Base station having at least two radio set units located at a distance from a central processing unit and a method of using the same

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT The preferred embodiments of the base station according to the invention are apparent from the appended dependent claims 2 to 7.
In the following, the invention will be explained in more detail by means of one preferred embodiment with reference to the accompanying figure illustrating a block diagram of the base station according to the invention.
The base station shown in the figure can be a base station of the GSM system, for example.
The structure and operation of the GSM system is explained e.
g.
in The GSM System for Mobile Communications, by M.
Mouly & M.
Pautet, Palaiseau, France, 1992, ISBN:2-9507190-0-0-7, wherefore it will not be described more closely in this context.
The base station in the figure differs from known base stations in that the equipment of the base station is decentralized to a large geographical area.
Therefore there is only a central processing unit of a base station BTS at the actual site of the base station to which radio set units 1 to 4 are connected via data transmission channels 5.
One or more radio set units are advantageously integrated (not shown in the figure) into the central processing unit of the base station BTS or placed in its immediate vicinity.
The central processing unit of the base station BTS comprises an operating and maintenance unit OMU that attends to the communication between the base station and the base station controller BSC and controls the operation of the base station.
The central processing unit BTS also comprises several baseband frame units BBU1 to BBU10 (Base Band Unit) which generate baseband modulation signals for radio set units 1 to 4, and which process the signals received and transmitted to the baseband by the radio set units 1 to 4 for forwarding them to the base station controller BSC.
Subscriber data and control data transmitted in frame units BBU1 to BBU10 are channel coded, interleaved and placed into TDMA frames (Time Division Multiple Access) after which they are supplied to the radio units situated in the radio set units in which they are modulated into a TDMA burst to a desired transmission baseband, that is, a radio channel