As part of upcoming expanded 4K content offerings via its Xfinity in UHD catalog, Comcast announced this week that it plans to launch an Ultra HD set-top box later this year. “The box, called the Xi4, will run on Comcast’s cloud-based, IP-capable X1 platform, enabling customers to create ‘virtual 4K linear channels’ via MSO’s UHD library,” reports Multichannel News. The company is also developing the Xi5 STB to support high dynamic range content. Late last year, Comcast launched an on-demand streaming app initially for Samsung UHD TVs.