diff --git a/openair1/PHY/impl_defs_top.h b/openair1/PHY/impl_defs_top.h
index 999d802654..9e2b01d296 100755
--- a/openair1/PHY/impl_defs_top.h
+++ b/openair1/PHY/impl_defs_top.h
@@ -328,10 +328,10 @@ typedef struct {
 #define NUMBER_OF_SUBBANDS_MAX 13
 #define NUMBER_OF_HARQ_PID_MAX 8
 
-#if defined(CBMIMO1) || defined(EXMIMO)
+#if defined(CBMIMO1) || defined(EXMIMO) || defined(OAI_USRP)
 #define MAX_FRAME_NUMBER 0x400
 #define NUMBER_OF_eNB_MAX 1
-#define NUMBER_OF_UE_MAX 16
+#define NUMBER_OF_UE_MAX 4
 #define NUMBER_OF_CONNECTED_eNB_MAX 3
 #else
 #define MAX_FRAME_NUMBER 0xFFFF