Telecom and Mobile equipments and software is so tailored that security testing is hard. Make sure your network doesn't crash or get compromised by robustness testing and fault injection (fuzzing) in your exact conditions.
Discover and identify new vulnerabilities (zero-days) in telecom and mobile equipments before you put them in production.
Qualify software and updates before they are put in production.
Identify areas of improvement on your equipment stack and bring your infrastructure to the next level with objective and constructive optimizations proposals.