ed delay for real-time gaming (which is an emerging service) or V2X (vehicle to X) messages. For mission critical services, such as mission critical push to talk (MCPTT) voice, and non-mission critical services there are defined QCIs 65 and 66, respectively, which were later added to the initial 9 QCIs. In a similar manner, QCI = 75 is also defined with GBR resource types, with a very low delay requirement for the V2X communication. QCI value 2 is targeted at video calls (and live streaming) which are sensitive to delay (e.g. in video calls the video has the same delay requirements as voice, due to the necessary syn- chronization between the audio and the accompanied video), while QCI = 4 is targeted 5.3 QoS in 4G Ultra-Broadband: LTE-Advanced-Pro at transfer of buffered video (i.e. VoD) provided by the mobile operator. All services served with GBR are in fact carrier-grade services because for Internet access services i is not possible to guarantee bitrates due to the network neutrality principle which is applied also for mobile Internet access. Therefore, Internet-based applications and services typically use QCIs values 8 and 9, which are served with the lowest priority, targeted for use by TCP-based applications (Web, email, Web-based services such as social networking, picture, and files sharing, etc.). There are defined non-GBR QCIs for voice, video calls, live video, critical and non- mission critical services. There are also defined QCI = 69 for mission critical signaling (which has the highest priority of all, noted as 0.5, which is higher priority than IMS signaling), QCI = 70 for mission critical data services and other TCP-based services (such as Web-based, email, etc.) with priority between GBR and non-GBR buffered video streaming, and QCI = 79 for V2X messages (with priority set in the range for non-GBR real-time and interactive services such as video streaming, voice, gaming, browsing, etc.). While in the past the most demanding service regarding delay was the voice, currently it is being "overrule