Implementation of CSMA/CA and ALOHA random-access protocols for packetizing wireless networks with model-based design

Abstract

Because of the reliability of deployment, cost efficiency, and flexibility of ad-hoc wireless local networks (WLAN). These wireless networks have grown to be the everywhere connection solution in residential and public access networking protocols. It is important to know which strategy performs better with the least amount of delay. The Multiple Access Control protocols (MAC) that are relied on ALOHA, and Carrier Sense Multiple Access with collision avoidance (CSMA/CA) as random access techniques, have substantially aided the rapid growth of such wireless access networks. This work provides a model-based design approach for modeling CSMA/CA and ALOHA random-access protocols for packetizing wireless networks. We analyze the TX and Back-off waveforms of the PHY/MAC transceiver of three radio nodes under CSMA/CA and ALOHA operation modes and compare the obtained results of the PHY/MAC Transceiver for the network nodes according to these modes. Every node is within a range such that the communication between each couple of nodes can be interfered with and received data from the third node. The MAC layer and the logical link control function composed the data link layer. Since the same radio band is used for TX and RX, the MAC function employed here is CSMA/CA and ALOHA, which had also called a random back-off. The MAC layer sends a control signal to the TX block to transmit either a data frame or an acknowledgment frame. The frame contents are loaded in the look-up tables. The contents can be changed in the workspace. The output of this block is a complex baseband IQ signal. The obtained results show the effectiveness of CSMA/CA over ALOHA modes when comparing the corresponding Back-off waveforms and when calculating the throughput values of the three network nodes