Mobile test set for a mobile-radio system

A mobile test set for testing a mobile-radio system containing system components to be tested and at least one operation and maintenance center. The mobile test set has a first interface for the exchange of test signals between the mobile test set and at least one of the system components and a second interface for the exchange of control signals between the mobile test set and at least one man-machine interface. The two interfaces are linked so that the exchange of the control signals takes place via at least one of the system components between the mobile test set and at least one man-machine interface installed in the operation and maintenance center.

BACKGROUND OF THE INVENTION 
1. Field of The Invention 
The present invention relates to a mobile test set for a mobile radio 
system containing system components to be tested and at least one 
operation and maintenance center. 
2. Background Information 
To check the operation of a given mobile-radio system (e.g., in the case of 
a very large number of subscribers, high changing traffic volume, or many 
coverage areas with greatly differing transmission conditions), various 
means are known. 
These are test sets or complex testing means, such as the test station 
illustrated on page 96 of the journal "Funkschau", No. 25, 1991. This test 
station is obtained if the D-network test set of Alcatel SEL is used 
"together with a laptop, a terminal, and a man-machine interface". 
The test set includes an interface for coupling it via a test link to the 
mobile-radio system, and a further interface for coupling it to means 
(such as the above-mentioned laptop) for operating the test set on-site by 
skilled personnel (experts). 
The test link is, for example, a radio link between the test set and a base 
station as specified in the GSM standard (GSM: Groupe Special Mobile, a 
working group of the CEPT for pan-European mobile radio, established in 
1982), or a standardized PCM30 transmission link for coupling the test set 
to a base station controller to be tested. The link between the test set 
and the laptop installed at the operator's position is designed to 
conform, for example, to the V.24 standard. The entire test station, i.e., 
the test set together with the operator's position, is mobile and, thus, 
usable at different locations within the mobile-radio system. 
SUMMARY OF THE INVENTION 
It is the object of the invention to design the mobile test set so that the 
need for the additional equipment and personnel hitherto required to set 
up a mobile test station is eliminated. 
This object is attained by providing a mobile test set having a first 
interface for the exchange of test signals and a second interface for the 
exchange of control signals wherein the two interfaces are linked so the 
exchange of control signals takes place by at least one system component 
between the test set and at least one man-machine interface according to 
the teaching of claim 1. 
According to the invention, provision is made for an exchange of control 
signals by means of the existing interfaces, so that the mobile test set 
can be operated from an operation and maintenance center of the 
mobile-radio system. This eliminates the need to operate the mobile test 
set at its location, since this can be done by technical means and by 
personnel of the respective operation and maintenance center. 
As the individual operation and maintenance centers, because of their 
monitoring and control tasks in the mobile-radio system, generally include 
the means necessary to control the mobile test set, such as computer, 
terminal, and system experts, use of the mobile test set is made possible 
without the need for additional equipment and personnel. 
Further advantageous features of the invention are described below. 
According to an embodiment of the invention, the exchange of control 
signals takes place via communication links which are already present in 
the given mobile-radio system and conform to a given standard, such as 
PCM30. These links may be both radio and wire communication links. The 
control signals are transmitted, for example, over time or frequency 
channels installed in these links. Accordingly, it is not necessary to 
provide any additional, i.e. new, links, but use is made of existing means 
and transmission capacities. 
According to another embodiment of the invention, the two interfaces 
together form a new single interface which conforms to a standard (e.g., 
the Abis interface specified in the GSM standard) and thus facilitates the 
use of the mobile test set in different mobile-radio systems provided that 
these systems include system components with the above standard interfaces 
.

DETAILED DESCRIPTION OFT HE PREFERRED EMBODIMENTS 
The given mobile-radio system contains an operation and maintenance center 
OMC with a built-in man-machine interface MM, various system components 
(e.g. base station SU1, base station controller SU2, mobile switching 
center SU3), and existing links xCOM, with the link RCOM between the 
mobile test set and the base station representing e.g. a TDMA radio link 
with eight time-slot channels as specified in the GSM standard, and the 
other links WCOM representing PCM30 wire transmission links. 
The mobile system test set MSTS includes a first interface I1 for coupling 
it to the base station SU1 via a radio link RCOM and, as in the prior art, 
for the exchange of test signals TS, which serve here to check the 
operation of the base station SU1. By the mobile system test set MSTS, the 
use of mobile stations is simulated, for example. Accordingly, the test 
signals TS correspond to the transmitted and received signals of at least 
one mobile station. By suitably shaping the transmitted signals, the 
mobile system test set MSTS can represent many radio-engineering problem 
situations, such as fading, multipath propagation, Doppler effect, and 
handoff. 
The control signals CS necessary to operate the mobile system test set MSTS 
are routed through a second interface I2 which, as in the prior art, can 
be used to couple the test set MSTS to an on-site man-machine interface MM 
(exchange of control signals with local operator's position, such as by a 
laptop). 
According to the invention, the second interface I2 is linked with the 
first interface I1 in such a way that the control signals CS are exchanged 
between the man-machine interface MM within the operation and maintenance 
center OMC and the mobile system test set MSTS for operation of the same. 
The linking of the two interfaces I1, I2 can be achieved, for example, by 
installing common interchange points (ports) or by providing for internal 
bidirectional protocol transfer. 
In the illustrated embodiment, the control signals CS are transmitted over 
the existing links (i.e., the TDMA radio link and two PCM30 transmission 
links in the mobile-radio system). 
The radio link RCOM is used here to transmit the test signals TS and the 
control signals CS. Consequently, the two linked interfaces I1, I2 form a 
single interface which is designed here as a GSM-standardized air 
interface. The test signals TS and control signals CS are transmitted in 
different TDMA time channels. 
Two existing PCM30 transmission links WCOM in the mobile-radio system, by 
being provided with at least one control channel, convey the control 
signals which permit operation of the mobile system test set MSTS from the 
operation and maintenance center. Information data, particularly measured 
data and test results from the base station, are also transmitted over 
these links in corresponding channels. 
By remote control of the mobile system test set MSTS, the mobile-radio 
system MRS and system components of the same (here base station SU1, for 
example) can be tested fully and exclusively from the operation and 
maintenance center OMC. 
If links already present in the mobile-radio system MRS are used for this 
purpose, it is not necessary to install additional links, in the test 
system as shown. 
In test configurations other than that of the illustrated embodiment, the 
first interface I1 can serve to exchange test signals over wire. In that 
case, the control of one or more base stations is simulated and checked, 
e.g., by PCM30 coupling of the mobile test system set MSTS to a base 
station controller to be tested. A combination of the two interfaces into 
I1, I2 a single standardized Abis interface permits simple and fast 
coupling to all system components having a corresponding standardized 
interface.