A Comprehensive Analysis of the MAC Unreliability Problem in IEEE 802.15.4 Wireless Sensor Networks

Abstract

-Wireless Sensor Networks (WSNs) represent a very promising solution in the field of wireless technologies for industrial applications. However, for a credible deployment of WSNs in an industrial environment, four main properties need to be fulfilled, i.e., energy efficiency, scalability, reliability, and timeliness. In this paper we focus on IEEE 802.15.4 WSNs and show that they can suffer from a serious unreliability problem. This problem arises whenever the power management mechanism is enabled for energy efficiency, and results in a very low packet delivery ratio, also when the number of sensor nodes in the network is very low (e.g., 5). We carried out an extensive analysis -based on both simulation and experiments on a real WSN -to investigate the fundamental reasons of this problem, and we found that it is caused by the contention-based MAC (Medium Access Control) protocol used for channel access and its default parameter values. We also found that, with a more appropriate MAC parameters setting, it is possible to mitigate the problem and achieve a delivery ratio up to 100%, at least in the scenarios considered in this paper. However, this improvement in communication reliability is achieved at the cost of an increased latency, which may not be acceptable for industrial applications with stringent timing requirements. In addition, in some cases this is possible only by choosing MAC parameter values formally not allowed by the standard.

Mutual interference in large populations of co-located IEEE 802.15.4 body sensor networks—A sensitivity analysis

“…The impact of the backoff exponent parameters (in particular macMinBE ) and payload size have been studied in [29,30] for IEEE 802.15.4 and Zigbee. Anastasi et al have investigated the effects of changing parameters like the packet arrival pattern (Poisson or periodic), the CSMA/CA parameters, beacon interval, packet size and different offered loads [31]. The impact of system parameters such as the packet arrival rate, number of stations, and packet size on the medium access probability or the queue length distribution is studied in [32] using Markov chain and queueing models.…”

Reliability and Energy-Efficiency in IEEE 802.15.4/ZigBee Sensor Networks: An Adaptive and Cross-Layer Approach

“…In the context IEEE 802.15.4-based WSNs, many papers [12], [13], [14] highlighted that a significant share of transmitted messages may be lost due to contention, especially when the number of sensor nodes and the message size are large. In addition, [6] and [7] have shown that serious reliability issues arise when power management is enabled, even in networks with a small number of sensor nodes. It is also shown that a suitable setting of the MAC parameters can alleviate the problem, such that it is possible to achieve a target level of reliability, as well as a higher energy efficiency.…”

“…It is also shown that a suitable setting of the MAC parameters can alleviate the problem, such that it is possible to achieve a target level of reliability, as well as a higher energy efficiency. However, [7], [6] are based on static (i.e., pre-defined) settings for the MAC parameters, hence they are not flexible enough to support dynamic operating conditions. In addition, a static parameter setting typically results in an energy consumption higher than necessary.…”

“…Indeed, it has been shown that WSNs based on IEEE 802.15.4/ZigBee suffer from serious unreliability issues, especially when power management is enabled for conserving energy [6], [7]. Therefore, effective and efficient mechanisms should be provided to achieve reliability with a low energy expenditure.…”

Comprehensive Energy Efficient Algorithm for WSN

“…Many communication protocols based on LEACH for WSN have been developed. The main research fields are energy efficiency, wireless link reliability [5], real-time capabilities [6], or quality-of-service. For the reason of sensor nodes just can use battery without power input.…”