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for high data rate and less delay. In this case, the In this paper, an interconnection between two spectrum management procedure does not require different simulators is proposed to establish and contending for frequencies to maximize the Quality realize a vertical coupling between network layer and of Service (QoS) performance. After some link layer simulators. This investigation is done for improvement it can keep the best channel for two reasons. One is to find the effects of upper layers guaranteed traffic e.g. video transmission. Video on the spectrum management, which is specified and transmission requires high transmission rate and less implemented in the link layer, and the other one is to delay. If the available QoS is not sufficient for see thperformance improvement of the network video the network can select a better channel by see the performance improvement Of the network .layer protocol by providing link layer info. Coupling using the spectrum management. Hence, the is done and tested for a simple scenario and some spectrum management protocol for the link layer can . . ..~~~~~~~~~be controlled bv the information from upper layers.data exchange results are shown in this paper. y r r y

Today spectrum demand for wireless communication is tremendous and even keeps growing. In contrast, there are no blank spots in the spectrum map. Additional spectrum opportunities are available in unlicensed bands and so-called nonexclusively licensed bands which are currently made available. This non-exclusive spectrum can be exploited whenever a license holder is not active.These spectrum opportunities cannot be exclusively accessed so that multiple systems need to coexist. Existing MAC protocols need to be enhanced to allow a system to meet own Quality of Service (QoS) demands while allowing other coexisting systems to meet their QoS requirements.In this work, methods for capacity calculation known from cellular networks are extended and applied to a scenario of coexisting IEEE 802.16 (WiMAX) systems. Developed methods are used to evaluate enhancements for interference mitigation which lead to increased capacity.