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

... to provide a uniform framework with the corresponding notions in GEDIR and MFR methods. Stoj- menovic [52] discusses the V-GEDIR, CH-MFR, and R-DIR methods, in which m is for- warded to exactly ... north–south direction, including neighbors of nodes in that path. A initiates two routing messages, in the directions north and south, whereas other nodes follow only one of the directions. Each .....

Ngày tải lên: 21/01/2014, 19:20

... 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

... transmitting. If the medium is found to be idle for an interval that exceeds the distributed interframe space (DIFS), the station continues with its transmission.* On the other hand (when the medium is busy), ... WLANs 155 Physical Layer Distributed Coordination Function Point Coordination Function Contention-free Contention Figure 7.6 IEEE 802.11 architecture. *To guarantee fair access to t...

Ngày tải lên: 24/12/2013, 13:16

... words, the RN with no-CD cannot distinguish between ambient noise and two or more transmissions colliding on the channel. A number of radio and cellular networks in- cluding AMPS, GSM, ALOHA-net, ... 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,...

Ngày tải lên: 24/12/2013, 13:16

... W. Brodersen, Low-power CMSO digital design, IEEE Journal of Solid State Circuits, 27(4), pp. 473–484, 1992. 20. Digital Inter Relay Communication (DIRC), http://www.dirc.net/home/index.html. 21. ... and J. D. Tornow, The DARPA packet radio network protocols, Proceedings of the IEEE, 75, 1, 21–32, 1987. 34. P. Karn, H. Price, and R. Diersing, Packet radio in amateur service, IEEE JSAC, SAC-3,...

Ngày tải lên: 24/12/2013, 13:16

... distribution of users. 1. Geographical distribution: On which satellite the user requests are expected to ar- rive. 2. Time distribution: How long they are expected to be active. 3. Rate distribution: ... model with different properties, such as MMPP or multifractal models [2] (for more details, we refer the reader to the survey in [13]). 22.3.2.2 Time Distribution The traditional way to...

Ngày tải lên: 21/01/2014, 19:20

... Service dis- covery and distributed computing are discussed in more detail. 27.4.1 Service Discovery Service discovery protocols are a key technology of pervasive computing. They give to distributed ... Service discovery protocols and distributed components architec- tures were addressed in more detail. Service discovery protocols, such as SLP and Jini, pro- vide mechanisms with which distrib...

Ngày tải lên: 26/01/2014, 15:20

... 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

... 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