, which is the time interval that the UE waits for, after waking up, to receive possible downlink con- trol channels; inactivity-timer, which measures the duration of time from the last successful detection that the UE waits to successfully decode a downlink control channel. If the UE fails to detect a relevant downlink allocation, it goes back to sleep mode; retransmission- timer measures the duration of time when a HARQ retransmission is expected; and cycle, which specifies the periodic repetition of the on-duration followed by a possible period of inactivity [16]. 172 Chapter 1 1.6 Quality-of-Service Framework We begin this section with a review of QoS framework in LTE to set the stage for the 5G QoS framework. As shown in Fig. 1.84, in EPC, the user traffic is classified into different SDFs each associated with different QoS classes based on the type of the service that is being provided through the SDFs. Different QoS rules are then applied to each SDF. Since SDFs are delivered through EPS bearers in an LTE network, the EPS bearer QoS has to be controlled in a way that SDF QoS is maintained. In an LTE network, the user traffic (IP flows or IP packets) is classified into SDF traffic and EPS bearer traffic. An SDF refers to a group of IP flows associated with a service that a user is utilizing, whereas an EPS bearer refers to IP flows of aggregated SDFs that have the same QoS class. The SDF and EPS bearers are detected by matching the IP flows against the packet filters, that is, SDF tem- plates for SDFs or traffic flow templates (TFTs) for EPS bearers. These packet filters are preconfigured by network operators in accordance with their policy and each of them typi- cally consists of 5-tuple (source IP address, destination IP address, source port number, des- tination port number, and protocol ID). In other words, in LTE network, IP flows with the same service characteristics that match the packet filters of an SDF template are designated to an SDF. SDFs that match the packet filters of a TFT are mapped to an 