Det-WiFi: A Multihop TDMA MAC Implementation for Industrial Deterministic Applications Based on Commodity 802.11 Hardware

Abstract

Wireless control system for industrial automation has been gaining increasing popularity in recent years thanks to their ease of deployment and the low cost of their components. However, traditional low sample rate industrial wireless sensor networks cannot support high-speed application, while high-speed IEEE 802.11 networks are not designed for real-time application and not able to provide deterministic feature. Thus, in this paper, we propose Det-WiFi, a real-time TDMA MAC implementation for high-speed multihop industrial application. It is able to support high-speed applications and provide deterministic network features since it combines the advantages of high-speed IEEE802.11 physical layer and a software Time Division Multiple Access (TDMA) based MAC layer. We implement Det-WiFi on commercial off-the-shelf hardware and compare the deterministic performance between 802.11s and Det-WiFi under the real industrial environment, which is full of field devices and industrial equipment. We changed the hop number and the packet payload size in each experiment, and all of the results show that Det-WiFi has better deterministic performance.

Elastic QoS Scheduling with Step-by-Step Propagation in IEEE 802.11e Networks with Multimedia Traffic

“…In particular, a QSTA, named VoIP, sends VoIP traffic encoded with G.729A codec whose Traffic Specification (TSPEC) parameters are summarized in Table 3. A QSTA, named VC, and five QSTAs named VS [1][2][3][4][5] transmit preencoded high quality MPEG4 trace files of 60 minutes each, taken from the Video Trace Library for Network Performance Evaluation [42]. These video traces are often used in literature and they are useful for performance comparison.…”

“…Moreover, some particular domains, e.g., industrial networks [3] or telerehabilitation, telemedicine, and virtual training [4], require a particular attention in providing and ensuring the required service, showing strict service expectation about delay, packets drop, and real-time guarantees.…”

“…This implies that, despite the evolution of physical layer, where the improvement of offered service is obtained making the bandwidth and frequency assignment more efficient optimizing the spectrum assignment (see, for instance, IEEE802.11ax), in the last years a new attention is 2 Wireless Communications and Mobile Computing rising also at the Medium Access Control (MAC) level; see [3,[10][11][12][13][14].…”

“…Thus, in such particular critical domains, physical improvements require to be supported also by MAC-level tools suitable to improve the provided QoS making the system more deterministic [3]. Furthermore, these improvements are useful also in the case of dense networks, where the high number of users jeopardizes the provided QoS and only physical solutions are not sufficient.…”

High-Performance Industrial Wireless: Achieving Reliable and Deterministic Connectivity over IEEE 802.11 WLANs

“…• We design HAR 2 D-Fi for industrial control applications. HAR 2 D-Fi design (Sections III) [15] and Det-WiFi [16]. The Industrial WLAN (IWLAN) [17], which is a proprietary technology, addresses the issues of deterministic and reliable performance through PCF at the MAC layer and seamless redundancy using PRP, respectively.…”