diff --git a/Src/AtGsmTelitLe910_Gnss.c b/Src/AtGsmTelitLe910_Gnss.c
index 3167a6a..f1431bc 100644
--- a/Src/AtGsmTelitLe910_Gnss.c
+++ b/Src/AtGsmTelitLe910_Gnss.c
@@ -278,81 +278,51 @@ AtCommandResult GsmWithGnss_StopRMCThread(tAtCmd *env) {
 }
 
 AtCommandResult GsmWithGnss_GetCGSN(tAtCmd *env, char *acpString, size_t *acpStringLen) {
-    AtCmdPrepare(env);
+    if (osMutexAcquire(env->access, 5000) == osOK) {
+        AtCmdPrepare(env);
+        AtCmdTxClear(env);
+        AtCmdSendStatic(env, "AT#CGSN\r\n");
 
-    AtCmdTxClear(env);
-    AtCmdSendStatic(env, "AT#CGSN\r\n");
-
-    SystemDelayMs(2000);
-    while (AtCmdReceiveNextLine(env, 15000) == AT_OK) {
-        if (AtCmdRxBeginWithStatic(env, "#CGSN: ")) {
-            static const uint16_t prefixSize = sizeof("#CGSN: ") - 1;
-            *acpStringLen = env->rxBuffer.len - (prefixSize + 2);
-            memcpy(acpString, env->rxBuffer.data + prefixSize, *acpStringLen);
-
-            return AT_OK;
-        }
-        if (AtCmdRxBeginWithStatic(env, "ERROR")) {
-            return AT_ERROR;
+        SystemDelayMs(2000);
+        while (AtCmdReceiveNextLine(env, 15000) == AT_OK) {
+            if (AtCmdRxBeginWithStatic(env, "#CGSN: ")) {
+                static const uint16_t prefixSize = sizeof("#CGSN: ") - 1;
+                *acpStringLen = env->rxBuffer.len - (prefixSize + 2);
+                memcpy(acpString, env->rxBuffer.data + prefixSize, *acpStringLen);
+                osMutexRelease(env->access);
+                return AT_OK;
+            }
+            if (AtCmdRxBeginWithStatic(env, "ERROR")) {
+                osMutexRelease(env->access);
+                return AT_ERROR;
+            }
         }
+        osMutexRelease(env->access);
     }
-
     return AT_TIMEOUT;
 }
 
 AtCommandResult GsmWithGnss_GetCCID(tAtCmd *env, char *acpStr, size_t *acpStrLen) {
-//    AtCmdPrepare(env);
-//    AtCmdRxClear(env);
-//    AtCmdSendStatic(env, "AT#CCID\r\n");
-//
-//    uint32_t timeout = 4000;
-//    uint32_t endMs = SystemGetMs() + timeout;
-//    uint32_t leftMs = timeout;
-//
-//    while ((AtCmdReceiveNextLine(env, leftMs) == AT_OK) && (SystemGetMs() < endMs)) {
-//        leftMs = endMs - SystemGetMs();
-//
-//        if (AtCmdRxBeginWithStatic(env, "OK")) {
-//            AtCmdRxClear(env);
-//            continue;
-//
-//        } else if (AtCmdRxBeginWithStatic(env, "ERROR")) {
-//            AtCmdRxClear(env);
-//            return AT_ERROR;
-//
-//        } else if (AtCmdRxBeginWithStatic(env, "#CCID: ")) {
-//
-//            static const uint16_t prefixSize = sizeof("#CCID: ") - 1;
-//            *acpStrLen = env->rxBuffer.len - (prefixSize + 2);
-//            memcpy(acpStr, env->rxBuffer.data+ prefixSize,*acpStrLen);
-//            AtCmdRxClear(env);
-//            return AT_OK;
-//
-//        } else {
-//            AtCmdProcessUnresolvedLine(env);
-//            AtCmdRxClear(env);
-//            continue;
-//        }
-//    }
-//    return AT_TIMEOUT;
-//
+    if (osMutexAcquire(env->access, 5000) == osOK) {
+        AtCmdPrepare(env);
+        AtCmdTxClear(env);
+        AtCmdSendStatic(env, "AT#CCID\r\n");
 
-    AtCmdPrepare(env);
+        while (AtCmdReceiveNextLine(env, 1500) == AT_OK) {
+            if (AtCmdRxBeginWithStatic(env, "#CCID: ")) {
+                static const uint16_t prefixSize = sizeof("#CCID: ") - 1;
+                *acpStrLen = env->rxBuffer.len - (prefixSize + 2);
+                memcpy(acpStr, env->rxBuffer.data+ prefixSize,*acpStrLen);
+                osMutexRelease(env->access);
+                return AT_OK;
+            }
 
-    AtCmdTxClear(env);
-    AtCmdSendStatic(env, "AT#CCID\r\n");
-
-    while (AtCmdReceiveNextLine(env, 1500) == AT_OK) {
-        if (AtCmdRxBeginWithStatic(env, "#CCID: ")) {
-            static const uint16_t prefixSize = sizeof("#CCID: ") - 1;
-            *acpStrLen = env->rxBuffer.len - (prefixSize + 2);
-            memcpy(acpStr, env->rxBuffer.data+ prefixSize,*acpStrLen);
-            return AT_OK;
-        }
-
-        if (AtCmdRxBeginWithStatic(env, "ERROR")) {
-            return AT_ERROR;
+            if (AtCmdRxBeginWithStatic(env, "ERROR")) {
+                osMutexRelease(env->access);
+                return AT_ERROR;
+            }
         }
+        osMutexRelease(env->access);
     }
     return AT_TIMEOUT;
 }