diff --git a/srsue/hdr/mac/demux.h b/srsue/hdr/mac/demux.h
index 8c9fb3a02..2f38a4dfc 100644
--- a/srsue/hdr/mac/demux.h
+++ b/srsue/hdr/mac/demux.h
@@ -41,7 +41,7 @@ namespace srsue {
 class demux : public srslte::pdu_queue::process_callback
 {
 public:
-  demux();
+  demux(uint8_t nof_harq_proc_);
   void init(phy_interface_mac_common* phy_h_, rlc_interface_mac *rlc, srslte::log* log_h_, srslte::timers* timers_db_);
 
   bool     process_pdus();
@@ -57,7 +57,6 @@ public:
   void     process_pdu(uint8_t *pdu, uint32_t nof_bytes, uint32_t tstamp);
   
 private:
-  const static int NOF_HARQ_PID    = 8; 
   const static int MAX_PDU_LEN     = 150*1024/8; // ~ 150 Mbps  
   const static int NOF_BUFFER_PDUS = 64; // Number of PDU buffers per HARQ pid
   uint8_t bcch_buffer[1024]; // BCCH PID has a dedicated buffer
@@ -77,6 +76,7 @@ private:
   srslte::log              *log_h;
   srslte::timers           *timers_db;
   rlc_interface_mac        *rlc;
+  uint8_t                   nof_harq_proc;
   
   // Buffer of PDUs
   srslte::pdu_queue pdus; 
diff --git a/srsue/hdr/mac/mux.h b/srsue/hdr/mac/mux.h
index b33cf0d19..1167af752 100644
--- a/srsue/hdr/mac/mux.h
+++ b/srsue/hdr/mac/mux.h
@@ -55,7 +55,7 @@ namespace srsue {
 class mux
 {
 public:
-  mux();
+  mux(uint8_t nof_harq_proc_);
   void     reset();
   void     init(rlc_interface_mac *rlc, srslte::log *log_h, bsr_interface_mux *bsr_procedure, phr_proc *phr_procedure_);
 
@@ -87,7 +87,7 @@ private:
   std::vector<lchid_t> lch; 
   
   // Keep track of the PIDs that transmitted BSR reports 
-  bool pid_has_bsr[MAX_HARQ_PROC]; 
+  std::vector<bool> pid_has_bsr;
   
   // Mutex for exclusive access
   pthread_mutex_t mutex; 
@@ -97,6 +97,7 @@ private:
   bsr_interface_mux *bsr_procedure;
   phr_proc          *phr_procedure;
   uint16_t           pending_crnti_ce;
+  uint8_t            nof_harq_proc;
   
   /* Msg3 Buffer */
   static const uint32_t MSG3_BUFF_SZ = 128; 
@@ -105,9 +106,6 @@ private:
   /* PDU Buffer */
   srslte::sch_pdu    pdu_msg; 
   bool msg3_has_been_transmitted;
-  
-  
-  
 };
 
 } // namespace srsue
diff --git a/srsue/src/mac/demux.cc b/srsue/src/mac/demux.cc
index 227bcc364..4fcb402fc 100644
--- a/srsue/src/mac/demux.cc
+++ b/srsue/src/mac/demux.cc
@@ -36,7 +36,7 @@
 
 namespace srsue {
     
-demux::demux() : mac_msg(20), pending_mac_msg(20)
+demux::demux(uint8_t nof_harq_proc_) : mac_msg(20), pending_mac_msg(20), nof_harq_proc(nof_harq_proc_)
 {
 }
 
@@ -68,9 +68,9 @@ void demux::deallocate(uint8_t* payload_buffer_ptr)
 uint8_t* demux::request_buffer(uint32_t pid, uint32_t len)
 {  
   uint8_t *buff = NULL; 
-  if (pid < NOF_HARQ_PID) {
+  if (pid < nof_harq_proc) {
     return pdus.request(len);
-  } else if (pid == NOF_HARQ_PID) {
+  } else if (pid == nof_harq_proc) {
     buff = bcch_buffer;
   } else {
     Error("Requested buffer for invalid PID=%d\n", pid);
@@ -119,9 +119,9 @@ void demux::push_pdu_temp_crnti(uint8_t *buff, uint32_t nof_bytes)
  */ 
 void demux::push_pdu(uint32_t pid, uint8_t *buff, uint32_t nof_bytes, uint32_t tstamp)
 {
-  if (pid < NOF_HARQ_PID) {    
+  if (pid < nof_harq_proc) {
     return pdus.push(buff, nof_bytes, tstamp);
-  } else if (pid == NOF_HARQ_PID) {
+  } else if (pid == nof_harq_proc) {
     /* Demultiplexing of MAC PDU associated with SI-RNTI. The PDU passes through 
     * the MAC in transparent mode. 
     * Warning: In this case function sends the message to RLC now, since SI blocks do not 
diff --git a/srsue/src/mac/mac.cc b/srsue/src/mac/mac.cc
index 9fe08166f..e1426780e 100644
--- a/srsue/src/mac/mac.cc
+++ b/srsue/src/mac/mac.cc
@@ -42,7 +42,9 @@
 namespace srsue {
 
 mac::mac() : ttisync(10240), 
-             timers_db((uint32_t) NOF_MAC_TIMERS), 
+             timers_db((uint32_t) NOF_MAC_TIMERS),
+             mux_unit(MAC_NOF_HARQ_PROC),
+             demux_unit(MAC_NOF_HARQ_PROC),
              pdu_process_thread(&demux_unit)
 {
   started = false;  
diff --git a/srsue/src/mac/mux.cc b/srsue/src/mac/mux.cc
index f81bcdfd2..5ab58fb50 100644
--- a/srsue/src/mac/mux.cc
+++ b/srsue/src/mac/mux.cc
@@ -37,7 +37,7 @@
 
 namespace srsue {
 
-mux::mux() : pdu_msg(MAX_NOF_SUBHEADERS)
+mux::mux(uint8_t nof_harq_proc_) : pdu_msg(MAX_NOF_SUBHEADERS), pid_has_bsr(nof_harq_proc_), nof_harq_proc(nof_harq_proc_)
 {
   pthread_mutex_init(&mutex, NULL);
   
@@ -141,7 +141,7 @@ srslte::sch_subh::cetype bsr_format_convert(bsr_proc::bsr_format_t format) {
 
 void mux::pusch_retx(uint32_t tx_tti, uint32_t pid)
 {
-  if (pid_has_bsr[pid%MAX_HARQ_PROC]) {
+  if (pid_has_bsr[pid%nof_harq_proc]) {
     bsr_procedure->set_tx_tti(tx_tti);
   }
 }
@@ -256,7 +256,7 @@ uint8_t* mux::pdu_get(uint8_t *payload, uint32_t pdu_sz, uint32_t tx_tti, uint32
   /* Generate MAC PDU and save to buffer */
   uint8_t *ret = pdu_msg.write_packet(log_h);   
 
-  pid_has_bsr[pid%MAX_HARQ_PROC] = bsr_is_inserted; 
+  pid_has_bsr[pid%nof_harq_proc] = bsr_is_inserted;
   if (bsr_is_inserted) {
     bsr_procedure->set_tx_tti(tx_tti);
   }