Edge computing is the term used to describe cloud-enabled application and data processing that takes place in multiple, highly distributed locations that are far closer to the sources of application data than private and public cloud computing locations are today. This proximity is typically measured in terms of round-trip latency, so edge computing locations are often 10 milliseconds (ms) or less away from the data source compared with public cloud data centres, which can be more than 100ms distant (as shown in Figure 1).
Both private and public cloud computing take place in a limited number of large data centres that centralise compute workloads to exploit economies of scale. For example, an organisation with multiple production facilities in various countries will nevertheless concentrate its cloud computing facilities in less than a handful of data centres that are shared by all its units. Public cloud computing services are offered from a few hundred locations worldwide, many of which are situated remotely to take advantage of low land values and a lack of contention for energy. In contrast, leading-edge organisations that are interested in edge computing expect to need tens of thousands of locations, both urban and rural, across a single country in future.
Private versus public edge computing. Private clouds provide dedicated processing support to applications and data that belong to a single organisation. Public cloud computing environments are shared by multiple organisations on a multi-tenant basis. The same distinction exists between private edge clouds, which provide edge computing services for a single organisation, and public edge clouds, the compute resources of which are made available on-demand to multiple customers by third-party public edge cloud providers.
Owners of high numbers of potential locations for edge computing are in a strong position to become public edge cloud providers. Telecoms operators match this profile since the delivery of telecoms networks requires them to have large numbers of highly distributed locations at the edges of their networks to house ‘last mile’ networking equipment. This is the equipment that is needed to deliver to consumer and enterprise customers the fixed and wireless access networks that connect their broadband devices, such as smartphones, home routers and enterprise customer premise equipment (CPE). The low-latency nature of telecoms services requires network edge locations to be near customers. Such sites include cell towers and street cabinets, central offices and metro data centres. Figure 1 shows the latency range supported by telecoms public edge computing locations compared with centralised clouds.
Multi-access edge computing (MEC). The 5G network will be a cloud-based network in which key network functions, such as the 5G standalone (5GC SA) mobile core and virtualised RAN (vRAN) functions are specialist software applications that will execute on cloud infrastructure. Operators therefore need to introduce cloud computing to their network edge locations to support such functions. Rakuten, for example, has initially deployed cloud infrastructure to 3000 edge locations in its new vRAN. The same edge computing capabilities that support network functions in operators’ access networks can also be made available to other organisations with the need to run low-latency applications of their own. MEC is an ETSI-defined architecture that enables the co-location of cloud-native network functions, such as 5GC SA as well as third-party applications in operator network edge clouds. Operators expect to charge for access to the compute resources in their MEC (network edge) clouds as a new source of revenue.
Edge computing and private 4G/5G networks. Private edge clouds are often deployed in conjunction with private wireless networks, both to run software-based mobile network functions (such as the mobile core) on enterprise premises and to support IoT and other applications that fulfil the enterprise’s use case(s).