A Raspberry Pi Mesh Sensor Network for Portable Perimeter Security Wireless sensor networks play an important role for perimeter monitoring in remote environments. While commercial wireless sensor networks for providing audiovisual monitoring exist, they are often expensive to deploy. In this paper, we describe and implement a wireless mesh network consisting of inexpensive batteryoperated Raspberry Pi nodes. The choice of the Raspberry Pi enables the construction of costeffective sensor nodes that are extendable and expendable. We conduct a series of test to illustrate the efficacy of our network in a building monitoring use case. Our nodes can be built for as little as 49.00 per node and is capable of nodetonode transmission of up to 50 feet. Custom sleep states enable battery life to last 14 hours on 4 AA batteries. Our results support our thesis that an allPi mesh sensor is capable of providing portable perimeter security.

Gathering Data with PacketinPacket in Wireless Sensor Networks Abstract   In many wireless sensor network (WSN) missioncritical applications, a collector, e.g., a drone acting as a data sink, is required to gather data from all the source nodes in the area of interest. It is, thus, an alltoone scenario. Data from each node (e.g., local temperature or its binary status) normally only consists of several bytes. Furthermore, often, data collection is expected to be done as fast as possible, especially for missioncritical applications or applications where a batterypowered sink is used (e.g., a drone). Thus, it is preferred that there is no preparation phase for the network to schedule or establish any routes in advance. Concurrent transmission (CT), a novel communication paradigm, has been shown to effectively achieve reliable and energyefficient flooding in lowpower wireless networks. With multiple nodes exploiting a receiveandforward scheme, this technique requires no routing and works effectively in floodingbased networks, i.e., in onetomany scenarios. Hence, CTbased communication is a good choice for fast data collection. However, a kind of global scheduling is essential for data collection in CTbased WSNs, in order to globally schedule a node that initiates a flooding in the network. In this article, to comply with the requirements of the aforementioned data collection application, we propose PacketinPacket (PiP), an energyefficient paradigm requiring no global scheduling for timely data collection in lowpower WSNs. PiP builds on concurrent transmissions and uses a packet concatenation capability to gather singlehop information in a besteffort manner. PiP does not require any prescheduling of traffic in the network, and thereby significantly reducing collection time. We compare PiP with a number of stateoftheart protocols by extensive experiments in two testbeds, FlockLab and Indriya, respectively. Experimental results show that PiP achieves high reliability and low latency in all the scenarios in the realworld testbeds. Specifically, when the transmission power of nodes is set to 0 dBm, PiP takes only 287 ms (at least 1.8xe2x80xafxc3x97xe2x80xaf faster than the stateoftheart protocols) to complete a 26toone data collection in FlockLab and 965 ms (1.1xe2x80xafxc3x97xe2x80xaf faster than a stateoftheart protocol LWB) to complete a 42toone collection in Indriya, respectively.