Biblio

In order to solve the problem of high data collision probability, high access delay and high-power consumption in random access process of power Internet of Things, an access scheme for large-scale micro-power wireless sensors based on slot-scheduling and hybrid mode is presented. This scheme divides time into different slots and designs a slot-scheduling algorithm according to network workload and power consumption. Sensors with different service priorities are arranged in different time slots for competitive access, using appropriate random-access mechanism. And rationally arrange the number of time slots and competing end-devices in different time slots. This scheme is able to meet the timeliness requirements of different services and reduce the overall network power consumption when dealing with random access scenarios of large-scale micro-power wireless sensor network. Based on the simulation results of actual scenarios, this access scheme can effectively reduce the overall power consumption of the network, and the high priority services can meet the timeliness requirements on the premise of lower power consumption, while the low priority services can further reduce power consumption.

The number of sensors and embedded devices in an urban area can be on the order of thousands. New low-power wide area (LPWA) wireless network technologies have been proposed to support this large number of asynchronous, low-bandwidth devices. Among them, the Cooperative UltraNarrowband (C-UNB) is a clean-slate cellular network technology to connect these devices to a remote site or data collection server. C-UNB employs small bandwidth channels, and a lightweight random access protocol. In this paper, a new application is investigated - the use of C-UNB wireless networks to support the Advanced Metering Infrastructure (AMI), in order to facilitate the communication between smart meters and utilities. To this end, we adapted a mathematical model for C-UNB, and implemented a network simulation module in NS-3 to represent C-UNB's physical and medium access control layer. For the application layer, we implemented the DLMS-COSEM protocol, or Device Language Message Specification - Companion Specification for Energy Metering. Details of the simulation module are presented and we conclude that it supports the results of the mathematical model.

We propose secure RAID, i.e., low-complexity schemes to store information in a distributed manner that is resilient to node failures and resistant to node eavesdropping. We generalize the concept of systematic encoding to secure RAID and show that systematic schemes have significant advantages in the efficiencies of encoding, decoding and random access. For the practical high rate regime, we construct three XOR-based systematic secure RAID schemes with optimal encoding and decoding complexities, from the EVENODD codes and B codes, which are array codes widely used in the RAID architecture. These schemes optimally tolerate two node failures and two eavesdropping nodes. For more general parameters, we construct efficient systematic secure RAID schemes from Reed-Solomon codes. Our results suggest that building “keyless”, information-theoretic security into the RAID architecture is practical.