FHSS: Changed retry backoffs when no BC schedule or TX slots (ARMmbed#2440)

Author: Jarkko Paso

source/Service_Libs/fhss/fhss_ws.c

@@ -859,13 +859,13 @@ static uint32_t fhss_ws_get_retry_period_callback(const fhss_api_t *api, uint8_t
     if (!fhss_structure) {
         return return_value;
     }
-    // We don't know the broadcast schedule, use large backoff with MAC retries
+    // We don't know the broadcast schedule, use randomised large backoff with MAC retries
     if (fhss_structure->ws->broadcast_timer_running == false) {
-        return 100000;
+        return (uint32_t) randLIB_get_random_in_range(20000, 45000);
     }
     // We don't know the TX/RX slots, use randomised large backoff with MAC retries
     if (fhss_structure->own_hop == 0xff) {
-        return ((uint32_t) randLIB_get_random_in_range(50, 150) * 1000);
+        return (uint32_t) randLIB_get_random_in_range(20000, 45000);
     }
     if (fhss_structure->ws->is_on_bc_channel == true) {
         return return_value;

test/nanostack/unittest/service_libs/fhss_ws/test_fhss_ws.c

@@ -566,7 +566,8 @@ bool test_fhss_ws_get_retry_period_callback()
     // Test when own hop not set
     fhss_common_stub.fhss_struct.ws->is_on_bc_channel = false;
     fhss_common_stub.fhss_struct.own_hop = 0xff;
-    if (fhss_common_stub.fhss_struct.fhss_api->get_retry_period(api, NULL, 0) != 100000) {
+    uint32_t retry_period = fhss_common_stub.fhss_struct.fhss_api->get_retry_period(api, NULL, 0);
+    if (retry_period < 20000 || retry_period > 45000) {
         return false;
     }
     // Test when on broadcast channel