Handover Delay in Mobile WiMAX: A Simulation Study

Author(s):  
Bhaskar Ashoka ◽  
David Eyers ◽  
Zhiyi Huang
2011 ◽  
Vol 60 (2) ◽  
pp. 605-617 ◽  
Author(s):  
Ji Hoon Lee ◽  
Sangheon Pack ◽  
Taekyoung Kwon ◽  
Yanghee Choi

2016 ◽  
Vol 8 (1) ◽  
pp. 47
Author(s):  
Ammatia Risty ◽  
Rendy Munadi ◽  
Ridha Muldina Negara

IEEE 802.16e-2005 teknologi mobile WiMAX merupakan salah satu alternatif yang dapat memberikan datarate 15 Mbps yang lebih baik daripada teknologi 3G, WLAN, dan lain-lain. Mobile WiMAX juga memberikan cakupan area yang luas. Oleh karena itu, WiMAX mampu memberikan layanan berbagai macam aplikasi multimedia seperti VoIP, IPTV, Video conferencing. dan aplikasi real-time lainnya. Selain itu, Mobile WiMAX juga mendukung mobility secara portable, mobile, dan nomadic. Saat ini IPTV muncul pada mobile phone, yang dinamakan mobile TV dimana layanan IPTV akan dapat diakses dalam keadaan bergerak. Hal itu membutuhkan suatu teknologi yang mendukung mobility namun tetap dapat menerima layanan IPTV dengan baik. Teknologi mobile WiMAX adalah teknologi yang cocok untuk mendukung layanan IPTV khususnya untuk user yang sedang bergerak. Akibat dari user yang bergerak maka memungkinkan user tersebut melakukan handover. Penelitian ini menganalisis parameter unjuk kerja yang mempengaruhi pada mobile TV saat user melakukan  handover  pada jaringan mobile WiMAX seperti jitter, end to end delay, throughput, handover delay dengan skenario perbedaan kecepatan dan perubahan jumlah user dalam satu cakupan area. Berdasarkan hasil simulasi untuk skenario perbedaan kecepatan (maksimum 100 km/jam) diperoleh nilai end to end delay sebesar 23.234 ms, jitter sebesar 0.047 ms, throughput sebesar 637.723 Kbps. Sedangkan skenario jumlah user diperoleh nilai end to end delay 27.218 ms, jitter sebesar 0.057 ms, throughput sebesar 558.881 Kbps. Hasil dari kedua skenario menunjukkan bahwa saat kecepatan dan jumlah user naik maka parameter kualitas layanan turun namun masih memenuhi syarat kualitas layanan Mobile TV (IPTV).


2006 ◽  
Vol 11 (1) ◽  
pp. 12-24 ◽  
Author(s):  
Alexander von Eye

At the level of manifest categorical variables, a large number of coefficients and models for the examination of rater agreement has been proposed and used. The most popular of these is Cohen's κ. In this article, a new coefficient, κ s , is proposed as an alternative measure of rater agreement. Both κ and κ s allow researchers to determine whether agreement in groups of two or more raters is significantly beyond chance. Stouffer's z is used to test the null hypothesis that κ s = 0. The coefficient κ s allows one, in addition to evaluating rater agreement in a fashion parallel to κ, to (1) examine subsets of cells in agreement tables, (2) examine cells that indicate disagreement, (3) consider alternative chance models, (4) take covariates into account, and (5) compare independent samples. Results from a simulation study are reported, which suggest that (a) the four measures of rater agreement, Cohen's κ, Brennan and Prediger's κ n , raw agreement, and κ s are sensitive to the same data characteristics when evaluating rater agreement and (b) both the z-statistic for Cohen's κ and Stouffer's z for κ s are unimodally and symmetrically distributed, but slightly heavy-tailed. Examples use data from verbal processing and applicant selection.


Methodology ◽  
2016 ◽  
Vol 12 (1) ◽  
pp. 11-20 ◽  
Author(s):  
Gregor Sočan

Abstract. When principal component solutions are compared across two groups, a question arises whether the extracted components have the same interpretation in both populations. The problem can be approached by testing null hypotheses stating that the congruence coefficients between pairs of vectors of component loadings are equal to 1. Chan, Leung, Chan, Ho, and Yung (1999) proposed a bootstrap procedure for testing the hypothesis of perfect congruence between vectors of common factor loadings. We demonstrate that the procedure by Chan et al. is both theoretically and empirically inadequate for the application on principal components. We propose a modification of their procedure, which constructs the resampling space according to the characteristics of the principal component model. The results of a simulation study show satisfactory empirical properties of the modified procedure.


Methodology ◽  
2015 ◽  
Vol 11 (1) ◽  
pp. 3-12 ◽  
Author(s):  
Jochen Ranger ◽  
Jörg-Tobias Kuhn

In this manuscript, a new approach to the analysis of person fit is presented that is based on the information matrix test of White (1982) . This test can be interpreted as a test of trait stability during the measurement situation. The test follows approximately a χ2-distribution. In small samples, the approximation can be improved by a higher-order expansion. The performance of the test is explored in a simulation study. This simulation study suggests that the test adheres to the nominal Type-I error rate well, although it tends to be conservative in very short scales. The power of the test is compared to the power of four alternative tests of person fit. This comparison corroborates that the power of the information matrix test is similar to the power of the alternative tests. Advantages and areas of application of the information matrix test are discussed.


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