Bilişsel radyo ağında pu korumalı su iletimleri için omnet++ modeli

The studies in cognitive radio networks (CRN) mostly focus on how the secondary users (SU) can use the spectrum most efficiently if there is no primary user (PU) transmitting in the medium. However, PU transmission must be protected while SU utilizes medium successfully. For this reason, in this thesis, we take into account PU transmission and studies are done to minimize the destructive effects of SU transmissions on PU transmission. We develop two different interweave spectrum sharing CRN models in the OMNET++ simulation program. In our first study, we model a single-channel CRN with a PU and a SU transceiver pairs based on INET Framework. One of the two modules that INET offers as a Medium Access Control (MAC) protocol, the Carrier Sense Multiple Access / Collision Avoidance (CSMA/CA) based CsmaCaMac module is suitable for SU. The other MAC protocol module offered, AckingMac, allows the user to transmit without listening to the medium, but it is not compatible with the CsmaCaMac module and does not have enough features for PU transmission. Therefore, we have developed a new module for PU transmission, which is compatible with the CsmaCaMac module. The PU module enables the user to transmit the medium without listening and has a retransmission and an acknowledgment (ACK) mechanism. Our second study is two-channel CRN model that we developed based on the crSimulator study. While crSimulator provides infrastructure for multi-channel CRN, it does not provide real communication for PUs. The PU node is only used as a transmitter to keep the medium busy. Packets transmitted from PU do not have a receiving node and point-to-point transmission is not performed. Therefore, in our two-channel CRN model, we model both receiver and transmitter PU nodes and guarantee the transmission of packets to the peer node with a retransmission and an ACK mechanism. We verify the two developed CRN models by taking various simulations. We examine the packet transmission for both users by changing packet sizes and the interval time of the PUs and performing the SU transmission over a relay node.