Performance Evaluation of Channel Access Methods for Dedicated IoT Networks

Abstract

Networking technologies dedicated for the Internet of Things are different from the classical mobile networks in terms of architecture and applications. This new type of network is facing several challenges to satisfy specific user requirements. Sharing the communication medium between (hundreds of) thousands of connected nodes and one base station is one of these main requirements, hence the necessity to imagine new solutions, or to adapt existing ones, for medium access control. In this paper, we start by comparing two classical medium access control protocols, CSMA/CA and Aloha, in the context of Internet of Things dedicated networks. We continue by evaluating a specific adaptation of Aloha, already used in low-power wide area networks, where no acknowledgement messages are transmitted in the network. Finally, we apply the same concept to CSMA/CA, showing that this can bring a number of benefits. The results we obtain after a thorough simulation study show that the choice of the best protocol depends on many parameters (number of connected objects, traffic arrival rate, allowed retransmission number), as well as on the metric of interest (e.g. packet reception probability or energy consumption).

Characterization of WiFi Modules Using an Open-Source Network Simulator

“…By checking the wireless channel status, and adapting the transmission rate, accordingly, allows the network not to be flooded. In [14] authors, conclude that the appropriate channel access management configurations depend primarily on interarrival packet rate, which in turn is closely related to the competing nodes of the network. Another remark, is that using control mechanisms for accessing the communication channel, has also a negative impact to the overall network performance.…”

Collision-Free Transmissions in an IoT Monitoring Application Based on LoRaWAN

“…In addition, the metric evaluated was the network throughput, whereas in IoT monitoring applications, metrics such as PDR, latency and energy consumption are more relevant. In [ 34 ], the authors show by simulation that to ensure a PDR with a transmission opportunity of corresponding for instance to the transmission of a message of 20 bytes with SF = 11, pure Aloha requires a number of EDs , wheras CSMA/CA allows up to 500 EDs. The reason is that CSMA/CA senses the medium before transmitting and differs the transmission if the medium is busy.…”

CCA Threshold Impact on the MAC Layer Performance in IoT Networks

“…Moreover, they show that using a non-persistent CSMA approach results in an energy consumption close to the one obtained by Aloha. In our previous work [13], we also looked at the impact of CSMA/CA in dedicated IoT networks, showing a significant increase in terms of packet reception ratio in dense networks, at a price of a much higher energy consumption (unlike [6], we tested a persistent CSMA approach, which consumes much more energy). However, [7] only considers a lightly loaded network, while [6] and [13] consider that the nodes have a very large carrier sense range, equivalent to the one of the IoT base station, an assumption we challenge in this work.…”