Hero image


The Important Role of Open5GS in Private 5G Network Development







The Important Role of Open5GS in Private 5G Network Development

Published: 2023/06/14

9 min read

Telecommunications customers’ requirements connected to the number of gigabytes used are rising every year. In recent months, there has been a trend to turn off 2G and 3G networks and optimize frequency bands for 4G and 5G. It is evident that 5G will be the foundation for future mobile advancements and services, as confirmed by this GSMA Mobile Economy 2023 report. It is predicted that the adoption of 5G will increase to 17% in 2023, and by 2030 it will rise to 54%, equivalent to about 5.3 billion connections.

As more people are adopting new mobile technology, the amount of mobile traffic is also increasing due to activities such as video streaming and online gaming. Video traffic is expected to make up about 70% of all mobile data traffic, and it is projected to increase to 80% by 2028. The growth of 5G technology is a significant factor in this trend. A survey by GSMA found that 5G users are more interested in adding services and content to their mobile plans than 4G users.

The current deployments and the near future of 5G

Currently, most 5G deployments you hear about today are Non-Standalone, meaning an operator uses the existing 4G core network to connect the 5G radio infrastructure. This is easier to implement because operators don’t have to do a full revamp of their existing and complex core network infrastructure, and it provides the advantages of the bigger bandwidth of the 5G radio. 

Read more: Automating legacy telcom platforms

However, this only enables some, but not all, of the advantages of 5G. A 5G network with its own 5G core allows for splitting network resources (a.k.a. Network Slicing) for optimal performance for many new applications (IoT, extremely low-latency, cloud gaming, high performance streaming etc.). The Standalone 5G architecture is the target step for all operators that want to provide all the advantages of 5G. 5G SA is also the target architecture for companies implementing so-called Private 5G Networks to address specific business needs, such as manufacturing, logistics, mining and other use cases. 

The tools to (continuously) develop a Standalone 5G core

Extensive planning, testing and development are required to successfully implement a 5G network. Many vendors and companies have to work together to help build a 5G core network that integrates with an existing ecosystem. 

Open5GS presents an excellent opportunity for companies like Software Mind and operators who want to start building new applications for 5G private networks or begin testing implementations and changes within an existing network. 

Open5GS implementations were last defined in the 3GPP Release 17 (R17), with the standardization Organization 3GPP already working on Release 18, planned to go live sometime in 2024. Open5GS is an active solution with ongoing updates, as evidenced by the project’s frequent activity on GitHub.

By using open source solutions, it is possible to quickly build and test applications for a 5G network. One open source 5G solution is the Open5GS project, available under AGPL-3.0 open source licenses and implemented in the C language. Open5GS comprises a range of software components and network functionalities that realize the core functions of 4G/5G NSA (Non-Standalone) and 5G SA (Standalone), including low latency and dedicated, highly customized data paths.

Read also: 5G Lab – Building and Connecting to Our Own 5G Network

Open5GS’s elements

The described open source project has core functionalities that prioritize customers’ needs, ensure efficient data transmission and deliver a smooth service. 

  • AMF (Access and Mobility Management Function) – handles network access (securely authenticates customers who want to access the 5G network) and manages user mobility (is responsible for the traffic transfer procedure to maintain connection continuity). The AMF is responsible for maintaining the subscriber’s registration status while the subscriber is on the move. The equivalent of AMF in the 4G network is the MME (Mobility Management Entity). 
  • SMF (Session Management Function) – manages the session between the user and the 5G network. In addition, SMF controls traffic in the 5G network under implemented QoS (Quality of Services) network policy, i.e., it prioritizes network traffic, controls bandwidth and manages network load.
  • UPF (User Plane Function) – facilitates the transmission of user data packets between gNodeB and the network. UPF ensures effective data transfer in accordance with the requirements of quality of service (QoS) and network policies, traffic management and security. It interacts with the SMF for tracking and maintaining the user session. It can be located anywhere geographically to improve network performance and latency. 
  • AUSF (Authentication Server Function) – authenticates users in the 5G network, verifies the identity of users and checks their authorization to use the network. For this purpose, it communicates with UDM, where subscriber information is stored. 
  • UDM (Unified Data Management) – manages subscriber data in the 5G network, such as the subscriber identifiers, keys, available network slices and data networks (DNN) among others. UDM provides SMF with subscriber data such as service profiles, preferences, policies and other information that is necessary to establish, manage and control subscriber sessions. In turn, the UDM provides the AMF with the necessary subscriber information, such as credentials, authentication, credentials and subscriber profile, so that the AMF is able to identify and authenticate subscribers when accessing the network. UDM is the equivalent of HSS (Home Subscriber Server) for 4G networks. 
  • UDR (Unified Data Repository) – acts as a back-end database used by nodes such as the UDM or PCF. It provides centralization of data storage for such nodes. 
  • PCF (Policy and Charging Function) – maintains session policy, makes decisions regarding the allocation of network resources in order to ensure optimal quality of service for various types of applications and user requirements. It operates based on specific policies that may include traffic prioritization, bandwidth management, and speed limiting. It’s similar in functionality to the PCRF in 4G. 
  • NRF (NF Repository Function) – stores information about all available Network Functions (NF). NRF is a central source of information for other elements of the 5G SA architecture, enabling dynamic management and discovery of network elements and functions. 
  • SCP (Service Communication Proxy) – manages communication between Network Functions (NF) and external applications or services. SCP is an intermediary that handles communications and enables the integration of various 5G system components to deliver advanced network services and features. In the 4G network, communication between network functions and applications takes place through multiply protocols such as Diameter. 
  • NSSF (Network Slice Selection Function) – enables selecting the appropriate network slice for a given service request, taking into account network policies. Works with other network functions to ensure consistency and compliance in managing networks slices 
  • BSF (Binding Support Function) – cooperates with the PCF with which it exchanges information regarding a subscriber is currently using (as they are normally located in pools).

How to easily install Open5GS for a 5G Standalone implementation?

The basics needed to start the process are to have a system from the Linux family, e.g., Debian, Ubuntu, Raspbian or xUbuntu. Open5GS requires the database MongoDB to be installed, and, once all the basic requirements are met, the next step is to install the Open5GS package. 

It’s worth noting that a graphical interface is available for beginner users of the Open5GS project. It requires the Node.js package to run and a graphical interface application – the web UI of Open5GS to manage subscribers. 

Read more: The difference between OSS vs BSS

Its possible to set up all the necessary elements so that you can have a complete working core network, or to connect the elements you’d like to an existing deployment. 

Taking advantage of the ServiceBased Architecture (a new model of connection between elements in 5G), makes it possible to forward traffic for a subset of subscribers to a particular element for which testing and new development can be done – without affecting the rest of the subscribers. 

There are also open source solutions available for IMS (IP Multimedia Subsystem) to run and test voice over 5G (also known as Voice over New Radio or VoNR). One of them is the open source Kamailio IMS, which can run on Linux family, e.g., Debian.  

Alternative solutions to Open5GS

Apart from Open5GS discussed earlier, several other open source projects are available for implementing 5G. Here are some worth considering. 

Aether – 5G/LTE Connected Edge Platform-as-a-Service solution developed by the Open Networking Foundation (ONF), Aether implements several solutions. The ROC Runtime configuration module is responsible for configuring all components of the Aether project, the SD-Core network stack supports both 4G and 5G core networks, SD-RAN provides near real-time RIC (RAN Intelligent Controller) and supports the development of xApps, as well as SD-Fabric, a SDN (Software-Defined Networking) programmable forwarding plane with UPF (User Plane Function) functionality. 

Free5GC – the main goal of this project is to realize the implementation of the 5G core network (5GC) as defined in 3GPP Release 15 (R15) and subsequent releases. The software is available on Apache 2.0 license. National Chiao Tung University (NCTU) from Taiwan contributed significantly to the project. Unfortunately, Free5GC had very low activity in recent months, as the last release went live a year ago (in June, with version 3.2.1).

Read also: How 5G is changing Steering of Roaming and How to Prepare for It 

NextEPC – available on Linux systems and requires MongoDB and NodeJS. The setup is similar to Open5GS. The software runs under the AGPLv3 license, but there is also a paid version of the software called NextEPC LTE/5G core network Enterprise Edition. Open5GS is derived from a previous version of NextEPC. 

OpenAirInterface – a project consisting of solutions such as OpenAirInterface 5G Radio Access Network Project (Implementation of 4G LTE and 5G Radio Access Network RAN for NodeB), OpenAirInterface 5G Core Network (Implementation of 4G LTE Evolved Packet Core (EPC) and 5G Core Network). These components are available on OAI Public License V1.1. The afore-mentioned solutions are still in the development phase – a road map detailing the implementation of solutions is to be released by the end of 2023.

Advantages and disadvantages of open source 5G solutions

One advantage of open source solutions is that the code is transparent. This means that each user, also known as a contributor, can modify the code. The Git system of the project typically tracks these changes and every found error can be easily corrected by the community. Open source solutions for 5G also comply with the 3GPP specification, which is an international consortium of standardization organizations that develops technical specifications for telecommunications systems.  

One major reason why open source solutions may be turned down is due to the absence of fast support from a particular vendor. This is commonly referred to as “use at your own risk”. Therefore, it is essential to select the right telecom software development partner to have the guarantees of an optimal and tested implementation. 

5G will be made better by open source

The implementation of open source 5G solutions may be the answer to the increasing consumption of Internet resources by telecommunications users. Customers expect fast and stable data transmission to listen to their favorite music via streaming services or watch movies on various streaming platforms in Full HD or 4K resolution. According to GSMA report, 5G is predicted to add almost $1 trillion to the global economy by 2030 and provide advantages to all sectors. This emphasizes the importance of maximizing the benefits of the new standard for as many users as possible, and open source 5G technology can be a pivotal factor in achieving this goal. 

In addition, operators can take advantage of the fact that 5G is a wireless technology and can reach smaller towns or villages where, for economic reasons, telecommunications operators do not invest in high-speed Internet connections (including fiber) to users’ homes. A 5G network is suitable for the Internet of Things because it offers high data speeds and low pings. 

Read also: Running a Fully Containerized 5G Core with Open5GS 

Open source 5G solutions are transparent, which means an operator can identify the code responsible for implementing a given process and make custom-made changes to the code in a short period.

Our team understands the unique challenges of adopting open source 5G solutions, and we’re here to ensure a smooth and seamless transition. Contact us using this form and unlock the full potential of open source 5G solutions.


About the authorAdrian Bełciak

System Engineer

A system engineer with five years of experience, Adrian is sometimes called a 'telecommunications geek’. Curious about new solutions and innovations in telecommunications, he follows current trends and advances in the field. Adrian works with telecom operators on a daily basis and has experience implementing a diverse range of telecom systems.

About the authorJorge Espinosa

System Engineer

A systems engineer passionate not only about the technical aspects of the telco industry, but also topics related to the telco business as a whole. He has vast experience with 3GPP and GSMA standards, such as the latest generation packet core (5G, LTE), voice platforms (IMS, VAS) and business applications (BSS). Jorge works with a great and knowledgeable team focused on delivering modern and highly customized solutions and support to partners and clients.

Subscribe to our newsletter

Sign up for our newsletter

Most popular posts