Nexign RCAF Fuels 5G Future Within Existing LTE Network

By Alexey Podolskiy, Product Marketing Manager at Nexign


As the number of subscribers and connected devices grows, telecom operators must deal with congestion to provide great experiences. Sometimes, there is enough network capacity. Often, not. Building out infrastructure or shifting to 5G is not always a practical answer since these approaches entail considerable expenses. In such a case, Nexign steps in with its Nexign Network Monetization Suite. Nexign RCAF, part of the Suite, helps telcos increase the overall network capacity, cut costs on network maintenance and expansion, and boost revenue by bringing new products to market.  

100% Network Monetization

Network monetization means that a telecom operator exploits the technical capabilities of the network to deliver services and, in return, gain revenue. This works in multiple ways and concerns different business aspects:

  • launching new products and options;
  • driving demand;
  • enhancing customer loyalty;
  • reducing expenses.

To address the challenges of network capacity and extensive traffic volumes, the next-generation 5G technology has been introduced. By leveraging 5G technical capabilities and exploring new lucrative business cases, telecom operators can increase Quality of Service and generate new revenue streams.

Alternatively, solutions that focus on making the best use of available resources are always in demand. This is especially true in markets where LTE development is on the agenda, but 5G rollouts may be low priority, hampered, or even restricted. The situation is typical for Russia, the CIS, Africa, and Latin America. In these regions, telecom operators are trying to apply 5G-driven concepts, technologies, and best practices to develop existing LTE networks.

For example, according to 3GPP, data analytics based on the Network Data Analytics Function (NWDAF) and the Network Exposure Function (NEF) are critical in the search for new ways to monetize 5G networks. At the same time, 4G already offers similar functions: the RAN Congestion Awareness Function (RCAF) and the Service Capability Exposure Function (SCEF) partly handle the same issues for the current network generation, although they are not widespread among telcos yet. 

Nexign Network Monetization Suite focuses on any network type and any network generation and comprises both of these functions as the same-named products. Thus, Nexign RCAF provides the capabilities described in the specifications and combined with the vendor’s know-how.

Defining RCAF 

RAN Congestion Awareness Function means that, when the network is overloaded, you are aware of congestion events and respond to them by implementing actions appropriate to the conditions in the network. Moreover, having deep visibility into what is occurring in the network can bring commercial benefits.

A common practice for telecom operators is to grapple with high traffic loads by fine-tuning the radio access network (RAN) with custom solutions. The support and development of such solutions always go hand in hand with impediments, as is typical for in-house systems. Therefore, 3GPP Release 13 and 14 specify a standardization approach represented by a separate RAN Congestion Awareness Function (RCAF) within the core network.

RCAF gathers data on congested base stations (primarily LTE) and affected subscribers. Then, the operator’s various systems can use this data as a centralized source of insights for both network optimization and new business opportunities.

Where the Congestion Data is Used

Congestion data serves the purpose of optimizing costs and improving operational efficiency of the network, enabling the following activities:

  • Warding off peak loads for a superb user experience;
  • Predicting and mitigating the congestion;
  • Optimizing network utilization;
  • Better RAN planning, in particular for efficient use of base stations;
  • Using license fees on expensive technologies sparingly, for example, by applying protocols and video optimization solely to the traffic in congested areas.

At the same time, the operator can dynamically implement congestion data gathered by RCAF. This helps unlock revenue streams by leveraging new opportunities, such as:

  • Increasing customer loyalty thanks to a high quality of experience even in congested areas. When the network is overloaded, for example, a high quality of service can be ensured for the majority of subscribers by slightly throttling high-data-rate applications to free up the necessary bandwidth.
  • Offering products with priority access on special terms. In heavy-load scenarios, for example, subscribers of a high-priced business bundle or high-margin services can be given top priority.
  • Keeping partner services informed, for example, when targeting subscribers based on user experience.

Some typical monetization cases involving RCAF were previously described here.

How the Congested Data is Collected

RCAF interacts with the RAN management system (NMS) and collects aggregated statistics on the load of base stations. Then, RCAF builds lists of affected subscribers with the help of the Mobility Management Entity (MME). 

Additionally, Nexign RCAF leverages its own techniques to receive real-time data from LTE base stations (for example, through X2 interface). As a result, key data on the network condition and affected subscribers is updated in seconds, while the complete picture of the congestion is available within a few minutes. 

Integration With Other Network Elements

First of all, the chief consumer of RCAF data is the Policy and Charging Rules Function (PCRF). It uses the congestion data for dynamic policy control, including real-time QoS management. It is PCRF that allows operators to configure priority access options and congestion-aware network optimization by managing QCI (QoS Class Identifier) and other parameters based on the provided data.

Then, the RCAF data is requested by the Service Capability Exposure Function (SCEF) for integration with partner services. SCEF can “prescribe” the services to decrease the load; for example, lower the video resolution or postpone downloading a noncritical update. Moreover, the services can take advantage of the data to adjust to each situation — for example, to offer special services or terms to affected customers during peak loads. SCEF also uses the RCAF insights when scheduling the delivery of noncritical data to IoT devices within Background Data Transfer.

Finally, the congestion data enriches the view of the user experience in different locations. It allows the help desk and sales department to keep an eye on the service quality and take much more informed decisions and actions. For example, when the contact center representative receives a ticket and sees that the customer is located in a congested sector, an immediate remedy is brought up on the dashboard, such as advising the customer to move to a base station nearby or activating a special high-priority option. 

The RCAF interfaces, needed to interact with other core network functions, are standardized in 3GPP. However, the format and scope of the key RAN NMS data vary depending on telecom operators and radio equipment vendors. Nexign RCAF provides out-of-the-box support for different formats to enable prompt deployment in multivendor networks, which is typical for major telcos.

Nexign RCAF’s primary sources and consumers of congestion data are illustrated in Figure 1.

Nexign RCAF Use Cases

RCAF is presented in Nexign Network Monetization Suite as Nexign RCAF and introduces network adaptation techniques designed to ensure a consistent quality of service. The use cases below highlight the role of the product in the creation of new options and support for flawless connectivity.

MegaFon: The New Pre-5G Option Boosts Internet Speed by 50%

MegaFon launched Pre-5G in March 2022, which speeded up mobile internet by 50%. The option was backed by automatic collection and detailed real-time analysis of large amounts of data on the network condition, traffic, applications, and active subscribers as well as intelligent policy management. Having these features, the telecom operator could give full play to the current infrastructure. Nexign RCAF was one of the products that enabled the operator to reshape traffic management.

Yota 2020: Service Quality at the Start of the COVID-19 Pandemic

Early in 2020, the load on base stations, coming from business applications, soared by 2.5 times under stringent lockdown because of a pandemic outbreak. Nexign RCAF enabled the operator to avoid costly infrastructure investments and ensure dynamic network adaptation to new load levels while maintaining service quality. 

What’s Next

Nexign keeps on developing RCAF by expanding its functionality and integration capabilities. RCAF is about to support even more base station vendors to conduct a unified data analysis for any mobile network. To provide a holistic approach to handling User Plane Congestion, Nexign is extending the traffic prioritization to backhaul networks. Another important new feature is congestion prevention algorithms based on predictive analytics. 

Nexign RCAF for Our Customers 

Nexign helps telcos deliver top-notch service, reaching as many end-users as possible. We ensure our customers undergo a smooth transition from 4G to 5G with a fast ROI. Maximizing 4G opportunities and implementing 5G-ready use cases in LTE networks with the help of Nexign Network Monetization Suite are crucial parts of this approach. 

Notably, in 5G Standalone networks, these functions become vital to set off desperately needed new business models for telecom operators’ prosperity. While SCEF and RCAF evolve into the Network Exposure Function (NEF) and Network Data Analytics Function (NWDAF) in 3GPP Release 16, they also bring tangible benefits in 4G networks, although their use requires a deliberate strategy and accurate implementation.