Tài liệu Sổ tay của các mạng không dây và điện toán di động P7 pdf

... focus on the radio interface adopted in the TD-CDMA system. This in-terface is named UMTS terrestrial radio access—time division duplex (UTRA-TDD). Tosupport data connections with different bit ... to in-dicate readiness to receive the data. This mechanism can be used to capture the channel con-trol before the transmission of long packets, thus avoiding “long collisions.” In addition, ... transmitting. If the medium is found to be idle for aninterval that exceeds the distributed interframe space (DIFS), the station continues with itstransmission.* On the other hand (when the medium is busy),...

Tài liệu Sổ tay của các mạng không dây và điện toán di động P1 pdf

... Usually, thehard 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 andsofter ... NETWORKS1.3.5 Prediction TechniquesPrediction techniques base the handoff decision on the expected future value of the re-ceived signal strength. A technique has been proposed and simulated to indicate ... QHis filled.In this case, we consider the case for MO= 0. The two-dimensional state-transition dia-gram becomes one-dimensional ( j = 0). Therefore, the state probabilities can easily be...

Tài liệu Sổ tay của các mạng không dây và điện toán di động P2 pdf

... the cells within a distance of D from the lastreported cell. The distance-based strategy is dynamic, and the distance threshold D can bedetermined on a per-user basis depending on his/her mobility ... mobile station at and around its predicated location in descending probability un-til the mobile station is found. Their simulation results show that the predictive distance-based scheme performs ... reasons. First, someimportant distributions such as the exponential, Erlang, and Chi-square distributions arespecial cases of the Gamma distribution. Second, the Gamma distribution has a simpleLaplace–Stieltjes...

Tài liệu Sổ tay của các mạng không dây và điện toán di động P9 pdf

... accordingly the value of its prefix sum. Inone additional time slot, station Skreveals its identity.The reader should have no difficulty confirming that when the protocol terminates,conditions ... set N ǟN + 1endifall stations set L ǟL – 1endifendwhile204RANDOMIZED INITIALIZATION PROTOCOLS FOR RADIO NETWORKSFigure 9.1 Illustrating a partition tree. 13. J. L. Bordim, J.Cui, T. ... Fifer and F. J. Bruno, Low cost packet radio, Proceedings of the IEEE, 75, 33–42, 1987.20. M. Gerla and T C. Tsai, Multicluster, mobile, multimedia radio network, Wireless Networks, 1,255–265,...

Tài liệu Sổ tay của các mạng không dây và điện toán di động P15 pdf

... broadcast medium at the LLC layer. A so-called distribution system handles the pack-et forwarding toward destination devices outside the cell across the wired network infra-structure. The distribution ... Ad Hoc Networking, Reading, MA: Addison-Wesley, 2000. 55. J. Rabaey, P. Wright, and B. Brodersen, The Pico radio project: http://www.eecs.berkeley.edu/Research/Pico_Radio.56. Report to the ... this band, 79 different radio fre-quency (RF) channels spaced 1 MHz apart are defined. The baseband and the Bluetooth radio layers compose the Bluetooth core protocols.Bluetooth radio provides...

Tài liệu Sổ tay của các mạng không dây và điện toán di động P21 pdf

... Prakash [27] discussed information dissemination inpartitionable mobile ad hoc networks. They studied the problem of getting the location ofsome other node in the network and the surroundings of ... north–south direction, including neighbors ofnodes in that path. A initiates two routing messages, in the directions north and south,whereas other nodes follow only one of the directions. Each ... as the cost measure.21.2.2 Distributed OperationWe shall divide all distributed routing algorithms into localized and nonlocalized. Local-ized algorithms [12] are distributed algorithms that...

Tài liệu Sổ tay của các mạng không dây và điện toán di động P22 pdf

... modelwith different properties, such as MMPP or multifractal models [2] (for more details, werefer the reader to the survey in [13]). 22.3.2.2 Time DistributionThe traditional way to model the distribution ... overlapping area and the distribution of22.4 ROUTING AND HANDOVER 4851. Geographical distribution: On which satellite the user requests are expected to ar-rive. 2. Time distribution: How long ... the satellite constellation context.22.3.2.3 Rate DistributionIt is quite natural to relate the rate distribution to the locations of the different parties of acommunication. In [36], the...

Tài liệu Sổ tay của các mạng không dây và điện toán di động P27 pdf

... Service dis-covery and distributed computing are discussed in more detail.27.4.1 Service DiscoveryService discovery protocols are a key technology of pervasive computing. They give todistributed ... and port numbers are discovered using different mechanisms. Up-dates need to be performed at two different places. The introduction of new types of ser-vices requires standardization of new names. ... of heterogeneity: devices anddistributed components are from different vendors and sources. Support of mobility anddistribution in such a context requires open distributed computing architectures...

Tài liệu Sổ tay của các mạng không dây và điện toán di động P3 pptx

... 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 bedivided into a set of disjoint and noninterfering radio channels. ... using different bench-marks following extended simulations with a variety of assumptions regarding the mobileradio environment. Some of these assumptions might be the cellular topology, the differ-ent...

Tài liệu Sổ tay của các mạng không dây và điện toán di động P4 doc

... Unit Disk GraphsUnit disk graphs are intersection graphs of equal sized disks in the plane. It is easy to seethat given the distance model, multicoloring is equivalent to coloring for unit disk ... onenode of each distinct base color, except for two pairs of heavy nodes, each correspondingto a base color different from v’s and from each other; (b) at most one node of each dis-tinct base ... of theFPA strategy discussed earlier has a performance ratio of k/2. In what follows, we discusssome specific classes of graphs that have been studied in the context of radio channel as-signment....

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