So in this section I'm going to start with the basics and explain what an EPC, or an evolved packet core, is and the role that it plays in the network, and then we'll talk about the motivations for virtualizing the EPC. So this is a quote from the introduction to a report by Deloitte from a couple of years ago. And it really just reminds us that the telecom sector continues to be a key enabler for many types of industries and for society as a whole. Now there are many new trends emerging over recent years. The number of new IoT devices coming onto the network, the explosive growth in video and media streaming over both fixed and wireless networks, and these have really driven the need to look to techniques such as virtualization to change the way that networks are built and to build those networks in a more flexible, scalable, and efficient way. Here's another quote that reminds us that one way to think about the global telecoms network is as the world's biggest machine. It's a complex web of networks that interoperate and work together to make data services available to our smartphones. And at the heart of this network, and particularly at the heart of the wireless network, is the evolved packet core, or EPC, that connects end users to the Internet. And we'll come on and describe that in much more detail in the coming slides. So whilst fixed access networks have been with us for significantly over a hundred years, the wireless networks have really been evolving very quickly over the past three or four decades. And the major steps in the evolution of these wireless networks have come to be known as generations. So we have 1G, 2G, 3G, today's 4G, and coming 5G, which we'll talk about some of the motivations for 5G. So back in the 1980s, the first generation, or 1G networks, which were analog networks were being deployed. These networks really only supported voice, supported a limited number of users. That takes us forward into the early 1990s when the first 2G network started to be deployed. One of the major differences between 1G and 2G networks is that 2G networks are based on digital technology. This allowed for much more efficient use of the available radio spectrum, the frequency spectrum, and allowed for a much larger number of users to be supported on these networks. 2G networks also started to introduce the first data services to wireless networks, most famously the SMS text service. So if we move forward approximately a decade into the early 2000s the first 3G networks were starting to be deployed, and we're really focused on improving the bandwidth available for data services and enabling a wider adoption of services, such as video calling and limited video access, Internet access. And finally on this picture in the early 2010's, LTE or 4G network started to be deployed. LTE stands for long term evolution, by the way, and with these networks the focus was really on achieving a broadband like Internet access, a data service to the end users. And, of course, the rise of these networks really coincided with the massive growth of the smartphone market. So this rather complicated picture just tries to give a high-level view of the Telco network end-to-end. And on the left-hand side of the picture we can see the various types of access technologies that are used for users to access services. These could be fixed line access cable, DSL, broadband access to both consumers in their homes and to enterprises. And really the focus of our discussion today is the radio access network for wireless access, which we see in the top left. The red circle shows the extended scope of a 5G network versus the yellow circle which really shows where the 4G core network, the EPC we're discussing today, plays today. One of the reasons that the the core network for a 5G network will have increased scope and will reach out more to the edges of the network closer to the users is some of the capabilities that will be expected from 5G networks to drive low latency very high bandwidth access to the network. So we've already started to talk a little bit about 5G networks, which are in development, and let's think about when those networks will be coming into production. This forecast from a report by Ericsson gives a view of when that transition will happen. And I think really the summary is that we will start to see very early adoption of 5G networks this year, in 2018, while we'll see more mainstream adoption from 2020 onwards. So what's driving the demand for a new network? What's driving the demand for 5G? One of the reasons is to enable ultra-reliable wireless connections to enable a new class of services which really were not able to rely on the wireless network until this point. Remote medical treatment might be such an example. To enable extreme real-time communications, i.e., communications with very fast response, very low latency. An example of this may be where you want to utilize a network such as this to enable robotic control in an industrial or a manufacturing environment where the feedback from issuing instruction to response needs to be extremely short. Of course, we continue to see the demand for broadband access high data rates everywhere. So the 5G networks will deliver high bandwidth to users. And also we see lots of new types of devices, IoT, Internet of Things devices coming onto the network. This is a challenge to existing networks both because of the sheer number of these devices and that they have very different requirements on the network, very different characteristics. So together all of these things and more are driving the demand for 5G. And let's come back now to looking at the LTE network, the 4G network. Here we have a simplified picture, a very high-level view of where the evolved packet core sits in the network and what its role is. So to the left of this picture we show a UE, a user equipment, i.e., a smartphone would be a perfect example of a UE, which connects to a radio access network. Which it goes by in the standards, 4G goes by the name of an E-UTRAN, an evolved universal terrestrial RAN. The role of the EPC, the role of the evolved packet core, is to connect that radio access network to the Internet, in its simplest form, and we'll come on and talk a little bit in bit more detail about the five major elements that go to make up an EPC in the next section. [SOUND]
