We started our series, Convergence in the New Service Edge, with a discussion on how 4G and 5G will have to coexist in the same transport network. In Part 2, we discussed how that transport network will support fixed as well as wireless traffic. 5G services are different. In this installment, we want to take a deeper look into the new services in 5G and how they will affect the transport network.
Some of the new 5G services will take advantage of the higher bandwidths available in 5G such as Enhanced Mobile Broadband (eMBB). High-speed connections in the gigabit range get a lot of attention because the existing transport networks were not designed to handle the cumulative impact of this much bandwidth from the user equipment. At the other extreme is Massive Machine Type Communication (mMTC) which, as the name implies will provide connections for a massive number of low-bandwidth IoT devices such as sensors.
Both of these will drive bandwidth albeit in different ways. eMBB obviously can add a lot of bandwidth to a given cell site and its connection to the transport network. mMTC’s impact on the network is not driven by the speed of the connection, but rather by the sheer volume of devices that can be attached.
The third class of services will be supported by Ultra-reliable Low Latency Communications (URLLC) which will provide new communications services for industrial automation, Smart City intelligent transportation systems, connected and autonomous vehicles, and telehealthcare.
URLLC is different from other services. For many existing industrial, medical, drone, and transportation, reliability and latency requirements surpass bandwidth needs. Thus, the network must deliver very low latency with high reliability. Moreover, most of these services will rely on some form of cloud computing. Conventional cloud data centers are concentrated in a few areas and are often quite distant from the user. Since signals cannot travel faster than the speed of light, distance translates into latency. The resulting latency will not meet the requirements for these emerging applications. These services will only work if the computing resources are much closer to the end-user or device.
Gartner predicts that “edge computing will become a dominant factor across virtually all industries and use cases as the edge becomes empowered with more sophisticated and specialized compute resources and more data storage.” The main driver for this focus on the edge comes from the need for Internet of Things (IoT) systems to deliver disconnected or distributed capabilities into the embedded IoT world. This will create an unstructured architecture consisting of a wide range of things and services connected in a flexible network with a set of distributed cloud services.
Applications like IoT may use both mMTC and URLLC as well as edge computing for a complete solution. URLLC needs computing at the edge to keep latency down. Edge computing offers a way to consolidate large amounts of sensor data from mMTC services so that the core network is not overwhelmed.
Thus, the new service edge must be able to support a broad range of services. Starting with RAN disaggregation, this will expand to encompass everything from low latency (URLLC) to high bandwidth (eMBB). Network slicing will be essential to delivering these new services. This requires the ability to spin up virtualized resources quickly. Since the service edge is now close to the customer, this will need to extend to the router so that separate virtual routers can be used right at the new service edge.