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Wireless personal area network (WPAN) is small-ranged network centered at an individual for interconnecting personal devices. For such a network, the bootstrapping mechanism with which the devices establish a secure group key is of critical importance. Most existing bootstrapping mechanisms require out-of-band channels and involve human interactions for authentication. In this paper, we aim to develop...
In this paper a Direct Sequence Spread Spectrum (DSSS) based offline wireless white light communication system is established. Field measurements are conducted to compare the performance with and without DSSS. The experimental results show that the DSSS is able to improve performance obviously.
An Field Programmable Gate Array (FPGA)-Based online visible light communication system with RGB LEDs and ordinary PIN is implemented and demonstrated. The system uses simple OOK modulation. With the help of over-sampling technique at the receiver, the synchronization problem is solved. A bitrate of 120Mbps across 1m with the bit error rate less than 10−3 can be theoretically achieved without using...
In Content-Centric Networks (CCN), multiple routers may cache the same content, which makes it possible to retrieve the content chunks in parallel. In this paper, we propose Multi-Source Request and Transmission mechanism (MSRT) for CCN. We develop a MinMax problem to compute the optimal solution to retrieve all the chunks from multiple sources in the shortest time. We prove that the problem is NP...
In typical data center networks, an overwhelming majority of the flows are smaller than 200 KB in size, while most transmitted bytes are from a small fraction of large flows. The small flows are usually from the applications interacting with end users, thus they require small completion times. Meanwhile, the data center owners hope to keep the high throughput of the network to make full use of their...
T/R-modules are key elements in active phased array antennas for radar and electronic warfare applications. Though much research has been carried out on the T/R microwave module operating characteristics, there are few actual studies on its assembly process. Considering many process failures found in T/R microwave module manufacturing, the assembly process, including welding and screwing, and environment...
Recent results find numerical scheme for interference alignment (IA) to approach the Shannon capacity in interference network. Requiring global perfect channel knowledge is an important concern for interference alignment schemes. Consider error channel estimate and perfect channel information, and use different system model expression, we show that the distribution of SNR both are exponential distribution...
Presented in this paper is an experimental research on the mobile sensor and communication system based on transmitting with ultraviolet in either line-of-sight or non-line-of-sight conditions. The performance of this type of communication system is shown on the experimental platform which is set up. It proves the feasibility of ultraviolet communication system.
Against the difficulty of current landslide displacement monitoring and the requirements of field application, by comprehensive comparison of several landslide displacement monitoring methods and existing monitoring system, we designed a low-cost landslides displacement real-time monitoring system based on real-time kinematic differential GPS algorithm and combined with GPRS wireless network. The...
The Physical Layer of the IEEE 802.11 standard family provides a set of different modulation and coding schemes and, thus, a multitude of data rates. However, the Standard itself does not specify a mechanism to select adaptively among these data rates to improve the network throughput. An efficient rate adaptation scheme should aim to improve channel utilization through selection of optimal data rates...
Developing mediators is an important means to enable interaction of functionally compatible Web services with mismatching interfaces. On the other hand, reliable exchange of messages is often critical to interacting enterprise Web services. Accordingly, mediators for such Web service interactions must ensure certain reliability properties. In this paper, we characterize the problem of how to synthesize...
To improve the efficiency of reliable broadcast/multicast MAC protocol in wireless multi-hop network, a location aid algorithm to eliminate redundant nodes was brought forward. Using the neighbor geographical location information, according to the principle of equivalent collision region, the algorithm could reduce redundant nodes from receivers, which is unnecessary for acknowledgement. Thus, the...
To improve the efficiency and flexibility of reliable broadcast/multicast MAC protocol in wireless multi-hop network, a novel adaptive reliable broadcast/multicast MAC protocol (ARBMAC) is brought forward. The core idea of it is based on the broadcast/multicast cost function, which is proposed by analyzing different realizations of reliable broadcast/multicast. According to the function, the most...
In this paper we discuss performance results of a novel real-time closed-loop power amplifier (PA) linearization technique that has originally been proposed by Ahmed and Li. The novel approach performs on-the-fly prediction and measurement of the PA AM/AM and AM/PM non-linearity, stores such non-linear characteristics and calculates their inverse functions in order to pre-distort the base-band amplitude...
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