—The each user behaviour and preferences for the television channels transmission at anytime and anywhere makes changes in broadcast of the digital Internet Protocol Television. These changes are affected by the different users’ behaviour for the channel search and selection during the channel change process. It affects on the quantity of requests for the channel change and its processing time in the network. Due to this, the authors proposed a method that modifies the process of the channel change in order to reduce the processing time of the requests. This method was created according the authors’ proposed model of users’ behaviour for television channel change process. The results of experiments showed, that it also increase the user’s perceived quality assessment for Internet Protocol Television service. Behaviour, Channel zapping time, IPTV, QoE. I. INTRODUCTION HE IPTV (Internet Protocol Television) service providers are looking for the newer ways to attract the users and retain them due to the increasing offers of TV (Television) services and the expansion of the number of new competitors. According to the users, there is a need for an easily used electronic program guide (EPG), the fast change process of IPTV channel, the functionality during TV program selection and so on. The supply of IPTV channels must meet the viewing tastes for the each of users. So many researchers are working on new methods and platforms, which allow automatically recommend the list of user’s favorite channels or use IPTV services at any time [1]5[3]. All these needs influence the attractiveness of IPTV service in respect of QoS (Quality of Service) and QoE (Quality of Experience) parameters. TV channel change duration, called channel zapping time, is the most important criteria influencing the subjective IPTV QoE evaluation [4], because the user’s visual perception of IPTV quality based on the evaluation of TV This work was supported in part by the State Studies Foundation of Lithuania under Grant No. BMP965/2011. Rasa Bruzgiene is with Department of Telecommunications at Kaunas University of Technology, Studentu str. 505452, Kaunas LT551368, Lithuania (corresponding author to provide by e5mail: rasa.bruzgiene@ktu.lt). Lina Narbutaite is with Department of Telecommunications at Kaunas University of Technology, Kaunas, Lithuania (e5mail: lina.narbutaite@ktu.lt). Tomas Adomkus is with Department of Telecommunications at Kaunas University of Technology, Kaunas, Lithuania (e5mail: tomas.adomkus@ktu.lt). channel change process. It was determined that the biggest impact on the user's visual perception has a black screen on TV tuner during the channel change process [5]. It means that, the longer the user does not see the selected channel, the more negative attitude formed on IPTV quality. A longer channel zapping time not only negatively affects the user of the service, but also increases the problems in the delivery process. A longer channel change process affects the parameters of the service quality: higher network delay, the loss of IP (Internet Protocol) packets, wrong IP packets, etc. The scientific research showed that IPTV service becomes unacceptable if the channel zapping time is longer that defined by ITU – T G.1030 [6]. According to this recommendation the channel zapping time should not exceed 2 seconds. Shorter than 500 ms channel zapping interval is perceived as instantaneous and the user doesn’t perceive adversely effect of the change process. If the channel zapping time takes longer than 2 seconds, the user may become frustrated. Many research methods have been proposed to reduce channel zapping time and to increase IPTV QoE. Some methods that improve the video encoding, flow scheduling methods, prejoining channels, predictive tuning or modify Protocol Independent Multicast5Sparse Mode (PIM5SM) protocol have been proposed [7]5[12]. Every single or a set of components of TV channel change process affect IPTV service delivery by problems tracked both of service users and service providers [13]. However, in addition to main components, IPTV channel change process and its zapping time is also affected by factors of user’s behaviour. Due to this, the model of TV channels’ search and the selection of TV programs must be evaluated individually for each user in order to improve the current prediction’s accuracy. Therefore, we proposed the modified IPTV channel change process method, which includes the main new aspect 5 loading the streams of the IPTV channels of small resolution Picture in Picture (PiP) in the aggregated devices. The impact of the proposed method on the processing time of the TV channel change requests and IPTV QoE according to the model user’s behaviour presented in this paper. The created modified process enable to ensure require parameters of QoS to the service provider by reducing the load of the network due to smaller number of the requests for the TV channel change and a shorter route for transmission of the requests. Changes in IPTV users’ needs: model of user’s behaviour and preferences on channel change process R. Bruzgiene, L. Narbutaite and T. Adomkus T INTERNATIONAL JOURNAL OF CIRCUITS, SYSTEMS AND SIGNAL PROCESSING Volume 8, 2014 ISSN: 1998-4464 577