Change stagger calculation to give more bandwidth to application

75% of the usable bandwidth is now allocated to the application

Usable data rate function created that is used in stagger calculation

OFDM modes are now supported with stagger calculation

prevent division by zero if no data rate set and use minimum of 25kbs

Author: Mika Tervonen

source/6LoWPAN/Bootstraps/Generic/protocol_6lowpan.c

@@ -83,7 +83,7 @@
 #define TRACE_GROUP "6lo"
 
 /* Data rate for application used in Stagger calculation */
-#define STAGGER_DATARATE_FOR_APPL(n) ((n)*25/100)
+#define STAGGER_DATARATE_FOR_APPL(n) ((n)*75/100)
 
 #ifdef HAVE_RPL
 rpl_domain_t *protocol_6lowpan_rpl_domain;
@@ -839,7 +839,7 @@ bool protocol_6lowpan_stagger_estimate_get(int8_t interface_id, uint32_t data_am
         datarate = 250000;
     } else if (ws_info(cur_interface)) {
         network_size = ws_common_network_size_estimate_get(cur_interface);
-        datarate = ws_common_datarate_get(cur_interface);
+        datarate = ws_common_usable_application_datarate_get(cur_interface);
     } else {
         // 6LoWPAN ND
         network_size = 1000;
@@ -850,6 +850,10 @@ bool protocol_6lowpan_stagger_estimate_get(int8_t interface_id, uint32_t data_am
         // If no data amount given, use 1kB
         data_amount = 1;
     }
+    if (datarate < 25000) {
+        // Minimum data rate used in calculations is 25kbs to prevent invalid values
+        datarate = 25000;
+    }
 
     /*
      * Do not occupy whole bandwidth, leave space for network formation etc...

source/6LoWPAN/ws/ws_cfg_settings.c

@@ -405,7 +405,8 @@ cfg_network_size_type_e ws_cfg_network_config_get(protocol_interface_info_entry_
         return CONFIG_SMALL;
     }
 
-    uint32_t data_rate = ws_get_datarate_using_operating_mode(phy_cfg.operating_mode);
+    uint32_t data_rate = ws_common_datarate_get_from_phy_mode(phy_cfg.phy_mode_id, phy_cfg.operating_mode);
+
     uint8_t index;
     if (data_rate < 150000) {
         index = 0;

source/6LoWPAN/ws/ws_common.c

@@ -223,7 +223,7 @@ phy_modulation_index_e ws_get_modulation_index_using_operating_mode(uint8_t oper
 int8_t ws_common_regulatory_domain_config(protocol_interface_info_entry_t *cur, ws_hopping_schedule_t *hopping_schdule)
 {
     (void)cur;
-    if (ws_get_datarate_using_operating_mode(hopping_schdule->operating_mode) == 0) {
+    if (ws_common_datarate_get_from_phy_mode(hopping_schdule->phy_mode_id, hopping_schdule->operating_mode) == 0) {
         //Unsupported operation mode
         return -1;
     }
@@ -663,11 +663,37 @@ uint32_t ws_common_latency_estimate_get(protocol_interface_info_entry_t *cur)
     return latency;
 }
 
+uint32_t ws_common_datarate_get_from_phy_mode(uint8_t phy_mode_id, uint8_t operating_mode)
+{
+    if (((phy_mode_id >= 34) && (phy_mode_id <= 38)) ||
+            ((phy_mode_id >= 51) && (phy_mode_id <= 54)) ||
+            ((phy_mode_id >= 68) && (phy_mode_id <= 70)) ||
+            ((phy_mode_id >= 84) && (phy_mode_id <= 86))) {
+        return ws_get_datarate_using_phy_mode_id(phy_mode_id);
+    }
+    return ws_get_datarate_using_operating_mode(operating_mode);
+}
+
 uint32_t ws_common_datarate_get(protocol_interface_info_entry_t *cur)
 {
-    return ws_get_datarate_using_operating_mode(cur->ws_info->hopping_schdule.operating_mode);
+    return ws_common_datarate_get_from_phy_mode(cur->ws_info->hopping_schdule.phy_mode_id, cur->ws_info->hopping_schdule.operating_mode);
 }
 
+uint32_t ws_common_usable_application_datarate_get(protocol_interface_info_entry_t *cur)
+{
+    /* Usable data rate is a available data rate when removed ACK and wait times required to send a packet
+     *
+     * Estimated to be around 70% with following assumptions with 150kbs data rate
+     * Average ACK size 48 bytes
+     * Average tACK 2ms
+     * Average CCA check time + processing 7ms
+     * Delays in bytes with 150kbs data rate 168 + 48 bytes for ACK 216 bytes
+     * Usable data rate is 1 - 216/(216 + 500) about 70%
+     */
+    return 70 * ws_common_datarate_get_from_phy_mode(cur->ws_info->hopping_schdule.phy_mode_id, cur->ws_info->hopping_schdule.operating_mode) / 100;
+}
+
+
 uint32_t ws_common_network_size_estimate_get(protocol_interface_info_entry_t *cur)
 {
     uint32_t network_size_estimate = 100;

source/6LoWPAN/ws/ws_common.h

@@ -164,8 +164,12 @@ uint32_t ws_common_version_timeout_get(uint8_t config);
 
 uint32_t ws_common_latency_estimate_get(protocol_interface_info_entry_t *cur);
 
+uint32_t ws_common_datarate_get_from_phy_mode(uint8_t phy_mode_id, uint8_t operating_mode);
+
 uint32_t ws_common_datarate_get(protocol_interface_info_entry_t *cur);
 
+uint32_t ws_common_usable_application_datarate_get(protocol_interface_info_entry_t *cur);
+
 uint32_t ws_common_network_size_estimate_get(protocol_interface_info_entry_t *cur);
 
 void ws_common_primary_parent_update(protocol_interface_info_entry_t *interface, mac_neighbor_table_entry_t *neighbor);
@@ -187,7 +191,9 @@ void ws_common_border_router_alive_update(protocol_interface_info_entry_t *inter
 #define ws_common_allow_child_registration(cur, eui64, aro_timeout) (2)
 #define ws_common_negative_aro_mark(interface, eui64)(false)
 #define ws_common_latency_estimate_get(cur) 0
+#define ws_common_datarate_get_from_phy_mode(phy_mode_id, operating_mode) 0
 #define ws_common_datarate_get(cur) 0
+#define ws_common_usable_application_datarate_get(cur) 0
 #define ws_common_network_size_estimate_get(cur) 0
 #define ws_common_primary_parent_update(interface, neighbor)
 #define ws_common_secondary_parent_update(interface)

test/nanostack/unittest/stub/ws_common_stub.c

@@ -102,6 +102,16 @@ uint32_t ws_common_datarate_get(protocol_interface_info_entry_t *cur)
     return 0;
 }
 
+uint32_t ws_common_usable_application_datarate_get(protocol_interface_info_entry_t *cur)
+{
+    return 0;
+}
+
+uint32_t ws_common_datarate_get_from_phy_mode(uint8_t phy_mode_id, uint8_t operating_mode)
+{
+    return 150000;
+}
+
 uint32_t ws_get_datarate_using_operating_mode(uint8_t operating_mode)
 {
     return 150000;