Technology
globally and extensively used by Wi-Fi and Bluetooth devices . ISM |
hacking . |
spectrum is also available in sub-1-GHz bands — a common destination for IoT applications . The sub-1-GHz band is centered at 868 MHz in Europe and 915 MHz in the U . S . |
Regardless of the mechanism , it is imperative that microcontrollers are equipped with the necessary integrity features to identify when a device has been corrupted . Once |
A challenge arises when multiple devices located in close |
identified , the microcontroller can either correct the error or shut |
proximity share the same ISM band . Transmitting devices can |
the device down , ensuring that the security of the wider system is |
interfere with nearby receiving devices , such as in public hospitals |
not breached . |
that have multiple machines within the same ISM band . A radio ’ s |
ability to function properly in the presence of such interferers is |
measured by the blocking specification . |
However , 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 incorporated to mitigate the effect of interferers . Radios being used for mission-critical data , such as the applications 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 prone to performance variations that depend on their surrounding environment . Such 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 device ’ s operating stability .
device . System designers must ensure that the components selected for the sensing and communication system are robust over changing environmental conditions .
Corrupted Memory Can Lead to Unexpected Outcomes
Designing for Reliability
Analog Devices ’ ADF7030-1 radio transceiver and ADuCM3029 Cortex-M3 microcontroller both help overcome the aforementioned challenges . They target performance levels and functionality features that lead to more robust communication links .
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 , resulting in a loss of communication . While less of a concern for a consumer device — which is rarely used in such extreme conditions — it would be unacceptable for an emergency- response system . At best , the cost is reputational damage to the end product , ending up in a service call to replace the faulty
In many cases , the ADF7030-1 will be able to receive radio signals that are 3 dB lower than other similar radios . And with blocking numbers in excess of 100 dB , the ADF7030-1 can achieve a level of interference resilience comparable to military and aerospace equipment — without the need for additional costly external components . This ultimately lowers overall cost while ensuring communication is maintained in the noisiest RF environments .
Through generations of collaboration with leading industrial manufacturers , Analog Devices has developed methods for coping with real-life environmental effects on radio transceivers . As an example , the output power transmitted by a device using the ADF7030-1 varies by less than 0.2 dB over the full operating temperature range . Competing radios , on the other hand , often vary by up to 2 dB .
The ADuCM3029 is designed with flash and error-correction-code ( ECC ) parity checks to ensure errors caused by memory corruption are identified and corrected where possible . The microcontroller also comes with battery-monitoring capability in sleep mode . This ensures that unexpected drops in voltage are detected , and that the processor is in turn alerted to a possible malicious threat or power-supply malfunction . The end device can then take appropriate action , either by alerting an administrator or entering a safe mode to ensure the wider system is not compromised .
Reliability is also a concern for the communications microcontroller . Although extremely reliable , both flash and non- volatile memory can occasionally become corrupted . This may occur as a result of unintended effects caused by the operating environment , or intentionally through malicious hardware
Technologies developed by Analog Devices inhabit every stage of the IoT signal chain , from sensing and measuring to interpreting and connecting the data . Ensuring the quality and integrity of the information created through this chain is a core design principle , and a fundamental requirement to fulfill the true potential of the IoT .
ELE Times | 26 | March , 2017