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Engineer (Circuit Core Operations)

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Date: 22-Nov-2021

Location: StarHub Green

Company: StarHub Ltd

Job Description



  • Provide technical and operational support for 3G/4G/5G Circuit Core sub-system (MSS/TAS/MGW), SDM sub-system (OneNDS), IMS sub-system (HSS/CSCF/PCS) and Application Servers
  • Provide technical support for project implementation and network elements system release upgrade / expansion
  • Provide International Roaming service-related support (IREG)


  • Perform daily operation and administration of 3G/4G/5G network elements (CS Core/SDM/IMS sub-system) to ensure smooth network operation
  • Develop and review system operations processes, "Method of Procedure" documents, and update network documentation that facilitates operation effectiveness
  • Carry out system maintenance activities eg installation and test of release upgrade, technical/change notes /change deliveries of CS/IMS/SDM Core sub-system network elements (MSS/TAS/MGW/CSCF/NTHLR/HSS/UDR)
  • Perform system, call flow and signalling message troubleshooting to isolate/ resolve network faults and service issues
  • Provide network operational and engineering support for system commissioning, integration, Acceptance Testing (SAT/UAT) of CS/IMS/SDM Core sub-system network elements
  • Perform proactive monitoring of network elements’ KPI/ alarms and network performance analysis to ensure we upkeep high service quality level
  • Perform system security hardening, vulnerability assessment, scanning, and implementing the necessary corrections or processes to address/ mitigate the security risks
  • Provide support to subscriber provisioning relating to issues and ad-hoc data migration support
  • Perform Standard IREG tests (IR.24/IR.32) and configurations update (IR.21) in the Core Network elements in order to ensure inbound and outbound roaming continues to operate
  • Provide ad-hoc support to international roaming partners/IREG/TADIG testing and technical troubleshooting, revenue assurance, and roaming fraud investigation 
  • Provide Regulatory/ LEA related support 
  • Perform 24x7 rotating standby support 


  • Bachelor degree in Electrical/ Electronics/ Telecommunications Engineering or equivalent
  • At least 2 years of experiences in related industry is preferred
  • Basic IP networking knowledge will be advantageous
  • Working knowledge of 3G/ 4G technologies, LTE, VoLTE, IMS, SDM, and TCP/IP
  • Hands-on knowledge of the following protocols: SOAP/XML, SIP, MAP, CAMEL, ISUP, SS7/SIGTRAN, SCTP, SNMP, SMTP, RADIUS, Diameter
  • Hands-on experiences in end-to-end troubleshooting of 3G voice calls, VoLTE call flow (P/I/S-CSCF, TAS), International Roaming (IREG/Camel) and Messaging Flow (SMS/MMS/RCS)
  • Proven ability to generate network packet/ system logs to perform network troubleshooting and performance analysis using Wireshark or other protocol analysis utilities
  • Knowledge of International Roaming or experience of GSMA standard IREG & TADIG testing
  • Experience in UNIX/Linux server Administration and basic shell scripting skills


*We regret that only shortlisted candidates will be notified.