The Need for Holistic Network Design

Alberto Leon-Garcia, Martha Steenstrup
2021 IEEE Communications Magazine  
At the ComSoc annual retreat in January of 2021, we established an ad hoc committee to assess the future directions of communications and network research. It has been clear for a few years now that networks are undergoing rapid and disruptive changes. They are no longer utility pipes providing transport; now they offer services to those that are attached to them. With the addition of services, the control planes of networks need to be a lot smarter and more responsive and handle the task of
more » ... viding security. Vincent Chan, ComSoc President T he communication network is changing from a provider of connectivity to a provider of services that enable a gamut of applications that are distributed, mobile, and intelligent. At the same time, consumers of network services are expanding beyond humans to a myriad of things, machines, and automated digital processes. In addition, the network must now respond to new socio-economic priorities such as privacy and environmental concerns. These trends drive the network to become an entire, or in some cases, an integral part of an application platform. We use the term 'holistic network design' for the essential challenge of creating a network architecture that supports the diversity of applications, while meeting new priorities, within a cohesive yet flexible set of design elements. The emergence of networks as massive-scale application platforms both builds on and reinforces cloud computing. Networks are essential to the creation of interconnected multi-clouds encompassing private, public, and network operator clouds that can support global-scale applications. Networks also enable the emergence of distributed multitier clouds that span devices, edge computing, and core computing that will support mobile and IoT applications. On the other hand, cloud computing principles, such as virtualization, microservices and orchestration, are revolutionizing how network services are realized largely by functions implemented in software running on this multitier cloud. The emerging multitier network will play a central role in the creation of intelligent applications that leverage AI and machine learning to provide continuous situational awareness, event detection and identification, and automated response. Some applications will be used by the network/cloud operator to manage the complexity of their infrastructure and services, while other applications will provide intelligence-as-a-service to customers of the network. Sensor data for both types of applications will be the coin of this realm because it will be the raw material needed in both model development and in live inference, classification, and control. The volume of data has the potential to generate huge demands for computing and bandwidth. However, the multitier cloud will allow the optimized placement of functions that implement the data analytics pipelines to collect and analyze data and formulate actions and responses. The orchestration system that defines and deploys the sequence of functions in a pipeline can promote the efficient use of resources as well as meet the diverse quality and cost constraints of different applica-tions. The centrality of data will also favor content-oriented and name-based architectures. Network security is the overarching challenge in emerging networks. The ongoing introduction of 5G mobile networks will provide higher data speeds, denser coverage, improved network quality and reliability, and very low latency. The intent is that these capabilities will make 5G networks essential in sectors such as e-Health, smart manufacturing, connected vehicles, transport and logistics, smart retail, and drone delivery. These capabilities will also transform critical infrastructures and systems including intelligent multi-mode transportation systems, environmental monitoring, smart-energy networks, water supply, and agriculture. 5G networks incorporate innovations that bring major benefits that enable new services and applications. However, the redesign of a highly complex system, such as the redesign of the 5G control plane to a service-based architecture, inevitably creates new vulnerabilities. Despite enormous effort to define protocols to eliminate vulnerabilities, it is impossible to know all vulnerabilities ahead of time, and there is the potential for very high impact from intentional or accidental disruptive events. We emphasize that while 5G networks are a central component of future networks, they are not the only component and must coexist with the Internet and its evolutions. The emerging network is being conceived during a period of changing socio-economic expectations that place new requirements on the network. Climate change demands that new networks must be sustainable and have low carbon footprint. Abuses in the unfettered use of personal information calls for effective and customizable privacy mechanisms. The pre-eminence of information and intelligence in society dictates that there be unbiased access to information technologies to promote equity and inclusiveness. The evolution of the network toward an application platform has the potential to address some of these requirements. It is clear from the above trends that the emerging network must integrate elements that fit its architecture in a holistic fashion within a future applications environment. We hesitate to call the emerging network "6G" because it may well turn out to be a dramatic departure that is unrecognizable from the ongoing progression of network generations. In particular, the above trends underscore the importance of the logical definition of network architectures which focus on the "what" instead of the "how" in the operation of a network. Hence logical functions can be implemented in a variety of ways, from software running on various types of computation devices, to processing integrated into radio, optical or quantum systems. One can discern the new network architecture as consisting of two new overarching layers, a Logical Layer, encompassing all logical aspects, and a Physical Layer, encompassing physical enabling technologies. Reflecting back on the five decades since the introduction of the OSI Reference model, we appreciate both the foresight of the early network architects as well as the revolutionary advances in networking that have transpired
doi:10.1109/mcom.2021.9530485 fatcat:2alxqckc5zcmzmbxbpgp5llnhu