Study On The System Simulation And Performance Analysis Of A Sub-1GHz Wireless Network

IEEE 802.11 ah Wireless Local Access Network, also known as Sub-1GHz(S1G) WLAN, is operating at S1 G frequency range. With the advantages of fine propagation characteristics, wide coverage area, large network capacity and low energy consumption, 802.11 ah is promised a bright future in the growing Internet of Things field. Targeting at the performance analysis of the S1 G network, the network capacity and Packet Delivery Ratio, along with the sysmetry of DL/UL traffic, is mainly analyzed.The mathematic modeling of S1 G network capacity and Packet Delivery Ratio(PDR) is discussed preferentially upon the detailed analysis of both the Traffic Indication Map frame patterns and DL/UL access processes. Then, both the quantitative relationship between the capacity and physical transmission rate and the PDR performance are studied. In addition, according to the three scenarios with three different types of DL/UL traffic proportion—Scenario A(1: 1), Scenario B(1: 2) and Scenario C(1: 3), the numerical simulation is conducted under the 2MHz subcarrier frequency band. The result reveals that 8191 stations could be accommodated in the S1 G network at 2.4Mbps(MCS 5) in Scenario A or 3.6Mbps(MCS 8) in Scenario B, while 7034 is the max capacity for Scenario C. Meanwhile. The outcome is also acquired that S1 G can reach the max PDR values, which is 90.01%, 84.28% and 88.46%, in the three scenarios above when the sums of stations are 1500, 1500 and 500.On purpose for more precision and flexibility, the simulation module of the Restricted Access Window(RAW), especially the five kinds of transmission control simulation timer and the media access control function, is implemented on the current NS2 codes after analyzing the demand for RAW. The contrast experiment with the traditional distributed coordination function(DCF) is conducted. The result proves the S1 G simulation platform validate, and the improvement on the network throughput with the growing number of the stations. And the better symmetry could be also seen in the S1 G simulation.