diff --git a/FDTD/engine_multithread.cpp b/FDTD/engine_multithread.cpp
index 0007955..1179b38 100644
--- a/FDTD/engine_multithread.cpp
+++ b/FDTD/engine_multithread.cpp
@@ -44,7 +44,7 @@ Engine_Multithread* Engine_Multithread::New(const Operator_Multithread* op, unsi
 	return e;
 }
 
-Engine_Multithread::Engine_Multithread(const Operator_Multithread* op) : Engine_SSE_Compressed(op)
+Engine_Multithread::Engine_Multithread(const Operator_Multithread* op) : ENGINE_MULTITHREAD_BASE(op)
 {
 	m_Op_MT = op;
 	m_type = SSE;
@@ -84,7 +84,7 @@ void Engine_Multithread::setNumThreads( unsigned int numThreads )
 void Engine_Multithread::Init()
 {
 	m_stopThreads = true;
-	Engine_SSE_Compressed::Init();
+	ENGINE_MULTITHREAD_BASE::Init();
 
 	// initialize threads
 	m_stopThreads = false;
@@ -144,7 +144,7 @@ void Engine_Multithread::Reset()
 		m_stopBarrier = 0;
 	}
 
-	Engine_SSE_Compressed::Reset();
+	ENGINE_MULTITHREAD_BASE::Reset();
 }
 
 bool Engine_Multithread::IterateTS(unsigned int iterTS)
@@ -241,7 +241,6 @@ void thread::operator()()
 	//std::cout << "thread::operator() Parameters: " << m_start << " " << m_stop << std::endl;
 	//DBG().cout() << "Thread " << m_threadID << " (" << boost::this_thread::get_id() << ") started." << endl;
 
-
 	while (!m_enginePtr->m_stopThreads)
 	{
 		// wait for start
@@ -278,6 +277,12 @@ void thread::operator()()
 			m_enginePtr->m_IterateBarrier->wait();
 			// voltage excitation finished
 
+#ifdef MPI_SUPPORT
+			if (m_threadID==0)
+				m_enginePtr->SendReceiveVoltages();
+			m_enginePtr->m_IterateBarrier->wait();
+#endif
+
 			// record time
 			DEBUG_TIME( m_enginePtr->m_timer_list[boost::this_thread::get_id()].push_back( timer1.elapsed() ); )
 
@@ -305,6 +310,12 @@ void thread::operator()()
 			m_enginePtr->m_IterateBarrier->wait();
 			// current excitation finished
 
+#ifdef MPI_SUPPORT
+			if (m_threadID==0)
+				m_enginePtr->SendReceiveCurrents();
+			m_enginePtr->m_IterateBarrier->wait();
+#endif
+
 			if (m_threadID == 0)
 				++m_enginePtr->numTS; // only the first thread increments numTS
 		}
diff --git a/FDTD/engine_multithread.h b/FDTD/engine_multithread.h
index 9e72159..536c0f7 100644
--- a/FDTD/engine_multithread.h
+++ b/FDTD/engine_multithread.h
@@ -32,6 +32,14 @@
 
 #include <sys/time.h>
 
+#ifdef MPI_SUPPORT
+	#define ENGINE_MULTITHREAD_BASE Engine_MPI
+	#include "engine_mpi.h"
+#else
+	#define ENGINE_MULTITHREAD_BASE Engine_SSE_Compressed
+#endif
+
+
 class Engine_Multithread;
 
 namespace NS_Engine_Multithread
@@ -69,7 +77,7 @@ protected:
 } // namespace
 
 
-class Engine_Multithread : public Engine_SSE_Compressed
+class Engine_Multithread : public ENGINE_MULTITHREAD_BASE
 {
 	friend class NS_Engine_Multithread::thread;
 	friend class Engine_CylinderMultiGrid;
diff --git a/FDTD/operator_multithread.cpp b/FDTD/operator_multithread.cpp
index 77c536e..11f7d7a 100644
--- a/FDTD/operator_multithread.cpp
+++ b/FDTD/operator_multithread.cpp
@@ -44,7 +44,7 @@ Engine* Operator_Multithread::CreateEngine() const
 	return e;
 }
 
-Operator_Multithread::Operator_Multithread() : Operator_SSE_Compressed()
+Operator_Multithread::Operator_Multithread() : OPERATOR_MULTITHREAD_BASE()
 {
 	m_CalcEC_Start=NULL;
 	m_CalcEC_Stop=NULL;
@@ -55,7 +55,7 @@ Operator_Multithread::Operator_Multithread() : Operator_SSE_Compressed()
 
 void Operator_Multithread::Init()
 {
-	Operator_SSE_Compressed::Init();
+	OPERATOR_MULTITHREAD_BASE::Init();
 
 	m_CalcEC_Start=NULL;
 	m_CalcEC_Stop=NULL;
@@ -82,7 +82,7 @@ void Operator_Multithread::Delete()
 void Operator_Multithread::Reset()
 {
 	Delete();
-	Operator_SSE_Compressed::Reset();
+	OPERATOR_MULTITHREAD_BASE::Reset();
 }
 
 void Operator_Multithread::CalcStartStopLines(unsigned int &numThreads, vector<unsigned int> &start, vector<unsigned int> &stop) const
@@ -132,7 +132,7 @@ int Operator_Multithread::CalcECOperator( DebugFlags debugFlags )
 		m_thread_group.add_thread( t );
 	}
 
-	return Operator_SSE_Compressed::CalcECOperator( debugFlags );
+	return OPERATOR_MULTITHREAD_BASE::CalcECOperator( debugFlags );
 }
 
 bool Operator_Multithread::Calc_EC()
diff --git a/FDTD/operator_multithread.h b/FDTD/operator_multithread.h
index fcb6f83..eefe188 100644
--- a/FDTD/operator_multithread.h
+++ b/FDTD/operator_multithread.h
@@ -22,7 +22,14 @@
 
 #include <boost/thread.hpp>
 
-class Operator_Multithread : public Operator_SSE_Compressed
+#ifdef MPI_SUPPORT
+	#define OPERATOR_MULTITHREAD_BASE Operator_MPI
+	#include "operator_mpi.h"
+#else
+	#define OPERATOR_MULTITHREAD_BASE Operator_SSE_Compressed
+#endif
+
+class Operator_Multithread : public OPERATOR_MULTITHREAD_BASE
 {
 	friend class Engine_Multithread;
 	friend class Operator_Thread;