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Core NSS Engineer


Salary: Competitive

Location: Porto Salvo, Portugal

Posted: 09 Apr 2019

Role Brief:

This role is to be integrated in the TechOps NSS team, within the Technology Operations group.

This team is responsible for maintaining and managing Truphone's core GSM network, whilst ensuring that the network platforms and services are performing under normal conditions, aiming to improve and keep high levels of service availability and performance.

This is a specialist technical role that requires transversal expertise of the entire Truphone core gsm network, with action over the CS, PS and VAS platforms, namely: HSS, ITP, MSS, MGW, MNP, MFS, DSC, OCS, IN, SMSC, GGSN, MCC, Voicemail and VVM, PCRF, M2M OTA GW, IoT platform, GMN, among others.

Key Accountabilities:

  1. Handle and investigate troubles raised under the problem management process.
  2. Resolve all cases related with platforms and services in production environments, according to the implemented designs.
  3. Support, troubleshoot and handle software and hardware problems in platforms and services in production environments, liaising with vendors and suppliers whenever required.
  4. Availability for 24/7 on-call support.
  5. Address internal/external support and fulfilment requests raised via the agreed processes and interfaces.
  6. Perform regular network assessments and proactively work in order to identify and diagnose service quality degradations or malfunctions before customers are impacted.
  7. Contribute to root cause analysis and post-actions follow-through.
  8. Routinely monitor and health-check platforms in production environments.
  9. Maintain a repository of documentation, configuration and procedures to effectively operate the systems, platforms and services.

10.  A flexible and pragmatic approach to problems and their resolution is required, as well as the ability to troubleshoot complex problems to quickly find solutions.

11.  Responsible for the definition, implementation and testing of temporary fixes (follow-through to permanent).

12.  Responsible for the definition, implementation and testing of new solutions (no impact on design).

13.  Contribute to solutions design with operational inputs and support changes on production environment.

14.  Ability to understand and interpret performance KPIs relating to network elements and services.

15.  Maintain and update Truphone's databases with all changes either external or Truphone internal roaming decisions.

16.  Producing roaming and service analysis & reporting for management against demanding timelines.

17.  Leading roaming operational performance meetings, discussions and improvements.

18.  Executing and documenting roaming tests in accordance with GSMA regulations and requirements: IR.24 for Voice and Short Message testing, IR.35 for GPRS testing and IR.60 for Pre-paid testing and IR.50 2G /2,5G /3G roaming testing.

19.  Testing & Enabling LTE roaming capabilities for all direct partners in accordance with GSMA standards by executing IR.38 LTE Roaming requirements (including LTE TADIG certification).

20.  Analysing IREG and TADIG problems, identifying root-causes and troubleshooting of voice, SMS, data UMTS, LTE, CAMEL and recommending and implementing solutions. Creating and maintaining data records, liaising with cross-functional departments and with International Roaming partners.

21.  Ensuring all set-up and configuration for tap-flow is in place to enable IREG.

22.  A flexible and pragmatic approach to problems and their resolution is required, as well as the ability to troubleshoot complex problems to find solutions quickly.

23.  Creating and actively maintaining Truphone's direct roaming and ISR service capabilities.

24.  Technical implementation for roaming partners' data in iHSS, IN and GPRS support nodes, as well as IR.21 updates of existing roaming relationships.

25.  Implement roaming data changes to: MSS, iHSS, STPs, I.N. platforms, GGSN, DSC when is required due to IREG testing configurations or IR.21 Updates.

26.  Updating, recording and maintaining the IREG tracker with actions, to ensure current status of tests and the expected dates of delivery are known and monitored.

27.  Ensuring the roaming test schedule is followed and completed as planned. Driving, monitoring and tracking weekly delivery against targets to ensure consistent and on-target delivery. Providing weekly delivery and status reports to provide transparency and clarity around IREG & TADIG status.

28.  Ensuring TADIG validations and certification post IREG completion is accurate and in accordance with planned timelines.

29.  Support IREG team in ad-hoc requests based on Business requirement.

30.  Ensuring SIMs despatch & SIMs received records are maintained accurately. 

Required Skills:

  1. Strong Core GSM networks operation and flows knowledge.
  2. Knowledge on mobile networks (2G/3G/4G) voice, SMS and data is mandatory.
  3. Proficiency on core signalling network nodes.
  4. Working experience with the following protocols:  TCP/IP, MAP, CAMEL, SIP, ISUP, H323, SIGTRAN; MGCP, MEGACO, SSN7, DSS1, Ethernet, among others.
  5. Hands-on experience on Unix/Linux systems administration.
  6. Good knowledge on working with MySQL, PostgreSQL, Oracle or MS SQL databases.
  7. IP networks troubleshooting capabilities.
  8. Experience with signalling analysis tools (Wireshark, Astellia).
  9. Ability to manage incidents involving complex networks, services and systems.

10.  Strong IREG troubleshooting background to ensure consistent delivery of targets, TADIG expertise with thorough understanding and knowledge of cost-impacts of failure.

11.  Ensure that partner technical documentation (e.g. IR.21s) is translated accurately into Truphone's systems to maintain seamless technical roaming capability.

Supporting skills:

  1. Versed in scripting and automation (bash, python, perl, ansible, etc.);
  2. Good understanding of VoIP and TDM technologies;
  3. Working experience of SNMP and monitoring systems;
  4. Experience with performance and capacity analysis methodologies;
  5. Asterisk administration.

Personal qualities:

  1. Great initiative, team player, able to work in multi-cultural environment and with minimal supervision;
  2. Problem solving attitude, with strong analytical capabilities;
  3. Comfortable in a fast-paced, intense and demanding environment;
  4. Innovative and inspiring, awesome to be around with.
  5. Flexible and pragmatic approach to challenges and ways to tackle them;
  6. Detail conscious, highly organised and methodical with a strong work ethic;
  7. Fast learner, eager to develop its competencies in new technologies and/or work methods;
  8. Ability to communicate clearly and concisely with people of different backgrounds;
  9. Excellent technical writing and formal presentation skills.


  1. Minimum 3+ years of experience working in a demanding and technology driven environment;
  2. Demonstrated autonomy regarding prioritization and decision making;
  3. Technical knowledge in networking, mobile, voice, data and IT technologies.
  4. Experience operating core GSM/UMTS/LTE network platforms;
  5. Strong working experience with the usual telco protocol stacks, IP and SS7;
  6. Holder of Computer Science or Telecommunications Engineering Degree.
Apply now

No agencies. We do not accept CVs from 3rd parties

Apply now

No agencies. We do not accept CVs from 3rd parties