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Recently, large amount of data is transferred over network. The available bandwidth of network varies momently, so it is important to realize the efficient data transfer by fully utilizing the time-varying network bandwidth. We are developing the method of efficient data communication by dynamically compressing data, assuming the use of the high performance of multi-core processors. Our method can...
Direct (or device-to-device, D2D) communications are being investigated in the framework of LTE- Advanced. They allow one-to-one communications between two endpoints, under the control of the eNodeB, which allocates resources for the d2d flow, but does not act as a relay for its traffic. The direct link can also be used for file transfer or proximity-based browsing, i.e. applications running on TCP...
In the last few years smartphones have increased their capabilities in terms of hardware and software. They are used for many purposes beyond the simple calls and messaging. Presently, industries are focusing on smartphone-devices integration. As a matter of fact, car-smartphone integration is an ever increasing field, even though the car equipments are still used as phone accessories. Our goal is...
We report the first W-band GaN receiver components using a next generation, highly scaled GaN device technology. This technology (40nm, fT= 220 GHz, fmax= 400 GHz, Vbrk > 40V) enables receiver components that meet or exceed performance reported by competing device technologies while maintaining > 5x higher breakdown voltage, higher linearity, dynamic range and RF survivability. This paper includes...
Spreading Internet of Thing devices, we need an effective method for managing the devices. For that reason, we proposed Instance Manager that can provide intelligent services to end users with effective way. The proposed system has virtual objects as representing devices released by many companies for integrating the services provided by each device. In this paper, we will explain how to devise Instance...
In multi-channel WLANs, MAC protocol allocates each transmission pair a channel selected for avoiding interference from each other. In the channel allocation phase, if the MAC protocol allocates the one channel iteratively to the multiple transmission pairs in narrowly-spaced, both channel utilization and network throughput can be improved. However, on such overloaded schedules, if any transmission...
Cognitive radios (CRs) are a promising solution for the spectrum scarcity problem. These radios access the spectrum in an opportunistic manner in order to take advantage of frequency bands, i.e. channels, left unused by primary users while not interfering with them. This opportunistic access model requires CRs to switch among channels searching for new opportunities and making contact with their neighbors...
This paper presents the performance evaluation of two Source Specific Multicast (SSM) protocols for IP networks: Protocol Independent Multicast (PIM) SSM and Lightweight PIM (LPIM). PIM SSM provides reliable, low latency IP Multicast transport services, but at the cost of high overhead in the signalling plane. The main design objective of LPIM is to improve PIM SSM scalability and to provide global...
Many incompatible wireless protocols proliferate in unlicensed bands, creating complex coexistence and connectivity problems. If the trend continues, such problems will continue to exist in future unlicensed bands. We take a different approach to spectrum sharing. Instead of proposing a distinct medium-access control (MAC) protocol for each type of application, we propose a family of parameterized...
PIM-SM (Protocol Independent Multicast - Sparse Mode) is a multicast routing protocol that uses one central node (which we refer to with the Rendezvous Point ??RP??) for all transmitters in a multicast group. It builds source-specific trees to the transmitters whose data rates exceed a predefined threshold. Investigations have been done to improve and provide an efficient mechanism for switching between...
Predicting exactly the performance for distributed simulation of multi-agent based systems has considerable significance. Some investigations were realized but they usually omitted issue of communication costs between computational nodes. In this paper, we address to the communication cost models and present a model for evaluating the performance of multi-agent based simulation on Ethernet switch...
This paper proposes a new approach to analyze crosstalk of coupled interconnects in the presence of process variations. The suggested method translates correlated process variations into orthogonal random variables by principle component analysis (PCA). combined with polynomial chaos expression (PCE), the technique utilizes Stochastic Collocation Method (SCM) to analyze the system response of coupled...
Current mode (CM) scheme provides suitable alternative for the high speed on-chip interconnect signaling. This paper presents a energy-delay optimization methodology for the current-mode (CM) signaling scheme. Optimization for the CM circuits for on-chip interconnects requires a joint optimization of driver and receiver device sizes, as their parameters which affect the energy-delay performance depend...
We propose QUEST (QUality ESTimation), a new method that accurately estimates IEEE 802.11 wireless link quality with no in-band signaling overhead. Existing link quality estimation methods either are based on hello exchanges by fixing or varying transmission rates or rely on the history (e.g., delivery ratio) of previously sent data packets in a per-rate/-neighbor manner. QUEST on the other hand,...
In this paper, we introduce and evaluate ScaleMesh, a scalable miniaturized dual-radio wireless mesh testbed based on IEEE 802.11b/g technology- ScaleMesh can emulate large-scale mesh networks within a miniaturized experimentation area by adaptively shrinking the transmission range of mesh nodes by means of variable signal attenuators. To this end, we derive a theoretical formula for approximating...
3D contactless technology based on capacitive coupling represents a promising solution for high-speed and low power signaling in vertically integrated chips. AC coupled interconnects do not suffer from mechanical stress, and the parasitic load is much reduced when compared to standard DC solutions, such as wire bonding and micro bumps. Communication system based on wireless interconnection scheme...
This paper describes a methodology for building a reliable internet core router that considers the vulnerability of its electronic components to single event upset (SEU). It begins with a set of meaningful system level metrics that can be related to product reliability requirements. A specification is then defined that can be effectively used during the system architecture, silicon and software design...
This paper proposes a fast forward medium access control protocol (FFMAC) for quality-of-service (QoS) guarantee in multihop IEEE 802.11s wireless mesh networks with multiple channels. To the best of our knowledge, the proposed protocol is the first one which considers the multihop and multichannel issues simultaneously. It provides higher priority for real-time applications, while remaining the distributed...
We designed and built a novel all-optical re-timing, re-amplifying, and re-shaping (3R) regeneration system based on terahertz optical asymmetric demultiplexers (TOADs) developed in our laboratory. The system is capable of parallel processing multiple wavelengths, a feature which will significantly improve the scalability of current wavelength division multiplexing (WDM) networks. Performance against...
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