As a new approach to architecting telecommunications networks, there is no doubt that Edge computing has significant potential to change the way that carriers and service providers deliver a range of services to their business and consumer customers.

But with the technology at such an early stage of its development, specific use cases are still under development - particularly as telcos work out the best way to exploit software-defined networking (SDN) and network functions virtualization (NFV) to drive down their own infrastructure costs and streamline provisioning, configuration, and management processes.

There is still debate over what the network Edge actually is, and no strict definition to clear up the confusion. Most see it as smaller data center hosting/processing facilities located closer to the end user, but others feel it could incorporate local workloads running on customer premise equipment and other points of presence with local (LANs) rather than wide area networks (WANs). Instead of a location, the Edge defines only a workload hosted at some indistinct node within the provider or customer infrastructure.

This feature appeared in the DCD Magazine Telco Supplement. Read the full issue for free here.

Telco Tower
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The telco Edge

According to network and telecommunications equipment manufacturer Cisco, the point of the Edge is threefold: to deliver lower latency to the end device to benefit application performance and improve the quality of the experience; implement Edge offloading for greater network efficiency; and perform computations that augment the capabilities of devices and reduce network transport costs. To that end, much of the ongoing innovation has so far focused on the enablement of fifth generation (5G) cellular networks.

Indeed most mobile operators agree that cost-efficient 5G service delivery is simply unfeasible without the deployment of some form of Edge data hosting and processing capability to override the need to transmit and crunch large volumes of information via centralized data centers and the core.

But Cisco’s imperatives apply equally to applications and services delivered over wired broadband connections as they do to 5G links, as much to Edge infrastructure workloads in cable broadband and gigabit-capable passive optical networks (GPON) access as to the 5G radio access network (RAN). As such, fixed line carriers and service providers too are looking at where Edge computing solutions can help them deliver wired broadband connectivity - and the range of IP-based voice and data services which that supports - to customers previously accessed via local loop telephone exchanges.

US telco AT&T, long at the vanguard of SDN/NFV adoption, is currently working to convert some of its estimated 4,700 telephone exchanges into mini data centers. The fixed and mobile network giant is close to achieving its goal of virtualizing 75 percent of its infrastructure by 2020, having already deployed SDN enabled broadband access (SEBA) to deliver superfast fiber broadband services to consumers and businesses in US cities such as Irving and Atlanta. SEBA is a set of open networking components that virtualize the software to run optical network terminals (ONTs) and optical network units (ONUs) on fiber networks, though it can be extended to other types of network including fixed wireless and Gfast that use copper cabling.

In the UK, BT is extending core network functions currently hosted within five to ten of its exchanges to around 100 metro locations. BT’s own Network Cloud will evolve to reduce data and application latency, again initially for 5G applications and services. But, once the infrastructure is in place, it can be used for a variety of different functions, including broadband, IP telephony, and unified communications as a service (UCaaS) provision to customers.

BT currently has around 1,200 local exchanges in the UK which serve as a first point of aggregation, more of which could be migrated to Edge facilities to meet the needs of different cloud hosted services in the future.

5G cell towers are another proposed location for Edge compute resources in the base of 5G cell towers which can also be used to accommodate fixed line operators’ equipment.

Defined by the Open Network Foundation (ONF), the Central Office Re-architected as a Datacenter (CORD) initiative combines NFV, SDN and commodity clouds to bring cost efficiency and cloud agility to the Telco Central Office (UK parlance the local telephone exchange), allowing them to dynamically configure new services for residential, enterprise and mobile customers in real time.

As voice, as well as data traffic, becomes IP enabled, routing and switching functions can be virtualized, making them easier to provision, configure and manage remotely. It is envisaged that the reference implementation of CORD will be built from commodity servers and white-box switches defined by the Open Compute Project (OCP) which are cheaper to buy than proprietary telecommunications hardware for example, alongside disaggregated access technologies (vOLT, vBBU, vDOCSIS), and open source software (OpenStack, ONOS, XOS).

Elsewhere, the European Telecommunications Standards Institute (ETSI) multi-access Edge computing (MEC) specification was designed to promote the convergence of mobile base stations and IT and telecommunications networking, ostensibly to support anticipated new business cases around video analytics, location services, IoT, augmented reality, data caching and optimized local content distribution (what used to be known as a content delivery network - CDN).

The 5G Edge

Those use cases were defined specifically with 5G in mind, but as software overlays devolved from the underlying network, there is no reason why they cannot be applied equally to wired broadband connections too (multi-access is included in the acronym for a reason). Similarly, Edge routers, designed to process data collected from thousands of different devices and end users, already provide various interfaces to both wired and radio-based transmission technologies and communication standards - everything from 5G and WiFi to Bluetooth and Ethernet.

Edge can compete with cloud, after a fashion. Telcos like AT&T and BT need to be able to deliver fast, reliable hosted voice and data services. They are a crucial element of commercial cloud strategies, but the cloud is delivered from centralized facilities, a sector where the telcos have failed.

IT giants like Amazon Web Services, Microsoft, Google, IBM and others have won in the enterprise space by investing heavily in building their own hyperscale facilities.

After finally admitting defeat, AT&T sold off its core data center assets to Brookfield Infrastructure for $1.1bn earlier this year, following similar divestitures by other telcos.

Having a distributed compute infrastructure at their disposal gives telcos something the cloud service providers do not, and would find very difficult to obtain for themselves: dedicated Edge hosting and processing facilities closer to the customer which are better able to support a range of latency sensitive applications for business customers. Those could include everything from infrastructure- (IaaS), platform- (PaaS), network- (NaaS) and unified communication-as-a-service (UCaaS) to industrial IoT (IIoT) and high definition video capture (e.g. CCTV surveillance and consumer retail applications), the provision of which (telcos hope) could be supplemented by value added systems integration and managed services contracts.

And building out their Edge facilities puts telcos in a prime position to make themselves indispensable to bigger cloud providers when it comes to delivering more latency sensitive services and applications to their own customers - a potential market carve up that plays to both sides’ strengths and reach.