Parity Codes for Error Detection WE NEED A GENERAL METHOD FOR TAKING ANY EXISTING ENCODING SCHEME AND TURNING IT INTO A SCHEME THAT LETS US DETECT ERRORS. ONE SIMPLE APPROACH IS TO ADD TO EACH EXISTING BINARY CODE AN EXTRA DIGIT CHOSEN SO THAT THE TOTAL NUMBER OF 1's WILL BE ODD (OR EVEN IF YOU PREFER): 01101011 BECOMES 011010110 01101100 BECOMES 011011001 IF ANY SINGLE BIT OF THE EXTENDED CODE IS CHANGED WE CAN NOTICE THE CHANGE BY JUST COUNTING THE 1's.

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This page is part of a section of lecture slides related to " Error Detecting Codes " within the topic "Data Delivery Obstacles". Other slides within this section and other sections of slides for the topic "Data Delivery Obstacles" can be accessed using the links below. Retransmission Techniques Acknowledgements and Retransmission Retransmissions and Timeouts Sequence Numbers Sequence Numbers (cont.) Message Reordering Reliability and Connections A Reliable Delivery Problem Cautious Generals Solving the General's Problem Solving the General's Problem (cont.) Connections Establishing Connections Persistent HTTP Connections Network Congestion Packet Loss and Congestion Congestion and Transmission Rate Congestion and TCP Connections Finding the Bottleneck Rate TCP Transmission Rate Adjustment Error Detecting Codes Damagaged Data Symbols and Meaning Interpreting Binary Symbols Evaluating Codes Error Detecting Codes Parity Codes for Error Detection Multiple Bit Errors Interleaved Transmission Error Correcting Codes Any Guesses? Digital Recording on Compact Discs Two-dimensional Parity Bits Spatial Interleaving