multiple access techniques in computer networks ppt

... unfairness by reducing the chances of transmission for the sending stations in the way of increasing the minimum conten- tion window size. The downlink compensation access (DCA) algorithm in [16] gives ... Analytical modeling of TCP clients in Wi-Fi hot spot networks, in Proceedings of IFIP Networking (2004) 36. S Choi, K Park, C Kim, Performance impact of inter-layer dependency in infrastructure ... services, intelligent traffic alerts, tracking, pinpointing child’s location, and local map pro- visioning have been dealt with much attention in the community [2-4]. Noticeable point is that...

Ngày tải lên: 21/06/2014, 00:20

... and efficient wireless access in challenging interference scenarios, for example, multiple networks deployed in the same geographical area and sharing a common band. In 1976, an ALOHA channel ... “Polarization Division Multiple Access With Polarization Modulation for LOS Wireless Communications” by Bin Cao, Qin-Yu Zhang, and Lin Jin discusses a potential multiple access and modulation ... algorithm increases only linearly with the number of users. In this algorithm, the different CFOs from different users destroy the orthogonality among training sequences and introduce multiple access...

Ngày tải lên: 21/06/2014, 17:20

... privacy-enhancing technologies. Information networks serve as the context in which privacy is investigated. Within information networks, the concepts of information ecosystems and con- tamination are introduced. ... different online registers or databases con- taining personal information may be combined by powerful search engines in order to get an apprehension about groups of individuals. In effect, this informa- tion ... and several startups joined in creat- ing Internet products and services. By the beginning of 2000, the Internet was supporting a great number of popular applications, including typical killer appli- cations...

Ngày tải lên: 16/01/2014, 16:33

... liên kết (connection- oriented)  Kết n ối điểm - điểm (point-to-point) và kết nối đa điểm (point-to-multi-point, multipoint-to-multipoint) 1.4. Mô hình tham chiếu và giao thức trên mạng 1.4.1. ... Learning bridge 3.2.3. Thuật toán cây spanning 3.3. Source routing bridge 3.3.1. Pure source routing bridge − Nguyên tắc chung − Thuật toán 3.3.2. SR-TB (Source routing to transparent bridging) ... [5] Jim Kurose, Keith Ross, Computer Networking: A Top-Down Approach Featuring the Internet, Addison-Wesley 2001 [6] J. Eberspaecher, Broadband Communication Networks, Lecture, Technical University...

Ngày tải lên: 24/01/2014, 04:20

... understanding the details of computer networking. Since the discussion of networking often includes talk of “extra layers”, this paper will address these unofficial layers as well. Finally , ... Classrooms, e-Learning, and On-site sessions, to meet your IT and management training needs. About the Author Paul Simoneau has over 37 years of experience in working with multiple aspects of computers ... founder and president of NeuroLink, Ltd., an international coaching and education com- pany specializing in professional development. NeuroLink’ s client list includes Cisco, AT&T, Lucent,...

Ngày tải lên: 24/01/2014, 09:20

... transitions a link to forwarding only if it is a point-to-point link. A point-to-point link is determined when the link is in full-duplex mode. 76736 MST Region CST 3-8 Cisco AVVID Network Infrastructure: ... Network Infrastructure: Implementing 802.1w and 802.1s in Campus Networks 956652 About this Guide Obtaining Technical Assistance Obtaining Technical Assistance Cisco provides Cisco.com as a starting ... Learning • Forwarding • Discarding The 802.1D states disabled, blocking, and listening have been merged into a unique 802.1w discarding state. Note In the Cisco implementation, the name blocking...

Ngày tải lên: 24/01/2014, 10:20

... metho- dology by incorporating advanced techniques from software engineering, moving toward third-genera- tion systems by incorporating expert systems, and returning to interactive techniques for ... propose an initial implementation. The expertise to be incorporated in this system includes linguistic, metalinguistic, and extralinguistic knowledge. The system is constructed by combining a "closed" ... taining and upgrading the lingware, even in an admittedly limited second generation CAT system, requires a good deal of expertise. Techniques are now being developed to maintain the linguistic knowledge...

Ngày tải lên: 08/03/2014, 18:20

... Denature DNA, 95 0 C, 30s-1min - Annealing, 55-60 o C, 1min  Step 3: Extension, 70-72 o C, 30s-1min Go to step 2, 32 cycles  Step 4: Holding, 4 o C, 0s  Steps programmed in PCR

Ngày tải lên: 23/03/2014, 22:20

... of paralinguistic code structure in computer conferencing. Moreover, the findings do not suggest that a clear code exists for the community of users. Rather, the code appears to be in a stage ... determining usage. The findings serve more to define questions for subsequent study than to provide answers about user variations. In addition, It is clear that the characteristics of the computer ... tonal and expressive informa- tion. Second, it is not easy to communicate this information. Users must work in computer conferencing to communicate information about their feelings and state of...

Ngày tải lên: 24/03/2014, 01:21

... SS (uplink traffic) and in the BS (downlink and uplink traffic). However, in this study, it is being addressed the scheduling packets for the uplink traffic in the BS. The uplink scheduling is ... environments, minimizing the average delay according to the MCSs used in the PHY. This algorithm also interacts with the polling mechanism, adapting the polling interval, and guaranteeing the mini- mal bandwidth ... is less complex than the one described in [18]. In [19], it was defined an analytical technique for obtaining an optimal polling interval. Using this polling interval, the BS should poll the SSs...

Ngày tải lên: 20/06/2014, 22:20

... particles in the algorithm. The training process could be p erformed manually by observing the behaviour of the particles in a specific system or using artificial intelligence techniques such as neural networks ... node selection process in an ad hoc network with 50 nodes. Both techniques are simulated and the gain of training the particles is demonstrated in relation to nontrained algorithm. In Table 2 we introduce ... channel gain in the RD link are chosen using similar method to that just described. However, the solution space will only contain the channel gains profile of the RD link described as following: S =     h RD 1 e j∅    2 ,    h RD 2 e j∅    2 ,...

Ngày tải lên: 21/06/2014, 17:20

... promising subject for research. References [1] M. Rabbat and R. Nowak, “Distributed optimization in sensor networks, ” in Proceedings of the 3rd International Symposium on Information Processing in ... dynamic fields. Online optimization of this criterion by adding or removing kernel functions from the dictionary also seems interesting. Finally, in a broader perspective, controlling the movement of ... of the training set, making them unsuitable for online applications. Therefore, it was essential to first propose a mechanism for controlling the increase in the model order as new input data...

Ngày tải lên: 21/06/2014, 17:20

Ngày tải lên: 21/06/2014, 22:20

Ngày tải lên: 21/06/2014, 22:20

Ngày tải lên: 22/06/2014, 22:20

Ngày tải lên: 22/06/2014, 23:20

Ngày tải lên: 23/06/2014, 00:20

Ngày tải lên: 27/06/2014, 01:20

Ngày tải lên: 11/07/2014, 21:20

... communication SNR levels. It is interesting to see that using more training symbols does not improve the performance of the MLE as expected, because inserting training symbols will reduce the energy ... first inequality in (76) and t he second inequality in (77) are satisfied. From the condition f(θ)(θ − Φ) < 0, it is not hard to find that the second inequality in (76) and the first inequality in ... Furthermore, since the estimation quality of the first stage is available, we use BLUE to obtain ˆ θ for exploiting the quality information instead of using the MLE in the M-step as in the standard...

Ngày tải lên: 20/06/2014, 04:20