Manufacturing of specialized railway equipment and accessories, rail transit communication equipment, railway rolling stock parts, electrical machinery and apparatus, computer application electronic equipment, and communication system equipment; sales of railway track accessories, rail transit communication equipment, electrical machinery, electronic products, electromechanical products, power equipment, and computer application electronic equipment; research and development of rail transit communication systems, electronic products, electromechanical products, power equipment, and electronic, communication, and automatic control technologies; repair of railway transport equipment, electrical equipment, instruments and meters, and general equipment; maintenance and servicing of rail transit locomotives, rolling stock, and equipment; production of electronic products; rail transit-related technical consulting and technical services; information electronic technology services.