1, communication system: including telephone, fax, network and other communication equipment and systems, which are required to be stable, reliable and efficient.

2. Security system: including access control, monitoring, alarm and other security equipment and systems, which are required to be safe, reliable and efficient.

3. Monitoring system: including production process monitoring, environmental monitoring and other equipment and systems, which are required to be accurate, reliable and efficient.

4. Audio and video system: including audio and video equipment and systems in conference rooms, training rooms, exhibition halls and other places, which are clear, stable and efficient.