 general- ized distributed cell can be regarded as the spaced MIMO structure (generalized distributed cells 4, 5, and 6 in Figure 2.2). When there are AEs distributed in each cell connected to the same AP, it changes to another structure called a distributed MIMO (AEs 1, 2, and 3). Additionally, UWB technology helps to realize the com- munication among several MTs nearby. Based on this, an AE in a cell and MTs within the corresponding coverage compose virtual MIMO structure (AE 18 and MTs 6, 7, and 8). The signals could be transmitted and received by all the antennas of the group by techniques such as MIMO, STC, and OFDMA (orthogonal frequency divi- sion multiple access). Therefore, the system's ability to resist interference could be improved, the handover times could be greatly decreased, and the system capacity could be increased. Furthermore, because the signal sources of the same general- ized distributed cell are identical, the MT does not need handover in intragen- eralized distributed cells. Only if the MT moves out of coverage of the current generalized distributed cell does the handover between the generalized distributed cells-generalized distributed cell handover occur. The generalized distributed cell handover can effectively avoid the frequent handover between cells. Generalized distributed cell handover is also classified into fixed handover and slide handover, © 2009 by Taylor & Francis Group, LLC Evolution from TD-SCDMA to FuTURE corresponding to the construction method of generalized distributed cells. Based on the slide handover strategy, the generalized distributed cell after handover could have some common areas with former generalized distributed cells. As shown in Figure 2.2, with the movement of MT4, the current generalized distributed cell (AEs 11, 12, and 13) that serves MT4 changes into other generalized distributed cells (AEs 12, 13, and 14). 2.2.2.1.3 Separation of Control Plane and User Plane Because the control plane and user plane scale differently in future data communi- cation, t