## 1 Introduction
In addition to real-time communication, reliability is also an essential requirement for communication in harsh industrial environments in the presence of interference. The links quality between a source and destination node can heavily influence the success of the delivery of sensor data to the destination when the application needs it. Several mechanisms exist to increase link reliability. A survey is given in [7]. One of the mechanisms used to improve link quality, by trying to eliminate or minimize interference, is channel hopping. It is a diversity technique that can help prevent external interference and multipath fading [8]. Channel hopping technique is used in several industrial 802.15.4-based [9] standards such as WirelessHART, ISA100.11a and IEEE 802.15.4e (Time Slotted Channel Hopping (TSCH) mode [10]). IEEE 802.15.4e is a MAC amendment of the existing standard 802.15.4-2006 designed for low power and low bandwidth reliable communication in industrial environments. Existing industrial wireless technologies such as WirelessHART and ISA100.11a use a centralized network management approach. While a centralized approach can generate optimal results for static networks, it has several drawbacks. Firstly, the network manager is prone to a single point of failure. In case of failure or network partitioning, nodes that do not have access to the network manager are left without management functionality. Secondly, the centralized approach incurs a high communication overhead and latency for exchanging management traffic. Lastly, they cannot cope with network dynamicity in a timely manner. These problems are exacerbated as the network scales up. We show in this paper that these problems are significant and we demonstrate how they can be solved. This paper presents a Distributed Management Scheme for Real-time applications (D-MSR) that is built for wireless industrial automation. Using a distributed approach, D-MSR could address the issues of high throughput and reliable communication as well as real-time requirements, while achieving higher efficiency in network management in terms of delay and overhead. Issues such as node joining, reserving communication resources for exchanging management messages, constructing end-to-end connections between sensors and gateway/actuators for addressing real-time requirements, handling of network dynamicity such as node or edge (in this paper \"edge\" means a node-to-node connection in the network layer) failures, and data delivery in case of lossy networks, are all addressed by D-MSR. According to our knowledge, this is the first distributed management scheme based on the IEEE 802.15.4e standard (TSCH), which supports the whole protocol stack and manages the nodes in different phases, from joining to publishing the sensor/process data in the network. Related work mainly focused on the data link layer that provides data delivery service in a timely and reliable manner in multi-hop wireless networks, which are discussed in Section 3.2.2. To address all the listed issues, we define different mechanisms and modifications in different OSI layers. In the data link layer, we define a two-hop neighborhood schedule-matrix that is used to construct a communication schedule between different pairs of network devices (the terms \"network device\" and \"node\" refer to a field device, such as a sensor and actuator, as well as router that improve network connectivity) in a distributed manner. In addition, two modules are defined in the upper data link layer: _neighbor connection manager_ and D-SAR. The _neighbor connection manager_ definesinitial communication links between each node and its neighbors. Therefore, the upper layers can use these primary links to communicate with a particular neighbor.