Apparatus for arbitrating requests for access from slave units by associating the requests with master units and determining the relative pendency thereof in a radio base station transceiver

Claim 1

A base station transceiver for use in a cellular radio digital communication system which includes a plurality of mobile station transceivers and wherein communication with the mobile station transceivers is carried out by the base station transceiver over a plurality of time division multiplex frequency division channels; characterized in that said base station transceiver comprises: a plurality of data processing units for coordinating and processing signal transmission in said channels, some of said data processing units being master units, others being slave units, and at least one being an arbitration unit; an internal data bus to which all of said data processing units are coupled to provide for data transfer there-between; each master unit being operative to request access to said bus in order to initiate a data transfer cycle and to supply control signals to other master units and to slave units; each slave unit being assigned to a master unit and being operative under control of the assigned master unit to request access to said bus for data transfer service when necessary to carry out a function ordered by the assigned master unit; and said arbitration unit being operative to arbitrate all pending requests for access to said bus by different requesting units by (i) examining all pending requests to determine the relative periods of pendency thereof; (ii) determining for each pending request a master unit associated therewith; and (iii) granting access to the master unit associated with a selected one of the pending requests; wherein access to said bus by a requesting slave unit is only granted by way of a master unit to which the requesting slave unit is assigned.