5G Expert (m/f/d)

at  NC GROUP GmbH

NET CHECK GmbH was founded in 1999 with the aim of improving the quality of communication networks. Since then, NET CHECK has developed into the leading partner for network operators and infrastructure providers of mobile and fixed networks across all technologies. Its core competencies include international network benchmarking (comparative measurements) as well as network planning and fault analysis. NET CHECK also has Germany’s largest crowdsourcing platform, which generates over 144 million data points every day. Our commitment to quality and security has earned us the trust of scientific and government institutions.
NET CHECK is headquartered in Berlin and is a part of the NC GROUP, which counts a total of over 180 employees operating from five offices in Germany as well as an office in Belgrade, Serbia. To further support our dynamic team we are currently, we are seeking a
5G Expert in Germany
The ideal candidate possesses strong problem-solving skills for diagnosing and troubleshooting complex issues, with analytical thinking to interpret test results and performance data. They are expected to have effective communication skills for documenting processes and reporting findings, to work collaboratively with cross-functional teams, and to demonstrate adaptability and a strong ability to learn. Additionally, they will provide support to our delivery and engineering teams, while also taking on the responsibility of mentoring and developing our young engineers.

Responsibilities:

• Collect Layer 3 logs that capture the signaling and control messages exchanged between network elements in the 5G core network and the Radio Access Network (RAN), focusing on messages related to session management, mobility management, and bearer establishment.
• Analyze Layer 3 logs to identify anomalies or patterns indicating potential issues, such as spotting failed handovers, session drops, authentication failures, or abnormal signaling traffic.
• Correlate Layer 3 logs with specific network events like call drops, failed data sessions, or degraded quality of service. Filter the logs to focus on relevant messages, such as NAS (Non-Access Stratum) signaling, S1AP (S1 Application Protocol), or X2AP (X2 Application Protocol) messages.
• Conduct a detailed examination of Layer 3 signaling flows to trace the root cause of the identified issues. This involves understanding the sequence of messages, analyzing parameters within the messages, and identifying deviations from expected behavior.
• Verify adherence to 5G protocol standards in the signaling exchanges between network elements. Check for protocol violations, misconfigurations, or interoperability issues between different vendors’ equipment.
• Reconstruct the sequence of events leading up to the issue by piecing together signaling messages. Understand the context and pinpoint the exact moment or condition that triggered the problem.
• Collaborate with other teams such as RAN engineers and core network specialists to validate findings from the Layer 3 log analysis. Share insights that may require further investigation in other layers or parts of the network.
• Document the root cause analysis based on Layer 3 logs, detailing the signaling flow, identified issues, and recommended actions. Provide clear and concise explanations that other teams can use to address the problem.
• Propose specific solutions or configuration changes based on the Layer 3 log analysis. Suggestions may include adjusting signaling parameters, optimizing mobility settings, or addressing protocol compliance issues.
• Share findings and lessons learned from Layer 3 log analysis with the broader team to improve collective understanding of signaling issues and enhance network performance.

Qualifications:

• A bachelor’s or master’s degree in Electrical Engineering, Telecommunications, Computer Science, or a related field.
• Telecommunications Fundamentals
• A solid grasp of telecom principles, including signal processing, modulation, and coding, along with digital signal processing (DSP) techniques like Fourier transforms and filtering. Proficiency in modulation schemes such as QAM, PSK, and FSK, as well as error correction methods like Turbo codes and LDPC, is essential.
• Proficiency in network protocols and architectures, such as TCP/IP, LTE, and 5G NR, is crucial. An understanding of the OSI model’s physical, data link, and network layers, along with familiarity with standards bodies like 3GPP, ITU, and IEEE, is also important.
• Wireless Communication Systems
• A strong grasp of wireless technologies (2G to 5G), including key advancements like CDMA, OFDMA, MIMO, and beamforming. Knowledge of carrier aggregation, VoLTE, 5G NSA/SA architectures is required.
• RAN components (eNodeB, gNodeB) are essential, along with experience in RF engineering and antenna theory. Familiarity with small cells, macrocells, and HetNets is also important.

• Collect Layer 3 logs that capture the signaling and control messages exchanged between network elements in the 5G core network and the Radio Access Network (RAN), focusing on messages related to session management, mobility management, and bearer establishment.
• Analyze Layer 3 logs to identify anomalies or patterns indicating potential issues, such as spotting failed handovers, session drops, authentication failures, or abnormal signaling traffic.
• Correlate Layer 3 logs with specific network events like call drops, failed data sessions, or degraded quality of service. Filter the logs to focus on relevant messages, such as NAS (Non-Access Stratum) signaling, S1AP (S1 Application Protocol), or X2AP (X2 Application Protocol) messages.
• Conduct a detailed examination of Layer 3 signaling flows to trace the root cause of the identified issues. This involves understanding the sequence of messages, analyzing parameters within the messages, and identifying deviations from expected behavior.
• Verify adherence to 5G protocol standards in the signaling exchanges between network elements. Check for protocol violations, misconfigurations, or interoperability issues between different vendors’ equipment.
• Reconstruct the sequence of events leading up to the issue by piecing together signaling messages. Understand the context and pinpoint the exact moment or condition that triggered the problem.
• Collaborate with other teams such as RAN engineers and core network specialists to validate findings from the Layer 3 log analysis. Share insights that may require further investigation in other layers or parts of the network.
• Document the root cause analysis based on Layer 3 logs, detailing the signaling flow, identified issues, and recommended actions. Provide clear and concise explanations that other teams can use to address the problem.
• Propose specific solutions or configuration changes based on the Layer 3 log analysis. Suggestions may include adjusting signaling parameters, optimizing mobility settings, or addressing protocol compliance issues.
• Share findings and lessons learned from Layer 3 log analysis with the broader team to improve collective understanding of signaling issues and enhance network performance