Wireless sensor device hardware architecture — Design and analysis for high availability

Wireless sensor node or end device or mote is an entity which gathers information from the sensors and communicates to a remote location through set of routers and gateway. The reliability, availability, periodic verification of its healthiness etc. are paramount important for enhancing the usability of WSN system for practical applications. The above can be fulfilled, by adopting various hardware and software design techniques, considerations and options which enable reliable and verifiable hardware/software. This work exclusively discusses hardware design and analysis for high availability of a mote. The various design aspects and considerations such as, dual RF, wakeup radios, redundant reliable power sources and efficient energy/power management, health check of power sources, dynamic voltage and frequency scaling, remote programming of end device, remote reset of end device, system level ESD protection, RF shielding, external watch dog timer and real-time clock etc. have been discussed and analyzed. The uniqueness of our design is reliable redundant power sources and management and on-board dual RF transceivers. The testing and characterization, RF performance results of the fabricated device including EMI/EMC tests have also been presented.