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In this paper we address the issues of timeliness and transmission reliability of existing industrial communication standards. We combine a Forward Error Correction coding schemeon the Medium Access Control layer with a lightweight routing protocol to form an IEEE 802.15.4-conformable solution, whichcan be implemented into already existing hardware without violating the standard. After laying the theoretical foundations,we conduct a performance evaluation of the proposed solution.The results show a substantial gain in reliability and reducedlatency, compared to the uncoded transmissions, as well ascommon Wireless Sensor Network routing protocols.

In this work we propose an Adaptive Forward Error Correction (AFEC) algorithm for best effort Wireless Sensor Networks. The switching model is described in terms of a finite-state Markov model and it is based on the channel behavior,observed via Packet Delivery Ratio in the recent past. We compare the performance of AFEC with static FEC, as well as uncoded transmissions. The results demonstrate a gain in PDR achieved by introducing FEC coding in uncoded IEEE 802.15.4 transmissions, as well as the advantages over static FEC schemes,namely increased throughput and reduced energy consumption.The proposed solution is IEEE 802.15.4-compliant and requires no additional feedback channels.

Noise and interference make a substantial impacton wireless transmissions in industrial environments, resulting infrequent erroneous packet deliveries. Existing industrial communication standards adopt the IEEE 802.15.4 specification, which provides no means to correct the detected errors. We propose an IEEE 802.15.4-compliant Forward Error Correction-basedapproach that can be easily retrofitted into the standard withoutthe need for any kind of interaction with chip manufacturers orstandardization bodies. We evaluate the approach on link- and network-level scenarios. Improvement of reliability by using FEC can yield multiple benefits: a reduced number of retransmissions,and lower average latency, to name a few. With respect to the uncoded system, the proposed solution provides identical codinggain as the traditional FEC method, at a significantly lower computational load of decoding.

High reliability and real-time performance are main research challenges in Industrial Wireless Sensor Networks (IWSNs). Existing routing protocols applied in IWSNs are either overcomplicated or fail to fulfill the stringent requirements. In this paper, we propose a reliable and flexible Received Signal Strength-based routing scheme. Our proposed solution can achieve a seamless transition in the event of topology change and can be applied in different industrial environments. The simulation results show that our solution outperforms conventional routing protocols in both reliability and latency. Furthermore, the result also proves that the changes of the network topology have no impact on data transmissions of other nodes by our scheme, whereas conventional routing protocols are shown to fail to recover the network in a short time. Finally, due to dynamic weighting mechanism, the proposed scheme is verified to achieve significantly higher reliability in scenarios with obstacles and avoid installation troubles, compared to location-based flooding scheme. Thus, our proposed scheme is considered to be more suitable for IWSNs than other routing protocols.

The major advantages with Industrial Wireless Sensor Networks (IWSNs) in process automation are cable cost reduction, enhanced flexibility and enabling new emerging applications such as wireless control. However, transmission over the wireless channel is prone to noise and interference which causes packets to be erroneous received at the receiver node. To improve the link reliability in lossy channels, error correcting codes are commonly used. In this paper we discuss the use of forward error correction (FEC) codes in IWSN in order not only to improve the link reliability but also to reduce the number of retransmissions in harsh industrial environments. We propose a FEC scheme suitable for MAC level protection where the packet is divided into groups and encoded using systematic FEC codes. We have implemented different FEC codes in a typical IWSN chip to evaluate memory consumption and to ensure that we are not violating the strict timing rules for acknowledgment. Our results show that some FEC codes are suitable to be implemented in a typical IWSN node while several fails due to large memory footprint or to long encoding and decoding time.