diff --git a/src/main.c b/src/main.c
index a01261f..3004d99 100644
--- a/src/main.c
+++ b/src/main.c
@@ -610,9 +610,14 @@ int main(int argc, char* argv[]){
   wx_pwr_switch_periodic_handle();
 
 #if defined(PARAMETEO)
+  // clear all previous powersave indication bits
+  backup_reg_reset_all_powersave_states();
+
   // swtich power to M4. turn on sensors but keep GSM modem turned off
   pwr_save_switch_mode_to_c1();
 
+  rte_main_reset_gsm_modem = 0;
+
   delay_fixed(300);
 
 #endif
@@ -1515,7 +1520,7 @@ int main(int argc, char* argv[]){
 				gsm_sim800_initialization_pool(main_gsm_srl_ctx_ptr, &main_gsm_state);
 			}
 
-			if (main_config_data_mode->gsm == 1  && io_get_cntrl_vbat_g() == 1) {
+			if (main_config_data_mode->gsm == 1  && io_get_cntrl_vbat_g() == 1 && rte_main_woken_up == 0) {
 
 				// check if GSM modem must be power-cycled / restarted like after
 				// waking up from deep sleep or chaning power saving mode
@@ -1523,6 +1528,8 @@ int main(int argc, char* argv[]){
 					// rest the flag
 					rte_main_reset_gsm_modem = 0;
 
+					srl_init(main_gsm_srl_ctx_ptr, USART3, srl_usart3_rx_buffer, RX_BUFFER_3_LN, srl_usart3_tx_buffer, TX_BUFFER_3_LN, 115200, 1);
+
 					// reset gsm modem
 					gsm_sim800_reset(&main_gsm_state);
 
@@ -1651,7 +1658,7 @@ int main(int argc, char* argv[]){
 			backup_reg_set_monitor(9);
 
 #ifdef PARAMETEO
-			if (main_config_data_mode->gsm == 1 && io_get_cntrl_vbat_g() == 1) {
+			if (main_config_data_mode->gsm == 1 && io_get_cntrl_vbat_g() == 1 && rte_main_woken_up == 0) {
 				gsm_sim800_poolers_ten_seconds(main_gsm_srl_ctx_ptr, &main_gsm_state);
 
 				packet_tx_tcp_handler();
diff --git a/src/pwr_save.c b/src/pwr_save.c
index 5921391..365418b 100644
--- a/src/pwr_save.c
+++ b/src/pwr_save.c
@@ -350,6 +350,9 @@ int pwr_save_switch_mode_to_c1(void) {
 	// disconnect APRS-IS connection if it is established
 	aprsis_disconnect();
 
+	// close and deconfigure port used for communication with GPRS module
+	srl_close(main_gsm_srl_ctx_ptr);
+
 	// turn ON +5V_S (and internal VHF radio module in HW-RevB)
 	io___cntrl_vbat_s_enable();
 
@@ -394,6 +397,9 @@ void pwr_save_switch_mode_to_c2(void) {
 	// disconnect APRS-IS connection if it is established
 	aprsis_disconnect();
 
+	// close and deconfigure port used for communication with GPRS module
+	srl_close(main_gsm_srl_ctx_ptr);
+
 	// turn OFF +5V_S (and internal VHF radio module in HW-RevB)
 	io___cntrl_vbat_s_disable();
 
@@ -472,6 +478,9 @@ int pwr_save_switch_mode_to_m4(void) {
 	// disconnect APRS-IS connection if it is established
 	aprsis_disconnect();
 
+	// close and deconfigure port used for communication with GPRS module
+	srl_close(main_gsm_srl_ctx_ptr);
+
 	// turn ON +5V_S (and internal VHF radio module in HW-RevB)
 	io___cntrl_vbat_s_enable();
 
@@ -551,6 +560,9 @@ void pwr_save_switch_mode_to_i5(void) {
 	// disconnect APRS-IS connection if it is established
 	aprsis_disconnect();
 
+	// close and deconfigure port used for communication with GPRS module
+	srl_close(main_gsm_srl_ctx_ptr);
+
 	// turn OFF +5V_S (and internal VHF radio module in HW-RevB)
 	io___cntrl_vbat_s_disable();
 
@@ -616,6 +628,9 @@ void pwr_save_switch_mode_to_l6(uint16_t sleep_time) {
 	// disconnect APRS-IS connection if it is established
 	aprsis_disconnect();
 
+	NVIC_DisableIRQ( USART3_IRQn );
+
+	// close and deconfigure port used for communication with GPRS module
 	srl_close(main_gsm_srl_ctx_ptr);
 
 	// disable ADC used for vbat measurement
@@ -711,6 +726,7 @@ void pwr_save_switch_mode_to_l7(uint16_t sleep_time) {
 	// disconnect APRS-IS connection if it is established
 	aprsis_disconnect();
 
+	// close and deconfigure port used for communication with GPRS module
 	srl_close(main_gsm_srl_ctx_ptr);
 
 	// disable ADC used for vbat measurement
@@ -814,8 +830,6 @@ void pwr_save_init(config_data_powersave_mode_t mode) {
 
 	}
 
-	//pwr_save_unclock_rtc_backup_regs();
-
 	// reset a status register
 	backup_reg_reset_all_powersave_states();
 	backup_reg_reset_inhibit_periodic_pwr_switch();
@@ -1006,6 +1020,8 @@ config_data_powersave_mode_t pwr_save_pooling_handler(	const config_data_mode_t
 						if (timers->wx_transmit_period >= 5) {
 							if (minutes_to_wx > 1) {
 								pwr_save_switch_mode_to_c2();
+
+								//reinit_gprs = 1;
 							}
 							else {
 								reinit_sensors = pwr_save_switch_mode_to_c0();
@@ -1024,6 +1040,8 @@ config_data_powersave_mode_t pwr_save_pooling_handler(	const config_data_mode_t
 						if (minutes_to_wx > 1) {
 							if (config->powersave_keep_gsm_always_enabled == 0){
 								reinit_sensors = pwr_save_switch_mode_to_m4();
+
+								//reinit_gprs = 1;
 							}
 							else {
 								reinit_sensors = pwr_save_switch_mode_to_m4a();
@@ -1082,6 +1100,8 @@ config_data_powersave_mode_t pwr_save_pooling_handler(	const config_data_mode_t
 					if (config->digi == 1) {		// DIGI + WX + GSM
 						if (minutes_to_wx > 1) {
 							pwr_save_switch_mode_to_c2();
+
+							//reinit_gprs = 1;
 						}
 						else {
 							reinit_sensors = pwr_save_switch_mode_to_c0();
@@ -1110,6 +1130,8 @@ config_data_powersave_mode_t pwr_save_pooling_handler(	const config_data_mode_t
 									// if there is 30 to 60 seconds to next wx packet
 									if (config->powersave_keep_gsm_always_enabled == 0){
 										reinit_sensors = pwr_save_switch_mode_to_m4();
+
+										//reinit_gprs = 1;
 									}
 									else {
 										reinit_sensors = pwr_save_switch_mode_to_m4a();