LTE stands for Long Term Evolution - that’s worth remembering because even as mobile operators roll out 5G, their 4G networks are still getting upgrades and adding customers. The two technologies must coexist for at least the rest of this decade - if not longer.
"4G LTE will support more mobile broadband users than 5G for many years to come," GSMA Intelligence says in its 2022 “Trends to Watch” report. "Operators must ensure that their network transformation strategies include a role for 4G, and that this focus is well understood by their network infrastructure suppliers, which will need to continue delivering 4G innovations."
A prime example is policy control, which directly affects the customer experience and thus key bottom-line metrics such as churn and ARPU. In 5G, the Policy Control Function (PCF) defines and applies the rules for resource allocation and consumption. It’s an extension of the 4G Policy and Charging Rules Function (PCRF), but with greater emphasis on quality of service, mobility rules, slicing and standard interfaces.
Although they have similar names, the PCF and PCRF operate in fundamentally different network architectures. For example, the PCRF was never designed to operate in 5G’s cloud native environment. Another factor is that customer devices will frequently switch between an operator’s 4G and 5G networks. That’s because it will take a few more years for 5G coverage to match 4G’s. Policies must be applied consistently as devices switch back and forth.
All for One
As a result, operators need a dual-mode 4G-5G policy system (Figure 1), which is capable of interworking with existing 4G online charging systems (OCS) and central subscriber databases. That’s challenging because those network functions have changed in the evolution to 5G. A dual-mode 4G-5G policy system also must be able to share quota across the two generations and provide consistent rule definition and distribution.
Figure 1. A Dual-Mode Policy Manager supports key aspects such as Policies, the Subscriber Database and Charging
A dual-mode solution solves a variety of policy challenges. As an example, under 3GPP standards, user devices have access only to the same generation of network elements. A dual-mode policy manager eliminates this restriction. That’s critical because it will take most operators several more years to build out their 5G coverage to match 4G’s. As a result, policies must be applied consistently as devices switch back and forth between their 4G and 5G networks.
It also will take many years for 4G’s IMS to migrate to 5G’s service-based architecture. A dual-mode policy manager can supportonline charging systems. That’s a plus because this is one of the most complex areas to change, so working with the legacy infrastructure means the operators has one fewer thing to worry about during its 5G migration.
A dual-mode policy manager also can maintain each subscriber’s specific network utilization parameters as their device switches networks. In addition to ensuring QoS and QoE consistency, integrating the 4G PRCF with a 5G UDR reduces the operator’s overhead costs by eliminating the need for separate subscriber databases. Now the operator can share the same bucket of customer, service, device, application and offer quotas for 4G and 5G and track all of that usage in real time.
Policy creation also should be quick and easy. A dual-mode solution enables operator staff to create a single policy that can be applied across 4G and 5G. This saves time - and money - while avoiding the potential for manual errors due to the increased complexity of 5G use cases.
Finally, the dual-mode policy manager also should be highly scalable, with the ability to support at least 10,000 policies. This empowers operators to be flexible and forward-looking. They can seamlessly create and monetize use cases such as quota sharing, network slicing, and the Internet of Things (IoT) across 4G and 5G.
For a deeper dive into these and other key aspects of 4G-5G policy management, sign up for "Think Twice: Dual-Mode Policy in the Path to 5G Service Monetization." This 30-minute webinar will be held Feb. 17 at 4PM CET / 10AM ET and available afterward on demand. To learn more, visit https://landing.owmobility.com/policy-webinar.
