diff --git a/grc/demapping/gsm_bcch_ccch_demapper.xml b/grc/demapping/gsm_bcch_ccch_demapper.xml
index f027f8e..b295ce1 100644
--- a/grc/demapping/gsm_bcch_ccch_demapper.xml
+++ b/grc/demapping/gsm_bcch_ccch_demapper.xml
@@ -3,7 +3,7 @@
   <name>BCCH + CCCH demapper</name>
   <key>gsm_bcch_ccch_demapper</key>
   <import>import grgsm</import>
-  <make>grgsm.universal_ctrl_chans_demapper($timeslot_nr, $starts_fn_mod51, $channel_types)</make>
+  <make>grgsm.universal_ctrl_chans_demapper($timeslot_nr, $downlink_starts_fn_mod51, $downlink_channel_types, $uplink_starts_fn_mod51, $uplink_channel_types)</make>
 
   <param>
     <name>Timeslot</name>
@@ -14,21 +14,37 @@
   </param>
 
   <param>
-    <name>starts_fn_mod51</name>
-    <key>starts_fn_mod51</key>
+    <name>downlink_starts_fn_mod51</name>
+    <key>downlink_starts_fn_mod51</key>
     <value>[2,6,12,16,22,26,32,36,42,46]</value>
     <type>int_vector</type>
     <hide>all</hide>
   </param>
 
   <param>
-    <name>channel_types</name>
-    <key>channel_types</key>
+    <name>downlink_channel_types</name>
+    <key>downlink_channel_types</key>
     <value>[1,2,2,2,2,2,2,2,2,2]</value>
     <type>int_vector</type>
     <hide>all</hide>
   </param>
 
+  <param>
+    <name>uplink_starts_fn_mod51</name>
+    <key>uplink_starts_fn_mod51</key>
+    <value>[]</value>
+    <type>int_vector</type>
+    <hide>all</hide>
+  </param>
+
+  <param>
+    <name>uplink_channel_types</name>
+    <key>uplink_channel_types</key>
+    <value>[]</value>
+    <type>int_vector</type>
+    <hide>all</hide>
+  </param>
+
   <sink>
     <name>bursts</name>
     <type>message</type>
diff --git a/grc/demapping/gsm_bcch_ccch_sdcch4_demapper.xml b/grc/demapping/gsm_bcch_ccch_sdcch4_demapper.xml
index 80e67d5..90b33ce 100644
--- a/grc/demapping/gsm_bcch_ccch_sdcch4_demapper.xml
+++ b/grc/demapping/gsm_bcch_ccch_sdcch4_demapper.xml
@@ -3,7 +3,7 @@
   <name>BCCH + CCCH + SDCCH/4 demapper</name>
   <key>gsm_bcch_ccch_sdcch4_demapper</key>
   <import>import grgsm</import>
-  <make>grgsm.universal_ctrl_chans_demapper($timeslot_nr, $starts_fn_mod51, $channel_types)</make>
+  <make>grgsm.universal_ctrl_chans_demapper($timeslot_nr, $downlink_starts_fn_mod51, $downlink_channel_types, $uplink_starts_fn_mod51, $uplink_channel_types)</make>
 
   <param>
     <name>Timeslot</name>
@@ -14,21 +14,37 @@
   </param>
 
   <param>
-    <name>starts_fn_mod51</name>
-    <key>starts_fn_mod51</key>
+    <name>downlink_starts_fn_mod51</name>
+    <key>downlink_starts_fn_mod51</key>
     <value>[2,6,12,16,22,26,32,36,42,46]</value>
     <type>int_vector</type>
     <hide>all</hide>
   </param>
 
   <param>
-    <name>channel_types</name>
-    <key>channel_types</key>
+    <name>downlink_channel_types</name>
+    <key>downlink_channel_types</key>
     <value>[1,2,2,2,7,7,7,7,135,135]</value>
     <type>int_vector</type>
     <hide>all</hide>
   </param>
 
+  <param>
+    <name>uplink_starts_fn_mod51</name>
+    <key>uplink_starts_fn_mod51</key>
+    <value>[0,6,10,37,41,47]</value>
+    <type>int_vector</type>
+    <hide>all</hide>
+  </param>
+
+  <param>
+    <name>uplink_channel_types</name>
+    <key>uplink_channel_types</key>
+    <value>[7,135,135,7,7,7]</value>
+    <type>int_vector</type>
+    <hide>all</hide>
+  </param>
+
   <sink>
     <name>bursts</name>
     <type>message</type>
diff --git a/grc/demapping/gsm_sdcch8_demapper.xml b/grc/demapping/gsm_sdcch8_demapper.xml
index 38a8112..c81032a 100644
--- a/grc/demapping/gsm_sdcch8_demapper.xml
+++ b/grc/demapping/gsm_sdcch8_demapper.xml
@@ -3,7 +3,7 @@
   <name>SDCCH/8 demapper</name>
   <key>gsm_sdcch8_demapper</key>
   <import>import grgsm</import>
-  <make>grgsm.universal_ctrl_chans_demapper($timeslot_nr, $starts_fn_mod51, $channel_types)</make>
+  <make>grgsm.universal_ctrl_chans_demapper($timeslot_nr, $downlink_starts_fn_mod51, $downlink_channel_types, $uplink_starts_fn_mod51, $uplink_channel_types)</make>
 
   <param>
     <name>Timeslot</name>
@@ -14,16 +14,32 @@
   </param>
 
   <param>
-    <name>starts_fn_mod51</name>
-    <key>starts_fn_mod51</key>
+    <name>downlink_starts_fn_mod51</name>
+    <key>downlink_starts_fn_mod51</key>
     <value>[0,4,8,12,16,20,24,28,32,36,40,44]</value>
     <type>int_vector</type>
     <hide>all</hide>
   </param>
 
   <param>
-    <name>channel_types</name>
-    <key>channel_types</key>
+    <name>downlink_channel_types</name>
+    <key>downlink_channel_types</key>
+    <value>[8,8,8,8,8,8,8,8,136,136,136,136]</value>
+    <type>int_vector</type>
+    <hide>all</hide>
+  </param>
+
+  <param>
+    <name>uplink_starts_fn_mod51</name>
+    <key>uplink_starts_fn_mod51</key>
+    <value>[15,19,23,27,31,35,39,43,47,0,4,8]</value>
+    <type>int_vector</type>
+    <hide>all</hide>
+  </param>
+
+  <param>
+    <name>uplink_channel_types</name>
+    <key>uplink_channel_types</key>
     <value>[8,8,8,8,8,8,8,8,136,136,136,136]</value>
     <type>int_vector</type>
     <hide>all</hide>
@@ -42,4 +58,4 @@
       Demapper for SDCCH/8 + SACCH/C8 control channels.
       This corresponds to channel combination vii specified in GSM 05.02, section 6.4
   </doc>
-</block>
\ No newline at end of file
+</block>
diff --git a/grc/demapping/gsm_universal_ctrl_chans_demapper.xml b/grc/demapping/gsm_universal_ctrl_chans_demapper.xml
index 1d8d202..3b522be 100644
--- a/grc/demapping/gsm_universal_ctrl_chans_demapper.xml
+++ b/grc/demapping/gsm_universal_ctrl_chans_demapper.xml
@@ -3,7 +3,7 @@
   <name>Universal ctrl chans demapper</name>
   <key>gsm_universal_ctrl_chans_demapper</key>
   <import>import grgsm</import>
-  <make>grgsm.universal_ctrl_chans_demapper($timeslot_nr, $starts_fn_mod51, $channel_types)</make>
+  <make>grgsm.universal_ctrl_chans_demapper($timeslot_nr, $downlink_starts_fn_mod51, $downlink_channel_types, $uplink_starts_fn_mod51, $uplink_channel_types)</make>
 
   <param>
     <name>timeslot_nr</name>
@@ -14,21 +14,37 @@
   </param>
 
   <param>
-    <name>starts_fn_mod51</name>
-    <key>starts_fn_mod51</key>
+    <name>downlink_starts_fn_mod51</name>
+    <key>downlink_starts_fn_mod51</key>
     <value>[2,6,12,16,22,26,32,36,42,46]</value>
     <type>int_vector</type>
     <hide>part</hide>
   </param>
 
   <param>
-    <name>channel_types</name>
-    <key>channel_types</key>
+    <name>downlink_channel_types</name>
+    <key>downlink_channel_types</key>
     <value>[1,2,2,2,2,2,2,2,2,2]</value>
     <type>int_vector</type>
     <hide>part</hide>
   </param>
 
+  <param>
+    <name>uplink_starts_fn_mod51</name>
+    <key>uplink_starts_fn_mod51</key>
+    <value>[0,6,10,37,41,47]</value>
+    <type>int_vector</type>
+    <hide>part</hide>
+  </param>
+
+  <param>
+    <name>uplink_channel_types</name>
+    <key>uplink_channel_types</key>
+    <value>[2,2,2,2,2,2]</value>
+    <type>int_vector</type>
+    <hide>part</hide>
+  </param>
+
   <sink>
     <name>bursts</name>
     <type>message</type>
@@ -37,4 +53,7 @@
     <name>bursts</name>
     <type>message</type>
   </source>
+  <doc>
+      Universal demapper for control channels.
+  </doc>
 </block>
diff --git a/grc/gsm_block_tree.xml b/grc/gsm_block_tree.xml
index f49f055..0b15562 100644
--- a/grc/gsm_block_tree.xml
+++ b/grc/gsm_block_tree.xml
@@ -13,6 +13,7 @@
     <cat>
       <name>Receiver</name>
       <block>gsm_receiver</block>
+      <block>gsm_receiver_with_uplink</block>
       <block>gsm_cx_channel_hopper</block>
       <block>gsm_fcch_burst_tagger</block>
       <block>gsm_sch_detector</block>
diff --git a/grc/receiver/CMakeLists.txt b/grc/receiver/CMakeLists.txt
index af7042d..bbc086f 100644
--- a/grc/receiver/CMakeLists.txt
+++ b/grc/receiver/CMakeLists.txt
@@ -21,6 +21,7 @@
     gsm_input.xml
     gsm_wideband_input.xml
     gsm_receiver.xml
+    gsm_receiver_with_uplink.xml
     gsm_fcch_burst_tagger.xml
     gsm_sch_detector.xml
     gsm_fcch_detector.xml
diff --git a/grc/receiver/gsm_receiver.xml b/grc/receiver/gsm_receiver.xml
index 2119fd2..2988243 100644
--- a/grc/receiver/gsm_receiver.xml
+++ b/grc/receiver/gsm_receiver.xml
@@ -3,7 +3,7 @@
   <name>GSM Receiver</name>
   <key>gsm_receiver</key>
   <import>import grgsm</import>
-  <make>grgsm.receiver($osr, $cell_allocation, $tseq_nums)</make>
+  <make>grgsm.receiver($osr, $cell_allocation, $tseq_nums, False)</make>
 
   <param>
     <name>Oversampling ratio</name>
diff --git a/grc/receiver/gsm_receiver_with_uplink.xml b/grc/receiver/gsm_receiver_with_uplink.xml
new file mode 100644
index 0000000..4b68336
--- /dev/null
+++ b/grc/receiver/gsm_receiver_with_uplink.xml
@@ -0,0 +1,71 @@
+<?xml version="1.0"?>
+<block>
+  <name>GSM Receiver (with uplink)</name>
+  <key>gsm_receiver_with_uplink</key>
+  <import>import grgsm</import>
+  <make>grgsm.receiver($osr, $cell_allocation, $tseq_nums, True)</make>
+
+  <param>
+    <name>Oversampling ratio</name>
+    <key>osr</key>
+    <value>4</value>
+    <type>int</type>
+  </param>
+
+  <param>
+    <name>Cell allocation</name>
+    <key>cell_allocation</key>
+    <value>[0]</value>
+    <type>float_vector</type>
+    <hide>part</hide>
+  </param>
+
+  <param>
+    <name>TSEQ numbers</name>
+    <key>tseq_nums</key>
+    <value>[]</value>
+    <type>int_vector</type>
+    <hide>part</hide>
+  </param>
+
+  <param>
+    <name>Num Streams</name>
+    <key>num_streams</key>
+    <value>1</value>
+    <type>int</type>
+    <hide>part</hide>
+  </param>
+
+  <check>$num_streams &gt;= 0</check>
+  
+  <sink>
+    <name>C</name>
+    <type>complex</type>
+    <nports>$num_streams</nports>
+  </sink>
+
+
+  <sink>
+    <name>C_up</name>
+    <type>complex</type>
+    <nports>$num_streams</nports>
+  </sink>
+
+  <source>
+    <name>C0</name>
+    <type>message</type>
+    <optional>1</optional>
+  </source>
+  
+  <source>
+    <name>CX</name>
+    <type>message</type>
+    <optional>1</optional>
+  </source>
+
+  <source>
+    <name>measurements</name>
+    <type>message</type>
+    <optional>1</optional>
+  </source>
+</block>
diff --git a/include/grgsm/demapping/universal_ctrl_chans_demapper.h b/include/grgsm/demapping/universal_ctrl_chans_demapper.h
index d8114f7..9d7240c 100644
--- a/include/grgsm/demapping/universal_ctrl_chans_demapper.h
+++ b/include/grgsm/demapping/universal_ctrl_chans_demapper.h
@@ -49,7 +49,7 @@
        * class. gsm::universal_ctrl_chans_demapper::make is the public interface for
        * creating new instances.
        */
-      static sptr make(unsigned int timeslot_nr, const std::vector<int> &starts_fn_mod51, const std::vector<int> &channel_types);
+      static sptr make(unsigned int timeslot_nr, const std::vector<int> &downlink_starts_fn_mod51, const std::vector<int> &downlink_channel_types, const std::vector<int> &uplink_starts_fn_mod51, const std::vector<int> &uplink_channel_types);
     };
 
   } // namespace gsm
diff --git a/include/grgsm/receiver/receiver.h b/include/grgsm/receiver/receiver.h
index 80124f7..00e749e 100644
--- a/include/grgsm/receiver/receiver.h
+++ b/include/grgsm/receiver/receiver.h
@@ -51,7 +51,7 @@
        * class. gsm::receiver::make is the public interface for
        * creating new instances.
        */
-      static sptr make(int osr, const std::vector<int> &cell_allocation, const std::vector<int> &seq_nums);
+      static sptr make(int osr, const std::vector<int> &cell_allocation, const std::vector<int> &seq_nums, bool process_uplink);
       
       virtual void set_cell_allocation(const std::vector<int> &cell_allocation) = 0;
       virtual void set_tseq_nums(const std::vector<int> & tseq_nums) = 0;
diff --git a/lib/demapping/universal_ctrl_chans_demapper_impl.cc b/lib/demapping/universal_ctrl_chans_demapper_impl.cc
index c711928..cbbbc32 100644
--- a/lib/demapping/universal_ctrl_chans_demapper_impl.cc
+++ b/lib/demapping/universal_ctrl_chans_demapper_impl.cc
@@ -36,16 +36,16 @@
   namespace gsm {
 
     universal_ctrl_chans_demapper::sptr
-    universal_ctrl_chans_demapper::make(unsigned int timeslot_nr, const std::vector<int> &starts_fn_mod51, const std::vector<int> &channel_types)
+    universal_ctrl_chans_demapper::make(unsigned int timeslot_nr, const std::vector<int> &downlink_starts_fn_mod51, const std::vector<int> &downlink_channel_types, const std::vector<int> &uplink_starts_fn_mod51, const std::vector<int> &uplink_channel_types)
     {
       return gnuradio::get_initial_sptr
-        (new universal_ctrl_chans_demapper_impl(timeslot_nr, starts_fn_mod51, channel_types));
+        (new universal_ctrl_chans_demapper_impl(timeslot_nr, downlink_starts_fn_mod51, downlink_channel_types, uplink_starts_fn_mod51, uplink_channel_types));
     }
 
     /*
      * The private constructor
      */
-    universal_ctrl_chans_demapper_impl::universal_ctrl_chans_demapper_impl(unsigned int timeslot_nr, const std::vector<int> &starts_fn_mod51, const std::vector<int> &channel_types)
+    universal_ctrl_chans_demapper_impl::universal_ctrl_chans_demapper_impl(unsigned int timeslot_nr, const std::vector<int> &downlink_starts_fn_mod51, const std::vector<int> &downlink_channel_types, const std::vector<int> &uplink_starts_fn_mod51, const std::vector<int> &uplink_channel_types)
       : gr::block("universal_ctrl_chans_demapper",
               gr::io_signature::make(0, 0, 0),
               gr::io_signature::make(0, 0, 0)),
@@ -56,75 +56,137 @@
         
         for(int ii=0; ii<51; ii++)
         {
-            d_starts_fn_mod51[ii]=0;
-            d_channel_types[ii]=0;
-	    d_subslots[ii] = 0;
-	    d_subslots[ii+51] = 0;
+            d_downlink_starts_fn_mod51[ii]=0;
+            d_downlink_channel_types[ii]=0;
+            d_downlink_subslots[ii] = 0;
+            d_downlink_subslots[ii+51] = 0;
+
+            d_uplink_starts_fn_mod51[ii]=0;
+            d_uplink_channel_types[ii]=0;
+            d_uplink_subslots[ii] = 0;
+            d_uplink_subslots[ii+51] = 0;
         }
         
         std::vector<int>::const_iterator s;
         std::vector<int>::const_iterator ch_type;
         
-        for(s=starts_fn_mod51.begin(), ch_type=channel_types.begin();s != starts_fn_mod51.end(); s++)
+        for(s=downlink_starts_fn_mod51.begin(), ch_type=downlink_channel_types.begin();s != downlink_starts_fn_mod51.end(); s++)
         {
             if((*s >= 0) and (*s <= (51-4)))
             {
                 for(int ii=0; ii<4; ii++){
-                    d_starts_fn_mod51[*s+ii] = *s;
-                    if(ch_type!=channel_types.end())
+                    d_downlink_starts_fn_mod51[*s+ii] = *s;
+                    if(ch_type!=downlink_channel_types.end())
                     {
-                        d_channel_types[*s+ii] = *ch_type;
+                        d_downlink_channel_types[*s+ii] = *ch_type;
                     }
                 }
-                if(ch_type!=channel_types.end())
+                if(ch_type!=downlink_channel_types.end())
                 {
                     ch_type++;
                 }
             }
         }
         
-        std::set<int> distinct_channels(channel_types.begin(), channel_types.end());
-	std::set<int>::iterator it;
-        unsigned int subslot;
-	
-	for (it=distinct_channels.begin(); it != distinct_channels.end(); it++)
-	{
-	    subslot = 0;
-	    for(s=starts_fn_mod51.begin();s != starts_fn_mod51.end(); s++)
-	    {
-		if ((d_channel_types[*s] == *it) and (*s >= 0) and (*s <= (51-4)))
-		{
-		    for(int ii=0; ii<4; ii++)
-		    {
-			d_subslots[*s+ii] = subslot;
-			d_subslots[*s+ii+51] = subslot;
-		    }
-		    subslot++;
-		}
-	    }
-	    
-	    if (*it == GSMTAP_CHANNEL_ACCH or 
-		*it == (GSMTAP_CHANNEL_ACCH|GSMTAP_CHANNEL_SDCCH) or
-		*it == (GSMTAP_CHANNEL_ACCH|GSMTAP_CHANNEL_SDCCH4) or
-		*it == (GSMTAP_CHANNEL_ACCH|GSMTAP_CHANNEL_SDCCH8) or
-		*it == (GSMTAP_CHANNEL_ACCH|GSMTAP_CHANNEL_TCH_F) or
-		*it == (GSMTAP_CHANNEL_ACCH|GSMTAP_CHANNEL_TCH_H)
-	    )
-	    {
-		for(s=starts_fn_mod51.begin();s != starts_fn_mod51.end(); s++)
-		{
-		    if ((d_channel_types[*s] == *it) and (*s >= 0) and (*s <= (51-4)))
-		    {
-			for(int ii=0; ii<4; ii++)
-			{
-			    d_subslots[*s+ii+51] = subslot;
-			}
-			subslot++;
-		    }
-		}
-	    }
-	}
+        for(s=uplink_starts_fn_mod51.begin(), ch_type=uplink_channel_types.begin();s != uplink_starts_fn_mod51.end(); s++)
+        {
+            if((*s >= 0) and (*s <= (51-4)))
+            {
+                for(int ii=0; ii<4; ii++){
+                    d_uplink_starts_fn_mod51[*s+ii] = *s;
+                    if(ch_type!=uplink_channel_types.end())
+                    {
+                        d_uplink_channel_types[*s+ii] = *ch_type;
+                    }
+                }
+                if(ch_type!=uplink_channel_types.end())
+                {
+                    ch_type++;
+                }
+            }
+        }
         
+        std::set<int> distinct_downlink_channels(downlink_channel_types.begin(), downlink_channel_types.end());
+        std::set<int>::iterator it;
+        unsigned int subslot;
+        
+        for (it=distinct_downlink_channels.begin(); it != distinct_downlink_channels.end(); it++)
+        {
+            subslot = 0;
+            for(s=downlink_starts_fn_mod51.begin();s != downlink_starts_fn_mod51.end(); s++)
+            {
+                if ((d_downlink_channel_types[*s] == *it) and (*s >= 0) and (*s <= (51-4)))
+                {
+                    for(int ii=0; ii<4; ii++)
+                    {
+                        d_downlink_subslots[*s+ii] = subslot;
+                        d_downlink_subslots[*s+ii+51] = subslot;
+                    }
+                    subslot++;
+                }
+            }
+            
+            if (*it == GSMTAP_CHANNEL_ACCH or 
+                *it == (GSMTAP_CHANNEL_ACCH|GSMTAP_CHANNEL_SDCCH) or
+                *it == (GSMTAP_CHANNEL_ACCH|GSMTAP_CHANNEL_SDCCH4) or
+                *it == (GSMTAP_CHANNEL_ACCH|GSMTAP_CHANNEL_SDCCH8) or
+                *it == (GSMTAP_CHANNEL_ACCH|GSMTAP_CHANNEL_TCH_F) or
+                *it == (GSMTAP_CHANNEL_ACCH|GSMTAP_CHANNEL_TCH_H)
+            )
+            {
+                for(s=downlink_starts_fn_mod51.begin();s != downlink_starts_fn_mod51.end(); s++)
+                {
+                    if ((d_downlink_channel_types[*s] == *it) and (*s >= 0) and (*s <= (51-4)))
+                    {
+                        for(int ii=0; ii<4; ii++)
+                        {
+                            d_downlink_subslots[*s+ii+51] = subslot;
+                        }
+                        subslot++;
+                    }
+                }
+            }
+        }
+        
+        std::set<int> distinct_uplink_channels(uplink_channel_types.begin(), uplink_channel_types.end());
+        for (it=distinct_uplink_channels.begin(); it != distinct_uplink_channels.end(); it++)
+        {
+            subslot = 0;
+            for(s=uplink_starts_fn_mod51.begin();s != uplink_starts_fn_mod51.end(); s++)
+            {
+                if ((d_uplink_channel_types[*s] == *it) and (*s >= 0) and (*s <= (51-4)))
+                {
+                    for(int ii=0; ii<4; ii++)
+                    {
+                        d_uplink_subslots[*s+ii] = subslot;
+                        d_uplink_subslots[*s+ii+51] = subslot;
+                    }
+                    subslot++;
+                }
+            }
+            
+            if (*it == GSMTAP_CHANNEL_ACCH or 
+                *it == (GSMTAP_CHANNEL_ACCH|GSMTAP_CHANNEL_SDCCH) or
+                *it == (GSMTAP_CHANNEL_ACCH|GSMTAP_CHANNEL_SDCCH4) or
+                *it == (GSMTAP_CHANNEL_ACCH|GSMTAP_CHANNEL_SDCCH8) or
+                *it == (GSMTAP_CHANNEL_ACCH|GSMTAP_CHANNEL_TCH_F) or
+                *it == (GSMTAP_CHANNEL_ACCH|GSMTAP_CHANNEL_TCH_H)
+            )
+            {
+                for(s=uplink_starts_fn_mod51.begin();s != uplink_starts_fn_mod51.end(); s++)
+                {
+                    if ((d_uplink_channel_types[*s] == *it) and (*s >= 0) and (*s <= (51-4)))
+                    {
+                        for(int ii=0; ii<4; ii++)
+                        {
+                            d_uplink_subslots[*s+ii+51] = subslot;
+                        }
+                        subslot++;
+                    }
+                }
+            }
+        }
+
         
         message_port_register_in(pmt::mp("bursts"));
         set_msg_handler(pmt::mp("bursts"), boost::bind(&universal_ctrl_chans_demapper_impl::filter_ctrl_chans, this, _1));
@@ -142,52 +204,102 @@
     {
         pmt::pmt_t header_plus_burst = pmt::cdr(msg);
         gsmtap_hdr * header = (gsmtap_hdr *)pmt::blob_data(header_plus_burst);
-            
+
         uint32_t frame_nr = be32toh(header->frame_number);
         uint32_t fn_mod51 = frame_nr % 51;
-        uint32_t fn51_start = d_starts_fn_mod51[fn_mod51];
-        uint32_t fn51_stop = fn51_start + 3;
-        uint32_t ch_type = d_channel_types[fn_mod51];
         
+        bool uplink_burst = (be16toh(header->arfcn) & 0x4000) ? true : false;
+
         if(header->timeslot==d_timeslot){
             int8_t new_msg[sizeof(gsmtap_hdr)+BURST_SIZE];
             gsmtap_hdr * new_hdr = (gsmtap_hdr*)new_msg;
             memcpy(new_msg, header, sizeof(gsmtap_hdr)+BURST_SIZE);
-            new_hdr->sub_type = ch_type;
-            new_hdr->sub_slot = d_subslots[fn_mod51 + (51 * (frame_nr % 2))];
             pmt::pmt_t msg_binary_blob = pmt::make_blob(new_msg,sizeof(gsmtap_hdr)+BURST_SIZE);
             pmt::pmt_t msg_out = pmt::cons(pmt::PMT_NIL, msg_binary_blob);
 	    
-            if(fn_mod51>=fn51_start && fn_mod51<=fn51_stop)
+            if(uplink_burst)
             {
-                uint32_t ii = fn_mod51 - fn51_start;
-                d_frame_numbers[ii] = frame_nr;
-                d_bursts[ii] = msg_out;
-            }
-            
-            if(fn_mod51==fn51_stop)
-            {
-                //check for a situation where some bursts were lost
-                //in this situation frame numbers won't be consecutive
-                bool frames_are_consecutive = true;
-                for(int jj=1; jj<4; jj++)
+                uint32_t fn51_start = d_uplink_starts_fn_mod51[fn_mod51];
+                uint32_t fn51_stop = fn51_start + 3;
+                uint32_t ch_type = d_uplink_channel_types[fn_mod51];
+
+                if(ch_type != 0)
                 {
-                    if((d_frame_numbers[jj]-d_frame_numbers[jj-1])!=1)
-                    {
-                        frames_are_consecutive = false;
-                    }
+                    new_hdr->sub_type = ch_type;
                 }
-                if(frames_are_consecutive)
+                new_hdr->sub_slot = d_uplink_subslots[fn_mod51 + (51 * (frame_nr % 2))];
+                
+                if(fn_mod51>=fn51_start && fn_mod51<=fn51_stop)
                 {
-                    //send bursts to the output
-                    for(int jj=0; jj<4; jj++)
+                    uint32_t ii = fn_mod51 - fn51_start;
+                    d_uplink_frame_numbers[ii] = frame_nr;
+                    d_uplink_bursts[ii] = msg_out;
+                }
+                
+                if(fn_mod51==fn51_stop)
+                {
+                    //check for a situation where some bursts were lost
+                    //in this situation frame numbers won't be consecutive
+                    bool frames_are_consecutive = true;
+                    for(int jj=1; jj<4; jj++)
                     {
-                        message_port_pub(pmt::mp("bursts"), d_bursts[jj]);
+                        if((d_uplink_frame_numbers[jj]-d_uplink_frame_numbers[jj-1])!=1)
+                        {
+                            frames_are_consecutive = false;
+                        }
                     }
-                } 
+                    if(frames_are_consecutive)
+                    {
+                        //send bursts to the output
+                        for(int jj=0; jj<4; jj++)
+                        {
+                            message_port_pub(pmt::mp("bursts"), d_uplink_bursts[jj]);
+                        }
+                    } 
+                }
+            }
+            else 
+            {
+                uint32_t fn51_start = d_downlink_starts_fn_mod51[fn_mod51];
+                uint32_t fn51_stop = fn51_start + 3;
+                uint32_t ch_type = d_downlink_channel_types[fn_mod51];
+
+                if(ch_type != 0)
+                {
+                    new_hdr->sub_type = ch_type;
+                }
+                new_hdr->sub_slot = d_downlink_subslots[fn_mod51 + (51 * (frame_nr % 2))];
+                
+                if(fn_mod51>=fn51_start && fn_mod51<=fn51_stop)
+                {
+                    uint32_t ii = fn_mod51 - fn51_start;
+                    d_downlink_frame_numbers[ii] = frame_nr;
+                    d_downlink_bursts[ii] = msg_out;
+                }
+                
+                if(fn_mod51==fn51_stop)
+                {
+                    //check for a situation where some bursts were lost
+                    //in this situation frame numbers won't be consecutive
+                    bool frames_are_consecutive = true;
+                    for(int jj=1; jj<4; jj++)
+                    {
+                        if((d_downlink_frame_numbers[jj]-d_downlink_frame_numbers[jj-1])!=1)
+                        {
+                            frames_are_consecutive = false;
+                        }
+                    }
+                    if(frames_are_consecutive)
+                    {
+                        //send bursts to the output
+                        for(int jj=0; jj<4; jj++)
+                        {
+                            message_port_pub(pmt::mp("bursts"), d_downlink_bursts[jj]);
+                        }
+                    } 
+                }
             }
         }
     }
   } /* namespace gsm */
 } /* namespace gr */
-
diff --git a/lib/demapping/universal_ctrl_chans_demapper_impl.h b/lib/demapping/universal_ctrl_chans_demapper_impl.h
index d4e1440..0316bf4 100644
--- a/lib/demapping/universal_ctrl_chans_demapper_impl.h
+++ b/lib/demapping/universal_ctrl_chans_demapper_impl.h
@@ -32,14 +32,19 @@
     class universal_ctrl_chans_demapper_impl : public universal_ctrl_chans_demapper
     {
      private:
-      unsigned int d_starts_fn_mod51[51];
-      unsigned int d_channel_types[51];
-      unsigned int d_subslots[102];
+      unsigned int d_downlink_starts_fn_mod51[51];
+      unsigned int d_uplink_starts_fn_mod51[51];
+      unsigned int d_downlink_channel_types[51];
+      unsigned int d_uplink_channel_types[51];
+      unsigned int d_downlink_subslots[102];
+      unsigned int d_uplink_subslots[102];
       unsigned int d_timeslot;
-      uint32_t d_frame_numbers[4];
-      pmt::pmt_t d_bursts[4];
+      uint32_t d_downlink_frame_numbers[4];
+      uint32_t d_uplink_frame_numbers[4];
+      pmt::pmt_t d_downlink_bursts[4];
+      pmt::pmt_t d_uplink_bursts[4];
      public:
-      universal_ctrl_chans_demapper_impl(unsigned int timeslot_nr, const std::vector<int> &starts_fn_mod51, const std::vector<int> &channel_types);
+      universal_ctrl_chans_demapper_impl(unsigned int timeslot_nr, const std::vector<int> &downlink_starts_fn_mod51, const std::vector<int> &downlink_channel_types, const std::vector<int> &uplink_starts_fn_mod51, const std::vector<int> &uplink_channel_types);
       ~universal_ctrl_chans_demapper_impl();
 
       void filter_ctrl_chans(pmt::pmt_t msg);
diff --git a/lib/receiver/receiver_config.cc b/lib/receiver/receiver_config.cc
index c8b85c7..0abf200 100644
--- a/lib/receiver/receiver_config.cc
+++ b/lib/receiver/receiver_config.cc
@@ -46,6 +46,33 @@
   return (*this);
 }
 
+burst_counter burst_counter::subtract_timeslots(unsigned int number_of_timeslots)
+{
+  int timeslot_nr = (int)d_timeslot_nr - (int)number_of_timeslots;
+  int t1,t2,t3;
+  if (timeslot_nr < 0) {
+    timeslot_nr = timeslot_nr + 8;
+
+    t2 = (d_t2 - 1) % 26;
+    t3 = (d_t3 - 1) % 51;
+
+    if ((d_t2 == 0) && (d_t3 == 0)) {
+      t1 = (d_t1 - 1) % (1 << 11);
+    } else
+    {
+      t1 = d_t1;
+    }
+  }
+  else
+  {
+    t1 = d_t1;
+    t2 = d_t2;
+    t3 = d_t3;
+  }
+  
+  return burst_counter(d_OSR, t1, t2, t3, timeslot_nr);
+}
+
 void burst_counter::set(uint32_t t1, uint32_t t2, uint32_t t3, uint32_t timeslot_nr)
 {
   d_t1 = t1;
diff --git a/lib/receiver/receiver_config.h b/lib/receiver/receiver_config.h
index 496e1fe..17b98c8 100644
--- a/lib/receiver/receiver_config.h
+++ b/lib/receiver/receiver_config.h
@@ -89,12 +89,14 @@
         d_t3(t3),
         d_timeslot_nr(timeslot_nr),
         d_offset_fractional(0.0),
-        d_offset_integer(0.0) {
+        d_offset_integer(0.0) 
+    {
       d_offset_integer = 0;
       d_offset_fractional = 0;
     }
 
     burst_counter & operator++(int);
+    burst_counter subtract_timeslots(unsigned int number_of_timeslots);
     void set(uint32_t t1, uint32_t t2, uint32_t t3, uint32_t timeslot_nr);
 
     uint32_t get_t1() {
diff --git a/lib/receiver/receiver_impl.cc b/lib/receiver/receiver_impl.cc
index bd2b306..09a3703 100644
--- a/lib/receiver/receiver_impl.cc
+++ b/lib/receiver/receiver_impl.cc
@@ -52,20 +52,21 @@
 namespace gsm
 {
 receiver::sptr
-receiver::make(int osr, const std::vector<int> &cell_allocation, const std::vector<int> &tseq_nums)
+receiver::make(int osr, const std::vector<int> &cell_allocation, const std::vector<int> &tseq_nums, bool process_uplink)
 {
     return gnuradio::get_initial_sptr
-           (new receiver_impl(osr, cell_allocation, tseq_nums));
+           (new receiver_impl(osr, cell_allocation, tseq_nums, process_uplink));
 }
 
 /*
  * The private constructor
  */
-receiver_impl::receiver_impl(int osr, const std::vector<int> &cell_allocation, const std::vector<int> &tseq_nums)
+receiver_impl::receiver_impl(int osr, const std::vector<int> &cell_allocation, const std::vector<int> &tseq_nums, bool process_uplink)
     : gr::sync_block("receiver",
                 gr::io_signature::make(1, -1, sizeof(gr_complex)),
                 gr::io_signature::make(0, 0, 0)),
     d_OSR(osr),
+    d_process_uplink(process_uplink),
     d_chan_imp_length(CHAN_IMP_RESP_LENGTH),
     d_counter(0),
     d_fcch_start_pos(0),
@@ -172,7 +173,7 @@
         {
             burst_start = get_sch_chan_imp_resp(input, &channel_imp_resp[0]); //get channel impulse response from it
             detect_burst(input, &channel_imp_resp[0], burst_start, output_binary); //detect bits using MLSE detection
-            if (decode_sch(&output_binary[3], &t1, &t2, &t3, &d_ncc, &d_bcc) == 0) //decode SCH burst
+            if (decode_sch(&output_binary[3], &t1, &t2, &t3, &d_ncc, &d_bcc) == 0)   //decode SCH burst
             {
                 d_burst_nr.set(t1, t2, t3, 0);                                  //set counter of bursts value
                 d_burst_nr++;
@@ -198,10 +199,15 @@
         int offset = 0;
         int to_consume = 0;
         unsigned char output_binary[BURST_SIZE];
-
         burst_type b_type;
+        unsigned int inputs_to_process=d_cell_allocation.size();
         
-        for(int input_nr=0; input_nr<d_cell_allocation.size(); input_nr++)
+        if(d_process_uplink)
+        {
+            inputs_to_process = 2*inputs_to_process;
+        }
+        
+        for(int input_nr=0; input_nr<inputs_to_process; input_nr++)
         {
             double signal_pwr = 0;
             input = (gr_complex *)input_items[input_nr];
@@ -827,10 +833,21 @@
     tap_header->version = GSMTAP_VERSION;
     tap_header->hdr_len = sizeof(gsmtap_hdr)/4;
     tap_header->type = GSMTAP_TYPE_UM_BURST;
-    tap_header->timeslot = static_cast<uint8_t>(d_burst_nr.get_timeslot_nr());
-    tap_header->frame_number = htobe32(d_burst_nr.get_frame_nr());
     tap_header->sub_type = burst_type;
-    tap_header->arfcn = htobe16(d_cell_allocation[input_nr]) ; 
+    bool uplink_burst = (input_nr >= d_cell_allocation.size());
+    if(!uplink_burst) // downlink burst
+    {
+        tap_header->timeslot = static_cast<uint8_t>(d_burst_nr.get_timeslot_nr());
+        tap_header->frame_number = htobe32(d_burst_nr.get_frame_nr());
+        tap_header->arfcn = htobe16(d_cell_allocation[input_nr]) ; 
+    }
+    else //uplink burst
+    {
+        tap_header->timeslot = static_cast<uint8_t>(d_burst_nr.subtract_timeslots(3).get_timeslot_nr());
+        tap_header->frame_number = htobe32(d_burst_nr.subtract_timeslots(3).get_frame_nr());
+        input_nr = input_nr - d_cell_allocation.size();
+        tap_header->arfcn = htobe16(d_cell_allocation[input_nr] | 0x4000);
+    }
     tap_header->signal_dbm = static_cast<int8_t>(d_signal_dbm);
     tap_header->snr_db = 0;
 
diff --git a/lib/receiver/receiver_impl.h b/lib/receiver/receiver_impl.h
index d668e14..c8d71f9 100644
--- a/lib/receiver/receiver_impl.h
+++ b/lib/receiver/receiver_impl.h
@@ -39,6 +39,7 @@
         /**@name Configuration of the receiver */
         //@{
         const int d_OSR; ///< oversampling ratio
+        bool d_process_uplink;
         const int d_chan_imp_length; ///< channel impulse length
         float d_signal_dbm;
         std::vector<int> d_tseq_nums; ///< stores training sequence numbers for channels different than C0
@@ -203,7 +204,7 @@
 
         
      public:
-       receiver_impl(int osr, const std::vector<int> &cell_allocation, const std::vector<int> &tseq_nums);
+       receiver_impl(int osr, const std::vector<int> &cell_allocation, const std::vector<int> &tseq_nums, bool process_uplink);
       ~receiver_impl();
       
       int work(int noutput_items, gr_vector_const_void_star &input_items, gr_vector_void_star &output_items);