Article contributed by Dimitris Mavrakis, Principal Analyst with Informa Telecoms & Media, who will be speaking in-depth about SDN and NFV at the forthcoming SDN World Conference in Barcelona on 11-13 June 2013, a uniquely operator-rich event featuring visionary contributions on the potential of SDN and NFV from operators around the globe.
With infrastructure vendors offering their own flavors of SDN, the interest – and confusion – in the telecoms industry is increasing. Early adopters begin to deploy SDN concepts while mainstream operators attempt to understand the cultural, technical and business implications of the new concepts.
In the context of telecom networks, telco SDN refers to separation of the control and data layers, virtualization of network components and service exposure, although each vendor may have a different strategy according to their technical legacy and existing product lines.
In many cases, telco SDN reminds of previous, somewhat unsuccessful initiatives, including IMS. But in a way, SDN is already an established concept in the IT domain in the form of OpenFlow and OpenStack; although this is in a different context, it offers similar benefits to both IT and telecoms service providers. Increased scalability, flexibility, cost savings and less dependence on overprovisioning for network design are a few examples of short-term benefits SDN brings to both IT and telecoms. In the long term, the concept will allow for new service architectures, service exposure, new revenue opportunities and more efficient operations.
SDN and IMS promise – among other things – horizontalization of network infrastructure and easier service exposure to third parties but are without clear new business and revenue opportunities. However, there are several differences from previous technologies, especially IMS.
Telco SDN (and NFV) has serious advantages over IMS: SDN is already being implemented in the IT domain, and operators and vendors will have learned from their involvement in IMS. Also, SDN is attempting to enter the market by applying practices and technologies from the IT domain to the telecoms environment – this is in contrast with IMS, which was a completely new and very optimistic concept. Moreover, the vendors involved in SDN and virtualization also come from the IT domain and have experience of large-scale IP networks – which is the ultimate convergence of mobile networks.
What is likely to evolve first
The benefits of telco SDN increase towards the edge of the network and are maximum when facing the end user. For example, a virtualized CPE will not require continuous upgrades when a fixed operator upgrades to new technologies. On the other hand, the cost to virtualize the edge of the network – especially when considering radio networks – is prohibitively expensive.
LTE networks have just been deployed and operators will require some from of ROI from these existing networks before investing billions once again. Cloud RAN is the first implementation of virtualization in the radio access layer, where baseband processing is pooled at a semi-centralized location to allow for more fluid resource allocation. This also requires high expenditure and is likely to be deployed once small cells become widespread.
On the other hand, the Enhanced Packet Core (EPC) is a part of the network that is more likely to be virtualized in the short term, due to its flat (IP) nature and the need for components to be flexible and scalable. The core network is far more centralized compared to the RAN and as such, easier to upgrade, maintain and virtualize. EPC components include the MME (mobility management) and gateways (PGW, SGW) which may be implemented in software and run from data centres in order to provide a more scalable and flexible architecture. Specific functionality of the network may be exposed to trusted third parties while operators will be able to create customized services for groups of customers, or even individual premium customers (SMEs or enterprises).
Why Telco SDN is revolutionary
Despite the failure of previous network technologies, Telco SDN arrives at the market at the right time, when the telecoms and IT worlds are starting to align. Mobile operators will soon find that relying on traffic forecasts and overdimensioning may not provide an adequate business case for rolling out nationwide networks.
Despite the fragmented and multi-vendor nature of existing mobile networks, Telco SDN and similar concepts can provide a real answer to achieving more flexible, scalable and adaptive networks for real world scenarios.