MEC (Mobile / Multi-Access Edge Computing) puts compute resources at the edge of telco networks. These servers can be used for distributing internal network functions – typically linked with NFV deployments – or made available to third-party developers as part of an “edge cloud” service offering. What are the realistic use cases, and can telcos monetise them?
A formal definition of MEC is that it enables IT, NFV and cloud-computing capabilities within the access network, in close proximity to subscribers. Those edge-based capabilities can be provided to internal network functions, in-house applications run by the operator, or potentially third-party partners / developers.
There has long been a vision in the telecoms industry to put computing functions at local sites. In fixed networks, operators have often worked with CDN and other partners on distributed network capabilities, for example. In mobile, various attempts have been made to put computing or storage functions alongside base stations – both big “macro” cells and in-building small/pico-cells. Part of the hope has been the creation of services tailored to a particular geography or building.
But besides content-cacheing, none of these historic concepts and initiatives have gained much traction. It turns out that “location-specific” services can be easily delivered from central facilities, as long as the endpoint knows its own location (e.g. using GPS) and communicates this to the server.
This is now starting to change. In the last three years, various market and technical trends have re-established the desire for localised computing. Standards have started to evolve, and early examples have emerged. Multiple groups of stakeholders – telcos and their network vendors, application developers, cloud providers, IoT specialists and various others have (broadly) aligned to drive the emergence of edge/fog computing. While there are numerous competing architectures and philosophies, there is clearly some scope for telco-oriented approaches.
While the origins of MEC (and the original “M”) come from the mobile industry, driven by visions of IoT, NFV and network-slicing, the pitch has become more nuanced, and now embraces fixed/cable networks as well – hence the renaming to “multi-access”.
Figure 1: A taxonomy of mobile edge computing
Source: IEEE Conference Paper, Ahmed & Ahmed, https://www.researchgate.net/publication/285765997
Background market drivers for MEC
Before discussing specific technologies and use-cases for MEC, it is important to contextualise some other trends in telecoms that are helping build a foundation for it:
- Telcos need to reduce costs & increase revenues: This is a bit “obvious” but bears repeating. Most initiatives around telco cloud and virtualisation are driven by these two fundamental economic drivers. Here, they relate to a desire to (a) reduce network capex/opex by shifting from proprietary boxes to standardised servers, and (b) increase “programmability” of the network to host new functions and services, and allow them to be deployed/updated/scaled rapidly. These underpin broader trends in NFV and SDN, and then indirectly to MEC and edge-computing.
- New telco services may be inherently “edge-oriented”: IoT, 5G, vertical enterprise applications, plus new consumer services like IPTV also fit into both the virtualisation story and the need for distributed capabilities. For example, industrial IoT connectivity may need realtime control functions for machinery, housed extremely close by, for millisecond (or less) latency. Connected vehicles may need roadside infrastructure. Enterprises might demand on-premise secure data storage, even for cloud-delivered services, for compliance reasons. Various forms of AI (such as machine vision and deep learning) involve particular needs and new ways of handling data.
- The “edge” has its own context data: Some applications are not just latency-sensitive in terms of response between user and server, but also need other local, fast-changing data such as cell congestion or radio-interference metrics. Going all the way to a platform in the core of the network, to query that status, may take longer than it takes the status to change. The length of the “control loop” may mean that old/wrong contextual data is given, and the wrong action taken by the application. Locally-delivered information, via “edge APIs” could be more timely.
- Not all virtual functions can be hosted centrally: While a lot of the discussion around NFV involves consolidated data-centres and the “telco cloud”, this does not apply to all network functions. Certain things can indeed be centralised (e.g. billing systems, border/gateway functions between core network and public Internet), but other things make more sense to distribute. For example, Virtual CPE (customer premises equipment) and CDN caches need to be nearer to the edge of the network, as do some 5G functions such as mobility management. No telco wants to transport millions of separate video streams to homes, all the way from one central facility, for instance.
- There will therefore be localised telco compute sites anyway: Since some telco network functions have to be located in a distributed fashion, there will need to be some data-centres either at aggregation points / central offices or final delivery nodes (base stations, street cabinets etc.). Given this requirement, it is understandable that vendors and operators are looking at ways to extend such sites from the “necessary” to the “possible” – such as creating more generalised APIs for a broader base of developers.
- Radio virtualisation is slightly different to NFV/SDN: While most virtualisation focus in telecoms goes into developments in the core network, or routers/switches, various other relevant changes are taking place. In particular, the concept of C-RAN (cloud-RAN) has taken hold in recent years, where traditional mobile base stations (usually called eNodeB’s) are sometimes being split into the electronics “baseband” units (BBUs) and the actual radio transmit/receive components, called the remote “radio head”, RRH. A number of eNodeB’s BBUs can be clustered together at one site (sometimes called a “hotel”), with fibre “front-haul” connecting the RRHs. This improves the efficiency of both power and space utilisation, and also means the BBUs can be combined and virtualised – and perhaps have extra compute functions added.
- Property business interests: Telcos have often sold or rented physical space in their facilities – colocation of equipment racks for competitive carriers, or servers in hosting sites and data-centres. In turn, they also rely on renting space for their own infrastructure, especially for siting mobile cell-towers on roofs or walls. This two-way trade continues today – and the idea of mobile edge computing as a way to sell “virtual” space in distributed compute facilities maps well to this philosophy.
- Executive Summary
- Background market drivers for MEC
- Why Edge Computing matters
- The ever-wider definition of “Edge”
- Wider market trends in edge-computing
- Use-cases & deployment scenarios for MEC
- Horizontal use-cases
- Addressing vertical markets – the hard realities
- MEC involves extra costs as well as revenues
- Current status & direction of MEC
- Standards path and operator involvement
- Integration challenges
- Conclusions & Recommendations
- Figure 1: A taxonomy of mobile edge computing
- Figure 2: Even within “low latency” there are many different sets of requirements
- Figure 3: The “network edge” is only a slice of the overall cloud/computing space
- Figure 4: Telcos can implement MEC at various points in their infrastructure
- Figure 5: Networks, Cloud and IoT all have different starting-points for the edge
- Figure 6: Network-centric use-cases for MEC suggested by ETSI
- Figure 7: MEC needs to integrate well with many adjacent technologies and trends