On the Impact of QoS Management in an Information-centric Internet of Things

The Internet of Things (IoT) comprises a relevant class of applications that require Quality of Service (QoS) assurances. Information Centric Networking (ICN) has shown promising characteristics in constrained wireless networks, but differentiated QoS has not yet fully emerged. In this paper, we design and analyze a QoS scheme that manages the NDN resources forwarding and queuing priorities, as well as the utilization of caches and of forwarding state space. In constrained wireless networks, these resources are scarce with a potentially high impact due to lossy radio transmission. We explore the two basic service qualities (i) prompt and (ii) reliable traffic forwarding. We treat QoS resources not only in isolation, but correlate their use on local nodes and between network members. Network-wide coordination is based on simple QoS code points that can be distributed via a routing protocol. Fairness measures that prevent resource starvation are part of this management scheme. Our findings indicate that our coordinated QoS management in ICN does not only effectively prioritize the privileged data chunks, but also improves regular data communication. We can show that appropriate QoS coordination can enhance the overall network performance by more than the sum of its parts and that it exceeds the impact QoS can have in the IP world

Quality of Service for ICN in the IoT

This document describes manageable resources in ICN IoT deployments and a lightweight traffic classification method for mapping priorities to resources. Management methods are further derived for controlling latency and reliability of traffic flows in constrained environments

Nonvolatile nuclear spin memory enables sensorunlimited nanoscale spectroscopy of small spin clusters

In nanoscale metrology, dissipation of the sensor limits its performance. Strong dissipation　has a negative impact on sensitivity, and sensor–target interaction even causes relaxation or　dephasing of the latter. The weak dissipation of nitrogen-vacancy (NV) sensors in room　temperature diamond enables detection of individual target nuclear spins, yet limits the　spectral resolution of nuclear magnetic resonance (NMR) spectroscopy to several hundred　Hertz, which typically prevents molecular recognition. Here, we use the NV intrinsic nuclear　spin as a nonvolatile classical memory to store NMR information, while suppressing sensor　back-action on the target using controlled decoupling of sensor, memory, and target. We　demonstrate memory lifetimes up to 4 min and apply measurement and decoupling protocols,　which exploit such memories efficiently. Our universal NV-based sensor device records　single-spin NMR spectra with 13 Hz resolution at room temperature

Protecting a Diamond Quantum Memory by Charge State Control

In recent years, solid-state spin systems have emerged as promising candidates for quantum information processing. Prominent examples are the nitrogen-vacancy (NV) center in diamond, phosphorus dopants in silicon (Si:P), rare-earth ions in solids, and VSi-centers in silicon-carbide. The Si:P system has demonstrated that its nuclear spins can yield exceedingly long spin coherence times by eliminating the electron spin of the dopant. For NV centers, however, a proper charge state for storage of nuclear spin qubit coherence has not been identified yet. Here, we identify and characterize the positively charged NV center as an electron-spin-less and optically inactive state by utilizing the nuclear spin qubit as a probe. We control the electronic charge and spin utilizing nanometer scale gate electrodes. We achieve a lengthening of the nuclear spin coherence times by a factor of 4. Surprisingly, the new charge state allows switching of the optical response of single nodes facilitating full individual addressability