Cell #7 Cell #3 Cell #1 Cell #6 Cell #4 Cell #5 Figure 4.12 Illustration of frequency offset assignment to cells in the proposed ICIC algorithms. If a collision occurs, the scheduler will need to assign more resources (RBs) to the UE to compensate the loss in the carried number of bits due to any of the pre- ceding consequences (i.e., fewer bits per RB, more retransmission, etc.). This means that more resources (and maybe longer time) will be used to carry the same amount of user bits in the no-ICIC case than in the ICIC case. However, it is important to observe that this difference in the number of RBs used to carry the given amount of data will not necessarily appear in the most typical performance measure, in the user throughput. Whether the collisions will have an effect on the throughput or not depends to a large extent on the type of the traffic model. We can differentiate full buffer and nonfull buffer traffic models, each of which can be further classified as peak rate limited or non-peak rate limited. The full buf- fer assumption means that an unlimited amount of data is waiting for transmission (i.e., basically one traffic source could utilize the full bandwidth in each subframe, unless the available power limits the number of RBs that can be assigned). In the nonfull buffer case, it is assumed that the traffic source generates finite amounts of data in bursts with certain interarrivals, where there is an idle period between the service time of two consecutive bursts (i.e., there is no continuous load on the system). Peak rate limitation means that the there is an upper limit on the maximum number of bits (or number of RBs) that can be assigned for transmission within a given time interval for the particular UE. In the simplest case, the peak © 2009 by Taylor & Francis Group, LLC Long Term Evolution: GPP LTE Radio and Cellular Technology rate limitation can be interpreted on the subframe time scale, imposing a limit on the maximum number of RBs that can be assigned to the UE in one subframe. In what fol