3,762 research outputs found

    WCDMA in Malaysia

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    Wideband Code Division Multiple Access (WCDMA) A 3G highspeed digital data service provided by cellular carriers that use the time division multiplexing (TDMA) or GSM technology worldwide, including AT&T (formerly Cingular) and T-Mobile in the U.S. WCDMA works on WCDMA cell phones as well as laptops and portable devices with WCDMA modems [1]. Users have typically experienced downstream data rates up to 400 Kbps [1]. WCDMA has been used in the Japanese Freedom of Mobile Multimedia Access (FOMA) system and in the Universal Mobile Telecommunications System (UMTS); a third generation follow-on to the 2G GSM networks deployed worldwide [1]. Although TDMA and GSM carriers both use TDMA modulation, WCDMA stems from CDMA. Part of the 3GPP initiative, the International Telecommunication Union (ITU) refers to WCDMA as the Direct Sequence (DS) interface within the IMT-2000 global 3G standards [1]

    Analysis of adaptive algorithms for an integrated communication network

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    Techniques were examined that trade communication bandwidth for decreased transmission delays. When the network is lightly used, these schemes attempt to use additional network resources to decrease communication delays. As the network utilization rises, the schemes degrade gracefully, still providing service but with minimal use of the network. Because the schemes use a combination of circuit and packet switching, they should respond to variations in the types and amounts of network traffic. Also, a combination of circuit and packet switching to support the widely varying traffic demands imposed on an integrated network was investigated. The packet switched component is best suited to bursty traffic where some delays in delivery are acceptable. The circuit switched component is reserved for traffic that must meet real time constraints. Selected packet routing algorithms that might be used in an integrated network were simulated. An integrated traffic places widely varying workload demands on a network. Adaptive algorithms were identified, ones that respond to both the transient and evolutionary changes that arise in integrated networks. A new algorithm was developed, hybrid weighted routing, that adapts to workload changes

    A Tutorial on Cross-layer Optimization Wireless Network System Using TOPSIS Method

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    Each other, leading to issues such as interference, limited bandwidth, and varying channel conditions. These challenges require specialized optimization techniques tailored to the wireless environment. In wireless communication networks is to maximize the overall system throughput while ensuring fairness among users and maintaining quality of service requirements. This objective can be achieved through resource allocation optimization, where the available network resources such as bandwidth, power, and time slots are allocated to users in an optimal manner. Optimization-based approaches in wireless resource allocation typically involve formulating the resource allocation problem as an optimization problem with certain constraints.. These techniques provide practical solutions with reduced computational complexity, although they may not guarantee optimality. In summary, optimization-based approaches have been instrumental in studying resource allocation problems in communication networks, including the wireless domain. While techniques from the Internet setting have influenced the understanding of congestion control and protocol design, specific challenges in wireless networks necessitate tailored optimization techniques that account for interference, limited bandwidth, and varying channel conditions. power allocation problem in wireless ad hoc networks Cross-layer optimization refers to the process of jointly optimizing the allocation of resources across different layers of wireless networks, the interactions between different layers become more complex due to the shared medium and time-varying channel conditions.  Nash equilibrium, where no user can unilaterally improve its own performance by changing its strategy. Game theory can capture the distributed nature of wireless networks and provide insights into the behavior of users in resource allocation scenarios Additionally, heuristics and approximation algorithms are often employed in wireless resource allocation due to the complexity of the optimization problems involved. In traditional cellular systems, each user is allocated a fixed time slot for transmission, regardless of their channel conditions. However, in opportunistic scheduling. Alternative parameters for “Data rate Ž kbps, Geographic coverage ,  Service requirements , cost ” Evaluation parameter for “Circuit-switched cell, CDPD, WLAN, Paging, Satellite.” “the first ranking training is obtained with the lowest quality of compensation.

    Packet forwarding for heterogeneous technologies for integrated fronthaul/backhaul

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    Proceeding of: 2016 European Conference on Networks and Communications (EuCNC)To meet the future mobile user demand at a reduced cost, operators are looking at solutions such as C-RAN and different functional splits to decrease the cost of deploying and maintaining cell sites. The use of these technologies forces operators to manage two physically separated networks, one for backhaul and one for fronthaul. To solve this issue, transport networks for 5G will carry both fronthaul and backhaul traffic operating over heterogeneous data plane technologies. Such an integrated fronthaul/backhaul (denoted as 5G-Crosshaul) transport network will be software-controlled to adapt to the fluctuating capacity demand of the new generation air interfaces. Based on a proposed data- and control-plane architecture for 5G-Crosshaul, we propose a frame format common to both fronthaul and backhaul traffic as well as a corresponding abstraction of the forwarding behavior of the network elements. The common frame format and the forwarding abstraction define the information to be exchanged at the southbound interface (SBI) of the 5G-Crosshaul Control Infrastructure (XCI). This paper derives requirements for the SBI from 5G use cases.The authors of this paper have been sponsored in part by the project H2020-ICT-2014-2 “5G-Crosshaul”: The 5G integrated fronthaul/backhaul” (671598
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