| In all networks that utilize a broadcast type of physical layer the control of the channel access is a very complex and important problem. The term link activation is used to describe the union of all procedures and protocols that determine the momentary association of the broadcast medium with the participating network entities. Mobile radio communications—by definition—rely on a shared broadcast medium, requiring very complex link activation solutions.; In this dissertation we investigate link activation in mobile radio networks from different perspectives. We look in detail into medium access protocols of packet switched networks and provide solutions to the improvement of link activation issues in multihop radio based packet switched networks—so called ad hoc networks. We show several methods to combine traditional medium access protocols in order to achieve lower delays, higher through-put, or reliability in the reception of packets by all physical neighbors. We then investigate never solved but important link activation issues in a new specification/standard—Blue-tooth—that could be used for the deployment of large scale ad hoc networks. We provide algorithms, that select the links to be activated in network with Bluetooth nodes.; To give a more comprehensive overview of link activation issues in radio networks, we also investigate circuit switched cellular radio technologies. We provide a framework for call degradation and analyze its effects on the link activation subtask of the call admission control. We show, that with our approach, important link activation cell characteristics can be improved, e.g., call blocking probabilities can be reduced. |