In wireless sensor networks (WSNs), specifically in industrial applications, the congestion has become a big challenge due to the different processing capacity of sensor nodes within network. This ineffectiveness reduces the overall performance of the network so that the congestion needs to be significantly controlled. A scalable approach to control the packet traffic in industrial WSNs (IWSNs) is proposed in this work. Relay nodes were introduced in the IWSN to boost the packet transmission rate. Furthermore, the introduced sensor nodes were systematically arranged to form tree-like topology for the purpose of network reliability and flexibility. The communication between nodes is executed under AN1066 MiWi protocol (protocol of IEEE 802.15.4 family). Using MATLAB simulating environment, it was shown that the proposed approach outperforms the congestion control algorithm relying with respect (w.r.t) to scheduling for communication within the nodes based on the dissimilar link capacities of adjacent nodes/ link capacity dissimilarity (LCD). This performance is due to employed relay nodes and AN1066 MiWi protocol which render the proposed approach more effective unlike former one which consists of assigning the capacity to every link between nodes; producing the wastage of the link capacity in case there are nodes that are not transmitting packets in the network.