Purpose of Novel Bar Code Symbology.  The Bar Code Symbology was developed to:

• Be novel such that it could be patented. This would allow the enforcement of a licence condition that the NU-ERA bar code may only be used when representing numbers drawn from the dPId unique number registry.
• Represent a 128 bit binary number of which 96 bits would be the "payload".  96 bits of data provides a number range from 0 to 79,228,162,514,264,337,593,543,950,336.  In other words, it would be possible to issue from the dPId registry one million, billion unique numbers per annum for approximately 79,228,162,514,264 years (~79 thousand billion years).  Provided these numbers were efficiently allocated, this range provides for an inexhaustible supply of unique numbers.
• Be highly resistant to dirt and damage.  This was achieved through large-scale redundancy.  The redundant pattern also facilitated the identification of a bar code in the field of view of an image sensor by the image processing circuitry.
  
• Provide a barcode with a low probability of erroneous read.  This would be achieved through using a 32 bit error code.
• Consist only of dots. Being so it could be printed using inexpensive equipment.  Having only dots is particularly suited to engraving items with the bar code using a simplified laser etching system.
  

Figure 1. Example of a NU-ERA 2D Bar Code

Figure 2. Damaged yet readable NU-ERA Bar Code

Figure 2 provides an example of the robustness of the NU-ERA Bar Code.  This robustness is achieved through the use of largescale redundancy, error detection (to determine if one of the arrays actually yields a valid value) and the processor "overlaying" arrays to determine the strongest summated signal from any "dot" making up each of the overlapped arrays.  Other systems such as Reed-Solomon encoding could be used for this purpose and may indeed be a more efficient use of dots but the redundancy also serves a another function and that is to assist the image processor speedily find a bar code pattern in the field of view of the image sensor.

For more detailed information on the NU-ERA technology suite, please click here to download the dPId information paper.