45277891
On the bandwidth of convex triangulation meshes
Abstract Hochberg et al. (1995) obtained the bandwidth of triangulated triangles. In this paper, we consider a more general class of graphs, called convex triangulation meshes and denoted by T l , m , n . We show that the bandwidth of T l , m , n is min { l , m , n }.
119947006
All (k;g)-cages are k-edge-connected
A (k;g)-cage is a k-regular graph with girth g and with the least possible number of vertices. In this paper, we prove that (k;g)-cages are k-edge-connected if g is even. Earlier, Wang, Xu, and Wang proved that (k;g)-cages are k-edge-connected if g is odd. Combining our results, we conclude that the (k;g)-cages are k-edge-connected. © 2005 Wiley Periodicals, Inc. J Graph Theory 48: 219–227, 2005
27475892
SILK: a simulated evolution router
The authors present a rip-up-and-rerouter based on a matrix representation scheme and simulated evolution technique for solving detailed routing problems in VLSI layout. The status of the routing region is represented as a matrix. Rip-up and reroute operations are emulated as matrix subtractions and additions, respectively. The quality of a routing result can be measured by a few simple matrix operations on the matrix. A rip-up and reroute switch-box/channel router, called SILK, using a simulated evolution technique has been implemented based on this representation alone. Experimental results showed that SILK, when solving all the benchmarks from the literature, outperformed WEAVER, the most successful switch-box router to date, in both quality and speed aspects. >
15619003
A Graphical User Interface Design for Network Simulation
Abstract This article describes a prototyping effort of a flexible graphical user interface (GUI) for a simulation tool called COPS. The GUI is designed to allow parameter setup for all modules in simulation model, and can be easily replaced by new GUIs implemented in different languages/graphical tools. This article provides design guidelines and implementation details of the flexible GUI.
206549585
vGPRS: a mechanism for voice over GPRS
This paper proposes vGPRS, a voice over IP (VoIP) mechanism for a general packet radio service (GPRS) network. In this approach, a new network element called VoIP mobile switching center (VMSC) is introduced to replace standard GSM MSC. The vGPRS approach is implemented using standard H.323, GPRS, and GSM protocols. Thus, existing GPRS and H.323 network elements are not modified. Furthermore, both standard GSM and GPRS mobile stations can be used to receive vGPRS service, which need not be equipped with the VoIP (i.e., H.323) terminal capabilities.
13768633
Software Defined Radio - A High Performance Embedded Challenge
Wireless communication is one of the most computationally demanding workloads. It is performed by mobile terminals (“cell phones”) and must be accomplished by a small battery powered system. An important goal of the wireless industry is to develop hardware platforms that can support multiple protocols implemented in software (software defined radio) to support seamless end-user service over a variety of wireless networks. An equally important goal is to provide higher and higher data rates. This paper focuses on a study of the wideband code division multiple access protocol, which is one of the dominant third generation wireless standards. We have chosen it as a representative protocol. We provide a detailed analysis of computation and processing requirements of the core algorithms along with the interactions between the components. The goal of this paper is to describe the computational characteristics of this protocol to the computer architecture community, and to provide a high-level analysis of the architectural implications to illustrate one of the protocols that would need to be accommodated in a programmable platform for software defined radio. The computation demands and power limitations of approximately 60 Gops and 100~300 mW, place extremely challenging goals on such a system. Several of the key features of wideband code division multiple access protocol that can be exploited in the architecture include high degrees of vector and task parallelism, small memory footprints for both data and instructions, limited need for complex arithmetic functions such as multiplication, and a highly variable processing load that provides the opportunity to dynamically scale voltage and frequency.
2805042
A new random walk model for PCS networks
This paper proposes a new approach to simplify the two-dimensional random walk models capturing the movement of mobile users in personal communications services (PCS) networks. Analytical models are proposed for the new random walks. For a PCS network with hexagonal configuration, our approach reduces the states of the two-dimensional random walk from (3n/sup 2/+3n-5) to n(n+1)/2, where n is the layers of a cluster. For a mesh configuration, our approach reduces the states from (2n2-2n+1) to (n/sup 2/+2n+4)/4 if n is even and to (n/sup 2/+2n+5)/4 if n is odd. Simulation experiments are conducted to validate the analytical models. The results indicate that the errors between the analytical and simulation models are within 1%. Three applications (i.e., microcell/macrocell configuration, distance-based location update, and GPRS mobility management for data routing) are used to show how our new model can be used to investigate the performance of PCS networks.