diff --git a/DAS/validator.py b/DAS/validator.py
index b16701e..b15d275 100644
--- a/DAS/validator.py
+++ b/DAS/validator.py
@@ -277,10 +277,8 @@ class Validator:
         reality of libp2p implementations where topics between two nodes are
         multiplexed over the same transport.
         """
-        progress = True
-        while (progress):
-            progress = False
 
+        def activeSendQueues():
             queues = []
             # collect and shuffle
             for rID, neighs in self.rowNeighbors.items():
@@ -293,14 +291,27 @@ class Validator:
                     if (neigh.sendQueue):
                         queues.append((1, cID, neigh))
 
-            for dim, lineID, neigh in shuffled(queues, self.shuffleQueues):
-                if dim == 0:
-                    self.checkSendSegmentToNeigh(lineID, neigh.sendQueue.popleft(), neigh)
-                else:
-                    self.checkSendSegmentToNeigh(neigh.sendQueue.popleft(), lineID, neigh)
-                progress = True
-                if self.statsTxInSlot >= self.bwUplink:
-                    return
+            return queues
+
+        progress = True
+        while (progress):
+
+            if hasattr(self, 'activeSendQueues'):
+                progress = False
+                for dim, lineID, neigh in self.activeSendQueues:
+                    if dim == 0:
+                        self.checkSendSegmentToNeigh(lineID, neigh.sendQueue.popleft(), neigh)
+                    else:
+                        self.checkSendSegmentToNeigh(neigh.sendQueue.popleft(), lineID, neigh)
+                    progress = True
+                    if self.statsTxInSlot >= self.bwUplink:
+                        return
+
+            self.activeSendQueues = activeSendQueues()
+            if self.activeSendQueues:
+                self.activeSendQueues = shuffled(activeSendQueues(), self.shuffleQueues)
+            else:
+                return
 
     def runSegmentShuffleScheduler(self):
         """ Schedule chunks for sending.