using) the medium; and B: how often and for how long the bearer gets access to the medium (see also Figure 4.5). © 2009 by Taylor & Francis Group, LLC Architecture and Protocol Support for RRM Maintain system level and O&M information: - System BW, "admission headroom" - Static partitioning of resources - QoS targets per radio bearer class delay Resources for the new RB are available - average and peak bit rate without "major" impact on the ongoing RBs? ("Abundance of resources" regime) "Tight resource" regime Maintain state information: - Parametrized table of ongoing flows Select RBs whose associated resources - UE measurements Measurement - eNB measurements Based Admission are affected by the admission of the new RB. Control (MBAC) (Maybe only non-GBR bearers are affected.) Estimate the resources that can be reallocated. Upon EPS (GBR) Bearer Setup Request: Estimate required A and B for the new radio bearer Resources for the new RB are - Estimate resource requirements for (can be made) available such that QoS A and B: and system stability are OK? Resources at eNB Resources at UE - Estimate (potential) QoS degradation of ongoing RBs Admit Reject Figure 4.5 A high-level (schematic) view of a possible admission control algo- rithm. It is important to realize that because AC is not standardized, different realizations of LTE RANs will run different admission control algorithms. In this figure we depict an approach according to which the AC algorithm divides the RAN load situation into a lightly loaded and a heavily loaded regime in order to facilitate fast admission (accept/reject) decisions. The first aspect (A) depends on the signal-to-interference-and-noise (SINR) ratio and the applied MCS on the scheduled resource blocks as well as on the number of scheduled resource blocks. The B aspect is determined by the load (in terms of ongo- ing EPS and physical layer [PHY] bearers) and the associated QoS requirements. It follows that the input parameters to the admission control algorithm must allow for the evaluation 