--- a/src/wimax/model/bs-uplink-scheduler-mbqos.cc	Thu Sep 06 16:35:31 2012 +0200
+++ b/src/wimax/model/bs-uplink-scheduler-mbqos.cc	Fri Sep 07 09:29:31 2012 -0700
@@ -195,7 +195,7 @@
 
                   // if backlogged < granted_bw then we don't need to provide granted_bw + min_bw in next window, but backlogged + min_bw
                   if (serviceFlow->GetRecord ()->GetBacklogged ()
-                      < ((uint32_t) std::abs (serviceFlow->GetRecord ()->GetBwSinceLastExpiry ())))
+                      < (serviceFlow->GetRecord ()->GetBwSinceLastExpiry ()))
                     {
                       serviceFlow->GetRecord ()->SetBwSinceLastExpiry (-serviceFlow->GetRecord ()->GetBacklogged ());
                     }