Public safety organizations provide a stable and secure environment for the society. Wireless communication between public safety officers is very important to transmit voice or data during an emergency crisis. When the public communication networks can not provide service during crisis, disaster and high traffic cases, Professional Mobile Radio systems (PMR) such as conventional Association of Public Safety Communications Officials (APCO25) and trunked Digital Mobile Radio (DMR) systems are needed to improve the service quality and to provide uninterrupted service provided to the users. While providing continuous voice and data service, it is very important to efficiently select the base station to be served and to ensure that a mobile user can seamlessly attach from one base station to another base station while moving within a cell. In this sense, it is critical to determine the base station to be served by efficient cell selection algorithms. Cell selection is the process of deciding the base station which provides services to the users. Cell selection plays an important role in balancing the system load and thus overall system performance. By means of efficient cell selection algorithms, it is aimed to reduce the waiting time and to connect a base station as soon as possible while establishing reliable transmission link for PMR systems in emergencies. In this thesis, the full set and the reduced set based cell selection algorithms are proposed by considering load based and traffic based cell selection algorithms. In load based cell selection algorithm, each user selects the base station according to the calculated utility value determined based on both received signal strength indicator (RSSI) value and cell load information. In addition, it is performed that each user selects the base station according to the calculated utility value determined based on both biased signal to interference plus noise ratio (SINR) value and cell load information. In traffic based cell selection algorithm, while calculating cell load information, traffic intensity is considered. The performances of the proposed algorithms are evaluated based on with various scenarios by taking into account different performance metrics for conventional APCO25 and trunked DMR systems.