It's common belief that new generations are more advanced than previous generations. The same can be said about network technology. Just as 4G increased speeds by tenfold when it was introduced in the late 2000s, fifth-generation wireless promises to eclipse 4G capabilities in terms of speed, latency and connectivity.
The core architecture is the foundation of a 5G network. With 5G core network architecture, network operators can more easily offer new features to users. Additionally, using software-defined networking (SDN), users will be able to validate devices safely and securely throughout the network and deploy features from a centralized location.
Current 5G deployment is still in its early stages among enterprises, and 5G core network architecture will take even longer to develop, partly because of the breadth of capabilities offered. Once implemented, operators and enterprises alike will need to observe the performance of their networks to ensure successful operations and maintain sufficient quality of service (QoS), according to author William Stallings. QoS can be guaranteed with service-level agreements (SLAs) between vendors and enterprises.
In Chapter 9 of 5G Wireless: A Comprehensive Introduction, from Pearson, Stallings explains QoS, network slicing, the requirements for core network functionality and more. His book gives an introductory overview of 5G networking.
In this Q&A, Stallings discusses the capabilities of 5G and more.
Editor's note: The following interview was edited for clarity and length.
What do enterprises need to prioritize when evaluating 5G deployment?
William Stallings: The issue for enterprises is when and how to exploit the opportunities provided by 5G capabilities. From an enterprise viewpoint, 5G provides faster speeds, lower latencies and more QoS support for more demanding applications than 4G. As with any major upgrade to the IT infrastructure of an enterprise, a business case needs to be made for taking advantage of the new services and capabilities.
How do SDN and NFV facilitate 5G?
Stallings: Two essential enablers of 5G services provided by core networks are SDN and NFV [network functions virtualization]. NFV and SDN are independent but complementary schemes.
SDN decouples the data and control planes of network traffic control, making the control and routing of network traffic more flexible and efficient. NFV decouples network functions from specific hardware platforms via virtualization to make the provisioning of these functions more efficient and flexible.
Virtualization can be applied to the data plane functions of the routers and other network functions, including SDN controller functions. Thus, either can be used alone, but the two can be combined to reap greater benefits.
Deployment of SDN and NFV in the core network provides network operators with the flexibility needed to support QoS demands, including the use of network slicing, moving functionality to the edge of the network and flexibly adding and subtracting network and computing resources. The result is reduced costs, enhanced network flexibility and scalability, and shortened time to market of new applications and services.
What requirements do enterprises need to consider for network slicing?
Stallings: One of the most important functions for 5G networks is network slicing. Indeed, network slicing is essential to the exploitation of the capabilities defined for 5G. Network slicing permits the creation of slices devoted to logical, self-contained and partitioned network functions. Network slicing supports the creation of virtual networks to provide a given QoS, such as guaranteed delay, throughput, reliability and priority.
An enterprise can request multiple network slices to support application areas with different QoS requirements. To aid in this process, standards organizations have defined the concept of the Generic [Network] Slice Template [GST], which has been specified by the GSM Association. GST provides a standardized list of attributes that can be used to characterize different types of network slices tailored to the needs of different application areas.
What is the difference between priority, policy control and QoS? Why is that distinction important?
Stallings: Policy control is a generic term. In a network, there are many different policies that can be implemented. For example, policies related to security, mobility, use of access technologies and so on. When discussing policies, it is important to understand the context.
Policies are sets of rules specifying the user plane services and functions available to a particular user supplied by the network. A policy specifies the priority to be applied to a given user's traffic and the QoS to be provided to the user.
Policy control is the process by which network resources are controlled to implement a given policy for a given user.
Priorities are values assigned to specific packets transmitted to or from a user that determines the relative importance of transmitting those packets during the upcoming opportunity to use the medium.
QoS is the measurable end-to-end performance properties of a network service, which can be guaranteed in advance by an SLA between a user and a service provider to satisfy specific customer application requirements. These properties may include throughput (bandwidth), transit delay (latency), error rates, security, packet loss, packet jitter and so on.
Priority is typically included under the category of QoS, but it's useful, when discussing policy control, to separate priority from other QoS parameters. The 5G network will support many commercial services and regulatory services that need priority treatment. Further, there are situations in which it is desirable to change the priority of a user connection but hold other QoS parameters constant, and vice versa.
How large of a role does QoS play in network functionality?
Stallings: The wide variety of applications and devices that will use 5G networks, including cloud computing, big data, the pervasive use of mobile devices on enterprise networks and the increasing use of video streaming, all contribute to the increasing difficulty in maintaining satisfactory network performance.
The key tool in characterizing and measuring the network performance an enterprise desires to achieve is QoS. QoS enables network pros to determine if the network is meeting user needs and to diagnose problem areas that require adjustment to network management and network traffic control.
How do SLAs between vendors and enterprises ensure proper QoS?
Stallings: An SLA is a contract between a network provider and a customer that defines specific aspects of the service that is to be provided. The definition is formal and typically defines quantitative thresholds that must be met. An SLA typically includes availability, latency, network packet delivery, and peak and average throughput. They can be defined for the overall network service. For 5G, typically, SLAs are defined on a network slice basis.
What prompted you to write this book?
Stallings: 5G is a sprawling topic that encompasses four main elements: applications and use cases; the radio interface between user equipment and the 5G network; the radio access network consisting of interconnected antenna base station systems; and the core network.
There was no one book that was a comprehensive overview and survey of all four areas, so that's what my book intends to provide.
What advice do you have for readers about 5G?
Stallings: Whatever your particular area of interest related to 5G, you will find it useful to have an overall understanding of all aspects of 5G.