Issue link: https://resources.mouser.com/i/1442787
A key attraction of connected devices in manufacturing includes the potential for yield improvements. To achieve this, it is often necessary to gain remote control of various devices in the production chain to implement adjustments. An example is a control valve for a boiler operating in a chemical production process. Immediate, autonomous control of this valve can make real-time adjustments, based on feedback from other stages in the process, leading to more optimized overall efficiency. Smart Healthcare: Vital Signs Monitoring Hospitals and care centers are looking to wireless connectivity to monitor patient vital signs. Clunky wired solutions can be replaced with wireless sensor patches connected through a local gateway. Such systems enable more effective patient monitoring while reducing the burden on healthcare staff. Smart City: Event Sensing for Emergency Response With advanced image and acoustic sensing and processing methods, systems mounted in public spaces, such as on lamp posts, can detect events such as vehicle accidents and criminal activity with a high degree of confidence. This information can be relayed via wireless communications to the appropriate agency or unit, along with the location information to enable faster emergency response. Key Challenges in Building Reliable Wireless Connectivity in Complex Environments RF Obstacles Cause Missed Packets Each of the examples previously mentioned are subject to distinct environmental challenges that can negatively impact wireless communication. The steel construction and thick walls of factories create large obstacles that can degrade the power of an RF signal to the point where it cannot be received by the target device. The receiver sensitivity of the radio used in the target device will determine how much signal degradation can be tolerated. As little as 2dB change in sensitivity could be the difference between the successful or unsuccessful reception of a signal. Communication system designers must pay close attention to receiver sensitivity when selecting a radio. Crowded Frequency Bands Cause Missed Packets Connected devices will typically operate in the relevant ISM (Industrial, Scientific, and Medical) band for that region. ISM bands are license free and can be used for a wide range of applications requiring wireless connectivity. 2.4GHz is standardized globally and is widely used by Wi-Fi and Bluetooth devices. There is also ISM spectrum available in sub-1GHz bands. These bands are commonly used for IoT applications. The band is centered at 868MHz in Europe and 915MHz in the U.S.A. challenge arises when multiple devices located in close proximity are sharing the same ISM band. Transmitting devices can interfere with nearby receiving devices, such as in public hospitals, where there are a wide variety of machines sharing the same ISM band. The ability of a radio to operate in the presence of such interferers is measured by the blocking specification. The challenge extends beyond devices operating within the ISM band. Without sufficient blocking capability, mobile phones or tablets operating nearby could cause a loss of communication in the system. In military and aerospace applications, very costly components are used to mitigate the effect of interferers. Radios being used for mission critical data, such as the applications previously mentioned, must achieve similar performance to military and aerospace without incurring the high cost of additional external components. Such radios will continue to receive messages with multiple interferers operating nearby. Environmental Effects Degrade Performance Radio transceivers are built on processes that are prone to variations in performance, depending on the environment in which they're operating. Some variations include temperature changes, voltage supply reductions as batteries discharge, and silicon manufacturing variations across devices. These real life events can cause changes in the operating stability of the device. Let's look at an event sensing emergency response system operating on a street light. Cold winter temperatures could cause the output power of a device to vary or the receiver sensitivity to degrade. This can cause loss of communication 22 IoT