KT IPTV (4K UHD) Service
(2) 'Most Popular Channels Now' (9-Channel View)
(3) 4-channel View
KT also offers 4-channel view service. This service is pretty similar to LG U+'s and has the following two options:
Figure 1. 4-channel view (operator-selected 4 sports channels)
In a recent test we conducted by using KT Giga Internet, Samsung's UHD TV and Kaonmedia's UHD STB , we found all 4 multicast streams are transmitted to STB in both cases - whether operator-selected or user-selected (see the screen shot of the traffic in Figure 2).
We also confirmed that both options allow for re-arrangement of the channels in the screen. So, a user can move channels around, for example, from the main window (seen in the left side of the figure below) to one of the 3 sub-windows (seen in the right side of the figure below), or the other way around.
Table 1. Codec and streaming information measured in 4-channel view (of operator-selected 4 sports channels)
Resolution | Codec | Encoding rate | Streaming rate | Network BW | QoS | |||||
Main window | SPOTV | 1920x1080 (Full HD) | H.264 | 4:2:0 | 10.9 Mbps | 11.2 Mbps | CBR | 0x80 | ||
Sub window 1 | SBS Sports | 720x480 (SD) | H.264 | 4:2:0 | 2.5Mbps | 3.5 Mbps | 3.6 Mbps | CBR | 0x80 | |
Sub window 2 | KBS N Sports | 720x480 (SD) | H.264 | 4:2:0 | 2.5Mbps | 3.5 Mbps | 3.6 Mbps | CBR | 0x80 | |
Sub window 3 | MBC Sports+ | 720x480 (SD) | H.264 | 4:2:0 | 2.5Mbps | 3.5 Mbps | 3.6 Mbps | CBR | 0x80 |
For 4-channel view, network bandwidth of 22Mbps (=11.2+3.6+3.6+3.6) is required.
Figure 2. Screen shot of traffic in 4-channel view (of operator-selected 4 sports channels)
The user-selected 4-channel view also had the same results as seen in Figure 2. KT's 4-channel view (operator or user-selected) allows all 4 channels to be independently transmitted in individual multicast streams. As a result, channels can be switched between the main and sub-windows, which makes KT's service different from others'.
In summary, KT's 4-channel view service features 3 SD sub-windows (of 3.6 Mbps each, in 720x480) and one Full HD main window (of about 11Mbps, in 1920x1080). Viewing all 4 channels in UHD (3840x2160) is not technically possible, yet.
I personally was very satisfied with the quality of the service (both operator and user-selected options). Especially, watching 4 different news channels all at once with a peace of mind that I am not missing any news was a great experience.
What I liked about the service most was that I could watch just what I wanted without having to watch all the annoying advertisements. Apparently, this kind of service will change the way people watch TV from now on.