Mtel is the biggest mobile operator in Bulgaria and is a wholly owned subsidiary of Telekom Austria Group (TAG). Mtel boasts millions of mobile subscribers but is working to expand the fixed network market and is binding mobile subscribers with fixed-network services. ZTE is well placed to help Mtel in develop its broadband user base.

ZTE has researched user behavior in Bulgaria and has introduced multiscreen integrated IPTV. This service allows subscribers to access the IPTV network through PCs, TVs, mobile phones and tablets. Customers can enjoy live TV, video-on-demand, reserved video recording, and OTT applications.

Mtel and ZTE trialed IPTV in September 2011 and signed a five-year cooperation agreement later that year. According to the agreement, ZTE would provide Mtel with customized end-to-end solutions, including IPTV middleware, digital rights management, a content delivery network, and set-top boxes. The scale of the network was expanded over several phases.

On February 12, 2013, Mtel showcased triple screen IPTV in a commercial launch and press conference in Bulgaria. This service allows mobile phones and tablets to access the IPTV system and supports broadcasting on a local triple screen client. The terminals can also share data and interact with a traditional STB. This is triple IPTV integration in its purest sense.

Professional Technical Solution

Mtel’s network previously used VBR encoding for channel streams that had large bit-rate fluctuations, i.e. 20 Mbit/s at the peak. Such fluctuations exceed the processing capacity of the STB and seriously affect channel broadcasting. ZTE worked out a number of technical solutions for Mtel:

●    CDN smoothly handles VBR streams, and STBs optimize UDP data processing to adapt to highly fluctuating VBR sources.

●    Unicast FCC is used to improve the speed of switching unicast channels and enhance user experience.

●    Fragment broadcast technology allows for time-shift broadcasting in the event of discontinuous recording caused by interruptible streams.

●    N+1 MDU backup increases the capacity of CDN nodes, and additional hardware investment is not needed.

●    IQAS is used to monitor the system in real time and improve user experience.

●    A security fortress is used to protect system security.

Swift Response

In January 2012, ZTE formed the Bulgaria Mtel IPTV commercial project team and started researching IPTV triple-screen service. In March, ZTE provided the first test version of the service. In April, Mtel Bulgaria put basic IPTV services into commercial operation. At the end of July, an optimized version of the service was released. In August, Mtel officially launched an IPTV triple-screen system. In September, a version for iOS and Android terminals was released. In November, Mtel commercially trialed the triple-screen service. In February 2013, the IPTV triple-screen service was officially commercialized in Bulgaria.

Efficient Customization

During implementation, ZTE leveraged its advantage of rapid customization to ensure Mtel could commercially launch IPTV on time. Mtel demanded single sign-on (SSO) on its existing network, so ZTE started working on the technology immediately and customized the logon process so that the IPTV system could seamlessly connect to Mtel’s existing system. The IPTV triple-screen system also needed to support a variety of mobile phone and tablet models. To meet this requirement, ZTE worked within a tight schedule to adapt its IPTV system to all software and hardware specified by Mtel.

Stable Subscriber Growth