Cell Extension for Fast Moving Users in a RoF Network

摘要

Radio-over-Fiber networks providing millimeter-waveband (mm-waveband) signals using wavelength-division-multiplexing techniques are foreseen as the next paradigm to provide broadband wireless access services.Millimeter wave band operating RoF provides high bandwidth due to its high frequency feature, so it is perfectly adapted to these system. But a limited cell range with propagation losses leads to frequent handovers when hopping from one remote antenna units to another causes numerous packet losses strongly, thus to reduce the whole system bandwidth. Moving cells concept is introduced for avoiding the classical handover time. Nevertheless, frequent switching in optical switches is inevitable in the resolution which also result in dropping calls. Therefore, a concept of cells extension to allievate the burden of handover in contral station is proposed. However, since the adjacent RAUs employ the same channel in an extensive larger cell, co-channel interference exists in the extension scheme. To avoid this, a time slot distributor in the star-tree architecture of RoF network to support the moving cell extension is proposed and a MAC protocol is designed for this concept to avoid the co-channel interference.