Voice and Services Engineer (Lisbon based)

1global; Porto; Hybrid; EUR 60,000 - 90,000; Full time

Job summary

1GLOBAL is expanding its voice and services team in Porto, focusing on design, testing and deployment of next-generation mobile core networks. You will define requirements, implement end-to-end solutions, and produce technical documentation to support lifecycle management.

The role demands hands-on experience with GSM/UMTS/LTE/IMS, SIP/RTP, and signaling protocols, plus a strong grasp of 3GPP/GSMA standards and NFV concepts. English fluency is required; OSS/BSS collaboration is common.

Qualifications

• Proven experience in live mobile telecom solutions design and deployment (GSM/UMTS/LTE/IMS).
• Strong knowledge of 3GPP/GSMA/ITU standards and network architectures.
• Experience with NGN-based networks incl. HLR/HSS/SBC/MSS/MGW and SIP/RTP.
• Experience defining voice interconnects and QoS.
• Understanding IMS architecture; familiarity with VoIP/VoLTE/VoWiFi.
• Experience with SMS routing/configuration.
• Knowledge of Diameter/SCTP and signaling gateways incl. SS7/SIGTRAN/MAP/CAMEL.
• Proficiency with protocol analyzers (Wireshark) for troubleshooting.
• Familiarity with ETSI NFV and MVNO architectures.
• Proficient in English; degree in Telecom/CS required.

Responsibilities

• Collaborate with Networks teams to define and deliver new solutions.
• Lead end-to-end project delivery including network design and migration strategy.
• Design new consumer and corporate telecom solutions.
• Create and maintain technical documentation (HLD/LLD/WO).
• Implement solutions in live environments and verify end-to-end testing.
• Define quality and performance indicators; drive improvements.
• Analyze capacity and performance; implement optimization plans.
• Configure services and resources across systems as required.
• Address cross-team processes and partner change requests.
• Maintain an up-to-date view of technology portfolio and evolutions.

Skills

GSM/UMTS/LTE/IMS

3GPP/GSMA/ITU standards

NGN networks

SIP/RTP

IMS architecture

VoIP/VoLTE/VoWiFi

Diameter/SCTP

Signaling Gateways (SS7/SIGTRAN/MAP/CX

Wireshark/Astelia

ETSI NFV

MVNO/MVNE/MVNA

English proficiency

Telecommunications or CS degree

Education

Bachelor's degree in Telecom Engineering or Computer Science

Job description

About Us

11GLOBAL is a technology-driven global mobile communications provider helping enterprises and consumer brands deliver seamless connectivity worldwide. Powered by a best-in-class telecom platform, proprietary eSIM technology, and its own mobile core network across 15 countries, 1GLOBAL operates as a fully regulated telecommunications provider in 43 countries.

Founded in 2022, 1GLOBAL has rapidly become one of Europe’s fastest-growing telecom technology companies, connecting more than 80 million people and devices globally. Our customers include leading banks, multinational enterprises, global retailers, travel companies, payment service providers, and digital-first businesses.

Headquartered in the Netherlands, with R&D hubs in Lisbon, Berlin, and São Paulo, 1GLOBAL employs over 550 professionals across 16 countries. With annual revenues exceeding US$200 million and a strong track record of profitability, we continue to invest in innovation, infrastructure, and international expansion as we redefine the future of global mobile connectivity.

About the Team

As a Network Engineering member, in the Voice and Services functional area, you will be responsible to propose, analyze and define the requirements for new and existing services and systems, related with the voice systems under the responsibility of the functional area. Prepare, design, test and provide new solutions or product changes of the already existing portfolio. Define and support the technology evolution roadmap for the systems under the functional area. Participate and support the other functional areas in cross functional projects.

About the Role

• Collaboration with other Networks teams in defining and managing the projects for delivery of new solutions
• Project delivery. Network design. Integration and migration strategy definition. Collaboration with other relevant departments. Responsible for end-to-end delivery
• Design of new consumer and corporate telecom solutions
• Creation of technical documentation (HLD’s, LLD’s, WO’s, etc.) and maintain it over the lifecycle of the solutions
• Perform implementations in live environment. Understanding of End to End system testing requirements
• Follow-up and define Quality and Performance indicators
• Capacity and Performance Analysis, Reporting and Improvement Solution Definition
• Service & Resource configuration definition and implementation on requested systems
• Work on complex solutions that influence the design of current products and addresses design issues for future products or technologies
• Close relationship with external partners like carriers, service providers
• Elaborate, and manage the process, for change requests to current partners in order to meet the network necessities
• Control the network elements roadmap, being responsible for the necessary software/hardware upgrade during the components lifecycle
• Generate and implement process improvements, including and especially cross-team processes
• Documents the existing technology portfolio and proposes recommendations for improvements and/or alternatives

About You

Must Have

• Proven experience on implementation of live solutions on mobile telecom (GSM, UMTS, LTE, IMS), networks design, capacity management, engineering and architecture
• Knowledge of 3GPP, GSMA, ITU standards and specifications
• Experience in the design, test and operation of NGN based networks, including MSS/MGW, HLR/HSS, SBC
• Experience in defining, establishing and maintaining voice interconnects, SIP/RTP based
• Understanding about IMS architecture. Knowledge about VoIP, VoLTE, VoWiFi, and QoS
• Experience with SMS service configuration and routing
• IMS Architecture with understanding of IMS nodes including P/S/I-CSCF, Application Servers
• IMS Protocol Interfaces – Gm Interface, ISC interface, Sh Interface, Cx, SOAP/XML, etc.
• Experience in mobile services charging (offline, online). Knowledge and experience of OCS and, Ro, Ro+, Ga and Bp interfaces
• Knowledge and experience with Diameter/SCTP networks and protocol
• Knowledge and experience with Signaling Gateways and protocols including SS7, SIGTRAN, MAP and CAMEL
• Experience with protocol analyzer tools like Wireshark, Astelia, and ability to use them to troubleshoot networks errors/problems for the mentioned protocols
• Experience with ETSI NFV architecture and solutions
• Familiar with MVNO/MVNE/MVNA architecture(s) and landscape
• English proficiency mandatory, other languages are a plus
• Degree in Telecom Engineering or Computer Science or equivalent experience

Nice to Have

• +3 years working on telecoms, designing and implementing mobile core networks
• Previous experience with Nokia, Oracle and Ribbon IMS products

Why 1GLOBAL?

• Growth Opportunities:Advance your career in one of the fastest growing telecommunications companies, expanding over 50% year-on-year under the leadership of successful tech entrepreneurs.
• Major Transaction Exposure:Be in the driver’s seat for transactions that will have an impact on the future telco industry.
• Work with a Talented Team:From the Board and the Founders to the Senior Management Team, you will collaborate daily with the most capable and renowned external advisors and constantly being exposed to talented and driven individuals.
• Dynamic Work Environment:Thrive in a collaborative, fast-paced workplace where innovation is encouraged, and every contribution counts.
• Professional Development:Work alongside industry experts to enhance your skills and knowledge in acutting-edgefield.
• International Experience:Gain opportunities to work in different 1GLOBAL offices around the world as you grow within the company.
• Open Communication Culture:Join a team where your ideas are heard, and open dialogue is encouraged, fostering a supportive and transparent work environment.
• Get Things Done Attitude:Be part of a results-driven team that values efficiency, creativity, and the drive to make a tangible impact in the industry.

1GLOBAL is an equal opportunity employer, we value your character as much as your talent. Diversity drives our innovation, and we offer a collaborative, dynamic, and international work environment. We are excited for you to join our mission to revolutionise connectivity globally.

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