Tài liệu Sổ tay của các mạng không dây và điện toán di động P6 ppt

... fixed Algorithm complexity medium medium high high Communication complexity low medium high medium Channel utilization medium high medium high Control overhead medium high high medium introduced in Sections ... broadcast problem in mobile radio net- works, Distributed Computing 10, 3, 129–135, April 1997. 26. I. Cidon and M. Sidi, Distributed assignment algorithms for multihop packet radio n...

Ngày tải lên: 24/12/2013, 13:16

... and code division can be used in order to divide the radio spectrum. In fre- quency division, the spectrum is divided into frequency bands. In time division, the us- age of the channel is divided ... growth of radio traffic, and other fac- tors. A given radio spectrum (bandwidth) dedicated for cellular communications can be divided into a set of disjoint and noninterfering radio channels. ......

Ngày tải lên: 15/12/2013, 05:15

... prediction model is used to determine whether a flow perceives a clean or dirty channel during each slot. (If the channel is dirty, we assume that the channel prediction model can also predict ... receive additional service only when leading flows relinquish slots. As a consequence of its compensation model, CIF-Q provides a graceful linear degra- dation in service for leading flows. Addition...

Ngày tải lên: 24/12/2013, 13:16

... the same disk. Data items are then selected from the disks for broadcast according to the relative broadcast frequencies assigned to the disks. This is achieved by further dividing each disk into ... [38]. 11.2.1.3 Broadcast Disks A hierarchical dissemination architecture, called broadcast disk (Bdisk), was introduced in [1]. Data items are assigned to different logical disks so that data ite...

Ngày tải lên: 24/12/2013, 13:16

... approximate them to the average distance among all training data, (ii) calculate the dis- tances among the centers in each dimension and use some percentage of this distance for the scale factor ... s n , j = [1, n] determine the scalar dis- persion in each direction. To increase the functionality of the function f, we propose to use the Mahalanobis dis- tance in the Gaussian function. This ....

Ngày tải lên: 24/12/2013, 13:16

... much superior for unit disk graphs. 16.5 DISTRIBUTED ALGORITHMS Two distinctly different distributed algorithms are described in this section. The first uti- lizes token passing to distribute the computation, ... consists of u and its distance-2 neighbors. The distance-2 degree D(u) of u is the number of distance-2 neighbors of u, and the distance-2 degree D of a net- work, is the maximum dis...

Ngày tải lên: 21/01/2014, 19:20

... providing data to mobile appli- cations. We have described a cache maintenance (invalidation) strategy called AS for a distributed system that is predisposed to frequent disconnections. Such disconnections happen ... to follow an exponential distribution with mean 1/ ␮ . Each MH generates a query according to a Poisson distribution with mean rate of ␭ . These queries are uni- formly distribu...

Ngày tải lên: 26/01/2014, 15:20

... Usually, the hard handoff can be further divided into two different types—intra- and intercell handoffs. The soft handoff can also be divided into two different types—multiway soft handoffs and softer ... strategies during overloading, might influence the overall performance. In the next section, we introduce different types of possible handoffs. In Section 1.3, we describe different handoff...

Ngày tải lên: 15/12/2013, 05:15

... traveled maximal distance exceeds the last reported maximal distance. The paging operation is based on the last reported cell and the maximal distance R. The system will search all R rings surrounding the ... the cells within a distance of D from the last reported cell. The distance-based strategy is dynamic, and the distance threshold D can be determined on a per-user basis depending on his/...

Ngày tải lên: 15/12/2013, 05:15

... Unit Disk Graphs Unit disk graphs are intersection graphs of equal sized disks in the plane. It is easy to see that given the distance model, multicoloring is equivalent to coloring for unit disk ... disk graph is the intersection graph of disks of equal diameter in the plane. They can also be described in terms of distance or proximity models, which consist of a value d Ն 0 and an embedding...

Ngày tải lên: 15/12/2013, 05:15