Impact of wireless channel parameters on quality of video streaming/ Belaidzio kanalo parametru itaka transliuojamo vaizdo kokybei

The problem of estimation of video quality obtained by end-user for mobile video streaming is addressed. Widely spreading mobile communication systems and increasing data transmission rates expand variety of multimedia services. One of such services is video streaming. So it is important to assess quality of this service. Consumers of video streaming are humans, and quality assessment must account human perception characteristics. Existing methods for user experienced video quality estimation as quality metrics usually use bit-error rate that has low correlation with by human perceived video quality. More advanced methods usually require too much processing power that cannot be obtained in handled mobile devices or intrusion into device firmware and/or hardware to obtain required data. However, recent research shows that channels throughput dedicated to some service (e.g. video streaming) can be tied to QoS perceived by an end-user indicator. This paper presents a research on impact of wireless channel parameters such as throughput and jitter on quality of video streaming. These wireless channel parameters can be easily obtained by monitoring IP level data streams in end-user's device by fairly simple software agent for indication of video streaming QoS. Ill. 5, bibl. 10 (in English; abstracts in English and Lithuanian). Plintant mobiliojo rysio sistemoms bei didejant duomenu perdavimo spartai, daug?ja ir multimedijos kategorijos paslaugu pasiula. Taigi svarbu ivertinti siu paslaugu kokybe. Vaizdo transliavimo paslaugos vartotojai yra zmones, todel kokybe turi buti vertinama atsizvelgiant i zmogaus suvokiama vaizdo kokybe. Dauguma vaizdo kokybes vertinimo metodu yra paremti klaidu atsiradimo tikimybe, kuri mazai susijusi su zmogaus suvokiama vaizdo kokybe. Pazangesniems metodams dazniausiai reikalingi dideli skaiciavimo pajegumai, kuriu neturi mobilus irenginiai, arba reikia isiterpti i gamintojo programine ir (arba) aparatine iranga, siekiant gauti reikiamus duomenis. Taciau neseniai atlikti tyrimai rodo, kad kanalo pralaida skirta konkreciai paslaugai teikti, gali buti susieta su vartotojo patirtos QoS indikatoriumi. Straipsnyje nagrinejama belaidzio kanalo parametru, tokiu kaip pralaida ir sytavimas, itaka transliuojamo vaizdo kokybei. Sie belaidzio kanalo parametrai gali buti nesunkiai gaunami galinio vartotojo renginyje idiegtu QoS funkcija, stebint IP lygmens duomenU srauta. Il. 5, bibl. 10 (angl? kalba; santraukos anglu ir lietuviu k.).