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This paper proposes a new algorithm called Path Associativity Centralized Explicit Congestion Control (PACEC). PACEC works on a Software Defined Networking (SDN) framework. In PACEC, a congestion control decision is based on global information network conditions. PACEC uses global information network to identify network resources along the path from the source to the destination and provides this...
In underlay cognitive radio (CR), secondary user (SU) are allowed to transmit simultaneously with primary user (PU) and must control transmission power to keep the aggregate interference still below PU's threshold, therefore, in underlay CR, SU will use lower transmission power than PU. However, the use of lower transmission power and interference due to PU and others SU cause SU performance decrease...
Interference is one of the factors influence the number of active sensors of the CDMA Wireless Sensor Network as it affects Eb/I0 on the received signal. The higher the interference, the smaller the capacity is. One of the methods to minimize the interference is cluster formation in the CDMA Wireless Sensor Network. Using cluster, the interference can be minimized because transmission power to send...
Long Term Evolution (LTE) technology brings a new feature called femtocells also called Enhanced Home NodeB (HeNB) which can improve indoor coverage area. On the other side, the HeNB cause interference, uplink and downlink interference. Uplink interference occurs between the user HeNB (HUE) and user eNB (MUE) and fellow HUE. This interference cause degrades system performance, especially in terms...
We proposed a new method for timing estimation in cognitive radio systems under a fractional bandwidth (FBW) scenario. A conventional timing estimation based on autocorrelation suffering performance reduction caused by interference and multipath channel distortion. The proposed method is developed based on normalized 4-th order moment for symmetric correlator. Based on these 4-th order moment, a binary...
Data consumption increased sharply, all triple play services such as Voice, Data-Internet & Video can be performed on one communication path, even fiber optic has also bandwidth limitations, previous studies tried to maintain the fairness among the users, but there is no fairness of service therefore the allocation of data transmission must be optimized as their needs. A Passive Optical Communication...
In this paper, we analyze flow-based routing schemes in SDN. Specifically, we study the flow-based routing performance; combining the knowledge of the link condition and updating the period for calculating the path. The framework uses centralized control of SDN where the SDN controller calculates available paths to determine the routing policy based on a global knowledge network. This flow-based routing...
This paper explains the design and implementation process of a microstrip antenna array on Ku-Band for satellite television reception. The proposed antenna was designed to operate at 11.8 GHz to 12.8 GHz with reflection coefficient or return loss ≤ 10 dB, and the antenna gain of ≥ 20 dBi. Antenna polarization was designed to be linear. The antenna was then fabricated on FR4 materials and shows that...
Software Defined Network is a new paradigm in data communication networks. In contrast to the traditional internet network, SDN separates the control function and the function forwarding. SDN controller operates on the principle of a centralized logical controller. This centralized control causes the controller to have a global network knowledge so that SDN can be more effective in managing the network...
In this paper, we present a mathematical analysis on the performance of uniformly distributed and non-uniformly distributed backoff timer based on binomial algorithm for contention window. We evaluates these protocols under mathematical modelling in order to analyze the average throughput, end-to-end delay and collision probability performance by using different value of hop distance during data transmission...
In OFDMA (Orthogonal Frequency Division Multiple Access) wireless system, environmental conditions and mobility of all users make the conditions of propagation of each user on all subcarriers changed at different times. Required radio resource allocation scheme that works with accurate, has a fairly low complexity and it is able to adapt to changing conditions. This research is to answer these issues...
Long Term Evolution Advanced (LTE-A) is a promising technology to achieve peak data rate of up to 1 Gbit/s in the downlink and 500 Mbit/s in the uplink. Because adjacent cells employs the same frequency in universal frequency reuse scheme, interference between adjacent cells may degrade the bit rate, particularly at the cell edges. Inter-Cell Interference Coordination (ICIC) based on carrier aggregation...
Routing protocols play important roles in mobile adhoc network performance. The Protocols find and decided the communication path with the routing algorithm to deliver the data along the networks. Channel qualities in wireless communication are an important factor in network performance. Previous research in routing protocol development did not much pay attention in this matter. This paper shows the...
In the future, mobile ad hoc network (MANET) is predicted to play more important roles for device communication with self organized infrastructure. Effectiveness of routing protocols and congestion control mechanisms, highly determines the performance of MANET. Previous research in protocol development did not pay much attention in selecting the appropriate protocol on other layers. Therefore, the...
We proposed a new method for accurate timing estimation in OFDM systems. A conventional timing estimation based on autocorrelation and crosscorrelation experience performance degradation due to multipath channel distortion. The proposed method is developed based on normalized 3rd-order central moment for symmetric correlator. Based on these 3rd-order central moment, a binary hypothesis testing problem...
Important factors that support the quality of communication in wireless ad hoc networks are routing and congestion controls. The protocols had many challenges in wireless ad hoc network such as high bit error, frequent changes of routing path, as well as limitations of power and bandwidth. To improve the performance of wireless ad hoc network, cross-layer optimization methods are currently gaining...
This paper describes the effect of power imbalance on multiuser detection of Direct Sequence Code Division Multiple Access (DS-CDMA) systems. Unlike the conventional single-user detection technique which considers interference between users or multiple access interference (MAI) as noise, in multiuser detection scheemes of DS-CDMA systems MAI is eliminated successively. However in the present of near-far...
An improved method for estimating the symbol timing offset based on symmetric correlator using statistical change of correlator in preamble-aided OFDM systems is presented. It uses a preamble structure that have symmetrical property and combines with statistical change of Correlator to achieve a near-ideal timing performance without degradation in multipath channel environment. Computer simulations...
This paper describes a successive multiuser detection technique for Direct Sequence Code Division Multiple Access (DS-CDMA) systems. In conventional CDMA system, single-user detection is employed, so that the interference between users or multiple access interference (MAI) component is considered as noise, which contributes to the statistics of detection variables affecting the quality of detection...
An efficient algorithm based on symmetric identical training symbol has been proposed for timing offset estimation in OFDM system. The scheme is based on the transmission of a training symbol composed of two identical halves that have symmetrical property in time domain. In this paper we improve this algorithm by adding phase shift to the second halve of training symbol at the receiver side. This...
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