In order to handle the huge amounts of data transmitted through hot spots and to increase cell coverage in buildings, this paper proposes a sectored cellular network with small cells (SCNSC) embedded in each sector. T...In order to handle the huge amounts of data transmitted through hot spots and to increase cell coverage in buildings, this paper proposes a sectored cellular network with small cells (SCNSC) embedded in each sector. Two region types, sectors and variable-radius small cells are classified in an SCNSC macro cell. Because the system capacity is enhanced by using fractional frequency reuse (FFR), the overall channel bandwidth is divided into two or three frequency bands depending on whether the number of sectors in a macro cell is even or odd. For the purpose of topological evaluation on the proposed SCNSC, we build an analytical model using Markov chain theory. The performance measures include new-call blocking and handoff-call dropping probabilities, average waiting times, and normalized throughputs in each sector and its embedded small cell by varying mobile stations’ moving speeds, the number of sectors, and the radius size of an embedded small cell. From the evaluation results, it is demonstrated that adjusting either the number of sectors or the coverage of an embedded cell can satisfy different service demands.展开更多
VHD(Virtual Hard Disk)文件格式是一种重要的虚拟硬盘格式。通过对VHD文件格式的详细分析,论述了虚拟硬盘和VHD文件地址之间的映射关系,以及怎样在宿主文件系统上向不同类型的VHD文件中存储数据。并通过了解VHD的新版本VHDX,明了新版...VHD(Virtual Hard Disk)文件格式是一种重要的虚拟硬盘格式。通过对VHD文件格式的详细分析,论述了虚拟硬盘和VHD文件地址之间的映射关系,以及怎样在宿主文件系统上向不同类型的VHD文件中存储数据。并通过了解VHD的新版本VHDX,明了新版本通过在结构上的改进,提高了性能指标。最后,对VHD、VHDX文件格式在虚拟化应用的前景做出展望。展开更多
文摘In order to handle the huge amounts of data transmitted through hot spots and to increase cell coverage in buildings, this paper proposes a sectored cellular network with small cells (SCNSC) embedded in each sector. Two region types, sectors and variable-radius small cells are classified in an SCNSC macro cell. Because the system capacity is enhanced by using fractional frequency reuse (FFR), the overall channel bandwidth is divided into two or three frequency bands depending on whether the number of sectors in a macro cell is even or odd. For the purpose of topological evaluation on the proposed SCNSC, we build an analytical model using Markov chain theory. The performance measures include new-call blocking and handoff-call dropping probabilities, average waiting times, and normalized throughputs in each sector and its embedded small cell by varying mobile stations’ moving speeds, the number of sectors, and the radius size of an embedded small cell. From the evaluation results, it is demonstrated that adjusting either the number of sectors or the coverage of an embedded cell can satisfy different service demands.
文摘NAND Flash具有存取速度快、体积小、成本低的特点,适宜作为海量数据的存储设备.本文设计了一种大容量NAND FLASH在WinCE系统上的实现方案.通过动态扇区分配、坏块管理和数据缓存等技术,提高了Flash驱动的安全性、稳定性和读写性能.经过优化后,平均读取速度2Mbyte/s,写入速度3Mbyte1/s.整个驱动通过了微软测试工具CETK(WinCE Test kit)的测试.
文摘VHD(Virtual Hard Disk)文件格式是一种重要的虚拟硬盘格式。通过对VHD文件格式的详细分析,论述了虚拟硬盘和VHD文件地址之间的映射关系,以及怎样在宿主文件系统上向不同类型的VHD文件中存储数据。并通过了解VHD的新版本VHDX,明了新版本通过在结构上的改进,提高了性能指标。最后,对VHD、VHDX文件格式在虚拟化应用的前景做出展望。
