Added CRC checks to 2,3 and 4 block PDU messages. Enforcing message validation via the message processor. Updated the P25 Activity Summary to show frequencies in megahertz and to add site aliasing to the summary text.

src/alias/AliasList.java

@@ -24,6 +24,10 @@ import javax.xml.bind.annotation.XmlAttribute;
 import javax.xml.bind.annotation.XmlRootElement;
 import javax.xml.bind.annotation.XmlSeeAlso;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import decode.p25.P25ActivitySummary;
 import alias.esn.Esn;
 import alias.fleetsync.FleetsyncID;
 import alias.fleetsync.StatusID;
@@ -49,6 +53,8 @@ import alias.uniqueID.UniqueID;
 @XmlRootElement( name = "alias_list" )
 public class AliasList implements Comparable<AliasList>
 {
+	private final static Logger mLog = LoggerFactory.getLogger( AliasList.class );
+
 	private String mName;
 	private ArrayList<Group> mGroups = new ArrayList<Group>();
 	

src/crc/CRCP25.java

@@ -59,6 +59,9 @@ public class CRCP25
 	/**
 	 * CRC-CCITT 16-bit checksums for a message length of 80 bits plus 16
 	 * additional checksums representing CRC checksum bit errors
+	 * 
+	 * Generated by:
+	 * CRCUtil.generate( 80, 16, 0x11021l, 0xFFFFl, true );
 	 */
 	public static final int[] CCITT_80_CHECKSUMS = new int[]
 	{
@@ -75,6 +78,150 @@ public class CRCP25
 	    0x0400, 0x0800, 0x1000, 0x2000, 0x4000, 0x8000
 	};
 	
+	/**
+	 * CRC-32 checksums for PDU1 ( HEADER + 1 Block ) messages, generated by:
+	 * 
+	 * CRCUtil.generate( 64, 32, 0x104C11DB7l, 0xFFFFFFFFl, true );
+	 */
+	public static final long[] PDU1_CHECKSUMS = new long[]
+	{
+	    0x86FFAACCl, 0x411F5BBDl, 0xA08FADDEl, 0x52275834l, 0x2B7322C1l, 
+	    0x95B99160l, 0x48BC466Bl, 0xA45E2335l, 0xD22F119Al, 0x6B770616l, 
+	    0x37DB0DD0l, 0x198D0833l, 0x8CC68419l, 0xC663420Cl, 0x61512FDDl, 
+	    0xB0A897EEl, 0x5A34C52Cl, 0x2F7AEC4Dl, 0x97BD7626l, 0x49BE35C8l, 
+	    0x26BF943Fl, 0x935FCA1Fl, 0xC9AFE50Fl, 0xE4D7F287l, 0xF26BF943l, 
+	    0xF935FCA1l, 0xFC9AFE50l, 0x7C2DF1F3l, 0xBE16F8F9l, 0xDF0B7C7Cl, 
+	    0x6DE530E5l, 0xB6F29872l, 0x5919C2E2l, 0x2EEC6FAAl, 0x1516B90El, 
+	    0x08EBD25Cl, 0x061567F5l, 0x830AB3FAl, 0x43E5D726l, 0x23926548l, 
+	    0x13A9BC7Fl, 0x89D4DE3Fl, 0xC4EA6F1Fl, 0xE275378Fl, 0xF13A9BC7l, 
+	    0xF89D4DE3l, 0xFC4EA6F1l, 0xFE275378l, 0x7D732767l, 0xBEB993B3l, 
+	    0xDF5CC9D9l, 0xEFAE64ECl, 0x75B7BCADl, 0xBADBDE56l, 0x5F0D61F0l, 
+	    0x2DE63E23l, 0x96F31F11l, 0xCB798F88l, 0x67DC491Fl, 0xB3EE248Fl, 
+	    0xD9F71247l, 0xECFB8923l, 0xF67DC491l, 0xFB3EE248l, 0x00000001l, 
+	    0x00000002l, 0x00000004l, 0x00000008l, 0x00000010l, 0x00000020l, 
+	    0x00000040l, 0x00000080l, 0x00000100l, 0x00000200l, 0x00000400l, 
+	    0x00000800l, 0x00001000l, 0x00002000l, 0x00004000l, 0x00008000l, 
+	    0x00010000l, 0x00020000l, 0x00040000l, 0x00080000l, 0x00100000l, 
+	    0x00200000l, 0x00400000l, 0x00800000l, 0x01000000l, 0x02000000l, 
+	    0x04000000l, 0x08000000l, 0x10000000l, 0x20000000l, 0x40000000l, 
+	    0x80000000l
+	};
+	
+	/**
+	 * CRC-32 checksums for PDU2 ( HEADER + 2 Blocks ) messages, generated by:
+	 * 
+	 * CRCUtil.generate( 160, 32, 0x104C11DB7l, 0xFFFFFFFFl, true );
+	 */
+	public static final long[] PDU2_CHECKSUMS = new long[]
+	{
+	    0x9D231959l, 0xCE918CACl, 0x6528488Dl, 0xB2942446l, 0x5B2A9CF8l, 
+	    0x2FF5C0A7l, 0x97FAE053l, 0xCBFD7029l, 0xE5FEB814l, 0x709FD2D1l, 
+	    0xB84FE968l, 0x5E477A6Fl, 0xAF23BD37l, 0xD791DE9Bl, 0xEBC8EF4Dl, 
+	    0xF5E477A6l, 0x7892B508l, 0x3E29D45Fl, 0x9F14EA2Fl, 0xCF8A7517l, 
+	    0xE7C53A8Bl, 0xF3E29D45l, 0xF9F14EA2l, 0x7E98298Al, 0x3D2C9A1El, 
+	    0x1CF6C3D4l, 0x0C1BEF31l, 0x860DF798l, 0x41667517l, 0xA0B33A8Bl, 
+	    0xD0599D45l, 0xE82CCEA2l, 0x7676E98Al, 0x395BFA1El, 0x1ECD73D4l, 
+	    0x0D063731l, 0x86831B98l, 0x41210317l, 0xA090818Bl, 0xD04840C5l, 
+	    0xE8242062l, 0x76729EEAl, 0x3959C1AEl, 0x1ECC6E0Cl, 0x0D06B9DDl, 
+	    0x86835CEEl, 0x412120ACl, 0x22F01E8Dl, 0x91780F46l, 0x4ADC8978l, 
+	    0x270ECA67l, 0x93876533l, 0xC9C3B299l, 0xE4E1D94Cl, 0x7010627Dl, 
+	    0xB808313El, 0x5E649644l, 0x2D52C5F9l, 0x96A962FCl, 0x49343FA5l, 
+	    0xA49A1FD2l, 0x502D8132l, 0x2A764E42l, 0x175BA9FAl, 0x09CD5A26l, 
+	    0x068623C8l, 0x01239F3Fl, 0x8091CF9Fl, 0xC048E7CFl, 0xE02473E7l, 
+	    0xF01239F3l, 0xF8091CF9l, 0xFC048E7Cl, 0x7C62C9E5l, 0xBE3164F2l, 
+	    0x5D783CA2l, 0x2CDC908Al, 0x140EC69El, 0x0867ED94l, 0x06537811l, 
+	    0x8329BC08l, 0x43F450DFl, 0xA1FA286Fl, 0xD0FD1437l, 0xE87E8A1Bl, 
+	    0xF43F450Dl, 0xFA1FA286l, 0x7F6F5F98l, 0x3DD72117l, 0x9EEB908Bl, 
+	    0xCF75C845l, 0xE7BAE422l, 0x71BDFCCAl, 0x3ABE70BEl, 0x1F3FB684l, 
+	    0x0DFF5599l, 0x86FFAACCl, 0x411F5BBDl, 0xA08FADDEl, 0x52275834l, 
+	    0x2B7322C1l, 0x95B99160l, 0x48BC466Bl, 0xA45E2335l, 0xD22F119Al, 
+	    0x6B770616l, 0x37DB0DD0l, 0x198D0833l, 0x8CC68419l, 0xC663420Cl, 
+	    0x61512FDDl, 0xB0A897EEl, 0x5A34C52Cl, 0x2F7AEC4Dl, 0x97BD7626l, 
+	    0x49BE35C8l, 0x26BF943Fl, 0x935FCA1Fl, 0xC9AFE50Fl, 0xE4D7F287l, 
+	    0xF26BF943l, 0xF935FCA1l, 0xFC9AFE50l, 0x7C2DF1F3l, 0xBE16F8F9l, 
+	    0xDF0B7C7Cl, 0x6DE530E5l, 0xB6F29872l, 0x5919C2E2l, 0x2EEC6FAAl, 
+	    0x1516B90El, 0x08EBD25Cl, 0x061567F5l, 0x830AB3FAl, 0x43E5D726l, 
+	    0x23926548l, 0x13A9BC7Fl, 0x89D4DE3Fl, 0xC4EA6F1Fl, 0xE275378Fl, 
+	    0xF13A9BC7l, 0xF89D4DE3l, 0xFC4EA6F1l, 0xFE275378l, 0x7D732767l, 
+	    0xBEB993B3l, 0xDF5CC9D9l, 0xEFAE64ECl, 0x75B7BCADl, 0xBADBDE56l, 
+	    0x5F0D61F0l, 0x2DE63E23l, 0x96F31F11l, 0xCB798F88l, 0x67DC491Fl, 
+	    0xB3EE248Fl, 0xD9F71247l, 0xECFB8923l, 0xF67DC491l, 0xFB3EE248l, 
+	    0x00000001l, 0x00000002l, 0x00000004l, 0x00000008l, 0x00000010l, 
+	    0x00000020l, 0x00000040l, 0x00000080l, 0x00000100l, 0x00000200l, 
+	    0x00000400l, 0x00000800l, 0x00001000l, 0x00002000l, 0x00004000l, 
+	    0x00008000l, 0x00010000l, 0x00020000l, 0x00040000l, 0x00080000l, 
+	    0x00100000l, 0x00200000l, 0x00400000l, 0x00800000l, 0x01000000l, 
+	    0x02000000l, 0x04000000l, 0x08000000l, 0x10000000l, 0x20000000l, 
+	    0x40000000l, 0x80000000l 
+	};
+	
+	/**
+	 * CRC-32 checksums for PDU3 ( HEADER + 3 Blocks ) messages, generated by:
+	 * 
+	 * CRCUtil.generate( 256, 32, 0x104C11DB7l, 0xFFFFFFFFl, true );
+	 */
+	public static final long[] PDU3_CHECKSUMS = new long[]
+	{
+	    0xAA5FA470l, 0x574F5CE3l, 0xABA7AE71l, 0xD5D3D738l, 0x68896547l, 
+	    0xB444B2A3l, 0xDA225951l, 0xED112CA8l, 0x74E8188Fl, 0xBA740C47l, 
+	    0xDD3A0623l, 0xEE9D0311l, 0xF74E8188l, 0x79C7CE1Fl, 0xBCE3E70Fl, 
+	    0xDE71F387l, 0xEF38F9C3l, 0xF79C7CE1l, 0xFBCE3E70l, 0x7F8791E3l, 
+	    0xBFC3C8F1l, 0xDFE1E478l, 0x6D907CE7l, 0xB6C83E73l, 0xDB641F39l, 
+	    0xEDB20F9Cl, 0x74B98915l, 0xBA5CC48Al, 0x5F4EEC9El, 0x2DC7F894l, 
+	    0x14837291l, 0x8A41B948l, 0x4740527Fl, 0xA3A0293Fl, 0xD1D0149Fl, 
+	    0xE8E80A4Fl, 0xF4740527l, 0xFA3A0293l, 0xFD1D0149l, 0xFE8E80A4l, 
+	    0x7D27CE89l, 0xBE93E744l, 0x5D297D79l, 0xAE94BEBCl, 0x552AD185l, 
+	    0xAA9568C2l, 0x572A3ABAl, 0x29F59386l, 0x169A4718l, 0x092DAD57l, 
+	    0x8496D6ABl, 0xC24B6B55l, 0xE125B5AAl, 0x72F2540El, 0x3B19A4DCl, 
+	    0x1FEC5CB5l, 0x8FF62E5Al, 0x459B99F6l, 0x20AD4220l, 0x12362FCBl, 
+	    0x891B17E5l, 0xC48D8BF2l, 0x60264B22l, 0x3273AB4Al, 0x1B595B7El, 
+	    0x0FCC2364l, 0x05869F69l, 0x82C34FB4l, 0x43012901l, 0xA1809480l, 
+	    0x52A0C49Bl, 0xA950624Dl, 0xD4A83126l, 0x68349648l, 0x367AC5FFl, 
+	    0x9B3D62FFl, 0xCD9EB17Fl, 0xE6CF58BFl, 0xF367AC5Fl, 0xF9B3D62Fl, 
+	    0xFCD9EB17l, 0xFE6CF58Bl, 0xFF367AC5l, 0xFF9B3D62l, 0x7DAD106Al, 
+	    0x3CB606EEl, 0x1C3B8DACl, 0x0C7D480Dl, 0x863EA406l, 0x417FDCD8l, 
+	    0x22DF60B7l, 0x916FB05Bl, 0xC8B7D82Dl, 0xE45BEC16l, 0x704D78D0l, 
+	    0x3A4632B3l, 0x9D231959l, 0xCE918CACl, 0x6528488Dl, 0xB2942446l, 
+	    0x5B2A9CF8l, 0x2FF5C0A7l, 0x97FAE053l, 0xCBFD7029l, 0xE5FEB814l, 
+	    0x709FD2D1l, 0xB84FE968l, 0x5E477A6Fl, 0xAF23BD37l, 0xD791DE9Bl, 
+	    0xEBC8EF4Dl, 0xF5E477A6l, 0x7892B508l, 0x3E29D45Fl, 0x9F14EA2Fl, 
+	    0xCF8A7517l, 0xE7C53A8Bl, 0xF3E29D45l, 0xF9F14EA2l, 0x7E98298Al, 
+	    0x3D2C9A1El, 0x1CF6C3D4l, 0x0C1BEF31l, 0x860DF798l, 0x41667517l, 
+	    0xA0B33A8Bl, 0xD0599D45l, 0xE82CCEA2l, 0x7676E98Al, 0x395BFA1El, 
+	    0x1ECD73D4l, 0x0D063731l, 0x86831B98l, 0x41210317l, 0xA090818Bl, 
+	    0xD04840C5l, 0xE8242062l, 0x76729EEAl, 0x3959C1AEl, 0x1ECC6E0Cl, 
+	    0x0D06B9DDl, 0x86835CEEl, 0x412120ACl, 0x22F01E8Dl, 0x91780F46l, 
+	    0x4ADC8978l, 0x270ECA67l, 0x93876533l, 0xC9C3B299l, 0xE4E1D94Cl, 
+	    0x7010627Dl, 0xB808313El, 0x5E649644l, 0x2D52C5F9l, 0x96A962FCl, 
+	    0x49343FA5l, 0xA49A1FD2l, 0x502D8132l, 0x2A764E42l, 0x175BA9FAl, 
+	    0x09CD5A26l, 0x068623C8l, 0x01239F3Fl, 0x8091CF9Fl, 0xC048E7CFl, 
+	    0xE02473E7l, 0xF01239F3l, 0xF8091CF9l, 0xFC048E7Cl, 0x7C62C9E5l, 
+	    0xBE3164F2l, 0x5D783CA2l, 0x2CDC908Al, 0x140EC69El, 0x0867ED94l, 
+	    0x06537811l, 0x8329BC08l, 0x43F450DFl, 0xA1FA286Fl, 0xD0FD1437l, 
+	    0xE87E8A1Bl, 0xF43F450Dl, 0xFA1FA286l, 0x7F6F5F98l, 0x3DD72117l, 
+	    0x9EEB908Bl, 0xCF75C845l, 0xE7BAE422l, 0x71BDFCCAl, 0x3ABE70BEl, 
+	    0x1F3FB684l, 0x0DFF5599l, 0x86FFAACCl, 0x411F5BBDl, 0xA08FADDEl, 
+	    0x52275834l, 0x2B7322C1l, 0x95B99160l, 0x48BC466Bl, 0xA45E2335l, 
+	    0xD22F119Al, 0x6B770616l, 0x37DB0DD0l, 0x198D0833l, 0x8CC68419l, 
+	    0xC663420Cl, 0x61512FDDl, 0xB0A897EEl, 0x5A34C52Cl, 0x2F7AEC4Dl, 
+	    0x97BD7626l, 0x49BE35C8l, 0x26BF943Fl, 0x935FCA1Fl, 0xC9AFE50Fl, 
+	    0xE4D7F287l, 0xF26BF943l, 0xF935FCA1l, 0xFC9AFE50l, 0x7C2DF1F3l, 
+	    0xBE16F8F9l, 0xDF0B7C7Cl, 0x6DE530E5l, 0xB6F29872l, 0x5919C2E2l, 
+	    0x2EEC6FAAl, 0x1516B90El, 0x08EBD25Cl, 0x061567F5l, 0x830AB3FAl, 
+	    0x43E5D726l, 0x23926548l, 0x13A9BC7Fl, 0x89D4DE3Fl, 0xC4EA6F1Fl, 
+	    0xE275378Fl, 0xF13A9BC7l, 0xF89D4DE3l, 0xFC4EA6F1l, 0xFE275378l, 
+	    0x7D732767l, 0xBEB993B3l, 0xDF5CC9D9l, 0xEFAE64ECl, 0x75B7BCADl, 
+	    0xBADBDE56l, 0x5F0D61F0l, 0x2DE63E23l, 0x96F31F11l, 0xCB798F88l, 
+	    0x67DC491Fl, 0xB3EE248Fl, 0xD9F71247l, 0xECFB8923l, 0xF67DC491l, 
+	    0xFB3EE248l, 0x00000001l, 0x00000002l, 0x00000004l, 0x00000008l, 
+	    0x00000010l, 0x00000020l, 0x00000040l, 0x00000080l, 0x00000100l, 
+	    0x00000200l, 0x00000400l, 0x00000800l, 0x00001000l, 0x00002000l, 
+	    0x00004000l, 0x00008000l, 0x00010000l, 0x00020000l, 0x00040000l, 
+	    0x00080000l, 0x00100000l, 0x00200000l, 0x00400000l, 0x00800000l, 
+	    0x01000000l, 0x02000000l, 0x04000000l, 0x08000000l, 0x10000000l, 
+	    0x20000000l, 0x40000000l, 0x80000000l 
+	};	
+
 	/**
 	 * Performs CRC check and corrects single-bit errors against the message.
 	 * @param message - bitsetbuffer containing a message of at least 64 bits.
@@ -115,6 +262,72 @@ public class CRCP25
 	}
 
 	/**
+	 * Performs error detection and single-bit error correction against the
+	 * data blocks of a PDU1 message.
+	 */
+	public static CRC correctPDU1( BitSetBuffer message )
+	{
+		return correctPDU( message, PDU1_CHECKSUMS, 224 );
+	}
+
+	/**
+	 * Performs error detection and single-bit error correction against the
+	 * data blocks of a PDU2 message.
+	 */
+	public static CRC correctPDU2( BitSetBuffer message )
+	{
+		return correctPDU( message, PDU2_CHECKSUMS, 320 );
+	}
+
+	/**
+	 * Performs error detection and single-bit error correction against the
+	 * data blocks of a PDU3 message.
+	 */
+	public static CRC correctPDU3( BitSetBuffer message )
+	{
+		return correctPDU( message, PDU3_CHECKSUMS, 416 );
+	}
+
+	public static CRC correctPDU( BitSetBuffer message, long[] checksums, int crcStart )
+	{
+		long calculated = 0; //Starting value
+		
+		int messageStart = 160;
+
+		/* Iterate the set bits and XOR running checksum with lookup value */
+		for (int i = message.nextSetBit( messageStart ); 
+				 i >= messageStart && i < crcStart; 
+				 i = message.nextSetBit( i+1 ) ) 
+		{
+			calculated ^= checksums[ i - messageStart ];
+		}
+		
+		long checksum = getLongChecksum( message, crcStart, 32 );
+
+		long error = calculated ^ checksum;
+		
+		if( error == 0 || error == 0xFFFFFFFFl )
+		{
+			return CRC.PASSED;
+		}
+		else
+		{
+			int errorLocation = getBitError( error, checksums );
+			
+			if( errorLocation >= 0 )
+			{
+				message.flip( errorLocation + messageStart );
+				
+				return CRC.CORRECTED;
+			}
+		}
+
+		return CRC.FAILED_CRC;
+	}
+
+	/**
+	 * Error detection and correction of single-bit errors for CCITT 16-bit
+	 * CRC protected 80-bit messages.
 	 */
 	public static CRC correctCCITT80( BitSetBuffer message, 
 									  int messageStart,
@@ -212,13 +425,13 @@ public class CRCP25
     
     public static void main( String[] args )
     {
-    	String raw = "0010011000000111101010111111001111100001111010011110000100010010000010011001000000101101110000000000000000000000000000000000000000000000000000000001011011001100";
+    	String raw = "0010011000001100101001010111110100010101011010011111110010101100001101111111110100000000000000000001001001101001100000010011101000000000000000001000110101001000000000010010011100111111111000110011110000111000011100000000000000001001111001000101101100001010";
     	
     	BitSetBuffer message = BitSetBuffer.load( raw );
     	
     	mLog.debug( "MSG:" + message.toString() );
 
-    	CRC results = correctCCITT80( message, 64, 144 );
+    	CRC results = correctPDU1( message );
 
     	mLog.debug( "COR:" + message.toString() );
 

src/crc/CRCUtil.java

@@ -17,8 +17,6 @@
  ******************************************************************************/
 package crc;
 
-import java.util.Arrays;
-
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -52,7 +50,7 @@ public class CRCUtil
 			
 			message.set( x );
 			
-			message = decode( message, polynomial, crcSize, messageSize );
+			message = decode( message, messageSize, polynomial, crcSize );
 			
 			long checksum = message.getLong( checksumIndexes );
 			
@@ -93,9 +91,9 @@ public class CRCUtil
 	 * placed in the crc field which starts at index messageLength
 	 */
 	public static BitSetBuffer decode( BitSetBuffer message,
+									   int messageSize,
 									   long polynomial,
-									   int crcSize,
+									   int crcSize )
-									   int messageSize )
 	{
 		int MESSAGE_START = 0;
 		
@@ -115,13 +113,19 @@ public class CRCUtil
 	
 	public static void main( String[] args )
 	{
-		long crcCCITT = 0x11021l;
-		long initialFill = 0xFFFFl;
-		
 		mLog.debug( "Starting" );
 
-		long[] table = generate( 80, 16, crcCCITT, initialFill, true );
+		long polynomial = 0x104C11DB7l;
 
+//		String raw = "101111101110000000000000001101111110001100111100001110000111000011111111101010111011000011100100";
+//		BitSetBuffer buffer = BitSetBuffer.load( raw );
+//		mLog.debug( "ORIG:" + buffer.toString() );
+//		BitSetBuffer processed = decode( buffer, 64, polynomial, 32 );
+//		mLog.debug( "PROC:" + processed.toString() );
+
+		long[] table = generate( 256, 32, 0x104C11DB7l, 0xFFFFFFFFl, true );
+		
+//		long[] table = generate( 80, 16, 0x11021l, 0xFFFFl, true );
 		mLog.debug( toCodeArray( table ) );
 		mLog.debug( "Finished" );
 	}

src/decode/p25/P25ActivitySummary.java

@@ -17,15 +17,20 @@
  ******************************************************************************/
 package decode.p25;
 
+import java.text.DecimalFormat;
 import java.util.HashMap;
 import java.util.Set;
 import java.util.TreeSet;
 
 import message.Message;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import sample.Listener;
+import alias.Alias;
 import alias.AliasList;
 import controller.activity.ActivitySummaryProvider;
-import decode.p25.message.P25Message;
 import decode.p25.message.pdu.PDUMessage;
 import decode.p25.message.pdu.osp.control.NetworkStatusBroadcastExtended;
 import decode.p25.message.pdu.osp.control.RFSSStatusBroadcastExtended;
@@ -42,6 +47,12 @@ public class P25ActivitySummary implements ActivitySummaryProvider,
 {
 	private static final int sINT_NULL_VALUE = -1;
 
+	private final static Logger mLog = 
+			LoggerFactory.getLogger( P25ActivitySummary.class );
+
+	private static final DecimalFormat mFrequencyFormatter = 
+			new DecimalFormat( "0.000000" );
+
 	private AliasList mAliasList;
 	
 	private NetworkStatusBroadcast mNetworkStatus;
@@ -69,6 +80,11 @@ public class P25ActivitySummary implements ActivitySummaryProvider,
 	@Override
     public void receive( Message message )
     {
+		if( !message.isValid() )
+		{
+			mLog.debug( "Got an invalid message!" );
+		}
+		
 		if( message instanceof TSBKMessage )
 		{
 			if( message instanceof AdjacentStatusBroadcast )
@@ -118,7 +134,7 @@ public class P25ActivitySummary implements ActivitySummaryProvider,
 
 		sb.append( "Activity Summary\n" );
 		sb.append( "Decoder:\tP25\n" );
-		sb.append( "---------- THIS SITE --------------" );
+		sb.append( "===================== THIS SITE ======================" );
 		
 		if( mNetworkStatus != null )
 		{
@@ -126,14 +142,6 @@ public class P25ActivitySummary implements ActivitySummaryProvider,
 			sb.append( "\nSYSTEM:\t" + mNetworkStatus.getSystemID() );
 			sb.append( "\nWACN:\t" + mNetworkStatus.getWACN() );
 			sb.append( "\nLRA:\t" + mNetworkStatus.getLocationRegistrationArea() );
-			sb.append( "\nSERVICES:\t" + SystemService.toString( 
-					mNetworkStatus.getSystemServiceClass() ) );
-			sb.append( "\nPCCH:\tDNLINK " + mNetworkStatus.getDownlinkFrequency() + 
-					" [" + mNetworkStatus.getIdentifier() + "-" + 
-					mNetworkStatus.getChannel() + "]\n" );
-			sb.append( "\tUPLINK " + mNetworkStatus.getUplinkFrequency() + " [" + 
-					mNetworkStatus.getIdentifier() + "-" +
-					mNetworkStatus.getChannel() + "]\n" );
 		}
 		else if( mNetworkStatusExtended != null )
 		{
@@ -141,13 +149,56 @@ public class P25ActivitySummary implements ActivitySummaryProvider,
 			sb.append( "\nSYSTEM:\t" + mNetworkStatusExtended.getSystemID() );
 			sb.append( "\nWACN:\t" + mNetworkStatusExtended.getWACN() );
 			sb.append( "\nLRA:\t" + mNetworkStatusExtended.getLocationRegistrationArea() );
+		}
+
+		String site = null;
+		
+		if( mRFSSStatusMessage != null )
+		{
+			site = mRFSSStatusMessage.getRFSubsystemID() + "-" + mRFSSStatusMessage.getSiteID();
+		}
+		else if( mRFSSStatusMessageExtended != null )
+		{
+			site = mRFSSStatusMessageExtended.getRFSubsystemID() + "-" +
+				   mRFSSStatusMessageExtended.getSiteID();
+		}
+
+		sb.append( "\nRFSS-SITE:\t" + site );
+		
+		if( mAliasList != null )
+		{
+			Alias siteAlias = mAliasList.getSiteID( site );
+			
+			if( siteAlias != null )
+			{
+				sb.append( " " + siteAlias.getName() );
+			}
+		}
+
+		if( mNetworkStatus != null )
+		{
+			sb.append( "\nSERVICES:\t" + SystemService.toString( 
+					mNetworkStatus.getSystemServiceClass() ) );
+			sb.append( "\nPCCH:\tDNLINK " + mFrequencyFormatter.format( 
+					(double)mNetworkStatus.getDownlinkFrequency() / 1E6d ) + 
+					" [" + mNetworkStatus.getIdentifier() + "-" + 
+					mNetworkStatus.getChannel() + "]\n" );
+			sb.append( "\tUPLINK " + mFrequencyFormatter.format( 
+					(double)mNetworkStatus.getUplinkFrequency() / 1E6d ) + " [" + 
+					mNetworkStatus.getIdentifier() + "-" +
+					mNetworkStatus.getChannel() + "]\n" );
+		}
+		else if( mNetworkStatusExtended != null )
+		{
 			sb.append( "\nSERVICES:\t" + SystemService.toString( 
 					mNetworkStatusExtended.getSystemServiceClass() ) );
-			sb.append( "\nPCCH:\tDNLINK " + mNetworkStatusExtended.getDownlinkFrequency() + 
+			sb.append( "\nPCCH:\tDNLINK " + mFrequencyFormatter.format( 
+					(double)mNetworkStatusExtended.getDownlinkFrequency() / 1E6d ) + 
 					" [" + mNetworkStatusExtended.getTransmitIdentifier() + "-" + 
 					mNetworkStatusExtended.getTransmitChannel() + "]\n" );
-			sb.append( "\tUPLINK " + mNetworkStatusExtended.getUplinkFrequency() + " [" + 
+			sb.append( "\tUPLINK " + mFrequencyFormatter.format( 
-					mNetworkStatusExtended.getReceiveIdentifier() + "-" +
+					(double)mNetworkStatusExtended.getUplinkFrequency() / 1E6d ) + 
+					" [" + mNetworkStatusExtended.getReceiveIdentifier() + "-" +
 					mNetworkStatusExtended.getReceiveChannel() + "]" );
 		}
 		
@@ -159,45 +210,33 @@ public class P25ActivitySummary implements ActivitySummaryProvider,
 		{
 			for( SecondaryControlChannelBroadcast sec: mSecondaryControlChannels )
 			{
-				sb.append( "\nSCCH:\tDNLINK " + sec.getDownlinkFrequency1() +
+				sb.append( "\nSCCH:\tDNLINK " + mFrequencyFormatter.format( 
+						(double)sec.getDownlinkFrequency1() / 1E6d ) +
 						" [" + sec.getIdentifier1() + "-" + sec.getChannel1() + "]\n" );
-				sb.append( "\tUPLINK " + sec.getUplinkFrequency1() + " [" +
+				sb.append( "\tUPLINK " + mFrequencyFormatter.format( 
+						(double)sec.getUplinkFrequency1() / 1E6d ) + " [" +
 						sec.getIdentifier1() + "-" + sec.getChannel1() + "]\n" );
 				
 				if( sec.hasChannel2() )
 				{
-					sb.append( "\nSCCH:\tDNLINK " + sec.getDownlinkFrequency2() +
+					sb.append( "\nSCCH:\tDNLINK " + mFrequencyFormatter.format( 
+							(double)sec.getDownlinkFrequency2() / 1E6d ) +
 							" [" + sec.getIdentifier2() + "-" + sec.getChannel2() + "]\n" );
-					sb.append( "\tUPLINK " + sec.getUplinkFrequency2() + " [" +
+					sb.append( "\tUPLINK " + mFrequencyFormatter.format( 
+							(double)sec.getUplinkFrequency2() / 1E6d ) + " [" +
 							sec.getIdentifier2() + "-" + sec.getChannel2() + "]" );
 				}
 			}
 		}
 
-		if( mRFSSStatusMessage != null )
-		{
-			sb.append( "\nRFSS:\t" + mRFSSStatusMessage.getRFSubsystemID() );
-			sb.append( "\nSITE:\t" + mRFSSStatusMessage.getSiteID() );
-
-			if( mAliasList != null )
-			{
-				/* Add site alias here */
-			}
-			
-		}
-		else if( mRFSSStatusMessageExtended != null )
-		{
-			sb.append( "\nRFSS:\t" + mRFSSStatusMessageExtended.getRFSubsystemID() );
-			sb.append( "\nSITE:\t" + mRFSSStatusMessageExtended.getSiteID() );
-		}
 		
 		
-		sb.append( "\n\n----------- NEIGHBORS -------------" );
+		sb.append( "\n\n=================== NEIGHBORS ======================" );
 		
 		if( mNeighborMap.isEmpty() )
 		{
 			sb.append( "\n\tNONE\n" );
-			sb.append( "------------------------\n" );
+			sb.append( "\n----------------------------------------------------" );
 		}
 		else
 		{
@@ -206,11 +245,25 @@ public class P25ActivitySummary implements ActivitySummaryProvider,
 				sb.append( "\nNAC:\t" + neighbor.getNAC() );
 				sb.append( "\nSYSTEM:\t" + neighbor.getSystemID()  );
 				sb.append( "\nLRA:\t" + neighbor.getLocationRegistrationArea() );
-				sb.append( "\nRFSS:\t" + neighbor.getRFSS()  );
+				
-				sb.append( "\nSITE:\t" + neighbor.getSiteID()  );
+				String neighborID = neighbor.getRFSS() + "-" + neighbor.getSiteID();
-				sb.append( "\nPCCH:\tDNLINK " + neighbor.getDownlinkFrequency() +
+				sb.append( "\nRFSS-SITE:\t" + neighborID  );
+				
+				if( mAliasList != null )
+				{
+					Alias siteAlias = mAliasList.getSiteID( neighborID );
+					
+					if( siteAlias != null )
+					{
+						sb.append( " " + siteAlias.getName() );
+					}
+				}
+				
+				sb.append( "\nPCCH:\tDNLINK " + mFrequencyFormatter.format( 
+						(double)neighbor.getDownlinkFrequency() / 1E6d ) +
 						" [" + neighbor.getIdentifier() + "-" + neighbor.getChannel() + "]" );
-				sb.append( "\n\tUPLINK:" + neighbor.getUplinkFrequency() + "\n" );
+				sb.append( "\n\tUPLINK:" + mFrequencyFormatter.format(  
+						(double)neighbor.getUplinkFrequency() / 1E6d ) + "\n" );
 				sb.append( "\nSERVICES:\t" + Service.getServices( neighbor.getSystemServiceClass() ) );
 				sb.append( "\n----------------------------------------------------" );
 			}

src/decode/p25/P25MessageProcessor.java

@@ -36,30 +36,33 @@ public class P25MessageProcessor implements Listener<Message>
 	@Override
     public void receive( Message message )
     {
-		/* Insert band identifier update messages into channel-type messages */
+		if( message.isValid() )
-		if( message instanceof IdentifierUpdateReceiver )
 		{
-			IdentifierUpdateReceiver receiver = (IdentifierUpdateReceiver)message;
+			/* Insert band identifier update messages into channel-type messages */
-			
+			if( message instanceof IdentifierUpdateReceiver )
-			int[] identifiers = receiver.getIdentifiers();
-			
-			for( int identifier: identifiers )
 			{
-				receiver.setIdentifierMessage( identifier, 
+				IdentifierUpdateReceiver receiver = (IdentifierUpdateReceiver)message;
-								mIdentifierMap.get( identifier ) );
+				
+				int[] identifiers = receiver.getIdentifiers();
+				
+				for( int identifier: identifiers )
+				{
+					receiver.setIdentifierMessage( identifier, 
+									mIdentifierMap.get( identifier ) );
+				}
 			}
+
+			/* Store band identifiers so that they can be injected into channel
+			 * type messages */
+			if( message instanceof IdentifierUpdate )
+			{
+				IdentifierUpdate identifierUpdate = (IdentifierUpdate)message;
+				
+				mIdentifierMap.put( identifierUpdate.getIdentifier(), identifierUpdate );
+			}
+			
+			mBroadcaster.broadcast( message );
 		}
-
-		/* Store band identifiers so that they can be injected into channel
-		 * type messages */
-		if( message instanceof IdentifierUpdate )
-		{
-			IdentifierUpdate identifierUpdate = (IdentifierUpdate)message;
-			
-			mIdentifierMap.put( identifierUpdate.getIdentifier(), identifierUpdate );
-		}
-		
-		mBroadcaster.broadcast( message );
     }
 	
 	public void dispose()

src/decode/p25/message/P25Message.java

@@ -143,7 +143,18 @@ public class P25Message extends Message
 	@Override
     public boolean isValid()
     {
-	    return true;
+		if( mCRC != null )
+		{
+			for( CRC crc: mCRC )
+			{
+				if( crc == CRC.FAILED_CRC )
+				{
+					return false;
+				}
+			}
+		}
+		
+		return true;
     }
 
 	/**

src/decode/p25/message/pdu/UnitToUnitChannelGrantExtended.java

@@ -1,5 +1,6 @@
 package decode.p25.message.pdu;
 
+import crc.CRCP25;
 import alias.AliasList;
 import bits.BitSetBuffer;
 import decode.p25.message.tsbk.osp.control.IdentifierUpdate;
@@ -45,6 +46,10 @@ public abstract class UnitToUnitChannelGrantExtended extends PDUMessage
             DataUnitID duid, AliasList aliasList )
     {
 	    super( message, duid, aliasList );
+
+	    /* Header block is already error detected/corrected - perform error
+	     * detection correction on the intermediate and final data blocks */
+	    mCRC[ 1 ] = CRCP25.correctPDU2( mMessage );
     }
 
     public String getMessage()

src/decode/p25/message/pdu/osp/control/AdjacentStatusBroadcastExtended.java

@@ -1,5 +1,6 @@
 package decode.p25.message.pdu.osp.control;
 
+import crc.CRCP25;
 import alias.AliasList;
 import bits.BitSetBuffer;
 import decode.p25.message.pdu.PDUMessage;
@@ -37,6 +38,10 @@ public class AdjacentStatusBroadcastExtended extends PDUMessage
             DataUnitID duid, AliasList aliasList )
     {
 	    super( message, duid, aliasList );
+	    
+	    /* Header block is already error detected/corrected - perform error
+	     * detection correction on the intermediate and final data blocks */
+	    mCRC[ 1 ] = CRCP25.correctPDU1( mMessage );
     }
 
     @Override

src/decode/p25/message/pdu/osp/control/CallAlertExtended.java

@@ -1,5 +1,6 @@
 package decode.p25.message.pdu.osp.control;
 
+import crc.CRCP25;
 import alias.AliasList;
 import bits.BitSetBuffer;
 import decode.p25.message.pdu.PDUMessage;
@@ -24,6 +25,10 @@ public class CallAlertExtended extends PDUMessage
             DataUnitID duid, AliasList aliasList )
     {
 	    super( message, duid, aliasList );
+	    
+	    /* Header block is already error detected/corrected - perform error
+	     * detection correction on the intermediate and final data blocks */
+	    mCRC[ 1 ] = CRCP25.correctPDU1( mMessage );
     }
 
     @Override

src/decode/p25/message/pdu/osp/control/GroupAffiliationQueryExtended.java

@@ -1,5 +1,6 @@
 package decode.p25.message.pdu.osp.control;
 
+import crc.CRCP25;
 import alias.AliasList;
 import bits.BitSetBuffer;
 import decode.p25.message.pdu.PDUMessage;
@@ -24,6 +25,10 @@ public class GroupAffiliationQueryExtended extends PDUMessage
             DataUnitID duid, AliasList aliasList )
     {
 	    super( message, duid, aliasList );
+	    
+	    /* Header block is already error detected/corrected - perform error
+	     * detection correction on the intermediate and final data blocks */
+	    mCRC[ 1 ] = CRCP25.correctPDU1( mMessage );
     }
 
     @Override

src/decode/p25/message/pdu/osp/control/GroupAffiliationResponseExtended.java

@@ -1,5 +1,6 @@
 package decode.p25.message.pdu.osp.control;
 
+import crc.CRCP25;
 import alias.AliasList;
 import bits.BitSetBuffer;
 import decode.p25.message.pdu.PDUMessage;
@@ -34,6 +35,10 @@ public class GroupAffiliationResponseExtended extends PDUMessage
             DataUnitID duid, AliasList aliasList )
     {
 	    super( message, duid, aliasList );
+	    
+	    /* Header block is already error detected/corrected - perform error
+	     * detection correction on the intermediate and final data blocks */
+	    mCRC[ 1 ] = CRCP25.correctPDU2( mMessage );
     }
 
     @Override

src/decode/p25/message/pdu/osp/control/MessageUpdateExtended.java

@@ -1,5 +1,6 @@
 package decode.p25.message.pdu.osp.control;
 
+import crc.CRCP25;
 import alias.AliasList;
 import bits.BitSetBuffer;
 import decode.p25.message.pdu.PDUMessage;
@@ -26,6 +27,10 @@ public class MessageUpdateExtended extends PDUMessage
             DataUnitID duid, AliasList aliasList )
     {
 	    super( message, duid, aliasList );
+	    
+	    /* Header block is already error detected/corrected - perform error
+	     * detection correction on the intermediate and final data blocks */
+	    mCRC[ 1 ] = CRCP25.correctPDU1( mMessage );
     }
 
     @Override

src/decode/p25/message/pdu/osp/control/NetworkStatusBroadcastExtended.java

@@ -1,5 +1,6 @@
 package decode.p25.message.pdu.osp.control;
 
+import crc.CRCP25;
 import alias.AliasList;
 import bits.BitSetBuffer;
 import decode.p25.message.pdu.PDUMessage;
@@ -36,6 +37,10 @@ public class NetworkStatusBroadcastExtended extends PDUMessage
             DataUnitID duid, AliasList aliasList )
     {
 	    super( message, duid, aliasList );
+	    
+	    /* Header block is already error detected/corrected - perform error
+	     * detection correction on the intermediate and final data blocks */
+	    mCRC[ 1 ] = CRCP25.correctPDU1( mMessage );
     }
 
     @Override

src/decode/p25/message/pdu/osp/control/ProtectionParameterBroadcast.java

@@ -1,5 +1,6 @@
 package decode.p25.message.pdu.osp.control;
 
+import crc.CRCP25;
 import alias.AliasList;
 import bits.BitSetBuffer;
 import decode.p25.message.pdu.PDUMessage;
@@ -38,6 +39,10 @@ public class ProtectionParameterBroadcast extends PDUMessage
             DataUnitID duid, AliasList aliasList )
     {
 	    super( message, duid, aliasList );
+	    
+	    /* Header block is already error detected/corrected - perform error
+	     * detection correction on the intermediate and final data blocks */
+	    mCRC[ 1 ] = CRCP25.correctPDU2( mMessage );
     }
 
     @Override

src/decode/p25/message/pdu/osp/control/RFSSStatusBroadcastExtended.java

@@ -1,5 +1,6 @@
 package decode.p25.message.pdu.osp.control;
 
+import crc.CRCP25;
 import alias.AliasList;
 import bits.BitSetBuffer;
 import decode.p25.message.pdu.PDUMessage;
@@ -37,6 +38,10 @@ public class RFSSStatusBroadcastExtended extends PDUMessage
             DataUnitID duid, AliasList aliasList )
     {
 	    super( message, duid, aliasList );
+	    
+	    /* Header block is already error detected/corrected - perform error
+	     * detection correction on the intermediate and final data blocks */
+	    mCRC[ 1 ] = CRCP25.correctPDU1( mMessage );
     }
 
     @Override

src/decode/p25/message/pdu/osp/control/RoamingAddressUpdateExtended.java

@@ -1,5 +1,6 @@
 package decode.p25.message.pdu.osp.control;
 
+import crc.CRCP25;
 import alias.AliasList;
 import bits.BitSetBuffer;
 import decode.p25.message.pdu.PDUMessage;
@@ -69,18 +70,34 @@ public class RoamingAddressUpdateExtended extends PDUMessage
 	    if( mMessage.size() == P25MessageFramer.PDU2_BEGIN )
 	    {
 	    	mFormat = Format.FORMAT_1;
+		    
+		    /* Header block is already error detected/corrected - perform error
+		     * detection correction on the intermediate and final data blocks */
+		    mCRC[ 1 ] = CRCP25.correctPDU1( mMessage );
 	    }
 	    else if( mMessage.size() == P25MessageFramer.PDU3_BEGIN )
 	    {
 	    	mFormat = Format.FORMAT_2;
+		    
+		    /* Header block is already error detected/corrected - perform error
+		     * detection correction on the intermediate and final data blocks */
+		    mCRC[ 1 ] = CRCP25.correctPDU2( mMessage );
 	    }
 	    else if( mMessage.size() == P25MessageFramer.PDU3_DECODED_END )
 	    {
 	    	mFormat = Format.FORMAT_3;
+		    
+		    /* Header block is already error detected/corrected - perform error
+		     * detection correction on the intermediate and final data blocks */
+		    mCRC[ 1 ] = CRCP25.correctPDU3( mMessage );
 	    }
 	    else
 	    {
 	    	mFormat = Format.FORMAT_1;
+		    
+		    /* Header block is already error detected/corrected - perform error
+		     * detection correction on the intermediate and final data blocks */
+		    mCRC[ 1 ] = CRCP25.correctPDU1( mMessage );
 	    }
     }
 

src/decode/p25/message/pdu/osp/control/StatusQueryExtended.java

@@ -1,5 +1,6 @@
 package decode.p25.message.pdu.osp.control;
 
+import crc.CRCP25;
 import alias.AliasList;
 import bits.BitSetBuffer;
 import decode.p25.message.pdu.PDUMessage;
@@ -24,6 +25,10 @@ public class StatusQueryExtended extends PDUMessage
             DataUnitID duid, AliasList aliasList )
     {
 	    super( message, duid, aliasList );
+	    
+	    /* Header block is already error detected/corrected - perform error
+	     * detection correction on the intermediate and final data blocks */
+	    mCRC[ 1 ] = CRCP25.correctPDU1( mMessage );
     }
 
     @Override

src/decode/p25/message/pdu/osp/control/StatusUpdateExtended.java

@@ -1,5 +1,6 @@
 package decode.p25.message.pdu.osp.control;
 
+import crc.CRCP25;
 import alias.AliasList;
 import bits.BitSetBuffer;
 import decode.p25.message.pdu.PDUMessage;
@@ -26,6 +27,10 @@ public class StatusUpdateExtended extends PDUMessage
             DataUnitID duid, AliasList aliasList )
     {
 	    super( message, duid, aliasList );
+	    
+	    /* Header block is already error detected/corrected - perform error
+	     * detection correction on the intermediate and final data blocks */
+	    mCRC[ 1 ] = CRCP25.correctPDU1( mMessage );
     }
 
     @Override

src/decode/p25/message/pdu/osp/control/UnitRegistrationResponseExtended.java

@@ -1,5 +1,6 @@
 package decode.p25.message.pdu.osp.control;
 
+import crc.CRCP25;
 import alias.AliasList;
 import bits.BitSetBuffer;
 import decode.p25.message.pdu.PDUMessage;
@@ -28,6 +29,10 @@ public class UnitRegistrationResponseExtended extends PDUMessage
             DataUnitID duid, AliasList aliasList )
     {
 	    super( message, duid, aliasList );
+	    
+	    /* Header block is already error detected/corrected - perform error
+	     * detection correction on the intermediate and final data blocks */
+	    mCRC[ 1 ] = CRCP25.correctPDU2( mMessage );
     }
 
     @Override

src/decode/p25/message/pdu/osp/data/GroupDataChannelGrantExtended.java

@@ -2,6 +2,7 @@ package decode.p25.message.pdu.osp.data;
 
 import java.util.Date;
 
+import crc.CRCP25;
 import alias.AliasList;
 import bits.BitSetBuffer;
 import decode.p25.message.pdu.PDUMessage;
@@ -42,6 +43,10 @@ public class GroupDataChannelGrantExtended extends PDUMessage
             DataUnitID duid, AliasList aliasList )
     {
 	    super( message, duid, aliasList );
+	    
+	    /* Header block is already error detected/corrected - perform error
+	     * detection correction on the intermediate and final data blocks */
+	    mCRC[ 1 ] = CRCP25.correctPDU1( mMessage );
     }
 
     @Override

src/decode/p25/message/pdu/osp/voice/GroupVoiceChannelGrantExplicit.java

@@ -1,5 +1,6 @@
 package decode.p25.message.pdu.osp.voice;
 
+import crc.CRCP25;
 import alias.AliasList;
 import bits.BitSetBuffer;
 import decode.p25.message.pdu.PDUMessage;
@@ -40,6 +41,10 @@ public class GroupVoiceChannelGrantExplicit extends PDUMessage
             DataUnitID duid, AliasList aliasList )
     {
 	    super( message, duid, aliasList );
+	    
+	    /* Header block is already error detected/corrected - perform error
+	     * detection correction on the intermediate and final data blocks */
+	    mCRC[ 1 ] = CRCP25.correctPDU1( mMessage );
     }
 
     @Override

src/decode/p25/message/pdu/osp/voice/TelephoneInterconnectChannelGrantExplicit.java

@@ -2,6 +2,7 @@ package decode.p25.message.pdu.osp.voice;
 
 import java.util.Date;
 
+import crc.CRCP25;
 import alias.AliasList;
 import bits.BitSetBuffer;
 import decode.p25.message.pdu.PDUMessage;
@@ -42,6 +43,10 @@ public class TelephoneInterconnectChannelGrantExplicit extends PDUMessage
             DataUnitID duid, AliasList aliasList )
     {
 	    super( message, duid, aliasList );
+	    
+	    /* Header block is already error detected/corrected - perform error
+	     * detection correction on the intermediate and final data blocks */
+	    mCRC[ 1 ] = CRCP25.correctPDU1( mMessage );
     }
 
     @Override

src/decode/p25/message/pdu/osp/voice/UnitToUnitAnswerRequestExplicit.java

@@ -1,5 +1,6 @@
 package decode.p25.message.pdu.osp.voice;
 
+import crc.CRCP25;
 import alias.AliasList;
 import bits.BitSetBuffer;
 import decode.p25.message.pdu.PDUMessage;
@@ -30,6 +31,10 @@ public class UnitToUnitAnswerRequestExplicit extends PDUMessage
             DataUnitID duid, AliasList aliasList )
     {
 	    super( message, duid, aliasList );
+	    
+	    /* Header block is already error detected/corrected - perform error
+	     * detection correction on the intermediate and final data blocks */
+	    mCRC[ 1 ] = CRCP25.correctPDU1( mMessage );
     }
 
     @Override

src/decode/p25/message/pdu/osp/voice/UnitToUnitVoiceChannelGrantUpdateExtended.java

@@ -1,5 +1,6 @@
 package decode.p25.message.pdu.osp.voice;
 
+import crc.CRCP25;
 import alias.AliasList;
 import bits.BitSetBuffer;
 import decode.p25.message.pdu.PDUMessage;
@@ -46,6 +47,10 @@ public class UnitToUnitVoiceChannelGrantUpdateExtended extends PDUMessage
             DataUnitID duid, AliasList aliasList )
     {
 	    super( message, duid, aliasList );
+	    
+	    /* Header block is already error detected/corrected - perform error
+	     * detection correction on the intermediate and final data blocks */
+	    mCRC[ 1 ] = CRCP25.correctPDU2( mMessage );
     }
 
     @Override