The Wireless Local Area Network (WLAN) has become a dominant piece of technology to carry wireless traffic for Internet of Things (IoT). The next-generation high-density WLAN scenario is very suitable for the development trend of the industrial wireless sensor network. However, in the high-density deployed WLAN scenarios, the access efficiency is low due to severe collisions, and the interference is diffused due to the scattered locations of the parallel access stations (STAs), which results in low area throughput, i.e., low spatial reuse gain. A spatial group-based multi-user full-duplex orthogonal frequency division multiple access (OFDMA) (GFDO) multiple access control (MAC) protocol is proposed. Firstly, the STAs in the network are divided into several spatial groups according to the neighbor channel sensing ability. Secondly, a two-level buffer state report (BSR) information collection mechanism based on P-probability is designed. Initially, intra-group STAs report their BSR information to the group header using low transmission power. After that, group headers report both their BSR information collected from their members and inter-group interference information to the access point (AP). Finally, AP schedules two spatial groups without mutual interference to carry on multi-user full duplex transmission on the subchannels in cascading mode. The closed-form formulas are theoretically derived, including the number of uplink STAs successfully collected by AP, the network throughput and area throughput under saturated traffic. The simulation results show that the theoretical analysis coincide with the simulation results. The system throughput of the GFDO protocol is 16.8% higher than that of EnFD-OMAX protocol.

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Based on the architecture of ZigBee wireless sensor network (WSN) and the hierarchical modeling mechanism of OPENT, an enhanced ZigBee simulation model was studied to improve the MAC layer process model of IEEE 802.15.4 protocol provided by OPNET. The ZigBee Protocolcompatible network layer protocol, the routing algorithm, and the network layer process model based on an embedded routing function of OPNET were designed, which enhanced the scalability of ZigBee simulation system. And the enhanced ZigBee model optimized the number of router nodes needed for nodes access network, network control overheads, and end-to-end delay under different network scales.

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This paper analyzes the support of mobile end devices and logical events and states in network processes through the network node model, the application layer process model and the network layer process model. A simulation system model of ZigBee wireless sensor network (WSN) was proposed to support mobile nodes. An improved AODV routing algorithm was embedded in the model to optimize the network accessing function and routing path selection of mobile nodes, and to support the movement of ZigBee end devices. When the ZigBee sensor has a failure in a node, the other nodes can quickly re-establish the network topology to keep network unimpeded.