Vittorio Bertola and Nicolo Zingales (17/12/2021). Interoperability. In Belli, L.; Zingales, N. & Curzi, Y. (Eds.), Glossary of Platform Law and Policy Terms (online). FGV Direito Rio. https://platformglossary.info/interoperability/.
Authors: Vittorio Bertola and Nicolo Zingales
Interoperability is the ability to transfer and render useful data and other information across systems, applications, or components. The combination of transmission and analysis involves several layers of the so-called Open Systems Interconnection model (OSI model), requiring the achievement of various levels of interoperability. At a minimum, one should distinguish the lower and the upper layer, pointing to a division between infrastructural interoperability and data interoperability.
At the infrastructure (lower) layer, interoperability is achieved with common protocols for the conversion, identification, and logical addressing of data to be transmitted over a network. The most common standards in this layer are Ethernet and TCP/IP. Protocols are also used for communication between computer programs over telecommunications equipment, through common languages such as HTTP for web content, and SMTP, IMAP, and POP3 for emails.
At the application (upper) layer, interoperability is attained by reading and reproducing specific parts of computer programs, called interfaces, which contain the information necessary to “run” programs in a compatible format. However, different interfaces are needed depending on who actually “runs” the program1550: if it is from the perspective of the user/consumer of the computer program, user interfaces are relevant to the ex-tent that they enable him or her to visualize and deploy a specific set of commands or modes of interaction with the program, that can potentially be replicated into another (different) application. Importantly, although this kind of interoperability can increase a program’s utility to the user, it is not required for the purpose of its technical functioning. Most choices for user interfaces are indeed dictated not so much by functional elements of the program, as by the pursuit of the goals of user-friendliness, aesthetical appeal, and promotion of brand-specific features.
In a data-driven economy, the importance of open technical standards can hardly be overstated: common technical and legal protocols for interconnection and data processing enable communication and portability, thereby stimulating innovation and promoting competition of services within a given technological paradigm.
The degree to which such standards are truly open is likely to be a significant point of contention among different types of businesses. Granting automatic access to technology implementers can affect a technology provider’s ability to appropriate the value of its innovation in downstream markets; this, in turn, may lead important players in the industry to not only abstain from standard-setting efforts but also implement strategies aimed at foreclosing interoperability with competitors’ technologies (horizontal interoperability) and preventing third parties from building on top of their technology (vertical interoperability).
From the perspective of the developer of a computer program, the relevant interfaces for interoperability are the Application Programming Interfaces, i.e., any well-defined software interfaces which define the service that one component, module, or application provides to other software elements. However, interoperable APIs do not necessarily imply the ability of either users or developers to meaningfully relate the outputs of interoperable computer programs, unless they are expressed in the same language (most commonly, JPEG for images, HTML for webpages, PDF for documents, and MP3 for music). This can be achieved through the so-called “data interfaces”, which are responsible for restoring and retrieving data in a specific format.
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