switch (byDurType) {
 
     case RTSDUR_BB:    //RTSDuration_bb
-        uCTSTime = BBuGetFrameTime(pDevice->byPreambleType, byPktType, 14, pDevice->byTopCCKBasicRate);
-        uDurTime = uCTSTime + 2*pDevice->uSIFS + s_uGetTxRsvTime(pDevice, byPktType, cbFrameLength, wRate, bNeedAck);
-        break;
-
     case RTSDUR_BA:    //RTSDuration_ba
-        uCTSTime = BBuGetFrameTime(pDevice->byPreambleType, byPktType, 14, pDevice->byTopCCKBasicRate);
-        uDurTime = uCTSTime + 2*pDevice->uSIFS + s_uGetTxRsvTime(pDevice, byPktType, cbFrameLength, wRate, bNeedAck);
-        break;
-
-    case RTSDUR_AA:    //RTSDuration_aa
-        uCTSTime = BBuGetFrameTime(pDevice->byPreambleType, byPktType, 14, pDevice->byTopOFDMBasicRate);
-        uDurTime = uCTSTime + 2*pDevice->uSIFS + s_uGetTxRsvTime(pDevice, byPktType, cbFrameLength, wRate, bNeedAck);
-        break;
-
-    case CTSDUR_BA:    //CTSDuration_ba
-        uDurTime = pDevice->uSIFS + s_uGetTxRsvTime(pDevice, byPktType, cbFrameLength, wRate, bNeedAck);
-        break;
-
     case RTSDUR_BA_F0: //RTSDuration_ba_f0
-        uCTSTime = BBuGetFrameTime(pDevice->byPreambleType, byPktType, 14, pDevice->byTopCCKBasicRate);
-       uDurTime = uCTSTime + 2 * pDevice->uSIFS + s_uGetTxRsvTime(pDevice,
-                       byPktType, cbFrameLength, wRate, bNeedAck);
-        break;
-
-    case RTSDUR_AA_F0: //RTSDuration_aa_f0
-        uCTSTime = BBuGetFrameTime(pDevice->byPreambleType, byPktType, 14, pDevice->byTopOFDMBasicRate);
-       uDurTime = uCTSTime + 2 * pDevice->uSIFS + s_uGetTxRsvTime(pDevice,
-                       byPktType, cbFrameLength, wRate, bNeedAck);
-        break;
-
     case RTSDUR_BA_F1: //RTSDuration_ba_f1
         uCTSTime = BBuGetFrameTime(pDevice->byPreambleType, byPktType, 14, pDevice->byTopCCKBasicRate);
        uDurTime = uCTSTime + 2 * pDevice->uSIFS + s_uGetTxRsvTime(pDevice,
                byPktType, cbFrameLength, wRate, bNeedAck);
         break;
 
+    case RTSDUR_AA:
+    case RTSDUR_AA_F0:
     case RTSDUR_AA_F1: //RTSDuration_aa_f1
         uCTSTime = BBuGetFrameTime(pDevice->byPreambleType, byPktType, 14, pDevice->byTopOFDMBasicRate);
        uDurTime = uCTSTime + 2 * pDevice->uSIFS + s_uGetTxRsvTime(pDevice,
                                byPktType, cbFrameLength, wRate, bNeedAck);
        break;
 
+    case CTSDUR_BA:
     case CTSDUR_BA_F0: //CTSDuration_ba_f0
-       uDurTime = pDevice->uSIFS + s_uGetTxRsvTime(pDevice,
-                               byPktType, cbFrameLength, wRate, bNeedAck);
-       break;
-
     case CTSDUR_BA_F1: //CTSDuration_ba_f1
        uDurTime = pDevice->uSIFS + s_uGetTxRsvTime(pDevice,
                                byPktType, cbFrameLength, wRate, bNeedAck);