Bar Code Symbologies - 2D & Multi-row

Bar code symbologies are relevant to the Internet of Things as data carriers for identifiers. The relevance of any particular technology and standard to the Internet of Things depends on the application definition of the "identifier". This does not need to be unique to the level of "instant of". This is because the level of granularity depends on the requirements of the domain and the particular IoT service.

This category is separated from linear symbologies because of the greater encoding capacity of 2D and multi-row symbologies, which can also support error correction techniques which increases their robustness.

The category includes three sub-types:

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2D matrix symbologies that are based on binary codeword structures for the channel encoding. Such symbologies are normally read by image scanners.

* Multi-row symbologies that are generally based on a non-binary codeword structures for the channel encoding. Such symbologies are normally read by laser scanners or image scanners. However, the overall geometry of the symbol is important to enable it to be read by an image scanner.
* Composite symbologies – currently only used in the GS1 applications – which link the linear bar code to a separate matrix or multi-row component.

Because the 2D and multi-row symbologies also have the capability of encoding data other than an identifier, this has implications for the development of IoT applications. For example, it means that an IoT service can be designed based on some local filtering based on the data captured from the symbol. A simple example is a product item identifier code supported by an batch number. The batch number can be used as a filter to call for an IoT service, irrespective of whether the product code is serialised or not. If serialised the common argument is that this can be looked up to find the batch number; but this can result in a significant portion of wasted searches.