Conventional wireless sensors for structural health monitoring do not accommodate the need of high frequency data acquisition. Lack of development of this type of wireless smart sensors will without doubt hinder the applications of active diagnostic methods, normally used in local damage interrogation. In this paper, a novel wireless smart sensor design, using FPGA as co-controller with ultra sensing capability, is presented. The development and some outstanding issues of the sensor are discussed in detail, and a preliminary experimental result is given to verify the effectiveness of this wireless smart sensor design.
The IEEE 802.17 Working Group has taken another step forward in providing standards to Resilient Packet Ring (RPR) architectures by approving draft 2.4 of the RPR standard. Some companies have already had their RPR equipments for good market perspectives before the final standardization of RPR specifications. These equipments can supply services such as Ethernet Private Line (EPL), Transparent LAN Service (TLS), Ethernet Line Aggregation (ELA) and so on. Quality of Service (QoS) is an important part implemented in these equipments. Only when there is promise of QoS for RPR equipment, can commercial clients put their key applications to its network. Both the edge and the ring of RPR equipment need take QoS into effect to get QoS guarantees. This paper mainly deals with edge QoS study of RPR equipment. Policing, classification, shaping, and scheduling that are used for edge QoS process are introduced in the paper. And a QoS process method for traffic across rings is discussed at the same time.
Resilient Packet Ring (RPR) is a newly developed Layer 2 access technology for ring topology based high speed network. Fairness Algorithm (FA), one of its key technologies, takes responsibility for regulating each station access to the ring. Since different methods emphasize particularly on different aspects, the RPR Work Group have tabled several proposals. This paper will discuss two of them and propose an improved algorithm, which can be seen as a generalization of the two schemes proposed in  and . The new algorithm is a distributed algorithm, and uses a multi level feedback mechanism. Each station calculates its own fair rate to regulate its access to the ring, and sends fairness control message (FCM) with its bandwidth demand information to the whole ring. All stations keep a bandwidth demand image, which update periodically based on the information of received FCM. The image can be used for local fair rate calculation to achieve fair access. In the properties study section of this paper, we compare our algorithm with the two existing one both in theoretical method and in scenario simulation. Our algorithm has successfully resolve lack of the awareness of multi congestion points in  and the drawback of weakness of fault tolerance in .
Most schemes of quantum key remote distribution available mainly deal with the quantum repeater based on quantum entanglement swapping. However, as the quantum repeater has many insurmountable shortcomings, this paper, relying on the existing fairly mature technique, proposes a highly efficient QKD scheme with authentication mechanism from a new perspective of scheme not based on entanglement swapping, overcoming the low efficiency of the entanglement swapping scheme. By means of the quantum authentication mechanism, this scheme is capable of preventing and detecting any active attacks from any point in the quantum network. The scheme proposed has realized authentication and key distribution in the quantum channel at the same time, providing the authentication mechanism of this type of remote key distribution network with a reference. This paper first briefly analyzes the shortcomings of the quantum repeater scheme based on entanglement swapping and introduces the idea of highly efficient quantum key negotiation by means of the pseudo random sequence. Then a key distribution with authentication protocol based on shared secret is presented followed by a description of the application of this scheme in the quantum key distribution network.
IEEE 802.11 WLAN is used widely because of the flexibility of Wireless LAN. Subscribers hope that the Wireless LAN can supply Real-time application as the wired network, for example, video and voice service, these require service differentiation in networks. Service differentiation at the IP layer is useless without support of that in lower layers. This support is even more critical in wireless networks because of its instability and limited bandwidth. This paper aims at the promotion of data stream transfer through research in TCP/UDP transfer over MAC layer supported by EDCF. Applications impose requirements on communication parameters, such as data rate and delay. In this paper we present ideas to provide service differentiation support for 802.11e and compare it with the legacy DCF of IEEE802.11 by simulation, and analyze the result in performance of the schemes with TCP and UDP flows.