Note: Descriptions are shown in the official language in which they were submitted.
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Description
Mobile radio transmitting/radio receiving
device, in particular the mobile unit of
a cordless telephone
The invention relates to a mobile radio trans-
mitting/radio receiving device, in particular the mobile
unit of a cordless telephone, according to the precharac-
terizing clause of patent claim 1.
Mobile radio transmitting/receiving devices are
used in wireless telecommunication as terminals in a
wireless telecommunication system. Wireless tele-
communication systems currently available on the market
are, for example, cordless, mobile-radio, satellite-
radio, trunked mobile-radio telephones etc.. The mobile
radio transmitting/radio receiving devices of the wire-
less telecommunication systems have in common device-
specific and -individual voltage supply units, from which
the devices obtain the electrical energy necessary for
telecommunication operation. Voltage supply units used
are, for example, batteries, chargeable accumulators
etc.. The power or energy consumption of the individual
wireless teleco~ml~niGation systems is essentially deter-
mined by the type of wireless telecommunication, which is
specified by d.ifferent ranges in the transmi~ion of
radio messages. Owing to the smaller transmission range,
the power or energy consumption is much less in the ca~e
of cordless telephones conforming to the DECT st~n~rd
with a transmission range of about 250 m (_igital
European Cordless _elecommunication; cf. (1) Nach-
richtentechnik Elektronik 42 (Jan./Feb. 1992), No. 1,
Berlin; U. Pilger; 'Struktur des DECT-St~n~rds" [Struc-
ture of the DECT ~t~n~rd]; pages 23 to 29; (2) Philips
Telecommunication Review: "DECT, Universal Cordless
Access System"; Vol. 49, No. 3, 09/1991, pages 68 to 73)
than in the case of cellular mobile radio telephones
conforming to the GSM st~n~rd with transmi~sion ranges
of about 2 to 15 km (_roupe & éciale Mobile or global
systems for mobile communication; cf. Informatik
Spektrum, Springer
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Verlag, Berlin, year 14, 1991, No. 3, pages 137 to 152,
"Der GsM-st~n~rd - Grundlage fur digitale europaische
Mobilfunknetze" [The GSM 6t~n~rd - basis for digital
European mobile radio networks]). For example, the
transmitting power in the case of DECT-gpecific cordless
telephones is about 250 mW (cf. European Tele-
communication St~n~rd - final draft - ; prETS 300 175-2,
5/1992, part 2, Chapter 5 and Annexe A.2, ETS-Institute
06921 Sofia Antipoles, France), while in the case of
mobile radio telephones about 2000 mW are required.
Figure 1 shows the basic structural design of a
DECT-specific cordless mobile unit PTl (Portable
Termination). Cordless mobile unit~ of such a structural
design have been introduced onto the market under the
product degignation "Gigaset 952" (c$. German journal:
Funkschau 12/1993, pages 24 and 25; "Digitale Freiheit -
Gigaset 952: Das erste DECT-Telefon" [Digital freedom -
Gigaset 952: The first DECT telephone]; author:
G. Weckwert - 1993). The structural design of the
cordless mobile unit is also known, furthermore, from (1)
the German journal: Funkschau 10/1993; pages 74 to 77;
title: "Digital kommunizieren mit DECT - DECT-Chipsatz
von Philips" [Digitally communicate with DECT - DECT chip
set from Philips]; author: Dr J. Nieder and (2) WO
94/10812 (Figure 1 with the associated description).
The cordless mobile unit PTl is assigned to a
cordless base station FT (Fixed _ermination) via a first
radio channel FRl. The cordless base station FT may, for
example, be further connected internally via a second
radio ch~nel F~2 to a further cordless mobile unit PT2
and externally via a telephone line FSL to a public or
private ~Ych~nge VA. While the cordless mobile unit PT2
is identical in construction to the cordless mobile unit
PTl, the cordless base station FT, based on WO 94/10812
(Figure 1 with the associated description), is con-
structed according to the representation in Figure 2.
In the case of DECT-specific cordless telephones,
the base station FT may be assigned up to 12 mobile units
PT. The electrical energy for the cordless
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telecommunication with the
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cordless base station FT is obtained by the cordless
mobile unit PTl from a voltage supply unit SVE assigned
to the mobile unit PT1. This voltage supply unit SVE
essentially comprises an accumulator, which is charged at
a charging station in the power-down mode of the cordless
mobile unit PT1 and can, furthermore, be exchanged if
need be. The voltage supply unit SVE serves here in
particular as an energy source for the transmitting
power, with which the cordless mobile unit PT1 transmits
radio messages to the cordless base station FT. These
radio messages are subsequently passed on by the base
station FT on the basis of the internal connection to the
mobile unit PT2 or on the basis of the external connec-
tion as a line me~sage to the e~ch~n~e VA. The radio
message is in this case generally transmitted with a
transmitting power of about 250 mW.
In order that the mobile-unit-individual radio
messages to be transmitted are also transmitted with this
transmitting power, the cordless mobile unit PT1 has a
microcontroller MIC and a burst-mode controller BMC,
which are connected to each other. While the micro-
controller MIC is connected to the voltage supply unit
SVE, the burst-mode controller BMC has in the trans-
mitting direction a connection to a radio unit FRT of the
mobile unit PT1. In the receiving direction, the cordless
mobile unit PT1 is capable, on account of a field inten-
sity measurement device FSME arranged between the radio
unit FRT and the burst-mode controller BMC, of acquiring
and evaluating field intensity values FSW inherently
contained in the reception message.
Furthermore, transmission errors, so-called CRC
values (Cycle _ed-n~nry Check; A-CRC, X-CRC; cf. in thi~
respect European _elecl ln;cation StAn~d - Final Draft
- ; prETS 300 175-3, 5/1992, Part 3, Chapters 6.2.5 and
10.8.1, ETS Institut~ 06921 Sofia Antipoles, France), can
be detected and evaluated in the burst-mode controller
BMC. The evaluation of the field intensity values FSW and
of the transmission error values A-CRC, X-CRC
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takes place in the microcontroller MIC. Thus, these
values are used, for example, according to WO 94/10764 as
an "Antenna Diversity" criterion or according to WO
94/10769 as a criterion for muting the radio
transmitting/radio receiving device (mute function).
In order to increase the mAY;~llm duration of
operation of the cordless mobile unit PTl wih an
n~hAnged voltage supply unit SVE, i.e. an l~nchAnged size
and energy capacity of the accumulator, according to
EP-0 330 166 B1 power excesses in radio systems are
avoided by regulating the transmitting power in depend-
ence on the transmission quality and the reception field
intensity. This take~ place by a combination of a recep-
tion level assessment and a quality assessment in a base
station of the mobile radio system based on the phase
jitter determined from the signal arriving in the base
station being used as control criteria for regulating the
transmitting power of a mobile handset of a mobile radio
system by performing the transmitting power regulation
below a specific reception level, predetermined as a set
value, on the basis of the control criterion of the
quality of the received signal and switching over the
transmitting power regulation above a specific reception
level to the control criterion of the reception level and
~k;ng the transmitter of the mobile handset reduce or
increase the transmitting power if the phase jitter or
the reception level exceeds or falls below a pre-
determined set value. A disadvantage in the case of this
type of transmitting power regulation is that the trans-
mitting power of the mobile handset can be regulated onlywith the support of the base station of the mobile radio
system.
The object underlying the invention is to enrich
the prior art in a mobile radio transmitting and/or radio
receiving device, in particular a mobile unit of a
cordless telephone, to the extent that both the known
disadvantage is avoided and the power consumption of the
mobile
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radio transmitting/radio receiving device is reduced and
consequently the maximum possible duration of operation
of the device is increased.
This object is achieved on the basis of the mobile radio
transmitting/radio receiving device defined in the
precharacterizing clause of patent claim 1 by the feat-
ures specified in the characterizing clause of patent
claim 1.
In the case of the mobile radio transmitting/
radio receiving device according to the invention, which
may be designed for example as the mobile unit of a
cordless telephone or as the mobile handset of a mobile
telephone, the device-specific transmitting power is
automatically regulated in dependence on special infor-
mation, for example field intensity values and/or trans-
mission error values (claims 7 and 8), received and
acquired in the mobile radio transmitting/radio receiving
device. For using the mobile radio transmitting/radio
receiving device as the mobile handset of a mobile radio
system according to claim 10, data relating to the
transmitting power of the mobile radio transmiter are
additionally required and are preferably contained in the
special information. For regulating the transmitting
power, the mobile radio transmitting/radio receiving
device according to claim 2 has a sequential control
circuit, in which the value of the controlled variable
(here the device-specific transmitting power) follows the
changing value of the co~m-n~ variable (here the received
and acquired special information).
Advantageous developments of the invention are
specified in the subclaims.
An exemplary embodiment of the invention is
explained with reference to Figure 3.
Figure 3 shows on the basis of Figure 1 the
cordless mobile unit PT1 modified for the purposes oi the
invention. The modification of the cordless mobile unit
PT1 consists in that the
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microcontroller MIC of the mobile unit PTl is assigned a
control circuit RR, which is formed by individual program
modules assigned to the microcontroller MIC. With this
control circuit RR, the field intensity values FSW and
transmission error values A-CRC, X-CRC available in the
microcontroller MIC are used and evaluated for regulating
the transmitting power of the mobile unit PTl. The
control circuit is in this case preferably designed as a
sequential control circuit, in which the value of the
controlled variable (here the transmitting power to be
regulated) follows the changing value of the C~m~= n~
variable (here the field intensity values FSW and trans-
mission error value~ A-CRC, X-CRC) (cf. in this respect
DIN 19226, May 1968 edition, "Regelungstechnik und
Steuerungstechnik - Begriffe und Benennungen" [Control
engineering - definitions and terms], Chapters 9 and 10,
pages 17 to 20).
The field intensity values FSW can be used to
derive a distance from the cordless base station FT,
while the transmission error values A-CRC, X-CRC can be
used to determine a measure of the quality of the
received radio messages. After this evaluation, the
controlled reduction or increase in the transmitting
power is initiated in the radio unit FRT by the micro-
controller MIC via I/O ports or registers, which may beassigned for example to the burst-mode controller BMC.
The regulation may in this case take place both con-
tinuously and in just a few large increments (dis-
continuously). Furthermore, it is possible to perform the
regulation as two-step control or multi-step control.
The control circuit RR described above for
regulating the tran~mitting power of the cordless mobile
unit PTl may alternatively also be used in mobile
handsets of mobile radio systems. For the regulation
referred to it is then necessary, however, for the
command variable additionally to contain data relating to
the transmitting power of the mobile radio transmitting
device. This is necessary because, in contrast to
cordless telephones, in the case of mobile radio
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telephone~ the respective
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transmitting device no longer trangmits with a constant
transmitting power.
