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Motivated by the need for robust and high throughput communication with airborne platforms, a variable rate MIMO scheme that combines the D-BLAST architecture with per antenna spreading was proposed. This paper is focused on the experimental study of this approach. We developed a software defined radio implementation of the variable rate MIMO system based on GNU Radio. Over the air transmission and...
Inter-application I/O contention and performance interference have been recognized as severe problems. In this work, we demonstrate, through measurement from Titan (world's No. 3 supercomputer), that high I/O variance co-exists with the fact that individual storage units remain under-utilized for the majority of the time. This motivates us to propose AID, a system that performs automatic application...
In order to improve network performance and cell-edge UE experience, a study item (SI) on "LTE coverage enhancements" has been proposed and approved for LTE-Advanced. In this SI, it was concluded that the coverage of medium data rate PUSCH (Physical uplink shared channel) is poorer than other LTE channels, with significant gap observed. Therefore, coverage improvement for medium data rate...
The service quality of a station in IEEE 802.11 wLAN (wireless Local Area Networks) is strongly influenced by which access point it associates with. Therefore, a key challenge is how to select an appropriate access point from multiple available ones. Conventional association protocols have been proved to be not effective. In this paper a strategy for differentiated access service selection based on...
Heterogeneous Network (HetNet) has been extensively discussed as a solution to increase the capacity of Long Term Evolution-Advanced (LTE-A) systems, which coexist of high power macro base stations (BS) and Low Power Nodes (LPNs) such as pico, femto and relay nodes. This paper focuses on the co-channel deployment of macro and pico cells, in which high spectrum reuse and co-channel interference coexist...
Behavior management and performance evaluation are two significant issues in the design and operation of automated manufacturing systems (AMS). The former constrains their dynamics so as to avoid improper behavior and eliminate downtime, while the latter aims to evaluate cycle time. Although abundant research has been conducted on each issue independently, researchers rarely address both in a correlative...
In this paper we study opportunistic spectrum access (OSA) policies in a multiuser multichannel random access setting, where users perform channel probing and switching in order to obtain better channel condition or higher instantaneous transmission quality. However, unlikely many prior works in this area, including channel probing and switching policies for a single user to exploit spectral diversity,...
10Gbps Ethernet Security Processor is very important in future network telecommunication. In order to meet the performance of ultra high throughput of 10Gbps ESP, An architecture of multiple SHA-1 IP cores paralleled based crossbar switch are proposed in this paper. Firstly, An ultra high throughput, low power consumption SHA-1 algorithm IP-core are designed, then, an effective scheduling architecture...
We present an evaluation of the fault-tolerance characteristics of several important data center network topologies, including Fat-tree, DCell, HyperBCube and BCube using several metrics, including average path length, aggregated bottleneck throughput and connection failure ratio. These enable us to present an objective comparison of the network topologies under faulty conditions.
We propose a Strip-oriented Asynchronous Prefetching (SoAP) for the parallel disk systems. This technique splits a prefetching request into multiple independent prefetching sub-requests, each of which contains a full data strip to exploit the maximum physical sequentiality of involved disks. In addition, SoAP associates each prefetching sub-request with a relative large time window, allowing every...
Mega data centers are being built around the world to provide various cloud computing services. As a result, data center networking has recently been a hot research topic in both academia and industry. A fundamental challenge in this research is the design of the data center network that interconnects the massive number of servers, and provides efficient and fault-tolerant routing service to upper-layer...
The emerging WiMAX technology (IEEE 802.16) is a fourth generation standard for low-cost, high-speed and long range wireless communications for a large variety of civilian and military applications. IEEE 802.16j has introduced the concept of mesh network model and a special type of node called Relay Station (RS) for traffic relay for Subscriber Stations (SSs). A WiMAX mesh network is able to provide...
Most researchers encountered the following two problems when working with real Wireless Sensor Networks (WSNs): (1) Sensor nodes cannot satisfy application requirements even though the nominal sensing/transmission rates of these nodes are much higher than required. (2) In a WSN deployed in a large area, it is difficult or infeasible to get runtime performance evaluation of sensor nodes. We found out...
Different applications in the network have different sensitivity for the certain QoS parameters. The existing mechanisms cannot modify the packet loss policy exactly according to the needs of QoS parameters. Therefore, the network will not maximize its overall efficiency. This paper proposes a novel cognitive approach for QoS. It classifies the applications by various combinations of the QoS parameters...
Wireless communications over water may suffer from serious multipath fading due to strong specular reflections from conducting water surfaces. Cognitive radios enable dynamic spectrum access over a large frequency range, which can be used to mitigate this problem. In this paper, we study how to leverage cognitive radios for effective communications in wireless networks over water. We formally define...
This paper analyzes the problems in the wireless network caused by using minimum hop count as its routing metric, and discusses ETX metric which invented by De Couto to solve these problems and the shortage of it in mobile environment, then modifies it by relatively counting as to make it suitable for such environment. This paper uses the new ETX as a metric for the OLSR routing protocol, and proves...
With the rapid development of network technology and the increasing expansion of its size, there are more and more services need to be provided by network, so modern users have an increasing demand for making servers that operate and provide these services highly available. Obviously, stand-alone system is unappeasable, we must use the cluster as the server that operate those services especially the...
In this paper, we study a re-entrant line with unreliable exponential machines and finite buffers, operating under last buffer first serve scheduling policy. First, an approximation method is presented to estimate the throughput of the re-entrant line. Then, a system approach to identify bottleneck based on blockage and starvation information is proposed. It has been shown that the approximation method...
Wireless Mesh Network (WMN) is a promising broadband wireless network architecture. Security is an important component of the WMN architecture but is not fully considered so far. In this paper, we introduce a prototype secure wireless mesh network testbed called SJTU-MESH built by Shanghai Jiao Tong University. The detailed design and implementation of secure WMN nodes are presented, and the construction...
This paper analyzes algorithmic characteristics of AES Encryption/Decryption, and proposes a design methodology for AES algorithm digital hardware circuit through integrating the technologies of pipeline and parallel connections with dynamic reconfiguration. And a dynamic reconfiguration circuit model was built to test out the design methodology. The results of simulation and verification experiments...
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