port format signaled in the scheduling assignment on PDCCH. The recommended trans- mission rank is an average over all the feasible set of sub-bands; the precoder matrix recommendation can be sent per sub-band (i.e., for different sub-bands, the UE may recommend different precoder matrices to use). The frequent reporting of CQI, pre- coder matrix, and transmission rank recommendations, commonly called channel feedback reporting (CFR), allows one to follow the fast fading link fluctuations with the adjustment of the multiantenna transmission parameters as well. However, the MIMO transmission mode (i.e., whether transmit diversity, spa- tial multiplexing, or beam forming mode is used) is configured semistatically via RRC signaling. The different MIMO transmission modes also imply different con- figurations of the required fast time scale channel reports and thereby the resources that need to be reserved on the uplink control channels for the channel reporting. The codebook restriction is also configured via the RRC protocol. In the case of codebook restriction, the eNode B can restrict the set of precoder matrices that the UE can recommend in the channel feedback report. 4.2.8 MBMS Resource Control The delivery of multicast broadcast multimedia services (MBMS) is supported in LTE via the following two transmission modes: MBMS single frequency network (MBSFN) transmission mode. In this mode of operation, multiple cells are transmitting exactly the same signal on the same resource at the same time. When the same OFDM signals (same wave- forms) arrive at the UE with delay differences less than the cyclic prefix of © 2009 by Taylor & Francis Group, LLC Long Term Evolution: 3GPP LTE Radio and Cellular Technology the OFDM signal, the multiple signals will be constructively added by the UE receiver without any additional action in the receiver. Basically, the signals arriving from different cells will appear exactly the same for the UE receiver as multipath components of the same signal. This mode of opera- tion is suitab