uint32_t _delay = action & 0xFFFFFF;
+
+    _mgr->queueOutbound(pkt, priority, futureMillis(_delay));
   }
 }
 

src/Dispatcher.h

@@ -36,6 +36,8 @@ public:
   */
   virtual uint32_t getEstAirtimeFor(int len_bytes) = 0;
 
+  virtual float packetScore(float snr, int packet_len) = 0;
+
   /**
    * \brief  starts the raw packet send. (no wait)
    * \param  bytes   the raw packet data
@@ -77,6 +79,8 @@ public:
   virtual int getFreeCount() const = 0;
   virtual Packet* getOutboundByIdx(int i) = 0;
   virtual Packet* removeOutboundByIdx(int i) = 0;
+  virtual void queueInbound(Packet* packet, uint32_t scheduled_for) = 0;
+  virtual Packet* getNextInbound(uint32_t now) = 0;
 };
 
 typedef uint32_t  DispatcherAction;
@@ -98,6 +102,8 @@ class Dispatcher {
   uint32_t n_recv_flood, n_recv_direct;
   uint32_t n_full_events;
 
+  void processRecvPacket(Packet* pkt);
+
 protected:
   PacketManager* _mgr;
   Radio* _radio;
@@ -112,6 +118,7 @@ protected:
   virtual DispatcherAction onRecvPacket(Packet* pkt) = 0;
   virtual void onPacketSent(Packet* packet);
   virtual float getAirtimeBudgetFactor() const;
+  virtual int calcRxDelay(float score, uint32_t air_time) const;
 
 public:
   void begin();

src/helpers/CustomLLCC68Wrapper.h

@@ -18,4 +18,14 @@ public:
   }
   float getLastRSSI() const override { return ((CustomLLCC68 *)_radio)->getRSSI(); }
   float getLastSNR() const override { return ((CustomLLCC68 *)_radio)->getSNR(); }
+
+  float packetScore(float snr, int packet_len) override {
+    int sf = ((CustomLLCC68 *)_radio)->spreadingFactor;
+    const float A = 0.7;
+    const float B = 0.4;
+  
+    float ber = exp(-pow(10, (snr / 10)) / (A * pow(10, (snr / 10)) + B * (1 << sf)));
+
+    return pow(1 - ber, packet_len * 8);
+  }
 };

src/helpers/CustomSX1262Wrapper.h

@@ -2,6 +2,7 @@
 
 #include "CustomSX1262.h"
 #include "RadioLibWrappers.h"
+#include <math.h>
 
 class CustomSX1262Wrapper : public RadioLibWrapper {
 public:
@@ -18,4 +19,14 @@ public:
   }
   float getLastRSSI() const override { return ((CustomSX1262 *)_radio)->getRSSI(); }
   float getLastSNR() const override { return ((CustomSX1262 *)_radio)->getSNR(); }
+
+  float packetScore(float snr, int packet_len) override {
+    int sf = ((CustomSX1262 *)_radio)->spreadingFactor;
+    const float A = 0.7;
+    const float B = 0.4;
+  
+    float ber = exp(-pow(10, (snr / 10)) / (A * pow(10, (snr / 10)) + B * (1 << sf)));
+
+    return pow(1 - ber, packet_len * 8);
+  }
 };

src/helpers/CustomSX1268Wrapper.h

@@ -18,4 +18,14 @@ public:
   }
   float getLastRSSI() const override { return ((CustomSX1268 *)_radio)->getRSSI(); }
   float getLastSNR() const override { return ((CustomSX1268 *)_radio)->getSNR(); }
+
+  float packetScore(float snr, int packet_len) override {
+    int sf = ((CustomSX1268 *)_radio)->spreadingFactor;
+    const float A = 0.7;
+    const float B = 0.4;
+  
+    float ber = exp(-pow(10, (snr / 10)) / (A * pow(10, (snr / 10)) + B * (1 << sf)));
+
+    return pow(1 - ber, packet_len * 8);
+  }
 };

src/helpers/RadioLibWrappers.h

@@ -25,6 +25,8 @@ public:
   uint32_t getPacketsSent() const { return n_sent; }
   virtual float getLastRSSI() const override;
   virtual float getLastSNR() const override;
+
+  float packetScore(float snr, int packet_len) override { return 0.85f; }  // stub impl
 };
 
 /**

src/helpers/StaticPoolPacketManager.cpp

@@ -57,7 +57,7 @@ void PacketQueue::add(mesh::Packet* packet, uint8_t priority, uint32_t scheduled
   _num++;
 }
 
-StaticPoolPacketManager::StaticPoolPacketManager(int pool_size): unused(pool_size), send_queue(pool_size) {
+StaticPoolPacketManager::StaticPoolPacketManager(int pool_size): unused(pool_size), send_queue(pool_size), rx_queue(pool_size) {
   // load up our unusued Packet pool
   for (int i = 0; i < pool_size; i++) {
     unused.add(new mesh::Packet(), 0, 0);
@@ -95,3 +95,10 @@ mesh::Packet* StaticPoolPacketManager::getOutboundByIdx(int i) {
 mesh::Packet* StaticPoolPacketManager::removeOutboundByIdx(int i) {
   return send_queue.removeByIdx(i);
 }
+
+void StaticPoolPacketManager::queueInbound(mesh::Packet* packet, uint32_t scheduled_for) {
+  // TODO
+}
+mesh::Packet* StaticPoolPacketManager::getNextInbound(uint32_t now) {
+  return NULL;  // TODO
+}

src/helpers/StaticPoolPacketManager.h

@@ -18,7 +18,7 @@ public:
 };
 
 class StaticPoolPacketManager : public mesh::PacketManager {
-  PacketQueue unused, send_queue;
+  PacketQueue unused, send_queue, rx_queue;
 
 public:
   StaticPoolPacketManager(int pool_size);
@@ -31,4 +31,6 @@ public:
   int getFreeCount() const override;
   mesh::Packet* getOutboundByIdx(int i) override;
   mesh::Packet* removeOutboundByIdx(int i) override;
+  void queueInbound(mesh::Packet* packet, uint32_t scheduled_for) override;
+  mesh::Packet* getNextInbound(uint32_t now) override;
 };