Abstract: The invention is related to radio resource usage in cellular telecommunication systems, more accurately to admission control methods used in establishing of new connections. In a method according to the invention, a bearer request is checked with two different tests before it is admitted or rejected. A test of a first kind is used for overall control, i.e. all bearers are treated in a roughly similar way. A test of a second kind is used for controlling bearers, which present a high load to the network. A bearer request must then pass a combination of a test of the first kind and a test of the second kind in order to be admitted. A two-part test according to the invention is able to efficiently handle both even and skewed traffic.

Abstract: The base station of a cellular radio system is in radio communication with the mobile stations of the cellular radio system by using mutually essentially orthogonal channels. In order to control the use of the channels, said channels are divided into groups with different priorities, so that the base station uses primarily the channel group with the highest priority. Channels belonging to different priority groups are put to use in a selective manner as a response to the loading of the base station.

Abstract: A method and system for performing a pre-reserved handover in a mobile communciation system is suggested, wherein an additional handover preparation step is performed by determining at least one candidate base station in advance, to which handover is likely to be performed. An additional downlink connection to the at least one candidate base station is established before handover execution is performed. Thereby, proper handover can be ensured for cell environments in which a serving cell disappears very quickly from a mobile station.

Abstract: A cellular radio system comprises base stations and mobile stations. In order to execute handover, there is chosen a group of potential new base stations and estimated the carrier to interference ratio that each potential new base station included in said group could offer. The carrier to interference ratio can be estimated separately for real-time and for non-real-time connections and/or for uplink and downlink connections.

Abstract: A radio connection is adapted to an environment changing over the connection in a cellular radio system where the radio traffic between the base station and the mobile stations is arranged on a multiple access principle, according to a given frame structure (402). For a given radio connection between the transmitting device and the receiving device, there is reserved a given data transmission capacity in said frame structure. The receiving device measures the connection quality (103) during the connection, and on the bases of the measured connection quality, the size of the data transmission capacity (104, 110) reserved for said connection in said frame structure is changed.