## 1 Introduction  
Wireless networks are a current trend, with varied applications, including biomedicine, residential automation, environmental surveillance and video security monitoring [1]. Consequently, industrial environments are also benefiting from such technology. The history of industrial wireless technologies (IWT) recalls the fieldbus war (1986-2002) [2], when several technologies appeared as _de facto_ standards for industrial networks (Modbus [3], Profibus [4], Fieldbus Foundation [5], HART [6], to name just a few). All of these technologies were based on structured cabling, and they had as a goal creating a universal protocol to meet all types of industrial demands [7]. Recently, industrial wireless technologies have attracted great interest, providing an environment with fewer cables, lowering the installation/maintenance costs and providing greater flexibility to the network [8]. However, despite the appearance of wireless technologies, the scenario has not been very different. A variety of wireless technologies coexist, and others are yet to be seen. There are even examples where wireless technology is used as an extension for a traditional wired technology, as reported by [9]. Establishing a conservative scenario, just one wireless solution will hardly be the universal standard for the industry. It is wiser to think that several solutions will coexist, each one having its own advantages and disadvantages and its specific niche applications. The literature contains many comparisons between the wireless technologies. A comparison of ISA100.11a (International Society of Automation 100) with WirelessHART can be seen in [10; 11; 12]. The Chinese standard WIA-PA (Wireless Networks for Industrial Automation-Process Automation) is added to the comparison with WirelessHART and ISA100.11a in [13]. In [14], a user perspective for the use of wireless technology in a power plant scenario is discussed, in order to aid the decision making process when choosing a wireless technology for this kind of environment. Furthermore, [15] presents a successful test where WirelessHART is used as a substitute for Profibus in a closed control loop. Among the aforementioned technologies, WirelessHART is pointed out by [16] as a feasible solution for wireless industrial networks, which will be the focus of the present paper. Industrial wireless sensor networks (IWSN) are commonly planned topologies, having low mobility nodes, and some devices in the network may be powered by batteries. However, the different applications and situations may require the optimization of specific characteristics, such as transmission delay [17; 18], energy consumption [19] and data reliability [20; 21; 22; 23]. The routing and scheduling algorithms used by the network are very important: they determine the routes, channels and the redundancy policy of the network, thus directly affecting the aforementioned network characteristics. Thus, there is a need to adequately combine WirelessHART technology with the proper routing and scheduling algorithms in order to enhance the specific characteristics that each application needs. The present paper aims to analyze the most recent approaches to routing and scheduling issues for WirelessHART and to provide a clear view of the actual scenario, as an aid for researchers and industries on what routing and scheduling schemes would fit their needs. Several surveys have been made for routing in wireless sensor networks (WSN). The surveys presented in [24, 25, 26] do not focus on specific characteristics, providing a broader overview of the present state-of-the-art. As the field of routing schemes is a wide area, there are surveys that deal specifically with protocols that present clearer optimization objectives. The surveys in [27, 28] focus on energy-efficient protocols, especially the latter one, which classifies more than fifty routing schemes. The [29] survey focuses on fault-tolerant protocols, evaluating issues, such as energy consumption, memory use, recovery time and overhead.