Accept do faster ETX caclculation after last ETX probe or unicast tra…

…ffic.

Added definition for define how many accelerated ETX update will be done before start follow cached value.

Change-Id: I59ba142ff0ee3a8b46566c7d4a2b7b98abe692b0

source/Service_Libs/etx/etx.c

@@ -131,7 +131,7 @@ static bool etx_update_possible(etx_sample_storage_t *storage, etx_storage_t *en
         }
     }
 
-    if (entry->etx_samples == 7) {
+    if (entry->etx_samples > ETX_ACCELERATED_SAMPLE_COUNT) {
         //Slower ETX update phase
         if (storage->sample_count < etx_info.min_sample_count || storage->etx_timer) {
             if (storage->sample_count < 0xff) {
@@ -140,7 +140,7 @@ static bool etx_update_possible(etx_sample_storage_t *storage, etx_storage_t *en
         }
     } else {
         //Accelerated ETX at for new neighbor
-        if (storage->sample_count < 3) {
+        if (storage->sample_count < ETX_ACCELERATED_INTERVAL) {
             return false;
         }
     }

source/Service_Libs/etx/etx.h

@@ -31,6 +31,25 @@
    Range for value can be from 1 to 11 */
 #define ETX_MOVING_AVERAGE_FRACTION      3     // n >> 3, 1/8
 
+/* ETX cache configuration definitions */
+
+/* Amount of accelerated ETX samples
+ * After this value is received the ETX calculation starts to follow the
+ * slower ETX cache configuration values.
+ *
+ * Maximum value is 7
+ */
+#define ETX_ACCELERATED_SAMPLE_COUNT      3
+
+/* Amount of samples before updating the ETX value when in accelerated mode.
+ *
+ * if set to 1 every sample updates an ETX value. if set to 2 every second
+ * ETX sample updates the ETX value.
+ *
+ * This value should be smaller than ETX_ACCELERATED_SAMPLE_COUNT
+ */
+#define ETX_ACCELERATED_INTERVAL          2
+
 typedef struct etx_storage_s {
     uint16_t        etx;                       /*!< 12 bits fraction */
     uint16_t        stored_diff_etx;           /*!< 12 bits fraction */