General projects: Technical services, technical development, technical consultation, technical exchange, technology transfer, and technology promotion; Professional repair of communication transmission equipment; Professional repair of communication switching equipment; Information system integration services; Intelligent control system integration; Sales of communication equipment; Foreign contracted projects; Engineering technical services (excluding planning management, survey, design, and supervision); Engineering management services; Maintenance of electronic and mechanical equipment (excluding special equipment); Computer system services; Information system operation and maintenance services; Information technology consulting services; Electrical installation services; Sales of security equipment; Professional design services; Security system monitoring services (except for projects that require approval in accordance with the law, operating activities shall be carried out independently with the business license in accordance with the law)