diff --git a/source/Service_Libs/fhss/channel_functions.c b/source/Service_Libs/fhss/channel_functions.c
index 58bad623004..04649a698f8 100644
--- a/source/Service_Libs/fhss/channel_functions.c
+++ b/source/Service_Libs/fhss/channel_functions.c
@@ -81,7 +81,7 @@ static int32_t tr51_get_rand(void)
  * @param nearest_prime Nearest prime number. Must be equal to or larger than number_of_channels.
  * @param channel_table Output channel table. Has to be at least nearest_prime in length.
  */
-static void tr51_calculate_channel_table(uint16_t number_of_channels, uint16_t nearest_prime, int32_t *channel_table)
+static void tr51_calculate_channel_table(uint16_t number_of_channels, uint16_t nearest_prime, int16_t *channel_table)
 {
     int32_t i,j,k;
     tr51_seed_rand(1);
@@ -131,7 +131,7 @@ static uint8_t tr51_find_excluded(int32_t channel, uint32_t *excluded_channels)
  * @param excluded_channels Bit mask where excluded channels are set to 1.
  * @return Number of channels in sequence.
  */
-static uint16_t tr51_calculate_hopping_sequence(int32_t *channel_table, uint16_t channel_table_length, uint8_t first_element, uint8_t step_size, int32_t *output_table, uint32_t *excluded_channels)
+static uint16_t tr51_calculate_hopping_sequence(int16_t *channel_table, uint16_t channel_table_length, uint8_t first_element, uint8_t step_size, uint8_t *output_table, uint32_t *excluded_channels)
 {
     uint16_t cntr = channel_table_length;
     uint8_t index = first_element;
@@ -194,33 +194,30 @@ int32_t dh1cf_get_bc_channel_index(uint16_t slot_number, uint16_t bsi, int16_t n
     return channel_number;
 }
 
-int32_t tr51_get_uc_channel_index(uint16_t slot_number, uint8_t *mac, int16_t number_of_channels, uint32_t *excluded_channels)
+int tr51_init_channel_table(int16_t *channel_table, int16_t number_of_channels)
+{
+    uint16_t nearest_prime = tr51_calc_nearest_prime_number(number_of_channels);
+    tr51_calculate_channel_table(number_of_channels, nearest_prime, channel_table);
+    return 0;
+}
+
+int32_t tr51_get_uc_channel_index(int16_t *channel_table, uint8_t *output_table, uint16_t slot_number, uint8_t *mac, int16_t number_of_channels, uint32_t *excluded_channels)
 {
     uint16_t nearest_prime = tr51_calc_nearest_prime_number(number_of_channels);
-    int32_t channel_table[nearest_prime];
-    int32_t output_table[number_of_channels];
     uint8_t first_element;
     uint8_t step_size;
-    tr51_calculate_channel_table(number_of_channels, nearest_prime, channel_table);
     tr51_compute_cfd(mac, &first_element, &step_size, nearest_prime);
-// Not sure yet which one is the correct second parameter
-//    tr51_calculate_hopping_sequence(channel_table, number_of_channels, first_element, step_size, output_table, NULL, 0);
     tr51_calculate_hopping_sequence(channel_table, nearest_prime, first_element, step_size, output_table, excluded_channels);
     return output_table[slot_number];
 }
 
-int32_t tr51_get_bc_channel_index(uint16_t slot_number, uint16_t bsi, int16_t number_of_channels, uint32_t *excluded_channels)
+int32_t tr51_get_bc_channel_index(int16_t *channel_table, uint8_t *output_table, uint16_t slot_number, uint16_t bsi, int16_t number_of_channels, uint32_t *excluded_channels)
 {
     uint16_t nearest_prime = tr51_calc_nearest_prime_number(number_of_channels);
-    int32_t channel_table[nearest_prime];
-    int32_t output_table[number_of_channels];
     uint8_t mac[8] = {0, 0, 0, 0, 0, 0, (uint8_t)(bsi >> 8), (uint8_t)bsi};
     uint8_t first_element;
     uint8_t step_size;
-    tr51_calculate_channel_table(number_of_channels, nearest_prime, channel_table);
     tr51_compute_cfd(mac, &first_element, &step_size, nearest_prime);
-// Not sure yet which one is the correct second parameter
-//    tr51_calculate_hopping_sequence(channel_table, number_of_channels, first_element, step_size, output_table, NULL, 0);
     tr51_calculate_hopping_sequence(channel_table, nearest_prime, first_element, step_size, output_table, excluded_channels);
     return output_table[slot_number];
 }
diff --git a/source/Service_Libs/fhss/channel_functions.h b/source/Service_Libs/fhss/channel_functions.h
index 990a7ac90e6..b36ea5418bd 100644
--- a/source/Service_Libs/fhss/channel_functions.h
+++ b/source/Service_Libs/fhss/channel_functions.h
@@ -17,25 +17,37 @@
 #ifndef CHANNEL_FUNC_H_
 #define CHANNEL_FUNC_H_
 
+/**
+ * @brief Initialize channel table for TR51 channel function.
+ * @param channel_table Channel table to be initialized.
+ * @param number_of_channels Number of channels.
+ * @return 0 Success, -1 Failure.
+ */
+int tr51_init_channel_table(int16_t *channel_table, int16_t number_of_channels);
+
 /**
  * @brief Compute the unicast schedule channel index using tr51 channel function.
+ * @param channel_table Channel table.
+ * @param output_table Table used to generate output channel.
  * @param slot_number Current slot number.
  * @param mac MAC address of the node for which the index is calculated.
  * @param number_of_channels Number of channels.
  * @param excluded_channels Excluded channels.
  * @return Channel index.
  */
-int32_t tr51_get_uc_channel_index(uint16_t slot_number, uint8_t *mac, int16_t number_of_channels, uint32_t *excluded_channels);
+int32_t tr51_get_uc_channel_index(int16_t *channel_table, uint8_t *output_table, uint16_t slot_number, uint8_t *mac, int16_t number_of_channels, uint32_t *excluded_channels);
 
 /**
  * @brief Compute the broadcast schedule channel index using tr51 channel function.
+ * @param channel_table Channel table.
+ * @param output_table Table used to generate output channel.
  * @param slot_number Current slot number.
  * @param bsi Broadcast schedule identifier of the node for which the index is calculated.
  * @param number_of_channels Number of channels.
  * @param excluded_channels Excluded channels.
  * @return Channel index.
  */
-int32_t tr51_get_bc_channel_index(uint16_t slot_number, uint16_t bsi, int16_t number_of_channels, uint32_t *excluded_channels);
+int32_t tr51_get_bc_channel_index(int16_t *channel_table, uint8_t *output_table, uint16_t slot_number, uint16_t bsi, int16_t number_of_channels, uint32_t *excluded_channels);
 
 /**
  * @brief Compute the unicast schedule channel index using direct hash channel function.
diff --git a/source/Service_Libs/fhss/fhss_ws.c b/source/Service_Libs/fhss/fhss_ws.c
index 0118d35792d..c18701bb00f 100644
--- a/source/Service_Libs/fhss/fhss_ws.c
+++ b/source/Service_Libs/fhss/fhss_ws.c
@@ -58,6 +58,7 @@ struct ws_ie_t {
     uint8_t id;
 };
 
+static int fhss_ws_manage_channel_table_allocation(fhss_structure_t *fhss_structure, uint16_t channel_count);
 static void fhss_event_timer_cb(int8_t timer_id, uint16_t slots);
 static void fhss_ws_update_uc_channel_callback(fhss_structure_t *fhss_structure);
 static void fhss_unicast_handler(const fhss_api_t *fhss_api, uint16_t delay);
@@ -91,6 +92,12 @@ fhss_structure_t *fhss_ws_enable(fhss_api_t *fhss_api, const fhss_ws_configurati
         return NULL;
     }
     memset(fhss_struct->ws, 0, sizeof(fhss_ws_t));
+    if (fhss_ws_manage_channel_table_allocation(fhss_struct, channel_count)) {
+        ns_dyn_mem_free(fhss_struct->ws);
+        fhss_free_instance(fhss_api);
+        tr_error("Failed to allocate channel tables");
+        return NULL;
+    }
 
     fhss_struct->fhss_event_timer = eventOS_callback_timer_register(fhss_event_timer_cb);
     fhss_struct->ws->fhss_configuration = *fhss_configuration;
@@ -103,6 +110,24 @@ fhss_structure_t *fhss_ws_enable(fhss_api_t *fhss_api, const fhss_ws_configurati
     return fhss_struct;
 }
 
+static int fhss_ws_manage_channel_table_allocation(fhss_structure_t *fhss_structure, uint16_t channel_count)
+{
+    // Must allocate channel table for TR51
+    if (!fhss_structure->ws->tr51_channel_table && !fhss_structure->ws->tr51_output_table) {
+        fhss_structure->ws->tr51_channel_table = ns_dyn_mem_alloc(sizeof(int16_t)*channel_count);
+        if (!fhss_structure->ws->tr51_channel_table) {
+            return -1;
+        }
+        fhss_structure->ws->tr51_output_table = ns_dyn_mem_alloc(sizeof(int16_t)*channel_count);
+        if (!fhss_structure->ws->tr51_output_table) {
+            ns_dyn_mem_free(fhss_structure->ws->tr51_channel_table);
+            return -1;
+        }
+        tr51_init_channel_table(fhss_structure->ws->tr51_channel_table, channel_count);
+    }
+    return 0;
+}
+
 static uint8_t fhss_set_txrx_slot_length(fhss_structure_t *fhss_structure)
 {
     uint8_t number_of_tx_slots = ((fhss_structure->ws->fhss_configuration.fhss_broadcast_interval - fhss_structure->ws->fhss_configuration.fhss_bc_dwell_interval) / WS_MAX_TXRX_SLOT_LEN_MS) / 2;
@@ -118,7 +143,7 @@ static int32_t fhss_ws_calc_bc_channel(fhss_structure_t *fhss_structure)
     int32_t next_channel = fhss_structure->ws->fhss_configuration.broadcast_fixed_channel;
 
     if (fhss_structure->ws->fhss_configuration.ws_bc_channel_function == WS_TR51CF) {
-        next_channel = tr51_get_bc_channel_index(fhss_structure->ws->bc_slot, fhss_structure->ws->fhss_configuration.bsi, fhss_structure->number_of_channels, NULL);
+        next_channel = tr51_get_bc_channel_index(fhss_structure->ws->tr51_channel_table, fhss_structure->ws->tr51_output_table, fhss_structure->ws->bc_slot, fhss_structure->ws->fhss_configuration.bsi, fhss_structure->number_of_channels, NULL);
         if (++fhss_structure->ws->bc_slot == fhss_structure->number_of_channels) {
             fhss_structure->ws->bc_slot = 0;
         }
@@ -332,7 +357,7 @@ static void fhss_ws_update_uc_channel_callback(fhss_structure_t *fhss_structure)
     if (fhss_structure->ws->fhss_configuration.ws_uc_channel_function == WS_FIXED_CHANNEL) {
         return;
     } else if (fhss_structure->ws->fhss_configuration.ws_uc_channel_function == WS_TR51CF) {
-        next_channel = fhss_structure->rx_channel = tr51_get_uc_channel_index(fhss_structure->ws->uc_slot, mac_address, fhss_structure->number_of_channels, NULL);
+        next_channel = fhss_structure->rx_channel = tr51_get_uc_channel_index(fhss_structure->ws->tr51_channel_table, fhss_structure->ws->tr51_output_table, fhss_structure->ws->uc_slot, mac_address, fhss_structure->number_of_channels, NULL);
         if (++fhss_structure->ws->uc_slot == fhss_structure->number_of_channels) {
             fhss_structure->ws->uc_slot = 0;
         }
@@ -391,7 +416,7 @@ static int fhss_ws_tx_handle_callback(const fhss_api_t *api, bool is_broadcast_a
         uint16_t destination_slot = fhss_ws_calculate_destination_slot(neighbor_timing_info, tx_time);
         int32_t tx_channel = neighbor_timing_info->uc_timing_info.fixed_channel;
         if (neighbor_timing_info->uc_timing_info.unicast_channel_function == WS_TR51CF) {
-            tx_channel = tr51_get_uc_channel_index(destination_slot, destination_address, neighbor_timing_info->uc_timing_info.unicast_number_of_channels, NULL);
+            tx_channel = tr51_get_uc_channel_index(fhss_structure->ws->tr51_channel_table, fhss_structure->ws->tr51_output_table, destination_slot, destination_address, neighbor_timing_info->uc_timing_info.unicast_number_of_channels, NULL);
         } else if(neighbor_timing_info->uc_timing_info.unicast_channel_function == WS_DH1CF) {
             tx_channel = dh1cf_get_uc_channel_index(destination_slot, destination_address, neighbor_timing_info->uc_timing_info.unicast_number_of_channels);
         } else if (neighbor_timing_info->uc_timing_info.unicast_channel_function == WS_VENDOR_DEF_CF) {
diff --git a/source/Service_Libs/fhss/fhss_ws.h b/source/Service_Libs/fhss/fhss_ws.h
index f09fb4b2461..cf4af1040cb 100644
--- a/source/Service_Libs/fhss/fhss_ws.h
+++ b/source/Service_Libs/fhss/fhss_ws.h
@@ -35,6 +35,8 @@ struct fhss_ws
     uint16_t min_synch_interval;
     uint32_t txrx_slot_length_ms;
     uint32_t synchronization_time;
+    int16_t *tr51_channel_table;
+    uint8_t *tr51_output_table;
     bool unicast_timer_running;
     bool is_on_bc_channel;
     struct fhss_ws_configuration fhss_configuration;