Mouse Chromosome 11

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46996/1/335_2004_Article_BF00648429.pd

Performance evaluation of candidate MAC protocols for LMCS/LMDS networks

Broadband Wireless Access (BWA) has attracted much interest these days for providing high speed data and multimedia services. It offers attractive features such as ease and speed for deployment, fast realization of revenues, and low infrastructure cost, compared to other alternative broadband access technologies, for example, HFC and xDSL. Recently, standarization of the BWA network has been undertaken by various groups (IEEE 802.16, ETSI-BRAN Hiper-Access group, ITU 8A9B). The main objective has been to define the system architecture, as well as physical and media access control (MAC) layers of BWA networks. This paper focuses on Medium Access Control (MAC) alternatives that can find application in an LMDS/LMCS network capable of supporting multimedia traffic. Multifrequency demand assignment TDMA-based schemes appear (at the moment) to be a suitable choice in this context. The selected protocol should be dynamically capable of providing multirate capabilities and quality-of-service guarantees. An obvious candidate for the aforementioned purpose is the LMDS-specific MAC proposal in the DAVIC 1.2 recommendation. For purposes of comparison, we also examine the evolving IEEE 802.14 MAC convergence protocol and MCNS (Multimedia Cable Network System) DOCSIS (ITU J-112) MAC Standard that are intended to support similar applications and services in an HFC (Hybrid Fiber Coax) environment. The three protocols are examined under noiseless and no

Local limit theorems for sequences of simple random walks on graphs

In this article, local limit theorems for sequences of simple random walks on graphs are established. The results formulated are motivated by a variety of random graph models, and explanations are provided as to how they apply to supercritical percolation clusters, graph trees converging to the continuum random tree and the homogenisation problem for nested fractals. A subsequential local limit theorem for the simple random walks on generalised Sierpinski carpet graphs is also presented