Failure of one or multiple critical nodes may partition wireless sensor networks into disjoint segments, and thus brings negative effect on the applications. We propose DCRS, a Distributed Connectivity Restoration Str...Failure of one or multiple critical nodes may partition wireless sensor networks into disjoint segments, and thus brings negative effect on the applications. We propose DCRS, a Distributed Connectivity Restoration Strategy to tolerate the failure of one critical node. Because of the energy restriction of sensor nodes, the energy overhead of the recovery process should be minimized to extend the lifetime of the network. To achieve it, we first design a novel algorithm to identify 2-critical nodes only relying on the positional information of 1-hop neighbors and some 2-hop neighbors, and then we present the criteria to select an appropriate backup for each critical node. Finally, we improve the cascaded node movement algorithm by determining whether a node can move to another non-adjacent node directly or not to reduce the number of nodes moved. The effectiveness of DCRS is validated through extensive simulation experiments.展开更多
This paper presents an up-conversion mixer for 2.4GHz wireless sensor networks in 0. 181xm RF complementary metal-oxide semiconductor （CMOS） technology. It is based on a double-balanced Gilbert cell type. With two G...This paper presents an up-conversion mixer for 2.4GHz wireless sensor networks in 0. 181xm RF complementary metal-oxide semiconductor （CMOS） technology. It is based on a double-balanced Gilbert cell type. With two Gilbert cells it was applied quadrature modulation. Operational ampli- tiers are used in this design to improve the conversion gain under low power consumption. The mixer design is based on 0.18txm RF CMOS process. And the mixer test results indicate that under 1.8V power supply, with input frequency 2.4 - 2.4835GHz, the conversion voltage gain is 1.2 - 2dB. When the output frequency is 2.4GHz, its power gain is -4.46dB, and its input referred 1 dB com- pression point is -11.5dBm and it consumes 1.77mA current.展开更多
This paper presents a new encryption embedded processor aimed at the application requirement of wireless sensor network （WSN）. The new encryption embedded processor not only offers Rivest Shamir Adlemen （RSA）, Adv...This paper presents a new encryption embedded processor aimed at the application requirement of wireless sensor network （WSN）. The new encryption embedded processor not only offers Rivest Shamir Adlemen （RSA）, Advanced Encryption Standard （AES）, 3 Data Encryption Standard （3 DES） and Secure Hash Algorithm 1 （SHA - 1 ） security engines, but also involves a new memory encryption scheme. The new memory encryption scheme is implemented by a memory encryption cache （MEC）, which protects the confidentiality of the memory by AES encryption. The experi- ments show that the new secure design only causes 1.9% additional delay on the critical path and cuts 25.7% power consumption when the processor writes data back. The new processor balances the performance overhead, the power consumption and the security and fully meets the wireless sensor environment requirement. After physical design, the new encryption embedded processor has been successfully tape-out.展开更多
文摘Failure of one or multiple critical nodes may partition wireless sensor networks into disjoint segments, and thus brings negative effect on the applications. We propose DCRS, a Distributed Connectivity Restoration Strategy to tolerate the failure of one critical node. Because of the energy restriction of sensor nodes, the energy overhead of the recovery process should be minimized to extend the lifetime of the network. To achieve it, we first design a novel algorithm to identify 2-critical nodes only relying on the positional information of 1-hop neighbors and some 2-hop neighbors, and then we present the criteria to select an appropriate backup for each critical node. Finally, we improve the cascaded node movement algorithm by determining whether a node can move to another non-adjacent node directly or not to reduce the number of nodes moved. The effectiveness of DCRS is validated through extensive simulation experiments.
基金Supported by the National High Technology Research and Development Program(No.2007AA01Z2A7)the Special Fund of Jiangsu Province for the Transformation of Scientific and Technological Achievements(No.BA2010073)
文摘This paper presents an up-conversion mixer for 2.4GHz wireless sensor networks in 0. 181xm RF complementary metal-oxide semiconductor （CMOS） technology. It is based on a double-balanced Gilbert cell type. With two Gilbert cells it was applied quadrature modulation. Operational ampli- tiers are used in this design to improve the conversion gain under low power consumption. The mixer design is based on 0.18txm RF CMOS process. And the mixer test results indicate that under 1.8V power supply, with input frequency 2.4 - 2.4835GHz, the conversion voltage gain is 1.2 - 2dB. When the output frequency is 2.4GHz, its power gain is -4.46dB, and its input referred 1 dB com- pression point is -11.5dBm and it consumes 1.77mA current.
文摘This paper presents a new encryption embedded processor aimed at the application requirement of wireless sensor network （WSN）. The new encryption embedded processor not only offers Rivest Shamir Adlemen （RSA）, Advanced Encryption Standard （AES）, 3 Data Encryption Standard （3 DES） and Secure Hash Algorithm 1 （SHA - 1 ） security engines, but also involves a new memory encryption scheme. The new memory encryption scheme is implemented by a memory encryption cache （MEC）, which protects the confidentiality of the memory by AES encryption. The experi- ments show that the new secure design only causes 1.9% additional delay on the critical path and cuts 25.7% power consumption when the processor writes data back. The new processor balances the performance overhead, the power consumption and the security and fully meets the wireless sensor environment requirement. After physical design, the new encryption embedded processor has been successfully tape-out.
