P25 work in progress

src/decode/p25/message/tsbk/osp/control/IdentifierUpdate.java

@@ -0,0 +1,153 @@
+package decode.p25.message.tsbk.osp.control;
+
+import alias.AliasList;
+import bits.BitSetBuffer;
+import decode.p25.message.tsbk.TSBKMessage;
+import decode.p25.reference.DataUnitID;
+import decode.p25.reference.Opcode;
+
+public class IdentifierUpdate extends TSBKMessage
+{
+    public static final int[] CHANNEL_IDENTIFIER = { 80,81,82,83 };
+
+    public static final int[] CHANNEL_SPACING = { 102,103,104,105,106,107,108,
+        109,110,111 };
+
+    public static final int[] BANDWIDTH = { 84,85,86,87,88,89,90,91,92 };
+    public static final int[] BANDWIDTH_VHF_UHF = { 84,85,86,87 };
+
+    public static final int[] TRANSMIT_OFFSET = { 93,94,95,96,97,98,99,100,101 };
+    public static final int TRANSMIT_OFFSET_VHF_UHF_SIGN = 88;
+    public static final int[] TRANSMIT_OFFSET_VHF_UHF = { 89,90,91,92,93,94,
+        95,96,97,98,99,100,101 };
+    
+    public static final int[] BASE_FREQUENCY = { 112,113,114,115,116,117,118,
+        119,120,121,122,123,124,125,126,127,128,129,130,131,132,133,134,135,136,
+        137,138,139,140,141,142,143 };
+    
+    public IdentifierUpdate( BitSetBuffer message, 
+                                DataUnitID duid,
+                                AliasList aliasList ) 
+    {
+        super( message, duid, aliasList );
+    }
+    
+    @Override
+    public String getEventType()
+    {
+        return Opcode.IDENTIFIER_UPDATE.getDescription();
+    }
+    
+    public String getMessage()
+    {
+        StringBuilder sb = new StringBuilder();
+        
+        sb.append( super.getMessage() );
+
+        sb.append( " CHAN:" + getIdentifier() );
+
+        sb.append( " DOWNLINK:" + getDownlinkFrequency() );
+        
+        sb.append( " UPLINK:" + ( getUplinkFrequency() ) );
+        
+        sb.append( " BW:" + getBandwidth() );
+        
+        sb.append( " SPACING:" + getChannelSpacing() );
+        
+        return sb.toString();
+    }
+
+    public int getIdentifier()
+    {
+        return mMessage.getInt( CHANNEL_IDENTIFIER );
+    }
+    
+    /**
+     * Channel spacing in hertz
+     */
+    public int getChannelSpacing()
+    {
+        return mMessage.getInt( CHANNEL_SPACING ) * 125; //Hertz
+    }
+
+    /**
+     * Base frequency in hertz
+     */
+    public long getBaseFrequency()
+    {
+        return mMessage.getLong( BASE_FREQUENCY ) * 5l; //Hertz
+    }
+    
+    public boolean isVHF_UHF()
+    {
+        long base = getBaseFrequency();
+        
+        return ( ( 136000000 <= base && base <= 172000000 ) ||
+                 ( 380000000 <= base && base <= 512000000 ) );
+    }
+
+    /**
+     * Channel bandwidth in hertz
+     */
+    public int getBandwidth()
+    {
+        int bandwidth = mMessage.getInt( BANDWIDTH );
+
+        if( isVHF_UHF() )
+        {
+            switch( bandwidth )
+            {
+                case 4:
+                    return 6250;
+                case 5:
+                    return 12500;
+                default:
+                    return 0;
+            }
+        }
+        else
+        {
+            return bandwidth * 125;
+        }
+    }
+
+    /**
+     * Transmit offset in hertz
+     */
+    public long getOffset()
+    {
+        if( isVHF_UHF() )
+        {
+            long offset = mMessage.getLong( TRANSMIT_OFFSET_VHF_UHF );
+            
+            if( mMessage.get( TRANSMIT_OFFSET_VHF_UHF_SIGN ) )
+            {
+                return offset;
+            }
+            else
+            {
+                return -offset;
+            }
+        }
+        else
+        {
+            return mMessage.getLong( TRANSMIT_OFFSET ) * 250l;
+        }
+    }
+    
+    /**
+     * Uplink ( radio to tower) frequency in hertz
+     */
+    public long getUplinkFrequency()
+    {
+        return getBaseFrequency() - getOffset();
+    }
+
+    /**
+     * Downlink ( tower to radio ) frequency in hertz
+     */
+    public long getDownlinkFrequency()
+    {
+        return getBaseFrequency();
+    }
+}