Design And Implementation Of Architecture And Resource Scheduling For VLC Access Network

With the rapid popularization of computers and intelligent devices, the scope of mobile digital terminals has undergone a revolutionary change,and the traditional access network technology has faced a great challenge.Visible light communication, as an access method with abundant spectrum resources, green energy and strong mobility, thus came into being.Compared with traditional light sources, light emitting diode (LED) has a series of advantages such as high brightness, long life, low power consumption, small size and so on. The cost of LED and its transmitter module, which is getting lower and lower, makes the visible light communication access network based on large-scale LED arrays possible.When the size of the network increases, the technology research of network level becomes very necessary.This paper focuses on the architecture and resource scheduling mechanism for visible light communication access network. By researching the advanced scientific research achievements in this field and setting up the experiment platform of the visible light communication access network, the following three innovations are obtained.A new extendible architecture of visible light communication access network and its generating method are proposed. In this paper, from the point of view that the LED in the visible light communication access network has strong expandability, we firstly analyze the influence of network architecture and network topology, then compare the performance of two common architectures in the visible light communication access network considering the factors of transmission delay and extending cost.After that, we have done some optimization about the access layer extension mode and convergence layer and core layer connection mode and redundancy strategy. Finally, we propose a new extendible architecture of visible light communication access network and its generating method, and carried out experimental verification. The experimental results show that the proposed network architecture can enhance the scalability and stability of the network to a certain extent.This paper proposes an adaptive resource scheduling mechanism based on service priority and a genetic algorithm resource scheduling mechanism based on subnet load optimization for different resource scheduling scenarios. When the total bandwidth resources requested by the access user are larger than the network’s, the uncertainties such as the user access timing and duration time and the diversity of the user requests bring lots of difficulty to the implementation of the resource scheduling scheme.Therefore, the resource scheduling mechanism we proposed based on service priority takes the service priority as the starting point. By comparing the request priority of the access user, the user waiting to be accessed and the bandwidth redundancy in the network, combined with different resource scheduling strategies, the network dynamically provides the optimal scheduling scheme. When the total bandwidth resources requested by the access user are less than the network’s, the study has found that the different access location affects the load pressure of the subnets.Further analysis shows that the problem is a global optimization problem,which means that we can schedule the user access location to achieve subnet load pressure optimization by given the network architecture and user communication matrix. Therefore, the genetic algorithm is designed to obtain the final access position of the users, so that the user access location and subnet can be reasonably scheduled and divided. Experiments show that the algorithm can effectively reduce the total amount of subnet communication and balance the load pressure of each subnet, which truly has certain effect.Design and implementation of indoor visible light communication access network experimental platform. The platform can transmit interactive signaling through software interface and serial port command for different experimental scenarios, thus realizing the functions of user access, mobile switching and positioning monitoring under different lights with the help of software control.