Job Description: CS Core / IMS / SVC EngineerJob SummaryWe are seeking a CS Core / IMS / SVC Engineer to support, operate, and evolve mobile core networks. The role covers CS, IMS, and SVC solutions, with responsibilities and technical depth aligned to the candidates experience level. Engineers will work in live network environments, ensuring service availability, performance, and continuous improvement.Experience LevelsMid-Level Engineer: 3–5 YearsSenior Engineer: 5–8 YearsExpert / Lead Engineer: More than 8 YearsResponsibilities & Technical Requirements by Experience Level3–5 Years (Mid-Level CS / IMS Engineer)Core Network KnowledgeUnderstand the basic structure of mobile communication networksKnowledge of CS / SVC solutions or IMS / SBC services with basic configuration capabilitiesSignaling & ProtocolsBasic knowledge of SS7, M3UA, signaling link configuration, and GT routingFamiliarity with ISUP, BICC, SIPUnderstanding of mobility control protocols:BSSAP, RANAP, MAP, CAPGeneral knowledge of SIP, SDP, DIAMETER, DNS, ENUMMobility & Subscriber ConceptsUnderstanding of authentication and encryption mechanismsKnowledge of LAI, LAC, cell, service area, paging, roaming, handover, STN-SRAbility to check subscriber profiles in HSS and understand basic subscriber parametersOperations & SupportPerform L1 health checks and maintain operational scriptsMonitor network performance, system logs, and capacityEnable traces and support basic call troubleshootingProvide first-line technical support for CS/IMS core network elements5–8 Years (Senior CS / IMS Engineer)Core ArchitectureStrong command of IMS architecture and components:CGP, SPG, CSC, ATS, MRP, SBC, CCFStrong understanding of CS Core architecture:MSC, MGW, HSS, STP, DRASignaling & ProtocolsSolid expertise in:MTP3, SCCP, and SS7 signaling networksM2UA, M3UA, H.248, MGCPISUP, BICC, SIPSIP, SDP, DIAMETER, DNS, ENUMUnderstanding of TCAP, CAMEL, INAPService Flows & MobilityMaster mobile communication procedures:Call, SMS, handover, location updateCSFB, SRVCC, eSRVCCAnchoring and domain selectionStrong understanding of codecs and WIN principlesIntegration & TroubleshootingConfigure and troubleshoot interconnections between CS/IMS and:DRA, EPC, 5GC, PCRF, HSS, INHandle configuration and troubleshooting of key services:Emergency calls, QoS, roaming, SRVCC, anchoringPerform B-number analysis and routingImplement flexible Diameter routing on DRATroubleshoot KPI degradation and performance issuesSVC KnowledgeGeneral understanding of SVC solution architecture and networking principlesMore Than 8 Years (Expert / Lead CS / IMS Engineer)Advanced Core & IMS ExpertiseExpert-level knowledge of CS, IMS, and SVC solutionsDeep experience with IMS & SBC products, including supplementary and commercial trunk servicesStrong hands-on expertise with MSOFTX, AGCF, SOFTX, MGWSignaling & Protocol MasteryAdvanced command of:M2UA, M3UA, and SCTPBSSAP, RANAP, MAP, CAP, SGSAP, GTP-C (Sv interface)TCAP, INAPRTP, RTCP, H.248Service Control & Mobility LeadershipMaster IN service signaling flowsDeep expertise in:Anchoring, domain selectionSRVCC / eSRVCC handoversEmergency call handling and resilience mechanismsNetwork Integration & Live OperationsLead interconnection design and troubleshooting between IMS and:DRA, EPC, 5GC, CS, PCRF, HSS, INNMS, BOSS, and charging systems in live networksStrong experience with:IP SMSQoS, roaming, resource reservationiFC configuration and modificationCloud IMS C/M separation platformsDesign, Evolution & StrategyOwn network design (HLD) and overlay networking schemesDrive evolution from traditional CS to SVCLead Cloud IMS upgrades and capacity expansionDefine networking requirements for CloudCore & CloudEdge co-deploymentTranslate customer requirements into end-to-end technical solutionsGeneral Competencies (All Levels)Strong analytical and troubleshooting skillsAbility to work in live telecom network environmentsClear documentation and communication skillsStrong teamwork and stakeholder coordination