Senior Engineer – Mobile Core and IMS

Senior Engineer – Mobile Core and IMS

Ref:SEMCIMS 26

Job Overview

Responsible for ensuring the availability, performance, and reliability of the mobile core network. The role involves monitoring and troubleshooting network services, supporting new service deployments, managing incidents, collaborating with vendors, and implementing network improvements to maintain high service quality and operational excellence.

Role & Responsibilities

• Support our Mobile Core network elements ensuring compliance with KPIs and SLAs.
• Maintain service availability, performance, and compliance with operational processes.
• Take part in 24 x 7 on-call rotation for proactive and reactive support.
• Contribute to service rollouts and coordinate with external suppliers when required.
• Address issues escalated by Customer Care and internal stakeholders.
• Open and manage tickets with vendors, ensuring proper follow-up.
• Take ownership of service degradation events and major incidents, ensuring rapid response.
• Identify root causes and implement mitigation actions to reduce service impact.
• Collaborate across teams to ensure timely resolution
• Troubleshoot complex issues across signalling protocols
• Capture and analyse protocol traces using internal or external tools
• Act as technical owner, overseeing platform support.
• Monitor KPIs, analyse performance trends, and support improvement forums.
• Review network changes to ensure they do not negatively impact service performance.
• Oversee alarm handling and ensure timely corrective actions
• Execute periodic system checks, backups, and monitoring activities.
• Perform resilience assessments and analyse failure scenarios.
• Collaborate with vendors to drive continuous improvements and optimisations.
• Configure new number ranges on the network (MSISDNs, IMSIs, Global Titles, Number Portability Prefixes).
• Support the rollout and maintenance of SIP interconnections with external carriers.
• Configure or change routing in CS or/and IMS networks
• Maintain and update operational procedures and documentation (SOPs)
• Support configuration and troubleshooting of roaming services, including Vo LTE roaming.
• Define and implement signalling rules and message manipulation logic.
• Implement fraud prevention actions.
• Work closely with vendors during software upgrades, migrations, and incident handling.
• Ensure all changes are executed in a controlled and compliant manner.
• Follow established processes for testing, validation, and documentation of new services.
• Facilitate knowledge transfer within the team and wider organisation.
• Provide support and guidance to operational teams.

Key Technical Skills/Requirements

• Solid understanding of Mobile Voice Core Networks IMS/CS architectures
• Proven experience in the operation and maintenance of, at least, the following Ericsson nodes:
  • MSC-S, M-MGw, STP
  • CSCF, MTAS, SBC and BGF
  • HLR-FE, Au C-FE, MNP-FE, HSS-FE
• Strong understanding of 2 G, 4 G, and 5 G mobile network architectures and the E 2 E call flows.
• Strong knowledge of telecom protocols including:
  • Circuit Switched: H.248, SS 7, ISUP, BICC, SIGTRAN, INAP, CAP, TCAP, MAP, SCCP
  • IMS (Mobile): SIP/SDP, Diameter (Cx, Sh, Rx)
• Evidence of active, hands-on Operations & Maintenance experience within the aforementioned Mobile Core environments, preferably within the Ericsson MSS, IMS and UDC family of products.
• Minimum 15 years of proven experience in Mobile Core Networks.

Key Non-Technical Skills/Requirements

• Strong written and verbal communication skills in English (Spanish is an advantage).
• High level of adaptability and willingness to learn new technologies through self-learning.
• Ability to perform effectively under pressure.

Desirable

• Knowledge of Ericsson Cloud Environment.
• Ability to quickly gain knowledge in a short period to operate and maintain the following Ericsson nodes:
  • MRF, IPWorks, UPG
  • CCDM
  • SDP
• Ability to quickly gain knowledge in a short period to operate and maintain the following nodes:
  • SMSC, Voice Mail
• Ability to quickly gain knowledge in a short period to maintain the following Ericsson nodes:
  • CCN, OCC, AIR, VS and CSR.
• Understanding of IP networking (routing, switching, protocols) and system security.
• Familiarity with virtualization, containerized environments, and Linux systems.

Working condtitions

• Take part in 24 x 7 on-call rotation for proactive and reactive support.
• Work closely with vendors during software upgrades, migrations, and incident handling.
• Collaborate with other key teams including Mobile Packet Core, Fixed Voice, Radio Access, Information Systems IS & IT, Roaming Services and NOC.

How to apply

To apply, send yourCVandcover letterto

Go Back

How to apply

To apply, send yourCV, cover letterand completed application formto

Download application form here

If you are interested in learning more about current employment opportunities at Gibtelecom, please contact:

Human Resources Department

(+350)