neighboring cells further in this example no user equipments are shown in the two neighboring cells so as to identify the serving cell from the neighboring cells alternatively each of the two neighboring cells may serve their own user equipments for example when the cell cell 2 is a serving cell of other ues the cells cell 1 cell 3 are neighboring cells the base stations bs 2 bs 3 also coordinate uplink scheduling of the user equipments in the cells cell 2 cell 3 respectively in a way similar to the base station bs 1 fig2 is a block diagram illustrating an example of a base station in the cellular radio communication system in fig1 the base station bs comprises a transceiver module tr a scheduler sch and an interface unit rnci the transceiver module transmits downlink data to user equipments ue 1 ue 2 and receives uplink data from the user equipments ue 1 ue 2 over a carrier the scheduler sch schedules downlink transmission and uplink transmission the base station bs communicates with the radio network controller through the interface unit rnci the main function of the base station bs is to perform the air interface l 1 processing channel coding and interleaving rate adaptation spreading etc it also performs some basic radio resource management operations as inner loop power control and scheduling the scheduler sch in the base station bs determines which time instance a user equipment ue 1 ue 2 can transmit data and what is the maximum data rate that the user equipment ue 1 ue 2 is.