Korean Experience in iptv service Customization Prof. Sunghun Park Dept of Mgt. Info. Sys
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- IPTV client customizations
- 5. References
| Korean Experience in IPTV Service Customization
Prof. Sunghun Park Dept. of Mgt. Info. Sys. Myongji University Seoul, Korea Abstract IPTV services in Korea have started from 2008 and have gained more than 40% market share of total TV subscriptions including cable TV by end of 2016(more than 10 million IPTV subscriptions)[7]. IPTV services are being provided by three major communication companies in Korea (KT, LGU+, SKT). Typical Korean IPTV service is being offered by company specific set-top box as client, Internet backbone networks and content servers. A detail of a typical IPTV service is well explained in NETMANIAS blog [2]. Korean internet community and forums [3, 4] have done IPTV service customization to overcome set-top box limitations such as no recordings, one viewing per one setup box, limited watching location tied to setup box, etc. These customizations have been done using open source software such as kodi [5] and tvheadend [6]. This paper summarizes these IPTV customization activities and discusses its pros and cons. Lessons for future IPTV services can be learned from these open source activities.
Typical IPTV service consists of three services, LIVE streaming through multicasting, mobile LIVE streaming service through multicasting and VOD (Video on Demand) service through unicasting. All IPTV services needs company specific client device called STB (set-top box)[8] which lets TV users select proper LIVE channels or pay per view videos. These setup box doesn’t allow any recordings and is lack of mobility. Most STBs are powered through wire so need to be installed to specific location. They are too heavy to carry around. They don’t come with screens and needs to be connected to TV or monitor set. These STBs are company specific such that every IPTV Company demands its own STB, though all three IPTV service company use very similar IP multicasting protocols. Details of Internet multicasting are explained in a NETMANIAS blog article [9]. This company specific STB approach can be compared to NETFLIX that provides services on web, tablets, mobile devices, etc. [10]. The portion of LIVE streaming channels is very high comparative to VOD(video on demand) service though the portion of VOD service grows in times. LIVE streaming uses Internet multicast protocol called IGMP snooping. Each channel runs a copy of LIVE video stream packets over Internet backbone network. Just one copy of packet is needed compared to N copies of packets for unicasting of VOD for N TV users. Each household requests a particular packet stream through STB and Internet AP(access point). Replicate of requested video packets are being delivered for viewing the channel. Compared to IPTV multicasting method, Netflix is designed to support maximum choices for TV users. Each TV request is handled by each unicast of video stream. So network backbone can waste its bandwidth by delivering multiple same copies of video packets. Netflix need to setup massive content replicate delivery system to cover wide range of areas. Otherwise this unicasting approach may overload network backbone to stall. To make better backbone network usage, NETFLIX content delivery system uses a distributed content replicate system. Each TV user connect to nearest content delivery system so that unicasting network usage is limited within a local area, not effecting the whole backbone network. But Netflix TV users have most choices from almost all the contents available within NETFLIX content database. Korean IPTV service compromises network bandwidth and user choices. If recordings of IPTV client are allowed, Korean IPTV approach may provide a better solution for TV user’s choices and network backbone usages. Video recording of IPTV clients need a flexible DRM (Digital rights management)[11] to protect the copy right of content providers. Netflix uses the extreme and simple way of protecting copyright. All contents should be stream serviced and won’t be allowed to be saving into local clients. If local savings are allowed, DRM can be very complicated. Playing back stored videos can be very restrictive or can be very flexible such as it can be encoded into smaller bandwidth and streamlined into mobile devices at remote.
To replace IPTV client and extend its functionality to be able to save video streams into local files, open source video server, Tvheadend [6] is selected to do its jobs. There are other candidates such as MythTV [12], VLC media player [13], etc. Tvheadend was chosen because it is one of the most active open source projects in home entertainment and one of the flexible solutions for IPTV. Tvheadend supports several input sources including IPTV streams. For setting up IPTV channels, all multicasting server IP address and port numbers are needed. This information is private and company specific but there are several community efforts to hack them by some scripts [3] and some tools [14]. All stream server IP addresses and port numbers need to be entered into Tvheadend configuration like Figure 1 
Figure 1. Setting up each IPTV channel To let TV users be able to save programs, EPG [15] needs to be set up properly. Tvheadend supports multiple EPG sources. There is no central EPG database available in Korea. Microsoft and Naver provided its EPG as a service and both stopped providing EPG service. Company specific is offering EPG, especially covering only the channels the company is serving. Community’s efforts [3] have been done to hack these companies specific EPG available at the company’s web site and convert them into XML so that Tvheadend can read them into its server. Tvheadend EPG can be checked or searched through EPG tab like Figure 2. A central database of EPG needs to be setup and should be shared by all the people. Maintenance of each channel EPG should be done by each content provider directly. This kind of central efforts can save efforts and reduce errors within EPG. Each IPTV companies are offering currently same copy of EPG. The only differences are list of channels they provide. Currently almost all channels in two IPTV companies are DRM free. Most LIVE channels can be accessed and manipulated through Tvheadend. But one company is applying encryptions on many channels. Encrypted stream need to be decrypted first for viewings and savings. 
Figure 2. Tvheadend EPG tab Recording and converting video streams can be done at Tvheadend server. Using EPG and Kodi client, user can reserve recordings of program. Recorded programs can be played back through Kodi client. Figure 3 show saved programs at Tvheadend server, which can be viewed later on. 
Figure 3. Recorded videos at Tvheadend server
A company specific STB has many limitations. Only one viewing is allowed per each STB, no recording of programs is allowed, and STB is fixed to a location due to its weight and power supply. All these limitations can be overcome by replacing Kodi [5] with IPTV STB. Kodi runs almost all computer platforms such as PC, Mac, Android, Linux, etc. Apple IOS is the only OS where Kodi can’t run due to Apple AppStore policy. Figure 4 shows multiple Kodi running on several devices at the same times. The biggest Kodi is running on raspberry pi2 connected to TV. Right Kodi is running on MacBook Pro. The smallest Kodi is running on Android smartphone. 
Figure 4. Several Kodi running A combination of Kodi and Tvheadend solved all the limitations of current STB (set-top box) client. One viewing per one STB, limited mobility of STB, no recording of videos for later viewing. Kodi running on smartphone and tablet let users watch TV wherever users are. But to support various wireless communications like 3G or LTE, the capability of converting video resolutions is mandatory at Tvheadend server. Unless video streams are converted into proper communication bandwidth, freezing and broken images happen so that regular viewing can be impossible. Converting video resolution format may have heavy loads on CPU of Tvheadend server. So enough computer power may be needed to support mobile viewings. Making recording reservations can be done using EPG. Figure 5 show a way of making a recording reservation at a channel. Visiting records submenu under TV menu like Figure 6 can do watching recorded videos. 
Figure 5. Window for recording program 
Figure 6. TV submenus including recordings Kodi is being developed for a platform for view multimedia including IPTV. It supports playing music, videos, pictures and extension programs as well. Kodi provides more functions than regular STB and is being developed actively. For IPTV viewing, only one plugin for tvheadend server in Figure 7 is applied. Korean IPTV customizations are done on LIVE TV streams only. VOD (Video on Demand) function cannot be offered due to its company specific closed implementation. 
Figure 7. Tvheadend PVR add-on module
Korean IPTV market is dominated by ISP (Internet Service Provider) companies and content multicasts do delivery IMGP snooping that minimize loads on backbone network trunk. Live TV stream channels are major service compared to VOD (Video on Demand) of Netflix. But Korean IPTV services are being offered through company specific STB (set-top box), which offers very strict and limited service only. Netflix doesn’t require any specific devices at all. Netflix is available to any device that can run Netflix application and don’t ask users to pay for company specific devices at all. Netflix offers family account so that all the family can watch his/her favorite program on any device available. Korean Internet Community have showed what Korean TV users want from IPTV by customizing IPTV service by using open source software, Kodi and Tvheadend. This customization is possible because IPTV service companies are not encrypting their Live TV streams yet. If channels are encrypted to protect copyright of content provider, this customization won’t work. But Kodi and Tvheadend with proper authentication checks and DRM (Digital Right Management) may be the right choice for Korean TV service companies to compete with foreign competitors like Netflix. IPTV clients with local saving capability may use network bandwidth more efficiently than Netflix that uses Unicast and content replicate methods. As video upgrades from HD (High Definition) to 4K and UHD (Ultra High Definition), the required network bandwidth will grow dramatically. The unicast method of Netflix may put heavy loads on network and will ask massive upgrade of network. Multicast IP packet snooping for Live TV streams and client saving of wanted videos may prove a better solution than unicast. Android set-top box from China or raspberry Pi can replace company specific IPTV STB (set-top box) with 1/10 of current STB costs. These android boxes can be upgraded easily and used for other purpose by installing other applications. Kodi and Tvheadend can be customized so that they can do proper billings and support DRM by adding extra add-ons. Company specific STB may provide short-term profit to IPTV service companies but this closed solution may be wrong in long term. Hardware and software for STB need to be open so that competition can reduce hardware cost and software innovation. Korean central service of EPG is highly needed. The current EPG services are company specific so that lists of channels supporting are different and there is no common EPG format. 5. References
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