Software Engineer - Telecommunications

Imagine being at the forefront of technology that keeps the world connected, from everyday mobile users to first responders on critical missions.

Join a global leader in communication technology with a storied legacy of innovation, delivering cutting‑edge mobile devices, mission‑critical communication systems, and intelligent connectivity solutions; celebrated for award‑winning design, durability, and performance, trusted by major carriers, enterprises, and emergency services worldwide, and recognised for creating iconic products that blend engineering excellence with practical, real-world impact.

Seize the opportunity to innovate and grow with a team that is shaping the future of communication and making connections that matter every day.

Responsibilities:

• SIP Signaling & Session Management: Develop C# components for high-concurrency SIP sessions, managing complex headers and MIME bodies to support features like "First-to-Answer" and Group Regroups.
• Real-Time Media Plane: Implement RTP/RTCP media handling for Mission Critical Voice (MCPTT) and Video (MCVideo), ensuring seamless floor control (transmission rights) in half-duplex environments.
• Data & Configuration: Build handlers for MCData services (SDS, File Distribution) using HTTP and SIP MESSAGE requests, and manage XCAP retrieval logic for XML configuration documents.
• Secure Communications: Integrate OIDC authentication flows and MIKEY-SAKKE encryption to ensure media transport remains secure and resilient.

Required Qualifications:

• C# / .NET Framework / .NET Core Mastery: 3+ years of professional experience with a deep focus on asynchronous network programming.
• .NET Frameworks Experience: WCF, SignalR, EF, ASP.NET, WebAPI
• Protocol Expertise: A solid understanding of the SIP Protocol Stack (INVITE, PUBLISH, SUBSCRIBE, etc.) and experience with RTP/RTCP stacks.
• Data Handling: Proficiency in parsing complex XML schemas (XSD) and handling multipart/mixed MIME bodies.
• Software Engineering Principles: Strong grasp of OOP, SOLID principles, and modern CI/CD workflows (Git, Pull Requests, Agile).

Preferred Skills

• 3GPP Standards: Familiarity with TS 24.379 (MCPTT) or related MCX standards.
• Security: Experience with SRTP, TLS, or Key Management lifecycles (KMS).
• Domain Knowledge: Previous experience with UK Police Control Room environments or the Emergency Services Network (ESN).

Contract Details:

• 6 Months
• Start Date: ASAP

Salary:

• Rate: £40 Per Hour