Abstrak

ABSTRACT

Nowadays, the system of W-CDMA which is used in communication requires a mechanism to maintain interference level to be exactly below the threshold determined by call admission system. In this case, Call Admission Control (CAC) is proper mechanism to control new-call traffic. This algorithm will control the call admission; whether a call can be accepted based on the stated rule in order to keep the interference level staying below the threshold and guarantee that new calls will be having good quality of service.

In this final project, the author worked about the performance of Noise Rise based Call Admission Control in W-CDMA seen from Blocking Probability, Dropping Probability, Blocking Data Probability and when the threshold is being varied. In this final project, matlab is used to simulate the performance. There are some parameters used in the simulation, namely Blocking and Dropping Probability Simulation Parameter, Calling-time varied Blocking Probability Simulation, Calling-time varied Blocking Data Probability Simulation, and the comparison between Blocking and Dropping Probability in term of threshold measurement.

Based on the result of the analysis and simulation, it can be stated that the result of the comparison of Blocking Probability with the average of users availability in which the Blocking Data Probability is bigger than both Blocking Probability and Dropping Probability, longer the calling-time in both voice and data communication, bigger the blocking and dropping probabilities. In addition, another result of this work is about the result of the comparison between Blocking Probability and Dropping Probability with threshold. It can be seen that bigger the threshold value used, smaller the Dropping and Blocking probability used. Finally, by the simulation and the analysis done, it can be concluded that to get good QoS level in Noise Rise, it’s necessary to use proper threshold namely 2.5.

Keywords: W-CDMA, Noise Rise, Call Admission Control (CAC), Blocking Probability, Dropping Probability, Quality Of Service (QoS)

ABSTRAK

Sistem W-CDMA yang digunakan dalam sistem komunikasi dewasa ini memerlukan suatu mekanisme untuk mempertahankan level interferensi tetap berada di bawah level threshold yang ditentukan dalam pengaturan kedatangan panggilan. Dalam hal ini Call Admission Control (CAC) merupakan mekanisme yang tepat digunakan untuk mengatur trafik panggilan baru. Alogaritma ini mengatur suatu panggilan akan diterima atau ditolak berdasarkan ketentuan yang akan ditetapkan sebelumnya sehingga besar level interferensi tetap berada di bawah threshold dan menjamin panggilan baru mempunyai quality of service (QoS) yang baik.

Dalam tugas akhir ini dibahas tentang unjuk kerja Noise Rise based Call Admission Control pada WCDMA dilihat dari Probabilitas Blocking, Probabilitas Dropping, dan Probabilitas Blocking Data, serta unjuk kerja Noise Rise based Admission Control apabila nila threshold divariasikan. Dalam hal ini, penulis menggunakan matlab dalam simulasi unjuk kerja. Terdapat beberapa parameter yang digunakan dalam simulasi, yakni Parameter Simulasi Probabilitas Blocking dan Dropping, Parameter Simulasi Probabilitas Blocking dengan Variasi Waktu Kependudukan, Parameter Simulasi Probabilitas Blocking Data dengan Variasi Waktu Kependudukan dan Parameter Simulasi Perbandingan Probabilitas Blocking dan Dropping dengan besaran Threshold,

Dari hasil analisis dan simulasi diperoleh hasil perbandingan probabilitas blocking dengan rata-rata jumlah user dimana nilai probabilitas blocking data (D-BP) lebih besar dari probabilitas blocking (BP) dan probabilitas dropping (DP); semakin lama waktu pendudukan pada komunikasi suara (voice) maupun komunikasi data maka besarnya probabilitas blocking dan probabilitas dropping semakin besar; hasil simulasi perbandingan probabilitas bocking dan probabilitas dropping dengan besarnya threshold terlihat bahwa semakin besar nilai threshold yang digunakan maka probabilitas blocking dan dropping semakin kecil. Dari analisis dan simulasi yang dilaksanakan dapat disimpulkan bahwa untuk memperoleh level QoS yang bagus pada algoritma Noise Rise digunakan threshold yang ideal yaitu 2.5.

Kata kunci:      W-CDMA, Noise Rise, Call Admission Control (CAC), Probabilitas Blocking, Probabilitas Dropping, Quality Of Service (QoS)