devices may communicate directly with the infrastructure edge using the last mile network or may use an intermediary device on the device edge such as a gateway to do so. An example of each type of device is a smartphone that has an integrated Long‐Term Evolution (LTE) modem and so is able to communicate directly with the LTE last mile network itself, and a device which instead has only local range Wi‐Fi network connectivity that is used to connect to a gateway which itself has last mile network access.
In comparison to infrastructure edge computing, many devices on the device edge are powered by batteries and subject to other power constraints due to their limited size or mobile nature. It would be possible to design cooperative processing scenarios using only device edge resources in which a device can utilise compute, storage, or network resources from neighbouring devices in an ad hoc fashion; however, for the vast majority of use cases and users, these approaches have proven to be unpopular at best with users not wishing to sacrifice their own limited battery power and processing resources to participate in such a scheme at a large scale outside of outliers such as Folding@home, a distributed computing project that is focused on using a network of mains powered computers, not mobile devices. Bearing this in mind, the need for access to dense compute resources in locations as close as possible to their users is provided to users at the device edge by the infrastructure edge (see Figure 2.2).
Although this book is primarily focused on infrastructure edge computing, topics related to device edge computing will be discussed as appropriate, especially as they relate to the interaction that exists between these two key halves of the edge computing ecosystem and their interoperation.
Figure 2.2 Device edge computing in context.
2.4 A Brief History
As with many technologies, upon close inspection, infrastructure edge computing represents an evolution more than the radical revolution that it may initially appear to be. This does not make it any less significant or impactful; it merely allows us to contextualise infrastructure edge computing within the broader trends which over time have driven much of the development of internet and data centre infrastructure since their inception. This progression lets us understand infrastructure edge computing not as the wild anomaly which it has been portrayed as in the past but as the clear progression of an ongoing theme in network design which has been present for decades and driven by the need to solve both key technical and business challenges using simple and proven principles.
2.4.1 Third Act of the Internet
One framework for understanding the technological progression which has brought us to the point of infrastructure edge computing is the three acts of the internet. This structure distils the evolution of the internet since its inception into three distinct phases, which culminate in the third act of the internet, a state which is driven by new use cases and enabled by infrastructure edge computing.
2.4.1.1 The First Act of the Internet
During the 1970s and 1980s, as the internet began to be available for academic and public use, the types of services it was able to support were basic compared to those which would emerge in the 1990s. Text‐based applications such as bulletin board systems (BBS) and early examples of email represented some of the most complex use cases of the system. With no real‐time element and a simple range of content, the level of centralisation was sufficient to support the small userbase.
It may seem obvious to us in hindsight that the internet would achieve the explosive growth that it has over its lifetime in terms of every possible characteristic from number of users to the volume of data that each individual user would transmit on a daily basis. However, it is a testament to the first principles of the design of the internet that its foundational protocols and technologies have, with the addition of more modern solutions where needed, been able to scale up over time as required.
2.4.1.2 The Second Act of the Internet
During the 1990s and 2000s, internet usage amongst consumers became mainstream as the types of applications and content which the internet supported grew exponentially. The combination of a rapidly growing userbase as millions of people began to connect to the internet for the first time using dial‐up modem connectivity and other technologies such as cable or DSL and the addition of more types of content, as well as far more content being available online in general, began to strain the infrastructure of the internet and led to the development and deployment of the first physical infrastructure solutions, which were designed specifically to address these newly emerging issues.
The widespread advent of cloud computing during the 2010s further exacerbated this trend as new generations of data centre facilities were required globally. As more applications and data began to move from local on‐premises facilities to remote data centres, the locations of these data centres became more important. Cloud providers began to separate their infrastructure on a per‐country basis and, in the case of the United States or other large countries, then began to subdivide their presence within that country into smaller regions, as Amazon Web Services (AWS) has done with their US East and US West regions to optimise performance and the cost of data transportation.
2.4.1.3 The Third Act of the Internet
With the internet now firmly established as a constant in the lives of billions of people across the world who rely on it every day for essential services; connectivity to work, family, and friends; and their primary source of entertainment, the same pressures which drove the evolution from the first to the second act of the internet are mounting once more. More users – now including both humans and machines which will both be essential users of the internet – and a range of new use cases that demand real‐time decision making are pushing the current generation of internet infrastructure beyond its original design intentions and capabilities from both a technical and business standpoint.
For these reasons, the 2020s are the first decade of the third act of the internet, a transformation of the network and data centre infrastructure which supports the internet on a global scale towards a new methodology of design, deployment, and operation which heavily relies on infrastructure edge computing to achieve its aims of improving performance, lowering operational costs, and enabling a new class of use cases which are impossible or impractical to support without this continued push towards new levels of network regionalisation and less reliance upon centralised infrastructure.
Now that the three acts of the internet have been established, it is worth considering additional detail in regard to network regionalisation and some early examples of this methodology being applied to the infrastructure of the internet in response to the emergence of the second act itself.
2.4.2 Network Regionalisation
The key trend which the three acts of the internet highlights is the increasing growth of network regionalisation that has occurred over the preceding decades in response to the need to support new use cases, reduce the opportunities for network congestion across the internet, and provide a measurable increase in performance to end users. From a network perspective, which is especially crucial when we are talking about the internet which is itself a global network of networks, generally the shortest path between the source and destination of data in transit is preferable for reasons of both optimal performance and lowest cost, all
