To achieve ultra-low energy consumption and decade-long battery lifetime for Internet of things (IoT) networks, wake-up radio (WuR) appears as an eminent solution. While keeping devices in deep sleep for most of the time, a WuR enabled IoT device can be woken up for data transmission at any time by a wake-up call (WuC). However, collisions happen among WuCs for transmitter-initiated data reporting and among data packets for receiver-initiated data collection. In this paper, we propose two novel hashing-based schemes in order to achieve collision-free data transmissions for receiver-initiated data collection. We consider first a simple scenario in which all devices in a region of interest are covered by a data collector and propose a scheme which facilitates a scheduled time for data uploading of each device. Then we extend our scheme to cover a more realistic scenario where IoT devices are distributed across a larger region that cannot be covered by a single data collector. In this case, we propose a partitioning algorithm for data collection across multiple partitions. Both analysis and simulations are performed to demonstrate the effectiveness of the proposed schemes.

Equivalence of multistage interconnection networks is an important concept because it reduces the number of networks to be studied. Equivalence among the banyan networks has been well studied. Occasionally, the study was extended to networks obtained by concatenating two banyan networks (identifying the output stage of the preceding network with the input stage of the succeeding one). Recently, equivalence among the class of networks that are obtained from banyan networks by adding extra stages has also been studied. Note that all these above-mentioned networks are in the general class of buddy networks. In this article we study equivalence of buddy networks with an arbitrary number of stages. © 2005 Wiley Periodicals, Inc. NETWORKS, Vol. 46(4), 171–176 2005

The goal of the fault diagnosis agreement (FDA) problem is to make each fault-free processor detect/locate a common set of faulty processors. The problem is examined on processors with mixed fault model (also referred to as hybrid fault model). An evidence-based fault diagnosis protocol is proposed to solve the FDA problem. The proposed protocol first collects the messages which have accumulated in the Byzantine agreement protocol as the evidence. By examining the collected evidence, a fault-free processor can detect/locate which processor is faulty. Then, the network can be reconfigured by removing the detected faulty processors and the links connected to these processors from the network. The proposed protocol can detect/locate the maximum number of faulty processors to solve the FDA problem.