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Modern data center storage systems are invariably networked to allow for consolidation and flexible management of storage. They also include high-performance storage devices based on flash or other emerging technologies, generally accessed through low-latency and high-throughput protocols such as Non-volatile Memory Express (NVMe) (or its derivatives) carried over the network. With the increasing complexity and data-centric nature of the applications, properly configuring the quality of service (QoS) for the storage path has become crucial for ensuring the desired application performance. Such QoS is substantially influenced by the QoS in the network path, in the access protocol, and in the storage device. In this article, we define a new transport-level QoS mechanism for the network segment and demonstrate how it can augment and coordinate with the access-level QoS mechanism defined for NVMe, and a similar QoS mechanism configured in the device. We show that the transport QoS mechanism not only provides the desired QoS to different classes of storage accesses but is also able to protect the access to the shared persistent memory devices located along with the storage but requiring much lower latency than storage. We demonstrate that a proper coordinated configuration of the three QoS’s on the path is crucial to achieve the desired differentiation, depending on where the bottlenecks appear. 

The tremendous potentials of sensing and communication technologies have been explored and implemented for different remote event monitoring applications over the last two decades. However, the applicability of sensing and communication technologies are not necessarily limited to above-ground environments, but also implementable and applicable for subterranean, underground scenarios. However, as opposed to air medium, underground communication medium is very harsh due to the presence of heterogeneous underground materials along with underground aqueous components. In this paper, we provide a technical overview of different underground wireless communication technologies, namely radio, acoustic, magnetic and visible light, along with their potentials and challenges for several underground applications. We also lay out a detailed comparison among these technologies along with their pros and cons using detailed experimental results. 

Sensing and communication technology has been used successfully in various event monitoring applications over the last two decades, especially in places where long-term manual monitoring is infeasible. However, the major applicability of this technology was mostly limited to terrestrial environments. On the other hand, underwater wireless sensor networks (UWSNs) opens a new space for the remote monitoring of underwater species and faunas, along with communicating with underwater vehicles, submarines, and so on. However, as opposed to terrestrial radio communication, underwater environment brings new challenges for reliable communication due to the high conductivity of the aqueous medium which leads to major signal absorption. In this paper, we provide a detailed technical overview of different underwater communication technologies, namely acoustic, magnetic, and visual light, along with their potentials and challenges in submarine environments. Detailed comparison among these technologies have also been laid out along with their pros and cons using real experimental results. 

Biomedical systems of implanted miniaturized sensors and actuators interconnected into an intra-body area net-work could revolutionize treatment options for chronic diseases afflicting internal organs. Considering the well-understood limitations of radio frequency (RF) propagation in the human body, we have explored magnetic resonance (MR) coupling for both communications and energy transfer through the body. In this paper, we have discussed the design and implementation of a software-defined prototype using Universal Software Radio Peripheral (USRP) boards. We have reported experimental results on the achieved packet error rates at different positions through-the-body distances and packet sizes. We have observed experimentally that the MR signal propagates through the body substantially better than in the air, and can provide a practical means for energy transfer and communications in intra-body networks. It also works better than the better understood galvanic coupling. 

Effective management of emerging medical devices can lead to new insights in healthcare. Thus, a human body communication (HBC) is becoming increasingly important. In this paper, we present magnetic resonance (MR) coupling as a promising method for intra-body network (IBNet). The study reveals that MR coupling can effectively send or receive signals in biological tissue, with a maximum path loss of PL 33 dB (i.e. at 13.56 MHz), which is lower than other methods (e.g., galvanic, capacitive, or RF) for the same distance. The angular orientation of the transmitter and receiver coils at short and long distances also show a minor variation of the path loss (0.19 PL 0.62 dB), but more dependency on the distance (0.0547 dB/cm). Additionally, different postures during the MR coupling essentially do not affect path loss (PL 0.21 dB). In the multi-nodal transmission scenario, the MR coupling demonstrates that two nodes can simultaneously receive signals with -16.77 dBm loss at 60 cm and 100 cm distances, respectively. Such multi-node MR transmission can be utilized for communication, sensing, and powering wearable and implantable devices.