diff --git a/include/superfemto.h b/include/superfemto.h
index 45831de..0c08156 100644
--- a/include/superfemto.h
+++ b/include/superfemto.h
@@ -13,7 +13,7 @@
 #include "gsml1const.h"
 
 #define SUPERFEMTO_API(x,y,z)    ((x << 16) | (y << 8) | z)
-#define SUPERFEMTO_API_VERSION   SUPERFEMTO_API(3,6,0)
+#define SUPERFEMTO_API_VERSION   SUPERFEMTO_API(3,8,1)
 
 /****************************************************************************
  *                                   Const                                  *
@@ -158,7 +158,10 @@ typedef struct SuperFemto_SystemFailureInd
  ***************************************************************************/
 typedef struct SuperFemto_ActivateRfReq
 {
-    // Timing source (FN/TN)
+    // Maximum cell Size
+	uint8_t u8MaxCellSize;				///< Maximum cell size in qbits (1 qbit = 138.4 meters, max 90 qbits)
+
+	// Timing source (FN/TN)
     struct
     {
         uint8_t u8TimSrc;               ///< Timing source (0:Slave/Get timing from remote master BTS, 1:Master/Generates its own timing)