Wireless transmission of data in industrial applications has been around for a long time but recently it has gained importance, with attention from both market leaders and medium- and small-sized competitors. Successful use of wireless sensors in systems such as supervisory control and data acquisition (SCADA) proved that these devices could effectively address the needs of industrial applications. The attempt in most critical process applications is to wirelessly communicate and monitor temperature, flow, level, and pressure parameters.
Although wireless sensing products for industrial applications now exist, the market is fragmented (Figure 1), consisting of a number of participants and a variety of applications. The adoption process has also been slow, as many challenges still need to be overcome despite the benefits offered.
Industrial applications offer a broad scope for growth in wireless sensor use, but this growth cannot be achieved without overcoming some of the key challenges facing the market:
- Multivendor equipment interoperability
- Demand for industrial-safety-rated wireless devices
- Lack of adequate open bandwidth
- Deployable network size and hopping challenge
- Constantly evolving standards
Interoperability is a major challenge for market participants. This is further exacerbated by the embedding of proprietary communication protocols and support software. Wireless communication technology is successful only if the equipment of different vendors can communicate. This multivendor interoperability environment is expected to be a long-term challenge - from a design standpoint - for both sensor and test vendors. In the future, we expect widespread use of different functions packaged together in a single control box and large-scale development of interoperable devices for industrial systems. Also, equipment must have plug-and-play options for ease of use as well as to improve market acceptance.
In terms of the development of industrial-safety-rated devices, vendors' ability to make a wireless sensor system fail-safe depends heavily on the type of application in which the wireless sensor is used. As such, understanding the application helps vendors to provide appropriate fail-safe measures that can be embedded into wireless systems.
Licensed bandwidths are a subject of disagreement in the market. Market leaders and large companies feel that the use of unlicensed bands interferes with the licensed ones and therefore should be completely eliminated. Tier-two and tier-three market participants feel that even though there are benefits to wireless sensor networks operating in licensed frequency bands, certain challenges remain to be solved. Presently most wireless sensor network devices operate in unlicensed bands such as 915 MHz and 2.4 GHz, and reliable communication can be affected by interference from other devices operating in the same frequency band. However, the majority of the market participants feel that the use of unlicensed bands is likely to bring in larger benefits accompanied by unrestricted growth as well as to provide equal opportunity to market participants operating on the same platform. There are various initiatives taken up by companies to promote open bandwidths.