added pch.c

openair1/PHY/LTE_TRANSPORT/pch.c

+/*******************************************************************************
+    OpenAirInterface
+    Copyright(c) 1999 - 2014 Eurecom
+
+    OpenAirInterface is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+
+    OpenAirInterface is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenAirInterface.The full GNU General Public License is
+   included in this distribution in the file called "COPYING". If not,
+   see <http://www.gnu.org/licenses/>.
+
+  Contact Information
+  OpenAirInterface Admin: openair_admin@eurecom.fr
+  OpenAirInterface Tech : openair_tech@eurecom.fr
+  OpenAirInterface Dev  : openair4g-devel@lists.eurecom.fr
+
+  Address      : Eurecom, Campus SophiaTech, 450 Route des Chappes, CS 50193 - 06904 Biot Sophia Antipolis cedex, FRANCE
+
+ *******************************************************************************/
+#include "PHY/defs.h"
+#include "PHY/extern.h"
+#include "assertions.h"
+
+const unsigned int Ttab[4] = {32,64,128,256};
+
+// This function implements the initialization of paging parameters for UE (See Section 7, 36.304)
+// It must be called after setting IMSImod1024 during UE startup and after receiving SIB2
+int init_ue_paging_info(PHY_VARS_UE *ue, long defaultPagingCycle, long nB) {
+
+   LTE_DL_FRAME_PARMS *fp = &ue->frame_parms;
+
+   unsigned int T         = Ttab[defaultPagingCycle];
+   unsigned int N         = (nB<=2) ? T : (T>>(nB-2));
+   unsigned int Ns        = (nB<2)  ? (1<<(2-nB)) : 1;
+   unsigned int UE_ID     = ue->IMSImod1024;
+   unsigned int i_s       = (UE_ID/N)%Ns;
+
+   
+   ue->PF = (T/N) * (UE_ID % N);
+
+   // This implements Section 7.2 from 36.304
+   if (Ns==1)
+     ue->PO = (fp->frame_type==FDD) ? 9 : 0; 
+   else if (Ns==2)
+     ue->PO = (fp->frame_type==FDD) ? (4+(5*i_s)) : (5*i_s); 
+   else if (Ns==4)
+     ue->PO = (fp->frame_type==FDD) ? (4*(i_s&1)+(5*(i_s>>1))) : ((i_s&1)+(5*(i_s>>1))); 
+   else
+     AssertFatal(1==0,"init_ue_paging_info: Ns is %d\n",Ns);
+
+   return(0);
+}