Network slicing is arguably the technology which will make the business case for 5G. But can it be implemented without making a high-stakes early move to a new network? Affirmed Networks, already known for pushing the boundaries of the virtualized evolved packet core (vEPC), says yes, with a new offering based on LTE.
Slicing allows an individual service or user to call up a virtualized slice of the network, on-demand, and optimized for its particular requirements for speed, latency, device capacity, security and so on. This would enable network owners to support a far wider range of services, some of them mission critical, without building separate infrastructure or overlays for each one; and to support web-like pay-as-you-go models.
Many vendors and operators are looking for ways to start gaining these benefits on current LTE networks. Indeed, for many, slicing will be a phased roadmap. The full vision of dynamic, ever-flexible slicing will be delivered optimally by the 5G radio – whose standards include slicing provisions – and its surrounding architecture. Highly context-aware platforms like the UK 5G Innovation Centre’s Flat Distributed Cloud (FDC), for instance; or the constantly self-adapting network envisaged by Telefonica and Huawei in their User-centric No Cell (UCNC) design – these will enable a vision of slicing which is not possible today.
However, that is not to say that operators should not start to take steps in that direction, as long as they can derive immediate commercial or efficiency benefits too. Arguably, even an end-to-end VPN, or a network-on-demand service, which allocates static chunks of capacity to enterprises or MVNOs, could be labelled as early-stage slicing. AT&T is seeing considerable uptake of its Network as a Service offering, which harnesses its software-driven architecture to enable new flexibility for enterprise customers over its fixed network.
Affirmed Networks, whose vEPC features in AT&T’s Domain 2.0 SDN program, as well as projects at Vodafone and others, is making bold claims for its Affirmed Virtual Slice Selection Function (vSSF), which it says enables fine-grained slicing without 5G. Unlike some pre-5G products, which can only create end-to-end slices if the RAN and EPC come from the same vendor, Affirmed says its technology runs on today’s LTE cores and across physical and virtual elements from multiple vendors.
Angela Whiteford, VP of product marketing and management, said: “The reality is, operators need this right now. It allows you to match the requirements of the service to the network resources available.”
The vSSF software sits between the Mobility Management Entity (MME) and the gateways in the EPC. It automates the current manual process by which operators can deliver some of the functions of slicing, by manually recoding functions in the APN (access point name – the gateway between the mobile network and the Internet). Whiteford says doing that manually is a “blunt instrument”.
The offering may target multivendor networks, but there is strong encouragement to use it in conjunction with other Affirmed products, such as its Service Automation Platform and its Virtual Probe. The SAP combination supports rapid slice deployment, which can reduce the cost and time to launch a new service by as much as 90%, says the vendor. By adding the probe, MNOs gain real time analytics on each slice and service, so they can monitor and improve quality and cost, and identify new service opportunities.
The vSSF allows network resources to be allocated by device type, location, service type and other criteria – though the ultimate vision, in which the service or device itself calls up and defines its slice, without operator intervention, remains a 5G concept. Importantly, that could help operators get round possible net neutrality obstacles, which some believe the stricter regulators may throw in the way of MNOs providing prioritized slices to selected services.
For now, those issues are far away and operators are more interested in seeing whether slicing, even in an early form, can deliver its promises and enhance their enterprise models. Affirmed says its product is already in trials with major operator customers around the world, and that Tier 1 and 2 companies are the targets – these are the frontrunners in virtualization, but also tend to have many gateways, making manual slicing onerous and limited in scope.
For all its limitations compared to the full slicing vision, this is a strong step forward, especially because it comes from a network-independent supplier with an interest in promoting a multivendor approach to virtualization and eventually 5G. This is of huge importance to the operators’ commercial hopes for 5G (see separate item ‘SK Telecom joins the battle to drive NFV interoperability and control’).
However, many of the pushes towards multivendor, interoperable virtualized networks – which will be critical to full slicing – are being made through the open source community. Several large operators have contributed aspects of their work on virtualized networks to open source efforts or to standards bodies like ETSI and 3GPP, rather than keeping them inhouse for differentiation. It will be interesting to see whether Affirmed goes the same way, given the obvious conflict of interest, for a vendor, between gaining widespread adoption via open platforms, versus the potential loss of revenue.
If it does, a logical place to start would be ONAP (Open Network Automation Protocol), the Linux Foundation-hosted initiative which is largely based on the ECOMP software devised by AT&T, a major Affirmed customer. Whiteford said the company is looking at how it might contribute to, or at least participate in, ONAP.
Affirmed CEO Hassan Ahmed summed up, saying in a statement: “Unrelenting mobile traffic growth and competition from over-the-top providers has changed service provider business models. Operators now require enormous control and flexibility from their networks to maximize profitability. The Affirmed vSSF fulfils this need in an operator’s existing legacy, virtualized, multivendor and future 5G networks with fine-grained network slicing.”
“Network slicing is fundamental to operators seeking to scale across different industrial sectors. By making network connectivity part of the fabric of an enterprise process, operators can diversify their customer base and increase revenues massively and sustainably,” says Gabriel Brown, principal analyst at Heavy Reading. “In 4G networks, virtual EPC, in combination with dynamic resource selection, offers operators the opportunity to introduce commercial ‘slicing’ propositions in the near term.”