diff --git a/drivers/modem/hl78xx/CMakeLists.txt b/drivers/modem/hl78xx/CMakeLists.txt
index 1320925476238..2897f935bb24d 100644
--- a/drivers/modem/hl78xx/CMakeLists.txt
+++ b/drivers/modem/hl78xx/CMakeLists.txt
@@ -13,6 +13,11 @@ zephyr_library_sources(
     hl78xx_apis.c
 )
 
+zephyr_library_sources_ifdef(
+    CONFIG_MODEM_HL78XX_AT_SHELL
+    hl78xx_at_shell.c
+)
+
 add_subdirectory_ifdef(CONFIG_HL78XX_EVT_MONITOR hl78xx_evt_monitor)
 
 zephyr_library_include_directories(
diff --git a/drivers/modem/hl78xx/Kconfig.hl78xx b/drivers/modem/hl78xx/Kconfig.hl78xx
index bed24a07276fa..08ae3a7f792c5 100644
--- a/drivers/modem/hl78xx/Kconfig.hl78xx
+++ b/drivers/modem/hl78xx/Kconfig.hl78xx
@@ -57,33 +57,21 @@ config MODEM_HL78XX_12_FW_R6
 
 endif # MODEM_HL78XX_12
 
-config MODEM_HL78XX_UART_BUFFER_SIZES
-	int "The UART receive and transmit buffer sizes in bytes."
-	default 512
-
-config MODEM_HL78XX_CHAT_BUFFER_SIZES
-	int "The size of the buffers used for the chat scripts in bytes."
-	default 512
-
-config MODEM_HL78XX_USER_PIPE_BUFFER_SIZES
-	int "The size of the buffers used for each user pipe in bytes."
-	default 512
-
-config MODEM_HL78XX_RECV_BUF_CNT
-	int "The number of allocated network buffers"
-	default 30
-
-config MODEM_HL78XX_RECV_BUF_SIZE
-	int "The size of the network buffers in bytes"
-	default 128
-
-config MODEM_HL78XX_RX_WORKQ_STACK_SIZE
-	int "Stack size for the Sierra Wireless HL78XX driver modem driver work queue"
-	default 2048
-	help
-	  This stack is used by the work queue to pass off net_pkt data
-	  to the rest of the network stack, letting the rx thread continue
-	  processing data.
+config MODEM_HL78XX_AT_SHELL
+	bool "AT command shell"
+	help
+	  Enable AT command shell for the modem.
+if MODEM_HL78XX_AT_SHELL
+config MODEM_AT_SHELL_RESPONSE_TIMEOUT_MS
+	int "Timeout waiting for response to AT command in milliseconds"
+	default 500
+config MODEM_AT_SHELL_COMMAND_MAX_SIZE
+	int "Maximum size of AT command"
+	default 32
+config MODEM_AT_SHELL_RESPONSE_MAX_SIZE
+	int "Maximum size of AT response"
+	default 64
+endif # MODEM_HL78XX_AT_SHELL
 
 choice MODEM_HL78XX_ADDRESS_FAMILY
 	prompt "IP Address family"
@@ -719,6 +707,55 @@ config MODEM_MIN_ALLOWED_SIGNAL_STRENGTH
 	    default -140
 	    range - 140 0
 
+config MODEM_HL78XX_AIRVANTAGE
+	bool "AirVantage"
+	help
+	  Enable HL78xx modules connect to the AirVantage DM Server over OMA
+
+if MODEM_HL78XX_AIRVANTAGE
+
+choice MODEM_HL78XX_AIRVANTAGE_SESSION_INITIATION
+	prompt "AirVantage Initialization"
+	default MODEM_HL78XX_AIRVANTAGE_HOST_INITIATED
+	help
+	  Choose this setting to enable HL78xx modules to connect to the AirVantage DM Server.
+config MODEM_HL78XX_AIRVANTAGE_HOST_INITIATED
+	bool "Host Initiated"
+	help
+	  The host application is responsible for initiating the connection to the AirVantage server.
+
+config MODEM_HL78XX_AIRVANTAGE_MODULE_INITIATED
+	bool "Module Initiated"
+	help
+	  The HL78xx module is responsible for initiating the connection to the AirVantage server.
+endchoice
+
+menuconfig MODEM_HL78XX_AIRVANTAGE_USER_AGREEMENT
+	bool "User Agreement Activation"
+	help
+	  Activating User Agreements enables the host processor application to control the FOTA flow. For instance, the host
+	  processor application, busy fulfilling a service (e.g. car is operating, ongoing payment transaction), can decide to
+	  postpone firmware download or install operations, as accepting a firmware installation will lead the embedded
+	  module to reboot upon FOTA completion.
+
+if MODEM_HL78XX_AIRVANTAGE_USER_AGREEMENT
+config MODEM_HL78XX_AIRVANTAGE_UA_CONNECT_AIRVANTAGE
+	bool "Connect to AirVantage"
+	help
+	  Module requests the user/application to connect to AirVantage
+
+config MODEM_HL78XX_AIRVANTAGE_UA_DOWNLOAD_FIRMWARE
+	bool "Download Firmware"
+	help
+	  AirVantage requests the device to download a firmware package
+
+config MODEM_HL78XX_AIRVANTAGE_UA_INSTALL_FIRMWARE
+	bool "Install Firmware"
+	help
+	  AirVantage requests the device to install the downloaded firmware package
+endif # MODEM_HL78XX_AIRVANTAGE_USER_AGREEMENT
+endif # MODEM_HL78XX_AIRVANTAGE
+
 config MODEM_HL78XX_ADVANCED_SOCKET_CONFIG
 	bool "Advanced socket configuration"
 	help
@@ -759,6 +796,14 @@ config MODEM_HL78XX_NUM_SOCKETS
 	help
 	  Maximum number of sockets that can be opened at the same time
 
+config MODEM_HL78XX_MAX_PDP_CONTEXTS
+	int "Maximum number of PDP contexts"
+	default 1
+	range 1 1 if !MODEM_HL78XX_ADVANCED_SOCKET_CONFIG
+	range 1 2 if MODEM_HL78XX_ADVANCED_SOCKET_CONFIG
+	help
+	  Maximum number of PDP contexts that can be defined at the same time
+
 config MODEM_HL78XX_SOCKETS_SOCKOPT_TLS
 	bool "TLS for sockets"
 	depends on NET_SOCKETS_SOCKOPT_TLS
@@ -766,38 +811,58 @@ config MODEM_HL78XX_SOCKETS_SOCKOPT_TLS
 	  This option enables TLS (Transport Layer Security) for sockets
 	  on the HL78xx modem.
 
-config MODEM_HL78XX_LOG_CONTEXT_VERBOSE_DEBUG
-	bool "Verbose debug output in the HL78xx"
-	depends on MODEM_MODULES_LOG_LEVEL_DBG
+config MODEM_HL78XX_UART_BUFFER_SIZES
+	int "The UART receive and transmit buffer sizes in bytes."
+	default 512
+
+config MODEM_HL78XX_CHAT_BUFFER_SIZES
+	int "The size of the buffers used for the chat scripts in bytes."
+	default 512
+
+config MODEM_HL78XX_USER_PIPE_BUFFER_SIZES
+	int "The size of the buffers used for each user pipe in bytes."
+	default 512
+
+config MODEM_HL78XX_RECV_BUF_CNT
+	int "The number of allocated network buffers"
+	default 30
+
+config MODEM_HL78XX_RECV_BUF_SIZE
+	int "The size of the network buffers in bytes"
+	default 128
+
+config MODEM_HL78XX_RX_WORKQ_STACK_SIZE
+	int "Stack size for the Sierra Wireless HL78XX driver modem driver work queue"
+	default 2048
 	help
-	  Enabling this setting will turn on VERY heavy debugging from the
-	  modem.  Do NOT leave on for production.
-	  This setting is depends on global log level debug.
+	  This stack is used by the work queue to pass off net_pkt data
+	  to the rest of the network stack, letting the rx thread continue
+	  processing data.
 
-config MODEM_HL78XX_DEV_POWER_PULSE_DURATION
+config MODEM_HL78XX_DEV_POWER_PULSE_DURATION_MS
 	int "Duration of the power-on pulse in milliseconds."
 	default 1500
 	help
 	  Trigger a power-on sequence by setting a power on GPIO pin high
 	  for a specific amount of time.
 
-config MODEM_HL78XX_DEV_RESET_PULSE_DURATION
+config MODEM_HL78XX_DEV_RESET_PULSE_DURATION_MS
 	int "Duration of the power-reset pulse in milliseconds."
 	default 100
 	help
 	  Trigger a power-reset sequence by setting a reset GPIO pin high
 	  for a specific amount of time.
 
-config MODEM_HL78XX_DEV_STARTUP_TIME
+config MODEM_HL78XX_DEV_STARTUP_TIME_MS
 	int "Wait before assuming the device is ready."
-	default 1000
+	default 120
 	help
 	  The expected time (in milliseconds) the modem needs to fully power on
 	  and become operational.
 
-config MODEM_HL78XX_DEV_SHUTDOWN_TIME
+config MODEM_HL78XX_DEV_SHUTDOWN_TIME_MS
 	int "Wait before assuming the device is completely off."
-	default 1000
+	default 120
 	help
 	  The amount of time (in milliseconds) the system should wait for the modem
 	  to fully shut down
@@ -817,6 +882,14 @@ config MODEM_HL78XX_OFFLOAD_INIT_PRIORITY
 	  Do not mess with it unless you know what you are doing.
 	  Make sure offload init priority higher than dev init priority
 
+config MODEM_HL78XX_LOG_CONTEXT_VERBOSE_DEBUG
+	bool "Verbose debug output in the HL78xx"
+	depends on MODEM_MODULES_LOG_LEVEL_DBG
+	help
+	  Enabling this setting will turn on VERY heavy debugging from the
+	  modem.  Do NOT leave on for production.
+	  This setting is depends on global log level debug.
+
 rsource "hl78xx_evt_monitor/Kconfig.hl78xx_evt_monitor"
 
 endif # MODEM_HL78XX
diff --git a/drivers/modem/hl78xx/hl78xx.c b/drivers/modem/hl78xx/hl78xx.c
index 92542a447abf2..a6cbd65771c15 100644
--- a/drivers/modem/hl78xx/hl78xx.c
+++ b/drivers/modem/hl78xx/hl78xx.c
@@ -109,6 +109,8 @@ static const char *hl78xx_state_str(enum hl78xx_state state)
 		return "await registered";
 	case MODEM_HL78XX_STATE_CARRIER_ON:
 		return "carrier on";
+	case MODEM_HL78XX_STATE_FOTA:
+		return "fota";
 	case MODEM_HL78XX_STATE_CARRIER_OFF:
 		return "carrier off";
 	case MODEM_HL78XX_STATE_SIM_POWER_OFF:
@@ -153,6 +155,28 @@ static const char *hl78xx_event_str(enum hl78xx_event event)
 		return "bus closed";
 	case MODEM_HL78XX_EVENT_SOCKET_READY:
 		return "socket ready";
+#ifdef CONFIG_MODEM_HL78XX_AIRVANTAGE
+	case MODEM_HL78XX_EVENT_WDSI_UPDATE:
+		return "wdsi update";
+	case MODEM_HL78XX_EVENT_WDSI_RESTART:
+		return "wdsi restart";
+	case MODEM_HL78XX_EVENT_WDSI_DOWNLOAD_REQUEST:
+		return "wdsi download request";
+	case MODEM_HL78XX_EVENT_WDSI_DOWNLOAD_PROGRESS:
+		return "wdsi download progress";
+	case MODEM_HL78XX_EVENT_WDSI_DOWNLOAD_COMPLETE:
+		return "wdsi download complete";
+	case MODEM_HL78XX_EVENT_WDSI_INSTALL_REQUEST:
+		return "wdsi install request";
+	case MODEM_HL78XX_EVENT_WDSI_INSTALLING_FIRMWARE:
+		return "wdsi installing firmware";
+	case MODEM_HL78XX_EVENT_WDSI_FIRMWARE_INSTALL_SUCCEEDED:
+		return "wdsi firmware install succeeded";
+	case MODEM_HL78XX_EVENT_WDSI_FIRMWARE_INSTALL_FAILED:
+		return "wdsi firmware install failed";
+#endif /* CONFIG_MODEM_HL78XX_AIRVANTAGE */
+	case MODEM_HL78XX_EVENT_MDM_RESTART:
+		return "modem unexpected restart";
 	default:
 		return "unknown event";
 	}
@@ -355,12 +379,28 @@ void hl78xx_on_cxreg(struct modem_chat *chat, char **argv, uint16_t argc, void *
 void hl78xx_on_ksup(struct modem_chat *chat, char **argv, uint16_t argc, void *user_data)
 {
 	int module_status;
+	struct hl78xx_data *data = (struct hl78xx_data *)user_data;
 	struct hl78xx_evt event = {.type = HL78XX_LTE_MODEM_STARTUP};
 
 	if (argc != 2) {
 		return;
 	}
 	module_status = ATOI(argv[1], 0, "module_status");
+	data->status.boot.status = module_status;
+	/* Check for unexpected restart */
+	if (data->status.boot.is_booted_previously == true &&
+	    module_status == (int)HL78XX_MODULE_READY) {
+		LOG_DBG("Modem unexpected restart detected %d", module_status);
+		hl78xx_delegate_event(data, MODEM_HL78XX_EVENT_MDM_RESTART);
+	} else if (data->status.boot.is_booted_previously == true &&
+		   module_status != (int)HL78XX_MODULE_READY) {
+		LOG_DBG("Modem failed to start %d", module_status);
+		hl78xx_delegate_event(data, MODEM_HL78XX_EVENT_SUSPEND);
+	} else {
+		data->status.boot.is_booted_previously = true;
+		LOG_DBG("Modem started successfully %d %d", module_status,
+			data->status.boot.is_booted_previously);
+	}
 	event.content.value = module_status;
 	event_dispatcher_dispatch(&event);
 	HL78XX_LOG_DBG("Module status: %d", module_status);
@@ -436,6 +476,20 @@ void hl78xx_on_cgmr(struct modem_chat *chat, char **argv, uint16_t argc, void *u
 	k_mutex_unlock(&data->api_lock);
 }
 
+void hl78xx_on_serial_number(struct modem_chat *chat, char **argv, uint16_t argc, void *user_data)
+{
+	struct hl78xx_data *data = (struct hl78xx_data *)user_data;
+
+	if (argc != 2) {
+		return;
+	}
+	HL78XX_LOG_DBG("Serial Number: %s %s", argv[0], argv[1]);
+	k_mutex_lock(&data->api_lock, K_FOREVER);
+	safe_strncpy((char *)data->identity.serial_number, argv[1],
+		     sizeof(data->identity.serial_number));
+	k_mutex_unlock(&data->api_lock);
+}
+
 void hl78xx_on_iccid(struct modem_chat *chat, char **argv, uint16_t argc, void *user_data)
 {
 	struct hl78xx_data *data = (struct hl78xx_data *)user_data;
@@ -475,6 +529,27 @@ void hl78xx_on_kstatev(struct modem_chat *chat, char **argv, uint16_t argc, void
 		event_dispatcher_dispatch(&event);
 	}
 }
+
+void hl78xx_on_cgact(struct modem_chat *chat, char **argv, uint16_t argc, void *user_data)
+{
+	struct hl78xx_data *data = (struct hl78xx_data *)user_data;
+	int act_status = -1;
+	int cid = -1;
+
+	if (argc != 3) {
+		return;
+	}
+	cid = ATOI(argv[1], -1, "cid");
+	act_status = ATOI(argv[2], -1, "act_status");
+	if (cid == -1 || act_status == -1 || cid > CONFIG_MODEM_HL78XX_MAX_PDP_CONTEXTS) {
+		/* Invalid parameters */
+		return;
+	}
+
+	data->status.gprs[cid - 1].is_active = (act_status == 1) ? true : false;
+	data->status.gprs[cid - 1].cid = cid;
+	HL78XX_LOG_DBG("CGACT: %s %s", argv[0], argv[2]);
+}
 #endif
 
 void hl78xx_on_ksrep(struct modem_chat *chat, char **argv, uint16_t argc, void *user_data)
@@ -590,7 +665,58 @@ void hl78xx_on_cops(struct modem_chat *chat, char **argv, uint16_t argc, void *u
 		     sizeof(data->status.network_operator.operator));
 	data->status.network_operator.format = ATOI(argv[2], 0, "network_operator_format");
 }
+#ifdef CONFIG_MODEM_HL78XX_AIRVANTAGE
+void hl78xx_on_wdsi(struct modem_chat *chat, char **argv, uint16_t argc, void *user_data)
+{
+	struct hl78xx_data *data = (struct hl78xx_data *)user_data;
+	struct hl78xx_evt event = {.type = HL78XX_LTE_FOTA_UPDATE_STATUS};
+	int wsi_status = -1;
+	uint32_t wsi_data = 0;
 
+	if (argc < 2) {
+		return;
+	}
+	wsi_status = ATOI(argv[1], -1, "wdsi");
+	if (wsi_status == -1) {
+		return;
+	}
+	data->status.wdsi.level = wsi_status;
+	if (argc == 3) {
+		wsi_data = ATOI(argv[2], 0, "data");
+		data->status.wdsi.data = wsi_data;
+	}
+	if (data->status.wdsi.level == WDSI_FIRMWARE_AVAILABLE) {
+		data->status.wdsi.fota_size = wsi_data;
+		hl78xx_delegate_event(data, MODEM_HL78XX_EVENT_WDSI_UPDATE);
+	} else if (data->status.wdsi.level == WDSI_BOOTSTRAP_CREDENTIALS_PRESENT) {
+		hl78xx_delegate_event(data, MODEM_HL78XX_EVENT_WDSI_RESTART);
+	} else if (data->status.wdsi.level == WDSI_FIRMWARE_DOWNLOAD_REQUEST) {
+		hl78xx_delegate_event(data, MODEM_HL78XX_EVENT_WDSI_DOWNLOAD_REQUEST);
+	} else if (data->status.wdsi.level == WDSI_DOWNLOAD_IN_PROGRESS) {
+		hl78xx_delegate_event(data, MODEM_HL78XX_EVENT_WDSI_DOWNLOAD_PROGRESS);
+		data->status.wdsi.progress = wsi_data;
+	} else if (data->status.wdsi.level == WDSI_FIRMWARE_DOWNLOADED) {
+		hl78xx_delegate_event(data, MODEM_HL78XX_EVENT_WDSI_DOWNLOAD_COMPLETE);
+	} else if (data->status.wdsi.level == WDSI_FIRMWARE_INSTALL_REQUEST) {
+		hl78xx_delegate_event(data, MODEM_HL78XX_EVENT_WDSI_INSTALL_REQUEST);
+	} else if (data->status.wdsi.level == WDSI_FIRMWARE_UPDATE_START) {
+		hl78xx_delegate_event(data, MODEM_HL78XX_EVENT_WDSI_INSTALLING_FIRMWARE);
+	} else if (data->status.wdsi.level == WDSI_FIRMWARE_UPDATE_SUCCESS) {
+		hl78xx_delegate_event(data, MODEM_HL78XX_EVENT_WDSI_FIRMWARE_INSTALL_SUCCEEDED);
+	} else if (data->status.wdsi.level == WDSI_FIRMWARE_UPDATE_FAILED) {
+		hl78xx_delegate_event(data, MODEM_HL78XX_EVENT_WDSI_FIRMWARE_INSTALL_FAILED);
+	} else {
+		/* other WDSI levels during FOTA can be handled here if needed */
+	}
+	if ((data->status.wdsi.level == WDSI_DOWNLOAD_IN_PROGRESS &&
+	     (data->status.wdsi.progress == 0 || data->status.wdsi.progress == 100)) ||
+	    data->status.wdsi.level != WDSI_DOWNLOAD_IN_PROGRESS) {
+		event.content.wdsi_indication = data->status.wdsi.level;
+		event_dispatcher_dispatch(&event);
+	}
+	HL78XX_LOG_DBG("WDSI: %d %d", wsi_status, wsi_data);
+}
+#endif /* CONFIG_MODEM_HL78XX_AIRVANTAGE */
 /* -------------------------------------------------------------------------
  * Pipe & chat initialization
  * - modem backend pipe setup and chat initialisation helpers
@@ -877,32 +1003,36 @@ static void hl78xx_await_power_on_event_handler(struct hl78xx_data *data, enum h
 {
 	switch (evt) {
 	case MODEM_HL78XX_EVENT_TIMEOUT:
-		hl78xx_enter_state(data, MODEM_HL78XX_STATE_RUN_INIT_SCRIPT);
+		modem_pipe_attach(data->uart_pipe, hl78xx_bus_pipe_handler, data);
+		modem_pipe_open_async(data->uart_pipe);
 		break;
 
 	case MODEM_HL78XX_EVENT_SUSPEND:
 		hl78xx_enter_state(data, MODEM_HL78XX_STATE_IDLE);
 		break;
 
+	case MODEM_HL78XX_EVENT_BUS_OPENED:
+		modem_chat_attach(&data->chat, data->uart_pipe);
+		hl78xx_run_post_restart_script_async(data);
+		break;
+
+	case MODEM_HL78XX_EVENT_SCRIPT_SUCCESS:
+		hl78xx_enter_state(data, MODEM_HL78XX_STATE_RUN_INIT_SCRIPT);
+		break;
+
 	default:
 		break;
 	}
 }
 static int hl78xx_on_run_init_script_state_enter(struct hl78xx_data *data)
 {
-	modem_pipe_attach(data->uart_pipe, hl78xx_bus_pipe_handler, data);
-	return modem_pipe_open_async(data->uart_pipe);
+	hl78xx_run_init_script_async(data);
+	return 0;
 }
 
 static void hl78xx_run_init_script_event_handler(struct hl78xx_data *data, enum hl78xx_event evt)
 {
 	switch (evt) {
-	case MODEM_HL78XX_EVENT_BUS_OPENED:
-		modem_chat_attach(&data->chat, data->uart_pipe);
-		/* Run init script via chat TU wrapper (script symbols live in hl78xx_chat.c) */
-		hl78xx_run_init_script_async(data);
-		break;
-
 	case MODEM_HL78XX_EVENT_SCRIPT_SUCCESS:
 		hl78xx_enter_state(data, MODEM_HL78XX_STATE_RUN_RAT_CONFIG_SCRIPT);
 		break;
@@ -967,11 +1097,10 @@ static void hl78xx_run_init_fail_script_event_handler(struct hl78xx_data *data,
 
 	case MODEM_HL78XX_EVENT_SCRIPT_FAILED:
 		if (!hl78xx_gpio_is_enabled(&config->mdm_gpio_wake)) {
-			LOG_ERR("modem wake pin is not enabled, make sure modem low power is "
-				"disabled, if you are not sure enable wake up pin by adding it "
-				"dts!!");
+			LOG_ERR("The modem wake pin is not enabled. Make sure that modem low-power "
+				"mode is disabled. If you’re unsure, enable it by adding the "
+				"corresponding DTS configuration entry.");
 		}
-
 		if (data->status.script_fail_counter++ < MAX_SCRIPT_AT_CMD_RETRY) {
 			if (hl78xx_gpio_is_enabled(&config->mdm_gpio_pwr_on)) {
 				hl78xx_enter_state(data, MODEM_HL78XX_STATE_POWER_ON_PULSE);
@@ -1008,6 +1137,7 @@ static int hl78xx_on_rat_cfg_script_state_enter(struct hl78xx_data *data)
 	}
 
 	if (modem_require_restart) {
+		HL78XX_LOG_DBG("Modem restart required to apply new RAT/Band settings");
 		ret = modem_dynamic_cmd_send(data, NULL, cmd_restart, strlen(cmd_restart),
 					     hl78xx_get_ok_match(), 1, false);
 		if (ret < 0) {
@@ -1027,17 +1157,13 @@ static int hl78xx_on_rat_cfg_script_state_enter(struct hl78xx_data *data)
 
 static void hl78xx_run_rat_cfg_script_event_handler(struct hl78xx_data *data, enum hl78xx_event evt)
 {
-	int ret = 0;
-
 	switch (evt) {
 	case MODEM_HL78XX_EVENT_TIMEOUT:
 		LOG_DBG("Rebooting modem to apply new RAT settings");
-		ret = hl78xx_run_post_restart_script_async(data);
-		if (ret < 0) {
-			hl78xx_delegate_event(data, MODEM_HL78XX_EVENT_SUSPEND);
-		}
 		break;
-
+	case MODEM_HL78XX_EVENT_MDM_RESTART:
+		hl78xx_enter_state(data, MODEM_HL78XX_STATE_RUN_INIT_SCRIPT);
+		break;
 	case MODEM_HL78XX_EVENT_SCRIPT_SUCCESS:
 		hl78xx_enter_state(data, MODEM_HL78XX_STATE_RUN_ENABLE_GPRS_SCRIPT);
 		break;
@@ -1116,7 +1242,7 @@ static void hl78xx_enable_gprs_event_handler(struct hl78xx_data *data, enum hl78
 	switch (evt) {
 	case MODEM_HL78XX_EVENT_SCRIPT_SUCCESS:
 	case MODEM_HL78XX_EVENT_SCRIPT_FAILED:
-		hl78xx_start_timer(data, MODEM_HL78XX_PERIODIC_SCRIPT_TIMEOUT);
+		hl78xx_enter_state(data, MODEM_HL78XX_STATE_AWAIT_REGISTERED);
 		break;
 
 	case MODEM_HL78XX_EVENT_TIMEOUT:
@@ -1169,6 +1295,11 @@ static void hl78xx_await_registered_event_handler(struct hl78xx_data *data, enum
 
 		break;
 
+	case MODEM_HL78XX_EVENT_MDM_RESTART:
+		LOG_DBG("Modem restart detected %d", __LINE__);
+		hl78xx_enter_state(data, MODEM_HL78XX_STATE_RUN_INIT_SCRIPT);
+		break;
+
 	case MODEM_HL78XX_EVENT_REGISTERED:
 		hl78xx_enter_state(data, MODEM_HL78XX_STATE_CARRIER_ON);
 		break;
@@ -1190,6 +1321,16 @@ static int hl78xx_on_await_registered_state_leave(struct hl78xx_data *data)
 
 static int hl78xx_on_carrier_on_state_enter(struct hl78xx_data *data)
 {
+#ifdef CONFIG_MODEM_HL78XX_RAT_GSM
+	int ret = 0;
+	/* Activate the PDP context */
+	ret = hl78xx_gsm_pdp_activate(data);
+	if (ret) {
+		LOG_ERR("Failed to activate PDP context: %d", ret);
+		hl78xx_delegate_event(data, MODEM_HL78XX_EVENT_SCRIPT_FAILED);
+		return ret;
+	}
+#endif /* CONFIG_MODEM_HL78XX_RAT_GSM */
 	notif_carrier_on(data->dev);
 	iface_status_work_cb(data, hl78xx_chat_callback_handler);
 	return 0;
@@ -1203,6 +1344,7 @@ static void hl78xx_carrier_on_event_handler(struct hl78xx_data *data, enum hl78x
 
 		break;
 	case MODEM_HL78XX_EVENT_SCRIPT_FAILED:
+		/* TODO: Handle script failure */
 		break;
 
 	case MODEM_HL78XX_EVENT_TIMEOUT:
@@ -1217,6 +1359,19 @@ static void hl78xx_carrier_on_event_handler(struct hl78xx_data *data, enum hl78x
 		hl78xx_enter_state(data, MODEM_HL78XX_STATE_INIT_POWER_OFF);
 		break;
 
+	case MODEM_HL78XX_EVENT_MDM_RESTART:
+		LOG_DBG("Modem restart detected %d", __LINE__);
+		hl78xx_enter_state(data, MODEM_HL78XX_STATE_RUN_INIT_SCRIPT);
+		break;
+#ifdef CONFIG_MODEM_HL78XX_AIRVANTAGE
+	case MODEM_HL78XX_EVENT_WDSI_UPDATE:
+	case MODEM_HL78XX_EVENT_WDSI_DOWNLOAD_REQUEST:
+	case MODEM_HL78XX_EVENT_WDSI_DOWNLOAD_PROGRESS:
+	case MODEM_HL78XX_EVENT_WDSI_INSTALL_REQUEST:
+		hl78xx_enter_state(data, MODEM_HL78XX_STATE_FOTA);
+		data->status.wdsi.in_progress = true;
+		break;
+#endif /* CONFIG_MODEM_HL78XX_AIRVANTAGE */
 	default:
 		break;
 	}
@@ -1227,7 +1382,118 @@ static int hl78xx_on_carrier_on_state_leave(struct hl78xx_data *data)
 	hl78xx_stop_timer(data);
 	return 0;
 }
+#ifdef CONFIG_MODEM_HL78XX_AIRVANTAGE
+static int hl78xx_on_fota_state_enter(struct hl78xx_data *data)
+{
+	HL78XX_LOG_DBG("Entering FOTA state");
+	hl78xx_start_timer(data, K_MSEC(100));
+	/* Decide best time to start FOTA */
+	return 0;
+}
 
+static void hl78xx_fota_event_handler(struct hl78xx_data *data, enum hl78xx_event evt)
+{
+	switch (evt) {
+	case MODEM_HL78XX_EVENT_TIMEOUT:
+		/* Start FOTA process */
+		if (data->status.wdsi.in_progress == true) {
+			if (data->status.wdsi.level == WDSI_FIRMWARE_DOWNLOAD_REQUEST &&
+			    data->status.wdsi.fota_state != HL78XX_WDSI_FOTA_DOWNLOADING) {
+				LOG_INF("FOTA available, notifying modem...");
+				hl78xx_delegate_event(data,
+						      MODEM_HL78XX_EVENT_WDSI_DOWNLOAD_REQUEST);
+			} else if (data->status.wdsi.level == WDSI_FIRMWARE_INSTALL_REQUEST &&
+				   data->status.wdsi.fota_state != HL78XX_WDSI_FOTA_INSTALLING) {
+				LOG_INF("FOTA downloaded, notifying modem...");
+				hl78xx_delegate_event(data,
+						      MODEM_HL78XX_EVENT_WDSI_INSTALL_REQUEST);
+			} else {
+				HL78XX_LOG_DBG("FOTA in progress, notifying modem...");
+				hl78xx_delegate_event(data, MODEM_HL78XX_EVENT_WDSI_UPDATE);
+			}
+		}
+		break;
+	case MODEM_HL78XX_EVENT_SCRIPT_SUCCESS:
+		HL78XX_LOG_DBG("FOTA script completed successfully.");
+		break;
+	case MODEM_HL78XX_EVENT_WDSI_UPDATE:
+		if (data->status.wdsi.level == WDSI_DM_SESSION_CLOSED) {
+			LOG_INF("FOTA DM session closed.");
+			if (data->status.wdsi.in_progress == true) {
+				LOG_INF("FOTA update process completed, rebooting modem...");
+			} else {
+				LOG_INF("FOTA update process not started, returning to "
+					"carrier on state...");
+			}
+			break;
+		}
+		break;
+	case MODEM_HL78XX_EVENT_WDSI_RESTART:
+		LOG_INF("FOTA modem restart occurred...%d", data->status.boot.is_booted_previously);
+		break;
+	case MODEM_HL78XX_EVENT_WDSI_DOWNLOAD_REQUEST:
+		if (data->status.wdsi.fota_state == HL78XX_WDSI_FOTA_DOWNLOADING) {
+			return;
+		}
+		LOG_INF("FOTA download requested File size %d bytes, starting download...",
+			data->status.wdsi.fota_size);
+		data->status.wdsi.fota_state = HL78XX_WDSI_FOTA_DOWNLOADING;
+		hl78xx_run_fota_script_download_accept_async(data);
+		break;
+	case MODEM_HL78XX_EVENT_WDSI_DOWNLOAD_PROGRESS:
+		LOG_INF("FOTA update in progress, completion... %d%%", data->status.wdsi.progress);
+		break;
+	case MODEM_HL78XX_EVENT_WDSI_DOWNLOAD_COMPLETE:
+		LOG_INF("FOTA download completed...");
+		data->status.wdsi.fota_state = HL78XX_WDSI_FOTA_DOWNLOAD_COMPLETED;
+		break;
+	case MODEM_HL78XX_EVENT_WDSI_INSTALL_REQUEST:
+		LOG_INF("FOTA install request received...");
+		data->status.wdsi.fota_state = HL78XX_WDSI_FOTA_INSTALLING;
+		hl78xx_run_fota_script_install_accept_async(data);
+		break;
+	case MODEM_HL78XX_EVENT_WDSI_INSTALLING_FIRMWARE:
+		LOG_INF("Install accepted, FOTA update installing...");
+		LOG_INF("This may take several minutes, please wait...");
+		LOG_INF("Do not power off the modem!!!");
+		break;
+	case MODEM_HL78XX_EVENT_WDSI_FIRMWARE_INSTALL_SUCCEEDED:
+		LOG_INF("FOTA firmware install succeeded...Waiting for modem +KSUP");
+		data->status.wdsi.fota_state = HL78XX_WDSI_FOTA_INSTALL_COMPLETED;
+		data->status.wdsi.in_progress = false;
+		data->status.wdsi.progress = 0;
+		break;
+	case MODEM_HL78XX_EVENT_WDSI_FIRMWARE_INSTALL_FAILED:
+		LOG_INF("FOTA firmware install failed...");
+		data->status.wdsi.in_progress = false;
+		data->status.wdsi.progress = 0;
+		/* TODO: fail, do something */
+		break;
+	case MODEM_HL78XX_EVENT_MDM_RESTART:
+		if (data->status.wdsi.in_progress == true) {
+			/* FOTA update in progress, waiting for it to complete */
+			data->status.wdsi.fota_state = HL78XX_WDSI_FOTA_IDLE;
+		} else {
+			LOG_INF("Exiting FOTA state, re-initializing modem...");
+			hl78xx_enter_state(data, MODEM_HL78XX_STATE_RUN_INIT_SCRIPT);
+		}
+		break;
+	case MODEM_HL78XX_EVENT_REGISTERED:
+		/* stay in FOTA state */
+		hl78xx_start_timer(data, K_MSEC(100));
+		break;
+	default:
+		break;
+	}
+}
+
+static int hl78xx_on_fota_state_leave(struct hl78xx_data *data)
+{
+	HL78XX_LOG_DBG("Exiting FOTA state");
+	hl78xx_stop_timer(data);
+	return 0;
+}
+#endif /* CONFIG_MODEM_HL78XX_AIRVANTAGE */
 static int hl78xx_on_carrier_off_state_enter(struct hl78xx_data *data)
 {
 	notif_carrier_off(data->dev);
@@ -1465,7 +1731,7 @@ static void hl78xx_event_handler(struct hl78xx_data *data, enum hl78xx_event evt
 	if ((int)s <= MODEM_HL78XX_STATE_AWAIT_POWER_OFF && hl78xx_state_table[s].on_event) {
 		hl78xx_state_table[s].on_event(data, evt);
 	} else {
-		LOG_ERR("%d %s unknown event", __LINE__, __func__);
+		LOG_ERR("%d unknown event %d", __LINE__, evt);
 	}
 	if (state != s) {
 		hl78xx_log_state_changed(state, s);
@@ -1682,7 +1948,6 @@ static int hl78xx_init(const struct device *dev)
 	if (ret < 0) {
 		goto error;
 	}
-
 #ifndef CONFIG_PM_DEVICE
 	hl78xx_delegate_event(data, MODEM_HL78XX_EVENT_RESUME);
 #else
@@ -1692,6 +1957,7 @@ static int hl78xx_init(const struct device *dev)
 #ifdef CONFIG_MODEM_HL78XX_STAY_IN_BOOT_MODE_FOR_ROAMING
 	k_sem_take(&data->stay_in_boot_mode_sem, K_FOREVER);
 #endif
+	LOG_INF("Modem HL78xx initialized");
 	return 0;
 error:
 	return ret;
@@ -1766,6 +2032,13 @@ const static struct hl78xx_state_handlers hl78xx_state_table[] = {
 		hl78xx_on_carrier_on_state_leave,
 		hl78xx_carrier_on_event_handler
 	},
+#ifdef CONFIG_MODEM_HL78XX_AIRVANTAGE
+	[MODEM_HL78XX_STATE_FOTA] = {
+		hl78xx_on_fota_state_enter,
+		hl78xx_on_fota_state_leave,
+		hl78xx_fota_event_handler
+	},
+#endif /* CONFIG_MODEM_HL78XX_AIRVANTAGE */
 	[MODEM_HL78XX_STATE_CARRIER_OFF] = {
 		hl78xx_on_carrier_off_state_enter,
 		hl78xx_on_carrier_off_state_leave,
@@ -1846,10 +2119,10 @@ static DEVICE_API(cellular, hl78xx_api) = {
 			      CONFIG_MODEM_HL78XX_DEV_INIT_PRIORITY, &hl78xx_api);
 
 #define MODEM_DEVICE_SWIR_HL78XX(inst)                                                             \
-	MODEM_HL78XX_DEFINE_INSTANCE(inst, CONFIG_MODEM_HL78XX_DEV_POWER_PULSE_DURATION,           \
-				     CONFIG_MODEM_HL78XX_DEV_RESET_PULSE_DURATION,                 \
-				     CONFIG_MODEM_HL78XX_DEV_STARTUP_TIME,                         \
-				     CONFIG_MODEM_HL78XX_DEV_SHUTDOWN_TIME, false, NULL, NULL)
+	MODEM_HL78XX_DEFINE_INSTANCE(inst, CONFIG_MODEM_HL78XX_DEV_POWER_PULSE_DURATION_MS,        \
+				     CONFIG_MODEM_HL78XX_DEV_RESET_PULSE_DURATION_MS,              \
+				     CONFIG_MODEM_HL78XX_DEV_STARTUP_TIME_MS,                      \
+				     CONFIG_MODEM_HL78XX_DEV_SHUTDOWN_TIME_MS, false, NULL, NULL)
 
 #define DT_DRV_COMPAT swir_hl7812
 DT_INST_FOREACH_STATUS_OKAY(MODEM_DEVICE_SWIR_HL78XX)
diff --git a/drivers/modem/hl78xx/hl78xx.h b/drivers/modem/hl78xx/hl78xx.h
index d48f5b2d88743..62857db7944eb 100644
--- a/drivers/modem/hl78xx/hl78xx.h
+++ b/drivers/modem/hl78xx/hl78xx.h
@@ -41,6 +41,7 @@
 #define MDM_MAX_DATA_LENGTH CONFIG_MODEM_HL78XX_UART_BUFFER_SIZES
 
 #define MDM_MAX_SOCKETS           CONFIG_MODEM_HL78XX_NUM_SOCKETS
+#define MDM_MAX_PDP_CONTEXTS      CONFIG_MODEM_HL78XX_MAX_PDP_CONTEXTS
 #define MDM_BASE_SOCKET_NUM       1
 #define MDM_BAND_BITMAP_LEN_BYTES 32
 #define MDM_BAND_HEX_STR_LEN      (MDM_BAND_BITMAP_LEN_BYTES * 2 + 1)
@@ -68,38 +69,43 @@
 #endif
 
 /* Modem Communication Patterns */
-#define EOF_PATTERN         "--EOF--Pattern--"
-#define TERMINATION_PATTERN "+++"
-#define CONNECT_STRING      "CONNECT"
-#define CME_ERROR_STRING    "+CME ERROR: "
-#define OK_STRING           "OK"
-
+#define EOF_PATTERN                              "--EOF--Pattern--"
+#define TERMINATION_PATTERN                      "+++"
+#define CONNECT_STRING                           "CONNECT"
+#define CME_ERROR_STRING                         "+CME ERROR: "
+#define OK_STRING                                "OK"
 /* RAT (Radio Access Technology) commands */
-#define SET_RAT_M1_CMD_LEGACY    "AT+KSRAT=0"
-#define SET_RAT_NB1_CMD_LEGACY   "AT+KSRAT=1"
-#define SET_RAT_GSM_CMD_LEGACY   "AT+KSRAT=2"
-#define SET_RAT_NBNTN_CMD_LEGACY "AT+KSRAT=3"
-
-#define KSRAT_QUERY      "AT+KSRAT?"
-#define DISABLE_RAT_AUTO "AT+KSELACQ=0,0"
-
-#define SET_RAT_M1_CMD    "AT+KSRAT=0,1"
-#define SET_RAT_NB1_CMD   "AT+KSRAT=1,1"
-#define SET_RAT_GMS_CMD   "AT+KSRAT=2,1"
-#define SET_RAT_NBNTN_CMD "AT+KSRAT=3,1"
-
+#define SET_RAT_M1_CMD_LEGACY                    "AT+KSRAT=0"
+#define SET_RAT_NB1_CMD_LEGACY                   "AT+KSRAT=1"
+#define SET_RAT_GSM_CMD_LEGACY                   "AT+KSRAT=2"
+#define SET_RAT_NBNTN_CMD_LEGACY                 "AT+KSRAT=3"
+#define SET_RAT_M1_CMD                           "AT+KSRAT=0,1"
+#define SET_RAT_NB1_CMD                          "AT+KSRAT=1,1"
+#define SET_RAT_GMS_CMD                          "AT+KSRAT=2,1"
+#define SET_RAT_NBNTN_CMD                        "AT+KSRAT=3,1"
+#define KSRAT_QUERY                              "AT+KSRAT?"
+#define DISABLE_RAT_AUTO                         "AT+KSELACQ=0,0"
+/* Enable/Disable RAT registration status */
+#define ENABLE_LTE_REG_STATUS_CMD                "AT+CEREG=5"
+#define ENABLE_GSM_REG_STATUS_CMD                "AT+CREG=3"
+#define DISABLE_LTE_REG_STATUS_CMD               "AT+CEREG=0"
+#define DISABLE_GSM_REG_STATUS_CMD               "AT+CREG=0"
 /* Power mode commands */
-#define SET_AIRPLANE_MODE_CMD_LEGACY       "AT+CFUN=4,0"
-#define SET_AIRPLANE_MODE_CMD              "AT+CFUN=4,1"
-#define SET_FULLFUNCTIONAL_MODE_CMD_LEGACY "AT+CFUN=1,0"
-#define SET_FULLFUNCTIONAL_MODE_CMD        "AT+CFUN=1,1"
-#define SET_SIM_PWR_OFF_MODE_CMD           "AT+CFUN=0"
-#define GET_FULLFUNCTIONAL_MODE_CMD        "AT+CFUN?"
-#define MDM_POWER_OFF_CMD_LEGACY           "AT+CPWROFF"
-#define MDM_POWER_FAST_OFF_CMD_LEGACY      "AT+CPWROFF=1"
+#define SET_AIRPLANE_MODE_CMD_LEGACY             "AT+CFUN=4,0"
+#define SET_AIRPLANE_MODE_CMD                    "AT+CFUN=4,1"
+#define SET_FULLFUNCTIONAL_MODE_CMD_LEGACY       "AT+CFUN=1,0"
+#define SET_FULLFUNCTIONAL_MODE_CMD              "AT+CFUN=1,1"
+#define SET_SIM_PWR_OFF_MODE_CMD                 "AT+CFUN=0"
+#define GET_FULLFUNCTIONAL_MODE_CMD              "AT+CFUN?"
+#define MDM_POWER_OFF_CMD_LEGACY                 "AT+CPWROFF"
+#define MDM_POWER_FAST_OFF_CMD_LEGACY            "AT+CPWROFF=1"
 /* PDP Context commands */
-#define DEACTIVATE_PDP_CONTEXT             "AT+CGACT=0"
-#define ACTIVATE_PDP_CONTEXT               "AT+CGACT=1"
+#define DEACTIVATE_PDP_CONTEXT                   "AT+CGACT=0"
+#define ACTIVATE_PDP_CONTEXT                     "AT+CGACT=1"
+/* Airvantage commands */
+/* User initiated connection */
+#define WDSI_USER_INITIATED_CONNECTION_START_CMD "AT+WDSS=1,1"
+#define WDSI_USER_INITIATED_CONNECTION_STOP_CMD  "AT+WDSS=1,0"
 
 /* Helper macros */
 #define ATOI(s_, value_, desc_) modem_atoi(s_, value_, desc_, __func__)
@@ -110,7 +116,7 @@
 		    (LOG_DBG(str, ##__VA_ARGS__)), \
 		    ((void)0))
 
-/* Enums */
+/* States */
 enum hl78xx_state {
 	MODEM_HL78XX_STATE_IDLE = 0,
 	MODEM_HL78XX_STATE_RESET_PULSE,
@@ -126,6 +132,7 @@ enum hl78xx_state {
 	 */
 	MODEM_HL78XX_STATE_AWAIT_REGISTERED,
 	MODEM_HL78XX_STATE_CARRIER_ON,
+	MODEM_HL78XX_STATE_FOTA,
 	/* Minimum functionality, SIM powered off, Modem Power down
 	 * CFUN=0
 	 */
@@ -152,7 +159,24 @@ enum hl78xx_event {
 	MODEM_HL78XX_EVENT_DEREGISTERED,
 	MODEM_HL78XX_EVENT_BUS_OPENED,
 	MODEM_HL78XX_EVENT_BUS_CLOSED,
+	/* Modem unexpected restart event */
+	MODEM_HL78XX_EVENT_MDM_RESTART,
 	MODEM_HL78XX_EVENT_SOCKET_READY,
+	MODEM_HL78XX_EVENT_NTN_POSREQ,
+#ifdef CONFIG_MODEM_HL78XX_AIRVANTAGE
+
+	/* WDSI FOTA events */
+	MODEM_HL78XX_EVENT_WDSI_UPDATE,
+	MODEM_HL78XX_EVENT_WDSI_RESTART,
+	MODEM_HL78XX_EVENT_WDSI_DOWNLOAD_REQUEST,
+	MODEM_HL78XX_EVENT_WDSI_DOWNLOAD_PROGRESS,
+	MODEM_HL78XX_EVENT_WDSI_DOWNLOAD_COMPLETE,
+	MODEM_HL78XX_EVENT_WDSI_INSTALL_REQUEST,
+	MODEM_HL78XX_EVENT_WDSI_INSTALLING_FIRMWARE,
+	MODEM_HL78XX_EVENT_WDSI_FIRMWARE_INSTALL_SUCCEEDED,
+	MODEM_HL78XX_EVENT_WDSI_FIRMWARE_INSTALL_FAILED,
+#endif /* CONFIG_MODEM_HL78XX_AIRVANTAGE */
+	MODEM_HL78XX_EVENT_COUNT
 };
 
 enum hl78xx_tcp_notif {
@@ -243,6 +267,7 @@ struct modem_identity {
 	uint8_t iccid[MDM_ICCID_LENGTH];
 	uint8_t manufacturer[MDM_MANUFACTURER_LENGTH];
 	uint8_t fw_version[MDM_REVISION_LENGTH];
+	uint8_t serial_number[MDM_SERIAL_NUMBER_LENGTH];
 	char apn[MDM_APN_MAX_LENGTH];
 };
 struct hl78xx_phone_functionality_work {
@@ -254,7 +279,34 @@ struct hl78xx_network_operator {
 	char operator[MDM_MODEL_LENGTH];
 	uint8_t format;
 };
-
+struct hl78xx_modem_boot_status {
+	bool is_booted_previously;
+	enum hl78xx_module_status status;
+};
+struct hl78xx_gprs_status {
+	bool is_active;
+	int8_t cid;
+};
+#ifdef CONFIG_MODEM_HL78XX_AIRVANTAGE
+/* WDSI FOTA states */
+enum hl78xx_wdsi_fota_states {
+	HL78XX_WDSI_FOTA_IDLE = 0,
+	HL78XX_WDSI_FOTA_DOWNLOADING,
+	HL78XX_WDSI_FOTA_DOWNLOAD_COMPLETED,
+	HL78XX_WDSI_FOTA_INSTALLING,
+	HL78XX_WDSI_FOTA_INSTALL_COMPLETED,
+	HL78XX_WDSI_FOTA_INSTALL_FAILED
+};
+struct hl78xx_wdsi_status {
+	enum wdsi_indication level;
+	uint32_t data;
+	size_t fota_size;
+	bool in_progress;
+	enum hl78xx_wdsi_fota_states fota_state;
+	bool completed;
+	int progress;
+};
+#endif /* CONFIG_MODEM_HL78XX_AIRVANTAGE */
 struct modem_status {
 	struct registration_status registration;
 	int16_t rssi;
@@ -265,18 +317,21 @@ struct modem_status {
 	int variant;
 	enum hl78xx_state state;
 	struct kband_syntax kbndcfg[HL78XX_RAT_COUNT];
+	struct hl78xx_gprs_status gprs[MDM_MAX_PDP_CONTEXTS];
+	struct hl78xx_modem_boot_status boot;
 	struct hl78xx_phone_functionality_work phone_functionality;
 	struct apn_state apn;
 	struct hl78xx_network_operator network_operator;
+#ifdef CONFIG_MODEM_HL78XX_AIRVANTAGE
+	struct hl78xx_wdsi_status wdsi;
+#endif /* CONFIG_MODEM_HL78XX_AIRVANTAGE */
 };
-
 struct modem_gpio_callbacks {
 	struct gpio_callback vgpio_cb;
 	struct gpio_callback uart_dsr_cb;
 	struct gpio_callback gpio6_cb;
 	struct gpio_callback uart_cts_cb;
 };
-
 struct modem_event_system {
 	struct k_work event_dispatch_work;
 	uint8_t event_buf[8];
diff --git a/drivers/modem/hl78xx/hl78xx_apis.c b/drivers/modem/hl78xx/hl78xx_apis.c
index e1af412b1730c..760696a6f9402 100644
--- a/drivers/modem/hl78xx/hl78xx_apis.c
+++ b/drivers/modem/hl78xx/hl78xx_apis.c
@@ -175,7 +175,10 @@ int hl78xx_api_func_get_modem_info_vendor(const struct device *dev,
 		safe_strncpy(info, (const char *)data->status.network_operator.operator,
 			     MIN(size, sizeof(data->status.network_operator.operator)));
 		break;
-
+	case HL78XX_MODEM_INFO_SERIAL_NUMBER:
+		safe_strncpy(info, (const char *)data->identity.serial_number,
+			     MIN(size, sizeof(data->identity.serial_number)));
+		break;
 	default:
 		break;
 	}
@@ -289,3 +292,34 @@ int hl78xx_api_func_modem_dynamic_cmd_send(const struct device *dev, const char
 	return modem_dynamic_cmd_send(data, NULL, cmd, cmd_size, response_matches, matches_size,
 				      true);
 }
+#ifdef CONFIG_MODEM_HL78XX_AIRVANTAGE
+int hl78xx_start_airvantage_dm_session(const struct device *dev)
+{
+	int ret = 0;
+	struct hl78xx_data *data = (struct hl78xx_data *)dev->data;
+
+	ret = modem_dynamic_cmd_send(data, NULL, WDSI_USER_INITIATED_CONNECTION_START_CMD,
+				     strlen(WDSI_USER_INITIATED_CONNECTION_START_CMD),
+				     hl78xx_get_ok_match(), 1, false);
+	if (ret < 0) {
+		LOG_ERR("Start DM session error %d", ret);
+		return ret;
+	}
+	return 0;
+}
+
+int hl78xx_stop_airvantage_dm_session(const struct device *dev)
+{
+	int ret = 0;
+	struct hl78xx_data *data = (struct hl78xx_data *)dev->data;
+
+	ret = modem_dynamic_cmd_send(data, NULL, WDSI_USER_INITIATED_CONNECTION_STOP_CMD,
+				     strlen(WDSI_USER_INITIATED_CONNECTION_STOP_CMD),
+				     hl78xx_get_ok_match(), 1, false);
+	if (ret < 0) {
+		LOG_ERR("Stop DM session error %d", ret);
+		return ret;
+	}
+	return 0;
+}
+#endif /* CONFIG_MODEM_HL78XX_AIRVANTAGE */
diff --git a/drivers/modem/hl78xx/hl78xx_at_shell.c b/drivers/modem/hl78xx/hl78xx_at_shell.c
new file mode 100644
index 0000000000000..695f0aca585e8
--- /dev/null
+++ b/drivers/modem/hl78xx/hl78xx_at_shell.c
@@ -0,0 +1,154 @@
+/*
+ * Copyright (c) 2025 Netfeasa Ltd.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/kernel.h>
+#include <zephyr/shell/shell.h>
+#include <zephyr/modem/chat.h>
+#include <zephyr/modem/pipelink.h>
+#include <zephyr/sys/atomic.h>
+#include <hl78xx.h>
+
+#include <zephyr/logging/log.h>
+LOG_MODULE_REGISTER(modem_at_shell, CONFIG_MODEM_LOG_LEVEL);
+
+#define AT_SHELL_STATE_SCRIPT_RUNNING_BIT 1
+
+const static struct device *modem = DEVICE_DT_GET(DT_ALIAS(modem));
+static struct modem_chat *at_shell_chat;
+static uint8_t at_shell_request_buf[CONFIG_MODEM_AT_SHELL_COMMAND_MAX_SIZE];
+static struct modem_chat_script_chat at_shell_script_chat[1];
+static struct modem_chat_match at_shell_script_chat_matches[2];
+static uint8_t at_shell_match_buf[CONFIG_MODEM_AT_SHELL_RESPONSE_MAX_SIZE];
+static const struct shell *at_shell_active_shell;
+static atomic_t at_shell_state;
+
+static void at_shell_print_any_match(struct modem_chat *chat, char **argv, uint16_t argc,
+				     void *user_data)
+{
+	if (at_shell_active_shell == NULL) {
+		return;
+	}
+
+	if (argc != 2) {
+		return;
+	}
+
+	shell_print(at_shell_active_shell, "%s", argv[1]);
+}
+
+static void at_shell_print_match(struct modem_chat *chat, char **argv, uint16_t argc,
+				 void *user_data)
+{
+	if (at_shell_active_shell == NULL) {
+		return;
+	}
+
+	if (argc != 1) {
+		return;
+	}
+
+	shell_print(at_shell_active_shell, "%s", argv[0]);
+}
+
+MODEM_CHAT_MATCHES_DEFINE(at_shell_abort_matches,
+			  MODEM_CHAT_MATCH("+CME ERROR:", "", at_shell_print_match),
+			  MODEM_CHAT_MATCH("ERROR", "", at_shell_print_match));
+
+static void at_shell_script_callback(struct modem_chat *chat, enum modem_chat_script_result result,
+				     void *user_data)
+{
+	atomic_clear_bit(&at_shell_state, AT_SHELL_STATE_SCRIPT_RUNNING_BIT);
+}
+
+MODEM_CHAT_SCRIPT_DEFINE(at_shell_script, at_shell_script_chat, at_shell_abort_matches,
+			 at_shell_script_callback, CONFIG_MODEM_AT_SHELL_RESPONSE_TIMEOUT_MS);
+
+static void at_shell_init_script_chat(void)
+{
+	/* Match anything except the expected response without progressing script */
+	modem_chat_match_init(&at_shell_script_chat_matches[0]);
+	modem_chat_match_set_match(&at_shell_script_chat_matches[0], "");
+	modem_chat_match_set_separators(&at_shell_script_chat_matches[0], "");
+	modem_chat_match_set_callback(&at_shell_script_chat_matches[0], at_shell_print_any_match);
+	modem_chat_match_set_partial(&at_shell_script_chat_matches[0], true);
+	modem_chat_match_enable_wildcards(&at_shell_script_chat_matches[0], false);
+
+	/* Match the expected response and terminate script */
+	modem_chat_match_init(&at_shell_script_chat_matches[1]);
+	modem_chat_match_set_match(&at_shell_script_chat_matches[1], "");
+	modem_chat_match_set_separators(&at_shell_script_chat_matches[1], "");
+	modem_chat_match_set_callback(&at_shell_script_chat_matches[1], at_shell_print_match);
+	modem_chat_match_set_partial(&at_shell_script_chat_matches[1], false);
+	modem_chat_match_enable_wildcards(&at_shell_script_chat_matches[1], false);
+
+	modem_chat_script_chat_init(at_shell_script_chat);
+	modem_chat_script_chat_set_response_matches(at_shell_script_chat,
+						    at_shell_script_chat_matches,
+						    ARRAY_SIZE(at_shell_script_chat_matches));
+	modem_chat_script_chat_set_timeout(at_shell_script_chat,
+					   CONFIG_MODEM_AT_SHELL_RESPONSE_TIMEOUT_MS);
+}
+
+static int hl78xx_at_shell_init(void)
+{
+	struct hl78xx_data *data = NULL;
+
+	if (device_is_ready(modem) == false) {
+		LOG_ERR("%d, %s Device %s is not ready", __LINE__, __func__, modem->name);
+	}
+	data = (struct hl78xx_data *)modem->data;
+	if (data == NULL) {
+		LOG_ERR("%d, %s Modem data is NULL", __LINE__, __func__);
+		return -EINVAL;
+	}
+	at_shell_chat = &data->chat;
+
+	at_shell_init_script_chat();
+	return 0;
+}
+
+static int at_shell_cmd_handler(const struct shell *sh, size_t argc, char **argv)
+{
+	int ret;
+
+	if (argc < 2) {
+		return -EINVAL;
+	}
+	if (atomic_test_and_set_bit(&at_shell_state, AT_SHELL_STATE_SCRIPT_RUNNING_BIT)) {
+		shell_error(sh, "script is already running");
+		return -EBUSY;
+	}
+	strncpy(at_shell_request_buf, argv[1], sizeof(at_shell_request_buf) - 1);
+	ret = modem_chat_script_chat_set_request(at_shell_script_chat, at_shell_request_buf);
+	if (ret < 0) {
+		return -EINVAL;
+	}
+	if (argc == 3) {
+		strncpy(at_shell_match_buf, argv[2], sizeof(at_shell_match_buf) - 1);
+	} else {
+		strncpy(at_shell_match_buf, "OK", sizeof(at_shell_match_buf) - 1);
+	}
+	ret = modem_chat_match_set_match(&at_shell_script_chat_matches[1], at_shell_match_buf);
+	if (ret < 0) {
+		return -EINVAL;
+	}
+	at_shell_active_shell = sh;
+	ret = modem_chat_run_script_async(at_shell_chat, &at_shell_script);
+	if (ret < 0) {
+		shell_error(sh, "failed to start script");
+		atomic_clear_bit(&at_shell_state, AT_SHELL_STATE_SCRIPT_RUNNING_BIT);
+	}
+	return ret;
+}
+
+SHELL_STATIC_SUBCMD_SET_CREATE(modem_sub_cmds,
+			       SHELL_CMD_ARG(at, NULL, "at <command> <response>",
+					     at_shell_cmd_handler, 1, 2),
+			       SHELL_SUBCMD_SET_END);
+
+SHELL_CMD_REGISTER(modem, &modem_sub_cmds, "Modem commands", NULL);
+
+SYS_INIT(hl78xx_at_shell_init, APPLICATION, CONFIG_APPLICATION_INIT_PRIORITY);
diff --git a/drivers/modem/hl78xx/hl78xx_cfg.c b/drivers/modem/hl78xx/hl78xx_cfg.c
index 461d066865b78..b62734d442c16 100644
--- a/drivers/modem/hl78xx/hl78xx_cfg.c
+++ b/drivers/modem/hl78xx/hl78xx_cfg.c
@@ -87,8 +87,8 @@ int hl78xx_rat_cfg(struct hl78xx_data *data, bool *modem_require_restart,
 		cmd_set_rat = (const char *)SET_RAT_NBNTN_CMD_LEGACY;
 		*rat_request = HL78XX_RAT_NBNTN;
 	}
-#endif
-#endif
+#endif /* CONFIG_MODEM_HL78XX_12_FW_R6 */
+#endif /* CONFIG_MODEM_HL78XX_12 */
 
 	if (cmd_set_rat == NULL || *rat_request == HL78XX_RAT_MODE_NONE) {
 		ret = -EINVAL;
@@ -104,7 +104,25 @@ int hl78xx_rat_cfg(struct hl78xx_data *data, bool *modem_require_restart,
 			*modem_require_restart = true;
 		}
 	}
-#endif
+#if defined(CONFIG_MODEM_HL78XX_12) &&                                                             \
+	(defined(CONFIG_MODEM_HL78XX_RAT_GSM) || defined(CONFIG_MODEM_HL78XX_AUTORAT))
+	if (*rat_request == HL78XX_RAT_GSM) {
+		/* For GSM RAT, no band configuration is needed */
+		ret = hl78xx_run_lte_dis_gsm_en_reg_status_script(data);
+		if (ret < 0) {
+			goto error;
+		}
+	} else {
+#endif /* CONFIG_MODEM_HL78XX_RAT_GSM */
+		/* For LTE RATs, enable LTE registration status and disable GSM */
+		ret = hl78xx_run_gsm_dis_lte_en_reg_status_script(data);
+		if (ret < 0) {
+			goto error;
+		}
+#ifdef CONFIG_MODEM_HL78XX_RAT_GSM
+	}
+#endif /* CONFIG_MODEM_HL78XX_RAT_GSM */
+#endif /* CONFIG_MODEM_HL78XX_AUTORAT */
 
 error:
 	return ret;
@@ -121,12 +139,16 @@ int hl78xx_band_cfg(struct hl78xx_data *data, bool *modem_require_restart,
 	if (rat_config_request == HL78XX_RAT_MODE_NONE) {
 		return -EINVAL;
 	}
+#ifdef CONFIG_MODEM_HL78XX_RAT_GSM
+	if (rat_config_request == HL78XX_RAT_GSM) {
+		return 0;
+	}
+#endif /* CONFIG_MODEM_HL78XX_RAT_GSM */
 #ifdef CONFIG_MODEM_HL78XX_AUTORAT
 	for (int rat = HL78XX_RAT_CAT_M1; rat <= HL78XX_RAT_NB1; rat++) {
 #else
 	int rat = rat_config_request;
-
-#endif
+#endif /* CONFIG_MODEM_HL78XX_AUTORAT */
 		ret = hl78xx_get_band_default_config_for_rat(rat, bnd_bitmap,
 							     ARRAY_SIZE(bnd_bitmap));
 		if (ret) {
@@ -192,13 +214,41 @@ int hl78xx_set_apn_internal(struct hl78xx_data *data, const char *apn, uint16_t
 	if (ret < 0) {
 		goto error;
 	}
+#ifdef CONFIG_MODEM_HL78XX_AIRVANTAGE
+	ret = modem_dynamic_cmd_send(data, NULL, "AT+WDSS=2,1", strlen("AT+WDSS=2,1"),
+				     hl78xx_get_ok_match(), 1, false);
+	if (ret < 0) {
+		goto error;
+	}
+#endif /* CONFIG_MODEM_HL78XX_AIRVANTAGE */
 	data->status.apn.state = APN_STATE_CONFIGURED;
 	return 0;
 error:
 	LOG_ERR("Set APN to %s, result: %d", apn, ret);
 	return ret;
 }
+#ifdef CONFIG_MODEM_HL78XX_RAT_GSM
+int hl78xx_gsm_pdp_activate(struct hl78xx_data *data)
+{
+	int ret = 0;
+	/* Activate the PDP context, Today only one pdp context is supported */
+	const char *cmd_activate_pdp = "AT+CGACT=1,1";
+	/* Check if the current RAT is GSM and if the PDP context is not already active */
+	if (data->status.registration.rat_mode == HL78XX_RAT_CAT_M1 ||
+	    data->status.registration.rat_mode == HL78XX_RAT_NB1 ||
+	    data->status.gprs[0].is_active) {
+		return 0;
+	}
 
+	ret = modem_dynamic_cmd_send(data, NULL, cmd_activate_pdp, strlen(cmd_activate_pdp),
+				     hl78xx_get_ok_match(), 1, false);
+	if (ret < 0) {
+		LOG_ERR("GSM PDP activation failed: %d", ret);
+		return ret;
+	}
+	return 0;
+}
+#endif /* CONFIG_MODEM_HL78XX_RAT_GSM */
 #if defined(CONFIG_MODEM_HL78XX_APN_SOURCE_ICCID) || defined(CONFIG_MODEM_HL78XX_APN_SOURCE_IMSI)
 int find_apn(const char *profile, const char *associated_number, char *apn_buff, uint8_t prefix_len)
 {
diff --git a/drivers/modem/hl78xx/hl78xx_cfg.h b/drivers/modem/hl78xx/hl78xx_cfg.h
index 5d8be2abe58d5..5387128384325 100644
--- a/drivers/modem/hl78xx/hl78xx_cfg.h
+++ b/drivers/modem/hl78xx/hl78xx_cfg.h
@@ -22,7 +22,9 @@ int hl78xx_rat_cfg(struct hl78xx_data *data, bool *modem_require_restart,
 
 int hl78xx_band_cfg(struct hl78xx_data *data, bool *modem_require_restart,
 		    enum hl78xx_cell_rat_mode rat_config_request);
-
+#ifdef CONFIG_MODEM_HL78XX_RAT_GSM
+int hl78xx_gsm_pdp_activate(struct hl78xx_data *data);
+#endif
 int hl78xx_set_apn_internal(struct hl78xx_data *data, const char *apn, uint16_t size);
 
 /**
diff --git a/drivers/modem/hl78xx/hl78xx_chat.c b/drivers/modem/hl78xx/hl78xx_chat.c
index 5b94791aa1d2e..0033ad588ca52 100644
--- a/drivers/modem/hl78xx/hl78xx_chat.c
+++ b/drivers/modem/hl78xx/hl78xx_chat.c
@@ -36,7 +36,10 @@ void hl78xx_on_cxreg(struct modem_chat *chat, char **argv, uint16_t argc, void *
 void hl78xx_on_cgdcontrdp(struct modem_chat *chat, char **argv, uint16_t argc, void *user_data);
 #if defined(CONFIG_MODEM_HL78XX_12)
 void hl78xx_on_kstatev(struct modem_chat *chat, char **argv, uint16_t argc, void *user_data);
-#endif
+#ifdef CONFIG_MODEM_HL78XX_RAT_GSM
+void hl78xx_on_cgact(struct modem_chat *chat, char **argv, uint16_t argc, void *user_data);
+#endif /* CONFIG_MODEM_HL78XX_RAT_GSM */
+#endif /* CONFIG_MODEM_HL78XX_12 */
 void hl78xx_on_socknotifydata(struct modem_chat *chat, char **argv, uint16_t argc, void *user_data);
 void hl78xx_on_ktcpnotif(struct modem_chat *chat, char **argv, uint16_t argc, void *user_data);
 /* Handler implemented to assign modem-provided udp socket ids */
@@ -65,35 +68,47 @@ void hl78xx_on_iccid(struct modem_chat *chat, char **argv, uint16_t argc, void *
 void hl78xx_on_ksrep(struct modem_chat *chat, char **argv, uint16_t argc, void *user_data);
 void hl78xx_on_ksrat(struct modem_chat *chat, char **argv, uint16_t argc, void *user_data);
 void hl78xx_on_kselacq(struct modem_chat *chat, char **argv, uint16_t argc, void *user_data);
-
+void hl78xx_on_serial_number(struct modem_chat *chat, char **argv, uint16_t argc, void *user_data);
+#ifdef CONFIG_MODEM_HL78XX_AIRVANTAGE
+void hl78xx_on_wdsi(struct modem_chat *chat, char **argv, uint16_t argc, void *user_data);
+#endif /* CONFIG_MODEM_HL78XX_AIRVANTAGE */
 MODEM_CHAT_MATCH_DEFINE(hl78xx_ok_match, "OK", "", NULL);
 MODEM_CHAT_MATCHES_DEFINE(hl78xx_allow_match, MODEM_CHAT_MATCH("OK", "", NULL),
 			  MODEM_CHAT_MATCH(CME_ERROR_STRING, "", NULL));
-
-MODEM_CHAT_MATCHES_DEFINE(hl78xx_unsol_matches, MODEM_CHAT_MATCH("+CREG: ", ",", hl78xx_on_cxreg),
+/* clang-format off */
+MODEM_CHAT_MATCHES_DEFINE(hl78xx_unsol_matches,
+			  MODEM_CHAT_MATCH("+KSUP: ", "", hl78xx_on_ksup),
+			  MODEM_CHAT_MATCH("+CREG: ", ",", hl78xx_on_cxreg),
 			  MODEM_CHAT_MATCH("+CEREG: ", ",", hl78xx_on_cxreg),
 #if defined(CONFIG_MODEM_HL78XX_12)
 			  MODEM_CHAT_MATCH("+KSTATEV: ", ",", hl78xx_on_kstatev),
-#endif
+#ifdef CONFIG_MODEM_HL78XX_RAT_GSM
+			  MODEM_CHAT_MATCH("+CGACT: ", ",", hl78xx_on_cgact),
+#endif /* CONFIG_MODEM_HL78XX_RAT_GSM */
+#endif /* CONFIG_MODEM_HL78XX_12 */
 			  MODEM_CHAT_MATCH("+KUDP_DATA: ", ",", hl78xx_on_socknotifydata),
 			  MODEM_CHAT_MATCH("+KTCP_DATA: ", ",", hl78xx_on_socknotifydata),
 			  MODEM_CHAT_MATCH("+KTCP_NOTIF: ", ",", hl78xx_on_ktcpnotif),
 #ifdef CONFIG_MODEM_HL78XX_LOG_CONTEXT_VERBOSE_DEBUG
 			  MODEM_CHAT_MATCH("+KUDP_RCV: ", ",", hl78xx_on_udprcv),
 #endif
+#ifdef CONFIG_MODEM_HL78XX_AIRVANTAGE
+			  MODEM_CHAT_MATCH("+WDSI: ", ",", hl78xx_on_wdsi),
+#endif /* CONFIG_MODEM_HL78XX_AIRVANTAGE */
 			  MODEM_CHAT_MATCH("+KBNDCFG: ", ",", hl78xx_on_kbndcfg),
 			  MODEM_CHAT_MATCH("+CSQ: ", ",", hl78xx_on_csq),
 			  MODEM_CHAT_MATCH("+CESQ: ", ",", hl78xx_on_cesq),
 			  MODEM_CHAT_MATCH("+CFUN: ", "", hl78xx_on_cfun),
 			  MODEM_CHAT_MATCH("+COPS: ", ",", hl78xx_on_cops));
-
-MODEM_CHAT_MATCHES_DEFINE(hl78xx_abort_matches, MODEM_CHAT_MATCH("+CME ERROR: ", "", NULL));
+/* clang-format on */
+MODEM_CHAT_MATCHES_DEFINE(hl78xx_abort_matches, MODEM_CHAT_MATCH(CME_ERROR_STRING, "", NULL));
 MODEM_CHAT_MATCH_DEFINE(hl78xx_at_ready_match, "+KSUP: ", "", hl78xx_on_ksup);
 MODEM_CHAT_MATCH_DEFINE(hl78xx_imei_match, "", "", hl78xx_on_imei);
 MODEM_CHAT_MATCH_DEFINE(hl78xx_cgmm_match, "", "", hl78xx_on_cgmm);
 MODEM_CHAT_MATCH_DEFINE(hl78xx_cimi_match, "", "", hl78xx_on_imsi);
 MODEM_CHAT_MATCH_DEFINE(hl78xx_cgmi_match, "", "", hl78xx_on_cgmi);
 MODEM_CHAT_MATCH_DEFINE(hl78xx_cgmr_match, "", "", hl78xx_on_cgmr);
+MODEM_CHAT_MATCH_DEFINE(hl78xx_serial_number_match, "+KGSN: ", "", hl78xx_on_serial_number);
 MODEM_CHAT_MATCH_DEFINE(hl78xx_iccid_match, "+CCID: ", "", hl78xx_on_iccid);
 MODEM_CHAT_MATCH_DEFINE(hl78xx_ksrep_match, "+KSREP: ", ",", hl78xx_on_ksrep);
 MODEM_CHAT_MATCH_DEFINE(hl78xx_ksrat_match, "+KSRAT: ", "", hl78xx_on_ksrat);
@@ -107,7 +122,6 @@ MODEM_CHAT_SCRIPT_DEFINE(hl78xx_periodic_chat_script, hl78xx_periodic_chat_scrip
 			 hl78xx_abort_matches, hl78xx_chat_callback_handler, 4);
 
 MODEM_CHAT_SCRIPT_CMDS_DEFINE(hl78xx_init_chat_script_cmds,
-			      MODEM_CHAT_SCRIPT_CMD_RESP("", hl78xx_at_ready_match),
 			      MODEM_CHAT_SCRIPT_CMD_RESP("AT+KHWIOCFG=3,1,6", hl78xx_ok_match),
 			      MODEM_CHAT_SCRIPT_CMD_RESP("ATE0", hl78xx_ok_match),
 			      MODEM_CHAT_SCRIPT_CMD_RESP("AT+CFUN=4,0", hl78xx_ok_match),
@@ -116,6 +130,8 @@ MODEM_CHAT_SCRIPT_CMDS_DEFINE(hl78xx_init_chat_script_cmds,
 			      MODEM_CHAT_SCRIPT_CMD_RESP("AT+CEDRXS=0", hl78xx_ok_match),
 			      MODEM_CHAT_SCRIPT_CMD_RESP("AT+KPATTERN=\"--EOF--Pattern--\"",
 							 hl78xx_ok_match),
+			      MODEM_CHAT_SCRIPT_CMD_RESP("AT+KGSN=3", hl78xx_serial_number_match),
+			      MODEM_CHAT_SCRIPT_CMD_RESP("", hl78xx_ok_match),
 			      MODEM_CHAT_SCRIPT_CMD_RESP("AT+CCID", hl78xx_iccid_match),
 			      MODEM_CHAT_SCRIPT_CMD_RESP("", hl78xx_ok_match),
 			      MODEM_CHAT_SCRIPT_CMD_RESP("AT+CMEE=1", hl78xx_ok_match),
@@ -136,12 +152,28 @@ MODEM_CHAT_SCRIPT_CMDS_DEFINE(hl78xx_init_chat_script_cmds,
 			      MODEM_CHAT_SCRIPT_CMD_RESP("AT+KSELACQ?", hl78xx_kselacq_match),
 			      MODEM_CHAT_SCRIPT_CMD_RESP("AT+KSRAT?", hl78xx_ksrat_match),
 			      MODEM_CHAT_SCRIPT_CMD_RESP("AT+KBNDCFG?", hl78xx_ok_match),
-			      MODEM_CHAT_SCRIPT_CMD_RESP("AT+CGACT?", hl78xx_ok_match),
-			      MODEM_CHAT_SCRIPT_CMD_RESP("AT+CREG=0", hl78xx_ok_match),
-			      MODEM_CHAT_SCRIPT_CMD_RESP("AT+CEREG=5", hl78xx_ok_match));
+#ifdef CONFIG_MODEM_HL78XX_AIRVANTAGE
+#ifdef CONFIG_MODEM_HL78XX_12
+			      MODEM_CHAT_SCRIPT_CMD_RESP("AT+WDSI=8191", hl78xx_ok_match),
+#elif defined(CONFIG_MODEM_HL78XX_00)
+			      MODEM_CHAT_SCRIPT_CMD_RESP("AT+WDSI=4479", hl78xx_ok_match),
+#else
+			      MODEM_CHAT_SCRIPT_CMD_RESP("AT+WDSI=?", hl78xx_ok_match),
+#endif /* CONFIG_MODEM_HL78XX_12 */
+#ifdef CONFIG_MODEM_HL78XX_AIRVANTAGE_UA_CONNECT_AIRVANTAGE
+			      MODEM_CHAT_SCRIPT_CMD_RESP("AT+WDSC=0,1", hl78xx_ok_match),
+#endif /* CONFIG_MODEM_HL78XX_AIRVANTAGE_UA_CONNECT_AIRVANTAGE */
+#ifdef CONFIG_MODEM_HL78XX_AIRVANTAGE_UA_DOWNLOAD_FIRMWARE
+			      MODEM_CHAT_SCRIPT_CMD_RESP("AT+WDSC=1,1", hl78xx_ok_match),
+#endif /* CONFIG_MODEM_HL78XX_AIRVANTAGE_UA_DOWNLOAD_FIRMWARE */
+#ifdef CONFIG_MODEM_HL78XX_AIRVANTAGE_UA_INSTALL_FIRMWARE
+			      MODEM_CHAT_SCRIPT_CMD_RESP("AT+WDSC=2,1", hl78xx_ok_match),
+#endif /* CONFIG_MODEM_HL78XX_AIRVANTAGE_UA_INSTALL_FIRMWARE */
+#endif /* CONFIG_MODEM_HL78XX_AIRVANTAGE */
+			      MODEM_CHAT_SCRIPT_CMD_RESP("AT+CGACT?", hl78xx_ok_match));
 
 MODEM_CHAT_SCRIPT_DEFINE(hl78xx_init_chat_script, hl78xx_init_chat_script_cmds,
-			 hl78xx_abort_matches, hl78xx_chat_callback_handler, 10);
+			 hl78xx_abort_matches, hl78xx_chat_callback_handler, 1000);
 
 /* Post-restart script (moved from hl78xx.c) */
 MODEM_CHAT_SCRIPT_CMDS_DEFINE(hl78xx_post_restart_chat_script_cmds,
@@ -177,6 +209,42 @@ MODEM_CHAT_SCRIPT_CMDS_DEFINE(hl78xx_pwroff_cmds,
 MODEM_CHAT_SCRIPT_DEFINE(hl78xx_pwroff_script, hl78xx_pwroff_cmds, hl78xx_abort_matches,
 			 hl78xx_chat_callback_handler, 4);
 
+/* GSM registration status disable / LTE registration status enable script */
+MODEM_CHAT_SCRIPT_CMDS_DEFINE(hl78xx_gsm_dis_lte_en_reg_status_script_cmds,
+			      MODEM_CHAT_SCRIPT_CMD_RESP("AT+CREG=0", hl78xx_ok_match),
+			      MODEM_CHAT_SCRIPT_CMD_RESP("AT+CEREG=5", hl78xx_ok_match));
+
+MODEM_CHAT_SCRIPT_DEFINE(hl78xx_gsm_dis_lte_en_reg_status_script,
+			 hl78xx_gsm_dis_lte_en_reg_status_script_cmds, hl78xx_abort_matches, NULL,
+			 4);
+
+#if defined(CONFIG_MODEM_HL78XX_12) &&                                                             \
+	(defined(CONFIG_MODEM_HL78XX_RAT_GSM) || defined(CONFIG_MODEM_HL78XX_AUTORAT))
+/* LTE registration status disable / GSM registration status enable script */
+MODEM_CHAT_SCRIPT_CMDS_DEFINE(hl78xx_lte_dis_gsm_en_reg_status_script_cmds,
+			      MODEM_CHAT_SCRIPT_CMD_RESP("AT+CEREG=0", hl78xx_ok_match),
+			      MODEM_CHAT_SCRIPT_CMD_RESP("AT+CREG=3", hl78xx_ok_match));
+MODEM_CHAT_SCRIPT_DEFINE(hl78xx_lte_dis_gsm_en_reg_status_script,
+			 hl78xx_lte_dis_gsm_en_reg_status_script_cmds, hl78xx_abort_matches, NULL,
+			 4);
+#endif /* CONFIG_MODEM_HL78XX_12 */
+#ifdef CONFIG_MODEM_HL78XX_AIRVANTAGE
+/* AirVantage script connect accept  */
+MODEM_CHAT_SCRIPT_CMDS_DEFINE(hl78xx_av_connect_accept_cmds,
+			      MODEM_CHAT_SCRIPT_CMD_RESP("AT+WDSR=1", hl78xx_ok_match));
+MODEM_CHAT_SCRIPT_DEFINE(hl78xx_av_connect_accept_script, hl78xx_av_connect_accept_cmds,
+			 hl78xx_abort_matches, hl78xx_chat_callback_handler, 10);
+/* FOTA script download accept */
+MODEM_CHAT_SCRIPT_CMDS_DEFINE(hl78xx_fota_download_accept_cmds,
+			      MODEM_CHAT_SCRIPT_CMD_RESP("AT+WDSR=3", hl78xx_ok_match));
+MODEM_CHAT_SCRIPT_DEFINE(hl78xx_fota_download_accept_script, hl78xx_fota_download_accept_cmds,
+			 hl78xx_abort_matches, hl78xx_chat_callback_handler, 10);
+/* FOTA script install */
+MODEM_CHAT_SCRIPT_CMDS_DEFINE(hl78xx_fota_install_accept_cmds,
+			      MODEM_CHAT_SCRIPT_CMD_RESP("AT+WDSR=4", hl78xx_ok_match));
+MODEM_CHAT_SCRIPT_DEFINE(hl78xx_fota_install_accept_script, hl78xx_fota_install_accept_cmds,
+			 hl78xx_abort_matches, hl78xx_chat_callback_handler, 10);
+#endif /* CONFIG_MODEM_HL78XX_AIRVANTAGE */
 /* Socket-specific matches and wrappers exposed for the sockets translation
  * unit. These were extracted from hl78xx_sockets.c to centralize chat
  * definitions.
@@ -374,3 +442,48 @@ int hl78xx_run_pwroff_script_async(struct hl78xx_data *data)
 	}
 	return modem_chat_run_script_async(&data->chat, &hl78xx_pwroff_script);
 }
+#if defined(CONFIG_MODEM_HL78XX_12) &&                                                             \
+	(defined(CONFIG_MODEM_HL78XX_RAT_GSM) || defined(CONFIG_MODEM_HL78XX_AUTORAT))
+/* Run the LTE disable GSM enable registration status script */
+int hl78xx_run_lte_dis_gsm_en_reg_status_script(struct hl78xx_data *data)
+{
+	if (!data) {
+		return -EINVAL;
+	}
+	return modem_chat_run_script(&data->chat, &hl78xx_lte_dis_gsm_en_reg_status_script);
+}
+#endif /* CONFIG_MODEM_HL78XX_RAT_GSM */
+/* Run the GSM disable LTE enable registration status script */
+int hl78xx_run_gsm_dis_lte_en_reg_status_script(struct hl78xx_data *data)
+{
+	if (!data) {
+		return -EINVAL;
+	}
+	return modem_chat_run_script(&data->chat, &hl78xx_gsm_dis_lte_en_reg_status_script);
+}
+#ifdef CONFIG_MODEM_HL78XX_AIRVANTAGE
+/* AirVantage script connect accept  */
+int hl78xx_run_av_connect_accept_script_async(struct hl78xx_data *data)
+{
+	if (!data) {
+		return -EINVAL;
+	}
+	return modem_chat_run_script_async(&data->chat, &hl78xx_av_connect_accept_script);
+}
+/* FOTA script download accept */
+int hl78xx_run_fota_script_download_accept_async(struct hl78xx_data *data)
+{
+	if (!data) {
+		return -EINVAL;
+	}
+	return modem_chat_run_script_async(&data->chat, &hl78xx_fota_download_accept_script);
+}
+/* FOTA script install accept */
+int hl78xx_run_fota_script_install_accept_async(struct hl78xx_data *data)
+{
+	if (!data) {
+		return -EINVAL;
+	}
+	return modem_chat_run_script_async(&data->chat, &hl78xx_fota_install_accept_script);
+}
+#endif /* CONFIG_MODEM_HL78XX_AIRVANTAGE */
diff --git a/drivers/modem/hl78xx/hl78xx_chat.h b/drivers/modem/hl78xx/hl78xx_chat.h
index eb3a1dec8365b..70cda45888577 100644
--- a/drivers/modem/hl78xx/hl78xx_chat.h
+++ b/drivers/modem/hl78xx/hl78xx_chat.h
@@ -31,6 +31,7 @@ void hl78xx_chat_callback_handler(struct modem_chat *chat, enum modem_chat_scrip
 /* Wrapper helpers so other translation units don't need compile-time
  * visibility of the MODEM_CHAT_* macro-generated symbols.
  */
+const struct modem_chat_match *hl78xx_get_at_ready_match(void);
 const struct modem_chat_match *hl78xx_get_ok_match(void);
 const struct modem_chat_match *hl78xx_get_abort_matches(void);
 const struct modem_chat_match *hl78xx_get_unsol_matches(void);
@@ -47,13 +48,25 @@ int hl78xx_run_init_fail_script_async(struct hl78xx_data *data);
 int hl78xx_run_enable_ksup_urc_script_async(struct hl78xx_data *data);
 int hl78xx_run_pwroff_script_async(struct hl78xx_data *data);
 int hl78xx_run_post_restart_script_async(struct hl78xx_data *data);
+#if defined(CONFIG_MODEM_HL78XX_12) && defined(CONFIG_MODEM_HL78XX_RAT_GSM) ||                     \
+	defined(CONFIG_MODEM_HL78XX_AUTORAT)
+/* Run the LTE disable GSM enable registration status script */
+int hl78xx_run_lte_dis_gsm_en_reg_status_script(struct hl78xx_data *data);
+#endif /* CONFIG_MODEM_HL78XX_RAT_GSM */
+/* Run the GSM disable LTE enable registration status script */
+int hl78xx_run_gsm_dis_lte_en_reg_status_script(struct hl78xx_data *data);
+#ifdef CONFIG_MODEM_HL78XX_AIRVANTAGE
+/* FOTA-related script runners */
+int hl78xx_run_av_connect_accept_script_async(struct hl78xx_data *data);
+int hl78xx_run_fota_script_download_accept_async(struct hl78xx_data *data);
+int hl78xx_run_fota_script_install_accept_async(struct hl78xx_data *data);
+#endif /* CONFIG_MODEM_HL78XX_AIRVANTAGE */
 /* Async runners for init/periodic scripts */
 int hl78xx_run_init_script_async(struct hl78xx_data *data);
 int hl78xx_run_periodic_script_async(struct hl78xx_data *data);
 
 /* Getter for ksrat match (moved into chat TU) */
 const struct modem_chat_match *hl78xx_get_ksrat_match(void);
-
 /* Socket-related chat matches used by the sockets TU */
 const struct modem_chat_match *hl78xx_get_sockets_ok_match(void);
 const struct modem_chat_match *hl78xx_get_connect_matches(void);
diff --git a/include/zephyr/drivers/modem/hl78xx_apis.h b/include/zephyr/drivers/modem/hl78xx_apis.h
index bffd35d0e0c7c..525a26a30d352 100644
--- a/include/zephyr/drivers/modem/hl78xx_apis.h
+++ b/include/zephyr/drivers/modem/hl78xx_apis.h
@@ -18,26 +18,27 @@ extern "C" {
 #endif
 
 /* Magic constants */
-#define CSQ_RSSI_UNKNOWN        (99)
-#define CESQ_RSRP_UNKNOWN       (255)
-#define CESQ_RSRQ_UNKNOWN       (255)
+#define CSQ_RSSI_UNKNOWN         (99)
+#define CESQ_RSRP_UNKNOWN        (255)
+#define CESQ_RSRQ_UNKNOWN        (255)
 /* Magic numbers to units conversions */
-#define CSQ_RSSI_TO_DB(v)       (-113 + (2 * (v)))
-#define CESQ_RSRP_TO_DB(v)      (-140 + (v))
-#define CESQ_RSRQ_TO_DB(v)      (-20 + ((v) / 2))
+#define CSQ_RSSI_TO_DB(v)        (-113 + (2 * (v)))
+#define CESQ_RSRP_TO_DB(v)       (-140 + (v))
+#define CESQ_RSRQ_TO_DB(v)       (-20 + ((v) / 2))
 /** Monitor is paused. */
-#define PAUSED                  1
+#define PAUSED                   1
 /** Monitor is active, default */
-#define ACTIVE                  0
-#define MDM_MANUFACTURER_LENGTH 20
-#define MDM_MODEL_LENGTH        32
-#define MDM_REVISION_LENGTH     64
-#define MDM_IMEI_LENGTH         16
-#define MDM_IMSI_LENGTH         23
-#define MDM_ICCID_LENGTH        22
-#define MDM_APN_MAX_LENGTH      64
-#define MDM_MAX_CERT_LENGTH     4096
-#define MDM_MAX_HOSTNAME_LEN    128
+#define ACTIVE                   0
+#define MDM_MANUFACTURER_LENGTH  20
+#define MDM_MODEL_LENGTH         32
+#define MDM_REVISION_LENGTH      64
+#define MDM_IMEI_LENGTH          16
+#define MDM_SERIAL_NUMBER_LENGTH 32
+#define MDM_IMSI_LENGTH          23
+#define MDM_ICCID_LENGTH         22
+#define MDM_APN_MAX_LENGTH       64
+#define MDM_MAX_CERT_LENGTH      4096
+#define MDM_MAX_HOSTNAME_LEN     128
 /**
  * @brief Define an Event monitor to receive notifications in the system workqueue thread.
  *
@@ -78,15 +79,21 @@ enum hl78xx_phone_functionality {
 };
 /** Module status codes */
 enum hl78xx_module_status {
+	/** Module is ready to receive commands for the TE. No access code is required. */
 	HL78XX_MODULE_READY = 0,
+	/** Module is waiting for an access code. Use AT+CPIN? to determine it. */
 	HL78XX_MODULE_WAITING_FOR_ACCESS_CODE,
+	/** SIM card is not present. */
 	HL78XX_MODULE_SIM_NOT_PRESENT,
+	/** Module is in “SIMlock” state. */
 	HL78XX_MODULE_SIMLOCK,
+	/** Unrecoverable error. */
 	HL78XX_MODULE_UNRECOVERABLE_ERROR,
+	/** Unknown state. */
 	HL78XX_MODULE_UNKNOWN_STATE,
+	/** Inactive SIM. */
 	HL78XX_MODULE_INACTIVE_SIM
 };
-
 /** Cellular modem info type */
 enum hl78xx_modem_info_type {
 	/* <APN> Access Point Name */
@@ -95,8 +102,9 @@ enum hl78xx_modem_info_type {
 	HL78XX_MODEM_INFO_CURRENT_RAT,
 	/* <Network Operator> */
 	HL78XX_MODEM_INFO_NETWORK_OPERATOR,
+	/* <Serial Number> */
+	HL78XX_MODEM_INFO_SERIAL_NUMBER,
 };
-
 /** Cellular network structure */
 struct hl78xx_network {
 	/** Cellular access technology */
@@ -115,7 +123,54 @@ enum hl78xx_evt_type {
 	HL78XX_LTE_REGISTRATION_STAT_UPDATE,
 	HL78XX_LTE_SIM_REGISTRATION,
 	HL78XX_LTE_MODEM_STARTUP,
+	HL78XX_LTE_FOTA_UPDATE_STATUS,
+};
+#ifdef CONFIG_MODEM_HL78XX_AIRVANTAGE
+/**
+ * Enum representing Device Services Indications (+WDSI)
+ */
+enum wdsi_indication {
+	/** Raised at startup if credentials for Bootstrap Server are present */
+	WDSI_BOOTSTRAP_CREDENTIALS_PRESENT = 0,
+	/** Device requests user agreement to connect to AirVantage */
+	WDSI_USER_AGREEMENT_REQUEST = 1,
+	/** AirVantage requests device to download firmware package */
+	WDSI_FIRMWARE_DOWNLOAD_REQUEST = 2,
+	/** AirVantage requests device to install firmware package */
+	WDSI_FIRMWARE_INSTALL_REQUEST = 3,
+	/** Starting authentication with Bootstrap or DM Server */
+	WDSI_AUTHENTICATION_START = 4,
+	/** Authentication failed */
+	WDSI_AUTHENTICATION_FAILED = 5,
+	/** Authentication succeeded, starting session */
+	WDSI_AUTHENTICATION_SUCCESS = 6,
+	/** Connection denied by server */
+	WDSI_CONNECTION_DENIED = 7,
+	/** DM session closed */
+	WDSI_DM_SESSION_CLOSED = 8,
+	/** Firmware package available for download */
+	WDSI_FIRMWARE_AVAILABLE = 9,
+	/** Firmware package downloaded and stored */
+	WDSI_FIRMWARE_DOWNLOADED = 10,
+	/** Firmware download issue, reason indicated by subcode */
+	WDSI_FIRMWARE_DOWNLOAD_ISSUE = 11,
+	/** Package verified and certified */
+	WDSI_PACKAGE_VERIFIED_CERTIFIED = 12,
+	/** Package verified but not certified */
+	WDSI_PACKAGE_VERIFIED_NOT_CERTIFIED = 13,
+	/** Starting firmware update */
+	WDSI_FIRMWARE_UPDATE_START = 14,
+	/** Firmware update failed */
+	WDSI_FIRMWARE_UPDATE_FAILED = 15,
+	/** Firmware updated successfully */
+	WDSI_FIRMWARE_UPDATE_SUCCESS = 16,
+	/** Download in progress, percentage indicated */
+	WDSI_DOWNLOAD_IN_PROGRESS = 18,
+	/** Session started with Bootstrap server +WDSI: 23,0*/
+	/** Session started with DM server +WDSI: 23,1*/
+	WDSI_SESSION_STARTED = 23
 };
+#endif /* CONFIG_MODEM_HL78XX_AIRVANTAGE */
 
 struct hl78xx_evt {
 	enum hl78xx_evt_type type;
@@ -123,6 +178,9 @@ struct hl78xx_evt {
 	union {
 		enum cellular_registration_status reg_status;
 		enum hl78xx_cell_rat_mode rat_mode;
+#ifdef CONFIG_MODEM_HL78XX_AIRVANTAGE
+		enum wdsi_indication wdsi_indication;
+#endif /* CONFIG_MODEM_HL78XX_AIRVANTAGE */
 		bool status;
 		int value;
 	} content;
@@ -450,7 +508,12 @@ int hl78xx_evt_monitor_unregister(struct hl78xx_evt_monitor_entry *mon);
  * @brief Convert HL78xx RAT mode to standard cellular API.
  */
 enum cellular_access_technology hl78xx_rat_to_access_tech(enum hl78xx_cell_rat_mode rat_mode);
-
+#ifdef CONFIG_MODEM_HL78XX_AIRVANTAGE
+/** Start a AirVantage Device Management (DM) session. */
+int hl78xx_start_airvantage_dm_session(const struct device *dev);
+/** Stop a AirVantage Device Management (DM) session. */
+int hl78xx_stop_airvantage_dm_session(const struct device *dev);
+#endif /* CONFIG_MODEM_HL78XX_AIRVANTAGE */
 #ifdef __cplusplus
 }
 #endif
diff --git a/samples/drivers/modem/hello_hl78xx/boards/mg100.conf b/samples/drivers/modem/hello_hl78xx/boards/mg100.conf
index 8faf74132ae1b..1f89aa111650d 100644
--- a/samples/drivers/modem/hello_hl78xx/boards/mg100.conf
+++ b/samples/drivers/modem/hello_hl78xx/boards/mg100.conf
@@ -1 +1,2 @@
 CONFIG_MODEM_HL7800=n
+CONFIG_MODEM_HL78XX_AUTORAT=n
diff --git a/samples/drivers/modem/hello_hl78xx/boards/nrf9160dk_nrf9160_ns.conf b/samples/drivers/modem/hello_hl78xx/boards/nrf9160dk_nrf9160_ns.conf
index d39bd9151a541..520c07714b047 100644
--- a/samples/drivers/modem/hello_hl78xx/boards/nrf9160dk_nrf9160_ns.conf
+++ b/samples/drivers/modem/hello_hl78xx/boards/nrf9160dk_nrf9160_ns.conf
@@ -8,7 +8,8 @@ CONFIG_UART_1_NRF_HW_ASYNC_TIMER=1
 CONFIG_ENTROPY_GENERATOR=y
 CONFIG_TEST_RANDOM_GENERATOR=y
 
-CONFIG_MODEM_HL78XX_DEV_STARTUP_TIME=1000
+CONFIG_MODEM_HL78XX_DEV_STARTUP_TIME_MS=120
+CONFIG_MODEM_HL78XX_DEV_SHUTDOWN_TIME_MS=120
 # Disable AT shell as SLM application has no AT mode user pipes
 CONFIG_MODEM_AT_SHELL=n
 # Increase log buffer size to accommodate large dumps
diff --git a/samples/drivers/modem/hello_hl78xx/boards/pinnacle_100_dvk.conf b/samples/drivers/modem/hello_hl78xx/boards/pinnacle_100_dvk.conf
index 8faf74132ae1b..1f89aa111650d 100644
--- a/samples/drivers/modem/hello_hl78xx/boards/pinnacle_100_dvk.conf
+++ b/samples/drivers/modem/hello_hl78xx/boards/pinnacle_100_dvk.conf
@@ -1 +1,2 @@
 CONFIG_MODEM_HL7800=n
+CONFIG_MODEM_HL78XX_AUTORAT=n
diff --git a/samples/drivers/modem/hello_hl78xx/prj.conf b/samples/drivers/modem/hello_hl78xx/prj.conf
index dc69dcd52f02b..f1a0e63ad7e52 100644
--- a/samples/drivers/modem/hello_hl78xx/prj.conf
+++ b/samples/drivers/modem/hello_hl78xx/prj.conf
@@ -53,7 +53,11 @@ CONFIG_MODEM_HL78XX=y
 
 # Statistics
 CONFIG_MODEM_STATS=y
+
+# shell
 CONFIG_SHELL=y
+CONFIG_MODEM_HL78XX_AT_SHELL=y
+CONFIG_MODEM_AT_SHELL_COMMAND_MAX_SIZE=256
 
 #apn source
 # CONFIG_MODEM_HL78XX_APN_SOURCE_KCONFIG=y
@@ -66,10 +70,17 @@ CONFIG_MODEM_HL78XX_AUTORAT=n
 # CONFIG_MODEM_HL78XX_AUTORAT_PRL_PROFILES="2,1,3"
 # CONFIG_MODEM_HL78XX_AUTORAT_NB_BAND_CFG="3,8,20,28"
 # CONFIG_MODEM_HL78XX_RAT_NB1=y
+# CONFIG_MODEM_HL78XX_RAT_GSM=y
 
 # Stay in boot mode until registered to a network
 # CONFIG_MODEM_HL78XX_STAY_IN_BOOT_MODE_FOR_ROAMING=y
 
+# Enable AirVantage support
+CONFIG_MODEM_HL78XX_AIRVANTAGE=y
+CONFIG_MODEM_HL78XX_AIRVANTAGE_USER_AGREEMENT=y
+CONFIG_MODEM_HL78XX_AIRVANTAGE_UA_CONNECT_AIRVANTAGE=y
+CONFIG_MODEM_HL78XX_AIRVANTAGE_UA_DOWNLOAD_FIRMWARE=y
+CONFIG_MODEM_HL78XX_AIRVANTAGE_UA_INSTALL_FIRMWARE=y
 #  Monitor modem events
 CONFIG_HL78XX_EVT_MONITOR=y
 # Logging