Performance of voice over IP (VoIP) over a wireless LAN (WLAN) for different audio/voice codecs

Content Provider	Semantic Scholar
Author	Mohd, Alias
Copyright Year	2007
Abstract	Kapasiti dan Kualiti Perkhidmatan (QoS) adalah antara dua isu penting yang perlu diselesaikan sebelum penggunaan VoIP melalui WLAN dapat dikomersialkan. Kapasiti banyak bergantung kepada jenis speech codec yang digunakan. Oleh sebab itu, beberapa jenis codec dinilai (G.711, G.723.1 dan G.729 'codec') untuk menentukan kesannya terhadap kapasiti yang mampu ditanggung. Selain daripada itu, faktor–faktor lain yang memberi kesan kepada QoS seperti kehilangan paket, jitter, throughput, dan lengah masa dalam beberapa kapasiti rangkaian yang berbeza dikenal pasti. Ini dilakukan dengan menjalankan penyelakuan trafik VoIP ke atas WLAN menggunakan 'Network Simulator 2 (ns2)' dan menganggarkan kualiti suara berdasarkan E–model. Keputusan daripada penyelakuan disahkan menggunakan analisis secara teori. Kesimpulannya, codec G.711 membenarkan akses 5 nod VoIP secara serentak, G.723.1 membenarkan sehingga 15 nod dan G.729 membenarkan sehingga 5 node bagi kualiti suara melebihi R=70 dalam jarak 10 meter daripada access point (AP). Kata kunci: Kualiti perkhidmatan (QoS), LAN tanpa wayar (WLAN), suara melalui IP (VoIP), codec suara Capacity and Quality of Service (QoS) are two of the most important issues that need to be resolved before the commercial deployment of VoIP over wireless LAN (WLAN). The capacity is highly dependent on the chosen speech codec. Thus, several codecs are studied (namely, G.711 and G.723.1 and G.729) to determine their effects on the available capacity supported. On top of that, factors affecting QoS such as packet loss, jitter, throughput, and delay for various capacity networks are studied in this paper. This was done by simulating VoIP traffics over the WLAN using Network Simulator 2 (ns2) and predicting voice quality based on E–model. The simulation measurements were verified by the theoretical analysis. In conclusion, G.711 codec allows up to 5 simultaneous VoIP nodes, G.723.1 codec allows up to 15 nodes and G.729 codec allows up to 5 nodes for a voice quality greater than R=70 and distance 10 meter from VoIP nodes to access point (AP). Key words: Quality of service (QoS), wireless LAN (WLAN), voice over IP (VoIP), voice code
Starting Page	39
Ending Page	60
Page Count	22
File Format	PDF HTM / HTML
DOI	10.11113/jt.v47.266
Volume Number	47
Alternate Webpage(s)	https://jurnalteknologi.utm.my/index.php/jurnalteknologi/article/download/266/256
Alternate Webpage(s)	http://eprints.utm.my/5721/1/AliasMohd2007_PerformanceOfVoiceOverIP.pdf
Alternate Webpage(s)	https://doi.org/10.11113/jt.v47.266
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article