Wireless Sensor Networks (WSNs) typically use in-network processing to reduce the communication overhead. Due to the fusion of data items sourced at different nodes into a single one during in-network processing, the ...Wireless Sensor Networks (WSNs) typically use in-network processing to reduce the communication overhead. Due to the fusion of data items sourced at different nodes into a single one during in-network processing, the sanctity of the aggregated data needs to be ensured. Especially, the data integrity of the aggregated result is critical as any malicious update to it can jeopardize not one, but many sensor readings. In this paper, we analyse three different approaches to providing integrity support for SDA in WSNs. The first one is traditional MAC, in which each leaf node and intermediate node share a key with parent (symmetric key). The second is aggregate MAC (AMAC), in which a base station shares a unique key with all the other sensor nodes. The third is homomorphic MAC (Homo MAC) that is purely symmetric key-based approach. These approaches exhibit diverse trade-off in resource consumption and security assumptions. Adding together to that, we also propose a probabilistic and improved variant of homomorphic MAC that improves the security strength for secure data aggregation in WSNs. We carry out simulations in TinyOS environment to experimentally evaluate the impact of each of these on the resource consumption in WSNs.展开更多
介绍无线网络技术在计算机网络组建中的优势,分析无线网在校园网网络搭建过程中的应用和在实际应用中可能存在的问题,对校园无线网络的部署实施、管理和运营等方面进行详细描述。主要从技术可行性及实际应用2个方面,对FAT AP和FIT AP 2...介绍无线网络技术在计算机网络组建中的优势,分析无线网在校园网网络搭建过程中的应用和在实际应用中可能存在的问题,对校园无线网络的部署实施、管理和运营等方面进行详细描述。主要从技术可行性及实际应用2个方面,对FAT AP和FIT AP 2种无线网接入方式进行了比较。并对无线网络部署中有线网络和无线网络一体化的热点问题进行讨论,分析有线无线一体化技术在实际网络拓扑搭建应用中的优势。展开更多
A fully integrated VCO and divider implemented in SMIC 0.13μm RFCMOS 1P8M technology with a 1.2 V supply voltage is presented. The frequency of the VCO is tuning from 8.64 to 11.62 GHz while the quadrature LO signals...A fully integrated VCO and divider implemented in SMIC 0.13μm RFCMOS 1P8M technology with a 1.2 V supply voltage is presented. The frequency of the VCO is tuning from 8.64 to 11.62 GHz while the quadrature LO signals for 802.1 1 a WLAN in 5.8 GHz band or for 802.1 1b/g WLAN and Bluetooth in 2.4 GHz band can be obtained by a frequency division by 2 or 4, respectively. A 6 bit switched capacitor array is applied for precise tuning of all necessary frequency bands. The testing results show that the VCO has a phase noise of-113 dBc @ 1 MHz offset from the cartier of 5.5 GHz by dividing VCO output by two and the VCO core consumes 3.72 mW. The figure-of-merit for the tuning-range （FOMT） of the VCO is -192.6 dBc/Hz.展开更多
文摘Wireless Sensor Networks (WSNs) typically use in-network processing to reduce the communication overhead. Due to the fusion of data items sourced at different nodes into a single one during in-network processing, the sanctity of the aggregated data needs to be ensured. Especially, the data integrity of the aggregated result is critical as any malicious update to it can jeopardize not one, but many sensor readings. In this paper, we analyse three different approaches to providing integrity support for SDA in WSNs. The first one is traditional MAC, in which each leaf node and intermediate node share a key with parent (symmetric key). The second is aggregate MAC (AMAC), in which a base station shares a unique key with all the other sensor nodes. The third is homomorphic MAC (Homo MAC) that is purely symmetric key-based approach. These approaches exhibit diverse trade-off in resource consumption and security assumptions. Adding together to that, we also propose a probabilistic and improved variant of homomorphic MAC that improves the security strength for secure data aggregation in WSNs. We carry out simulations in TinyOS environment to experimentally evaluate the impact of each of these on the resource consumption in WSNs.
文摘介绍无线网络技术在计算机网络组建中的优势,分析无线网在校园网网络搭建过程中的应用和在实际应用中可能存在的问题,对校园无线网络的部署实施、管理和运营等方面进行详细描述。主要从技术可行性及实际应用2个方面,对FAT AP和FIT AP 2种无线网接入方式进行了比较。并对无线网络部署中有线网络和无线网络一体化的热点问题进行讨论,分析有线无线一体化技术在实际网络拓扑搭建应用中的优势。
基金Project supported by the National High Technology Research and Development Program of China(No.2009AA011605)
文摘A fully integrated VCO and divider implemented in SMIC 0.13μm RFCMOS 1P8M technology with a 1.2 V supply voltage is presented. The frequency of the VCO is tuning from 8.64 to 11.62 GHz while the quadrature LO signals for 802.1 1 a WLAN in 5.8 GHz band or for 802.1 1b/g WLAN and Bluetooth in 2.4 GHz band can be obtained by a frequency division by 2 or 4, respectively. A 6 bit switched capacitor array is applied for precise tuning of all necessary frequency bands. The testing results show that the VCO has a phase noise of-113 dBc @ 1 MHz offset from the cartier of 5.5 GHz by dividing VCO output by two and the VCO core consumes 3.72 mW. The figure-of-merit for the tuning-range （FOMT） of the VCO is -192.6 dBc/Hz.
