diff --git a/backend/src/graphql/resolver/util/sendTransactionsToDltConnector.ts b/backend/src/graphql/resolver/util/sendTransactionsToDltConnector.ts
index 1c338d564..8b94707d9 100644
--- a/backend/src/graphql/resolver/util/sendTransactionsToDltConnector.ts
+++ b/backend/src/graphql/resolver/util/sendTransactionsToDltConnector.ts
@@ -3,40 +3,56 @@ import { DltTransaction } from '@entity/DltTransaction'
 
 import { DltConnectorClient } from '@/apis/DltConnectorClient'
 import { backendLogger as logger } from '@/server/logger'
+import { Monitor } from '@/util/Monitor'
 
 export async function sendTransactionsToDltConnector(): Promise<void> {
-  const dltConnector = DltConnectorClient.getInstance()
-  if (dltConnector) {
-    const dltTransactions = await DltTransaction.find({
-      where: { messageId: IsNull() },
-      relations: ['transaction'],
-      order: { createdAt: 'ASC', id: 'ASC' },
-    })
-    for (const dltTx of dltTransactions) {
-      logger.debug('sending dltTx=', dltTx)
-      if (dltTx.transaction && (dltTx.transaction ?? false)) {
-        try {
-          const messageId = await dltConnector.transmitTransaction(dltTx.transaction)
-          logger.debug('received messageId=', messageId)
-          const dltMessageId = Buffer.from(messageId, 'hex')
-          logger.debug('dltMessageId as Buffer=', dltMessageId)
-          if (dltMessageId.length !== 32) {
-            logger.error(
-              'Error dlt message id is invalid: %s, should by 32 Bytes long in binary after converting from hex',
-              dltMessageId,
-            )
-            return
+  // check if this logic is still occupied, no concurrecy allowed
+  if (!Monitor.isLocked) {
+    // mark this block for occuption to prevent concurrency
+    Monitor.lockIt()
+
+    try {
+      const dltConnector = DltConnectorClient.getInstance()
+      if (dltConnector) {
+        const dltTransactions = await DltTransaction.find({
+          where: { messageId: IsNull() },
+          relations: ['transaction'],
+          order: { createdAt: 'ASC', id: 'ASC' },
+        })
+        for (const dltTx of dltTransactions) {
+          logger.debug('sending dltTx=', dltTx)
+          if (dltTx.transaction && (dltTx.transaction ?? false)) {
+            try {
+              const messageId = await dltConnector.transmitTransaction(dltTx.transaction)
+              logger.debug('received messageId=', messageId)
+              const dltMessageId = Buffer.from(messageId, 'hex')
+              logger.debug('dltMessageId as Buffer=', dltMessageId)
+              if (dltMessageId.length !== 32) {
+                logger.error(
+                  'Error dlt message id is invalid: %s, should by 32 Bytes long in binary after converting from hex',
+                  dltMessageId,
+                )
+                return
+              }
+              dltTx.messageId = dltMessageId.toString()
+              await DltTransaction.save(dltTx)
+              logger.info('store messageId=%s in dltTx=%d', dltTx.messageId, dltTx.id)
+            } catch (e) {
+              logger.error(
+                `error while sending to dlt-connector or writing messageId of dltTx=${dltTx.id}`,
+                e,
+              )
+            }
           }
-          dltTx.messageId = dltMessageId.toString()
-          await DltTransaction.save(dltTx)
-          logger.info('store messageId=%s in dltTx=%d', dltTx.messageId, dltTx.id)
-        } catch (e) {
-          logger.error(
-            `error while sending to dlt-connector or writing messageId of dltTx=${dltTx.id}`,
-            e,
-          )
         }
       }
+    } catch (e) {
+      logger.error('error on sending transactions to dlt-connector.', e)
+    } finally {
+      // releae Monitor occuption
+      Monitor.releaseIt()
     }
+  } else {
+    logger.info('sendTransactionsToDltConnector currently locked by monitor...')
   }
 }
diff --git a/backend/src/util/Monitor.ts b/backend/src/util/Monitor.ts
new file mode 100644
index 000000000..a01eefc5d
--- /dev/null
+++ b/backend/src/util/Monitor.ts
@@ -0,0 +1,18 @@
+export class Monitor {
+  private static lock = false
+
+  // eslint-disable-next-line no-useless-constructor, @typescript-eslint/no-empty-function
+  private constructor() {}
+
+  public static isLocked = (): boolean => {
+    return Monitor.lock
+  }
+
+  public static lockIt(): void {
+    Monitor.lock = true
+  }
+
+  public static releaseIt(): void {
+    Monitor.lock = false
+  }
+}