In order for mobile communication technologies to operate reliably, they must be tested under real-world conditions. Frequencies, local regulations, network edge cases – all of this makes global testing a logistically challenging and costly endeavor. 

Our specially equipped 4G/5G Mobility Lab can eliminate the burden of global testing by providing an impressive range of testing capabilities for mobile communication technologies on-site. It enables engineers, developers, and researchers to comprehensively test the performance, functionality, and interoperability of mobile networks and devices under realistic and controlled conditions. The flexibility and scalability of the lab allow for the simulation of a wide variety of scenarios – from simple single-cell tests to complex multi-cell and roaming scenarios.

Core Functions of a 4G/5G Mobility Lab

Network Simulation and Emulation

The network simulation and emulation using CarByte Software Defined Radio (SDR)-based solutions enables the replication of realistic network environments by emulating complete 4G LTE and 5G NR networks, including key core network components such as MME, SGW, and PGW (for 4G) as well as AMF, SMF, and UPF (for 5G). This allows devices to be comprehensively tested without the need for a real mobile network. Moreover, the solution permits the simulation of various network topologies, from single cells to complex multi-cell environments that consider different frequency bands, cell sizes, and interference conditions. Additionally, relevant network parameters such as frequency bands, bandwidths, cell IDs, TAC/PLMN IDs, QoS parameters, and handover thresholds can be precisely configured to cover specific test cases.

Another key function is the simulation of controlled interference signals, which enables a realistic assessment of network performance. Furthermore, the solution supports various radio technologies and allows for the simultaneous use of 4G LTE and 5G NR in different modes (Standalone and Non-Standalone), ensuring comprehensive interoperability testing.

Device Testing

Device testing includes a variety of tests to ensure the functionality, performance, and compatibility of devices in different scenarios.

• Functional tests verify basic functions such as network registration, call setup (e.g., VoLTE and VoNR), data transmission, as well as SMS and MMS functionality.

• Performance tests measure key performance indicators like uplink and downlink throughput, latency, jitter, and packet loss under various network conditions.

• Mobility tests focus on the evaluation of handover scenarios between cells, both within the same frequency (intra-frequency) and between different frequencies (inter-frequency) or radio technologies (inter-RAT), to ensure connection stability during movement.

• Stress tests assess the resilience of devices under high network load and repeated actions.

• Battery consumption tests measure the energy consumption of devices in different network states and usage scenarios.

• Compatibility tests ensure that devices work seamlessly with various network configurations and software versions.

Application and Service Testing

Application and service testing assesses the performance and user experience of applications and services over mobile networks. Real application scenarios such as video streaming, online gaming, or IoT applications are emulated to test the functionality and quality of applications under different network conditions. Quality of Service (QoS) tests verify the correct implementation and enforcement of QoS policies in the network and their impact on application performance. Furthermore, tests in conjunction with edge computing platforms enable the simulation of scenarios where data processing and storage occur closer to the end device. This helps reduce latency and optimize application performance, particularly for time-sensitive services.

Diverse Test Cases with CarByte Solutions

Based on the capabilities of the CarByte platform, a variety of test cases can be realized. Here are some examples:

5G Non-Standalone (NSA) interoperability test:
In this scenario, a device connects simultaneously with an LTE anchor band and a 5G NR band. The goal is to verify bandwidth aggregation, smooth data transfer across both radio technologies, and signaling between the device and the emulated network. Handover scenarios between LTE and 5G NR cells are also tested. For this purpose, the Carbyte 4G/5G Mobility Lab with a 5G NSA software license is used, which facilitates the configuration of LTE eNB, 5G NR gNB, and the associated core network.

5G Standalone (SA) mobility test:
This scenario simulates the movement of a device between various 5G NR cells, managed by the emulated 5G Core Network (5GC). The test objectives include validating the handover process, ensuring connection maintenance and service continuity, as well as measuring handover latency and its impact on ongoing data transmissions. For this, the CarByte 4G/5G Mobility Lab with a 5G SA software license is utilized, which allows the emulation of gNB and a complete 5GC (AMF, SMF, UPF).

VoLTE (Voice over LTE) quality test:
This involves conducting a voice call over the LTE network (VoLTE) while simulating various network conditions such as variable signal strength or interference. The goal is to evaluate voice quality (e.g., based on the MOS score), ensure the proper setup and stability of the voice connection, and analyze handover effects during an active call. The CarByte Callbox Classic or Callbox Mini with VoLTE software license is used to emulate the LTE network, including IMS functionalities.

IoT application test over NB-IoT/LTE-M:
This scenario emulates an NB-IoT or LTE-M network to test communication with IoT devices utilizing these technologies. The tests include verifying device registration, data exchange (uplink/downlink), power consumption, as well as coverage and performance at low bandwidth and high latency. For this, the CarByte 4G/5G Mobility Lab with corresponding NB-IoT or LTE-M software licenses is deployed.

Network slicing test in 5G SA:
In this scenario, different network slices in the emulated 5G SA network are configured and tested. Each slice has specific QoS requirements and network functions. The tests validate the isolation and resource management of the slices, check compliance with QoS parameters, and assess end-to-end performance for applications assigned to the slices. The CarByte 4G/5G Mobility Lab with 5G SA and Network Slicing software license is used for this.

Interoperability test between different device manufacturers:
The CarByte 4G/5G Mobility Lab supports a wide range of test frequencies and standards in combination with various commercially available devices. In this scenario, the interoperability of the emulated network with devices from different manufacturers and models is tested. The goal is to identify and resolve compatibility issues, such as those related to protocol implementation, frequency band support, or handover behavior.

Roaming tests (Inter-PLMN handover):
The handover process between two or more emulated mobile network operators (PLMNs) is tested. The validation includes encryption mechanisms (e.g., Air Interface Encryption, IPsec), authentication procedures (e.g., SUCI Protection), as well as the simulation of attack scenarios to assess the response of the network and devices. The CarByte 4G/5G Mobility Lab provides functionalities for monitoring and analyzing signaling and traffic, which are essential for security testing.

Further Opportunities:

Beyond the mentioned examples, a 4G/5G Mobility Lab with CarByte solutions opens up additional innovative application fields. These range from optimizing connected mobility solutions to developing new technologies for vehicle communication.

Custom Protocol Testing: Implementation and testing of custom or proprietary protocols and extensions.

Integration with Test Automation Frameworks: Connection to common test automation tools for conducting repeatable and comprehensive test runs.

Field Simulations: Replication of specific radio environments and propagation conditions that may occur in real-world application scenarios.

Conclusion

With the increasing complexity of modern mobile communication technologies, the demands for reliable testing environments are also rising. A 4G/5G Mobility Lab is not just a tool for error analysis – it is an innovation platform. Companies, research institutes, and developers have the opportunity to validate new ideas under realistic conditions before they are put into practice. Those who invest in quality today are actively shaping the network of tomorrow.