作为物联网关键技术之一的机器通信(Machine Type Communications,MTC)中包含了大量的MTC设备,如果这些大规模MTC设备直接接入到现有的无线接入网络,将会导致接入效率低、功率消耗大和丢包等问题。针对以上问题,提出了一种基于定时提前(...作为物联网关键技术之一的机器通信(Machine Type Communications,MTC)中包含了大量的MTC设备,如果这些大规模MTC设备直接接入到现有的无线接入网络,将会导致接入效率低、功率消耗大和丢包等问题。针对以上问题,提出了一种基于定时提前(Timing Advance,TA)值比较的改进型机器通信设备随机接入机制。这种机制在基于TA值比较的基础上,以"最大接入效率"为目标,根据接入设备数量的变化,动态地对前导资源进行分配和运用接入类别限制机制对接入设备数量进行控制,可以减少大规模接入时的冲突概率,并且能够保持相对较高的随机接入效率。展开更多
Nonvolatile memory devices based on filamentary resistance switching （KS） are among the frontrunners to fuel future devices and sensors of the internet of things （IoT） era. The capability of many two distinctive r...Nonvolatile memory devices based on filamentary resistance switching （KS） are among the frontrunners to fuel future devices and sensors of the internet of things （IoT） era. The capability of many two distinctive resistive states in response to an external electrical stimulus has been demonstrated. Through years of selection, cells based on the drift of metal ions, namely conductive-bridge memory devices, have shown a wide range of applications with nanosecond switching speeds, nanometer scalability, high-density, and low power-consumption. However, for low （sub-10-~A） current operation, a critical challenge is still represented by programming variability and by the stability of the conductive filament over time. Here, by introducing the concept of reverse filament growth （RFG）, we managed to control the structural reconfiguration of the conductive filament inside a memory cell with significant enhancements of each of the aforementioned properties. A first-in-class Cu-based switching device is demonstrated, with a dedicated stack that enabled us to systematically trigger RFG, thus tuning the device＇s properties. Along with nanosecond switching speeds, we achieved an endurance of up to 106 cycles with a 102 read window, with outstanding disturb immunity and optimal stability of the filament over time. Furthermore, by tuning the filament＇s shape, an excellent control of multi-level bit operations was achieved. Thus, this device offers high flexibility in memory applications.展开更多
文摘作为物联网关键技术之一的机器通信(Machine Type Communications,MTC)中包含了大量的MTC设备,如果这些大规模MTC设备直接接入到现有的无线接入网络,将会导致接入效率低、功率消耗大和丢包等问题。针对以上问题,提出了一种基于定时提前(Timing Advance,TA)值比较的改进型机器通信设备随机接入机制。这种机制在基于TA值比较的基础上,以"最大接入效率"为目标,根据接入设备数量的变化,动态地对前导资源进行分配和运用接入类别限制机制对接入设备数量进行控制,可以减少大规模接入时的冲突概率,并且能够保持相对较高的随机接入效率。
文摘Nonvolatile memory devices based on filamentary resistance switching （KS） are among the frontrunners to fuel future devices and sensors of the internet of things （IoT） era. The capability of many two distinctive resistive states in response to an external electrical stimulus has been demonstrated. Through years of selection, cells based on the drift of metal ions, namely conductive-bridge memory devices, have shown a wide range of applications with nanosecond switching speeds, nanometer scalability, high-density, and low power-consumption. However, for low （sub-10-~A） current operation, a critical challenge is still represented by programming variability and by the stability of the conductive filament over time. Here, by introducing the concept of reverse filament growth （RFG）, we managed to control the structural reconfiguration of the conductive filament inside a memory cell with significant enhancements of each of the aforementioned properties. A first-in-class Cu-based switching device is demonstrated, with a dedicated stack that enabled us to systematically trigger RFG, thus tuning the device＇s properties. Along with nanosecond switching speeds, we achieved an endurance of up to 106 cycles with a 102 read window, with outstanding disturb immunity and optimal stability of the filament over time. Furthermore, by tuning the filament＇s shape, an excellent control of multi-level bit operations was achieved. Thus, this device offers high flexibility in memory applications.
