As a new generation of mobile communication technology

5 G has the characteristics of enhanced mobile broadband

ultra-reliable low-latency communications

and massive machine-type communications. 5 G can bring users a revolutionary business experience

and can also develop new business models

providing communication operators with new growth momentum. In order to meet the requirements of the three major business scenarios of 5 G technology

the front-haul technology is required to meet the requirements of low latency and high reliability

and comprehensive consideration of various factors such as network resources

cost

and technology maturity. In this paper

through the analysis of the existing pre-transmission technology

the advantages and disadvantages of the original technology are clarified

and a semi-active wavelength division multiplexing scheme is proposed. The solution adopts an asymmetric device configuration

adapts to the C-RAN networking

and utilizes existing mature technologies to ensure simple technology and reduce equipment costs on the basis of providing network management and protection and recovery functions. Compared with the existing pre-transmission scheme

this scheme has obvious comprehensive advantages.