Takeo Hamada

On data gathering protocols for in-body biomedical sensor networks

This paper investigates the effectiveness of data gathering protocols for in-body biomedical sensor networks. We studied the performance of representatives from each of three major protocol categories: (1) low energy adaptive clustering hierarchy (LEACH), a cluster-based protocol, (2) power efficient gathering for sensory information systems (PEGASIS), a chain-based protocol, and (3) hybrid indirect transmissions (HIT), a hybrid of chains and clusters. First, the ability of each protocol to perform in-network source separation was judged. We consider a human-machine interaction application in which implanted bio-sensors communicate motor unit actions of human muscles to a remote computer. Motor unit action potentials (MUAPs) were modeled, and source separation and recovery at each sensor was simulated. We compare the performance of HIT and LEACH in terms of signal distortion ratios and the energy costs of fusion and communication. Second, we report on the efficiency of each protocol for in-body data collection, using Gupta et als propagation loss model for biomedical applications (PMBA) - an accurate model of power loss due to signal absorption by the human body. We investigate the effectiveness of HIT, LEACH, and PEGASIS under this model, and compare their performance in terms of energy efficiency and network lifetime

Macro pipelining based scheduling on high performance heterogeneous multiprocessor systems

Presents a technique for pipelining heterogeneous multiprocessor systems, macro pipelining based scheduling. The problem can be identified as a combination of optimal task/processor assignment to pipeline stages as well as a scheduling problem. The authors propose a new technique based on iterative applications of partitioning and scheduling schemes whereby the number of pipeline stages are identified and the scheduling problem is solved. The pipeline cycle is optimized in two steps. The first step finds a global coarse solution using the ratio cut partitioning technique. This is subsequently improved by the iterative architecture driven partitioning and the repartitioning and time axis relabeling techniques of the second step. The authors have considered a linear interprocessor communication cost model in scheduling. The proposed technique is applied to several examples. They find that for these examples, the proposed macro pipelining based scheduling can improve the throughput rate several times that of the conventional homogeneous multiprocessor scheduling algorithms. >

Tina: Its achievements and its future directions

The telecommunications information networking architecture (TINA) has reached a mature state and TINA solutions are now appearing in the market. This article presents a brief sketch of TINAs past and the overall objectives as they are seen today. It further describes the current technological state of the architecture with its business model, the computing environment requirements, the session model, the networking resource model, and its impact on the network technology evolution. Eventually, the path TINA will take into the future is indicated by outlining the TINA Trial project and the workgroup activities; the driving forces during TINAs current phase.

Prime: A Timing-Driven Placement Tool Using A Piecewise Linear Resistive Network Approach

An approach toward path-oriented timing-driven placement is proposed. We first transform the placement with timing constraints to a Lagrange problem. A primal-dual approach is used to find the optimal relative module locations. In each primal dual iteration, the primal problem is solved by a piecewise linear resistive network method, while the dual process is used to update the Lagrange multiplier. The sparsity of the piecewise linear resistive network is exploited to obtain dramatic improvement on the efficiency of the calculation. Up to 22.0% of clock cycle reduction was observed for Primary2 test case.

A differentiated services architecture for multimedia streaming in next generation Internet

This paper presents a DiAerentiated Services (DiAserv or DS) architecture for multimedia streaming applications. Specifically, we define two types of services in the context of Assured Forwarding (AF) per hop behavior (PHB) that are diAerentiated in terms of reliability of packet delivery: the High Reliable (HR) service and the Less Assured (LA) service. We propose a novel node mechanism called Selective Pushout with Random Early Detection (SPRED) that is capable of simultaneously achieving the following four objectives: (1) a core router does not maintain any state information for each flow (i.e., core-stateless); (2) the packet sequence within each flow is not re-ordered at a node; (3) packets from HR service are delivered more reliably than packets from LA service at a node during congestion; and (4) packets from TCP traAc are dropped randomly to avoid global synchronization during congestion. We show that SPRED is a generalized buAer management algorithm of both tail-dropping and Random Early Detection (RED), and combines the best features of pushout (PO), RED and RED with In/Out (RIO) mechanisms. Simulation results demonstrate that under the same link speed and network topology, network nodes employing our DiAserv architecture have substantial performance improvement over the current Best EAort (BE) Internet architecture for multimedia streaming applications. ” 2000 Elsevier Science B.V. All rights reserved.

A wire length estimation technique utilizing neighborhood density equations

A new wire length estimation technique is presented. Wire length distribution is modeled by wire density on a 2-D lattice. Assuming a pointwise independent branching process, the wire length distribution is found by solving the neighborhood density equations. For several industrial circuits tested, this technique achieved an estimation error of 9.0% with a maximum deviation of +16.3%, which compared favorably with other techniques recently proposed.<<ETX>>

Peer-to-peer traffic in metro networks: analysis, modeling, and policies

We report studies on peer-to-peer (P2P) traffic analysis, modeling, and evaluation of policies for the management P2P traffic in metropolitan networks. We conducted crawler-based measurement and analysis of P2P traffic using Gnutella. Based on the empirical parameters obtained through the measurement, known modeling techniques of P2P peers and contents, and GeoPoint, a geomapping technology, we built a P2P traffic simulator using J-Sim, a Java-based network simulation tool. The simulator is scenario-driven, allowing its user to customize network settings and service environment to examine the behavior of P2P traffic. With the P2P simulator, we were able to recreate a spatio-temporal traffic pattern characteristic to P2P services observed in August 2002. We then evaluated three different P2P traffic management policies, showing that traffic localization using a peer selection policy at super peers is possible, containing P2P traffic to the local metropolitan network as much as 40%.

Optical Burst Transport: A Technology for the WDM Metro Ring Networks

We propose a sublambda traffic-grooming scheme on wavelength-division-multiplexing ring networks, named optical burst transport. The network protocol and architecture are designed to support dynamic bandwidth allocation, which is more reasonable for bursty data traffic. To verify our network protocol and architecture, we build a testbed which supports burst-mode transmission. Also, we transmit streaming video over Ethernet as an application

Service quality in TINA: quality of service trading in open network architecture

Enterprise-level QoS issues are discussed, from which QoS evolution paths are derived. Service-level QoS issues are identified, and they have been studied as a part of service quality issues in TINA service architecture. TINA stream binding and its role in the TINA QoS framework are presented. Soft guarantee of stream quality is proposed, which does not require strict resource reservation. The soft guarantee concept combined with TINA stream binding architecture supports progressive evolution of service quality.

Traffic grooming for WDM rings using optical burst transport

A sublambda traffic-grooming scheme on wavelength-division-multiplexed (WDM) rings, which is called optical burst transport (OBT), is proposed. The network protocol and architecture allow increased flexibility to tailor the transport network behavior for efficient delivery of bursty data traffic. Using different network parameters, its performance is analyzed via simulation, and the implementation issues including the media-access-control (MAC) protocol, tunable-filter controller, and burst-mode receiver are addressed. Finally, the feasibility of the OBT with an experimental testbed built by the authors is demonstrated and a streaming-video application is used to present its overall functionality.