Bi-Direction Traffic Characteristic Analysis For Access Network

With the rapid development of wireless communication technology and network, traffic type in the wireless network become more and more diversified, from application of voice and text-based to multi-media data such as image and video. These new applications often have very large user groups, and consume more bandwidth resources, leading to rapid increase in demand for bandwidth resource. The conflict between resource supply and user needs becomes more and more urgent. How to optimize the network configuration and improve the efficiency of resource use is critical. Accurate description of the traffic flow characteristics is one of the most important foundations to achieve the goal.As we know that traffic flow contain up to four types sub-flow: positive control sub-flow, reverse control sub-flow, positive data sub-flow and reverse data sub-flow. These sub-flows have different roles and there are close relationship among them. These relationships are the focus of this paper. There are two major issues. Firstly, study the relationship between the control sub-flow and data sub-flow of the traffic flow. Secondly, study the relationship between the positive data sub-flow and the reverse data sub-flow. In order to solve the above issues, this paper gives the reference model of two-way traffic first of all. Then we use the joint probability matrix to describe the relationship between the two data sub-flow, and conclude the characteristics of the matrix: interaction, symmetry and correlation. Then the role of the control sub-flow is analyzed. Finally, we capture large amounts of network data from UWB wireless personal area network and local area network to study the issues in detail.The main contributions of this paper are as follows.Firstly, we divide traffic flow into four parts: positive and negative control sub-flow, positive and negative data sub-flow. There are closely related between control sub-flow and data sub-flow, and between positive data sub-flow and negative data sub-flow. On this basis, we modify the reference model of packets traffic flow. Joint probability matrix is used to analyze the model, and characteristics of two-way traffic flow are proposed, which include: interaction, symmetry, correlation.Secondly, we study the relationship between control sub-flow and valid data sub-flow by analyzing the performance of TCP traffic flow in the UWB wireless personal area network. The results show that in the UWB wireless network, bandwidth of control sub-flow which is about 1/8 of valid data sub-flow can't be ignored. And there are different affect for TCP traffic performance between control sub-flow and valid data sub-flow, control sub-flow has smaller affect in high-speed traffic flow. In addition, we find optimal bandwidth ratio between the two type sub-flows. These conclusions are an elicitation in other wireless network.Finally, we study the relationship between positive valid data sub-flow and negative valid data sub-flow. By analyzing capture data, we obtain joint probability matrix of ten typical traffics, and calculate parameters of interaction, symmetry and correlation. Then we compare parameters of different traffic to conclude the relationship between positive and negative valid data.