diff --git a/src/didacticNet.cpp b/src/didacticNet.cpp
index 54dacbcf39745d212d3a932c5b49f58184fa28e7..67fc6c552a253b1d8e3b8626c6a339b2ea53459f 100644
--- a/src/didacticNet.cpp
+++ b/src/didacticNet.cpp
@@ -49,7 +49,9 @@ bool didacticPSNet::handleNetwork(){
   	else if(_dataToSend){
   		//send data to network
       //TODO: test added CSMA_CHECKDELAY + 2nd checkData()
-      delayMicroseconds(CSMA_CHECK_DELAY_US);
+      unsigned long delayStartTime = micros();
+      while(micros() < delayStartTime + CSMA_CHECK_DELAY_US);
+      //delayMicroseconds(CSMA_CHECK_DELAY_US); //removed: blocking SoftSerial-interrupts
       if(!checkData()){
       	if(!sendData()){
     			return false;
diff --git a/src/didacticNet.h b/src/didacticNet.h
index 6d4642ea8e3ee1769dbd47da74a560bf04bb0492..d7057777660f18aaad894d4e512a8d9044bc88aa 100644
--- a/src/didacticNet.h
+++ b/src/didacticNet.h
@@ -31,7 +31,7 @@
 #define CSMA_MID_DELAY_MS 20
 #define CSMA_MAX_DELAY_MS 30
 
-#define MAX_NR_TOPICS_CLIENT  5
+#define MAX_NR_TOPICS_CLIENT  10
 #define MAX_NR_TOPICS_BROKER  20
 #define MAX_LEN_TOPICS 10
 #define MAX_LEN_DATA   20