A convergent billing system for the 5G era (2024)

Rockred Zhang, president of Software Business Unit，Huawei

Huawei contributed 45 per cent of the technical reports submitted to the billing working group in the formulation of 3GPP Release 15 standards. We are committed to tackling the many challenges of convergent billing in the 5G era.

The three major challenges encountered in the process are dealing with changes in the convergent billing architecture, creating enterprise capabilities and introducing monetisation capabilities.

Changes in convergent billing architecture

4G networks adopted different convergent billing architectures for online and offline modes. Users are required to choose prepaid or post-paid mode.

With 5G networks, the 3GPP introduced the convergent billing architecture, with the core network adopting convergent architecture for both online and offline billing mode. This billing system can choose online or offline billing modes according to the service needs, bringing more flexibility. As an advocate of convergent billing architecture, Huawei launched its Convergent Billing System (CBS) in 2007.

Chart 1: Convergent charging architecture ( Source: 3GPP )

In the 3PGG R15 specifications, the Charging Data Function (CDF) and Charging Gateway Function (CGF) have been integrated into the Convergent Charging System (CCS) to simplify the network structure. Huawei’s Convergent Charging Gateway, released in 2019, complies with the R15 specifications and is responsible for producing 5G service call detail records.

Enterprise service capabilities

Huawei’s Convergence Billing System (CBS) provides various enterprise service capabilities to support 5G applications like autonomous driving and industrial automation.

After subscribing to a service, users can leverage the user plane function (UPF) at the edge and access the applications and content deployed on the mobile edge computing (MEC) server to experience low-latency services. Huawei’s CBS allows OTTs to use open APIs to sign up new users, for example, to cloud gaming services deployed on the edge by a gaming vendor.

Chart 2: 5G UPF and MEC ( Source: ETSI )

Huawei CBS also can use various billing criteria of cloud computing, such as CPUs and memory, to charge OTTs usage on the edge computing server.

Its CBS supports billing for 5G slices according to the quality of service. The Huawei CBS R20, which will be released in 2020 and complies with 3GPP R16 specifications, can manage 5G slices and support service quality assurance billing. For example, if the actual service quality does not meet the standard of the service level agreement, the corresponding compensation can be applied for the user.

Monetisation capability

In the 5G era, leading operators will build their core business model based on service experience monetisation. Huawei’s CBS offers more than 100 service experience related billing dimensions, including uplink or downlink access speed, service latency, traffic destination and flexible combinations of these elements. This enables operators provide optimal charging experience for users in the 5G era like online real-time subscription and effective in real time. Therefore, operators will generate revenue from the key benefits of 5G: larger bandwidth and lower latency.

Huawei’s CBS has made contributions is three key areas:

1. Cloud-native architecture

The CBS has applied the micro-services architecture in the 5G billing field. It complies with the principles of stateless micro-services and separation of data and applications. The balanced design of micro-services enables flexibility and high performance at the same time.

The 5G billing micro-services deployed in containers (e.g. Docker) enables not only flexible scaling and self-healing, but also allows different versions of micro-services to be deployed in a ‘gray zone’, where pilot users can test new capabilities before they are released to general users.

The benefit of stateless micro-services and data and application separation, all key applications of the CBS, is a distributed architecture. Multiple instances of a single service can be simultaneously deployed and access to any service instance is identical.

Chart 3: Distributed architecture

Applications can be flexibly scaled or upgraded by adding or stopping service instances, with service continuity not affected. Moreover, the traditional active-standby pair, as well as disaster recovery pairs, are no longer required.

Huawei’s CBS adopts smaller containers to deploy its micro-services, and these can be directly deployed on bare metal servers. Container-level fault isolation, zero-touch healing and active system health checks are provided to make the system more reliable and easier to maintain.

Benefitting from self-developed high-performance codec algorithms, as well as high-performance HTTP stacks, the end-to-end billing response time was reduced by 30 per cent. The throughput of the 5G service-based billing interface is also more than 30 per cent higher than the traditional 4G billing interface, and can withstand 10-times the surge traffic.

2. Smooth migration

As the largest telecoms equipment vendor, Huawei’s CBS has more than 200 customers around the world and provides billing services to 2.2 billion customers. It designed a smooth migration path from the traditional physical machine or virtual machine deployment architecture to the cloud native architecture, protecting the operator’s investment.

3. Continuous development and delivery

The faster and improved service experience brought by 5G requires more agile IT systems to support monetisation. Huawei, as an industry pioneer, continuously develops the technologies. Various new tools have been applied in the development and delivery processes, significantly reducing implementation times, from four to six months to one month or less.

Chart 4: Improved development and delivery

In addition, the process shown in chart 4 can be integrated with an operator’s own delivery processes, enabling it to quickly reap the benefits of a new version of the software.

As most countries will deploy 5G services commercially before 2021, and considering billing system upgrades can take 9 to 18 months, 2020 will be a crucial year for reconstruction of the 5G billing system.