Telecommunications – Radiotelephone system – Zoned or cellular telephone system
Reexamination Certificate
1999-12-17
2003-06-03
Vuong, Quochien (Department: 2681)
Telecommunications
Radiotelephone system
Zoned or cellular telephone system
C455S067150, C455S226100, C455S226200
Reexamination Certificate
active
06574472
ABSTRACT:
CROSS-REFERENCES TO RELATED APPLICATIONS
(Not Applicable)
STATEMENT REGARDING FEDERALLY-SPONSORED RESEARCH AND DEVELOPMENT
(Not Applicable)
REFERENCE TO AN APPENDIX
(Not applicable)
BACKGROUND OF THE INVENTION
1. Field of Invention
The invention is directed towards a transmitting/receiving device for amplification of the transmitted signals between a stationary transmitting station and a mobile transmitting station in a full-coverage radio network and also towards a process for operating such a transmitting/receiving device.
2. Description of the Related Art
The various possibilities of mobile radiotelephones were recognised very quickly by the business world and in the meantime have formed the basis for the success of many a businessman. This results from the advantage that, in principle, a person can be reached everywhere, and consequently at any time, via a mobile radiotelephone. However, this does not apply without restriction. For, as a consequence of the low transmitting power of mobile radiotelephones, house walls of normal thickness are already able to bring about such an attenuation of the radio signals that the received field strength is insufficient for communication. Therefore the communication often fails precisely at those times when a businessman is located together with his mobile radiotelephone in his own house or office. As a result, many a business deal can slip though his fingers, and many businessmen would be pleased if the received field strength in their own house or office were sufficient for communication.
Co-channel broadband repeaters have already been employed for this purpose. In this case the decoupling between transmitting aerial and receiving aerial is very critical, and interference phenomena arise as a result of the amplification of additional frequencies which are not required, as well as, in certain circumstances, a heightened background noise, so these devices have not found widespread application in practice.
Although a transmitting/receiving device for amplification of the radio signals in a closed building has become known from EP 0 342 858, the installation effort associated with such a device is considerable, since on the one hand an aerial has to be placed on the roof of the building, and on the other hand this transmitting/receiving device is provided with a band-pass filter, the frequency of which has to be tuned by a person skilled in the art to the frequencies that are used in the radio cell in question. The effort associated with the installation of such a system is therefore enormously high.
This results in the problem giving rise to the invention, namely to create a transmitting/receiving device for selective amplification of, exclusively, the channels pertaining to a radio cell, which can be installed without prior knowledge and also with minimal effort and consequently also by technically unskilled people.
BRIEF SUMMARY OF THE INVENTION
The invention solves this problem by means of a device for automatic recognition of the radio channels or radio frequencies that are used in a radio cell pertaining to the radio network. Although the transmitting/receiving device according to the invention is, on the one hand, transparent—that is to say, it is not perceived at all, either by the radio network or by a mobile transmitting station—it is nonetheless provided with its own intelligence which permits it to be harmoniously integrated into the “frequency landscape” of the radio network. With a transmitting/receiving device of this type, therefore, no manual equalisation whatsoever of filter frequencies has to be carried out; rather, the setting-up procedure in accordance with simple rules which are specified in an operating manual is sufficient.
The channel spectrum of conventional mobile radio networks encompasses several types of radio channel: in each radio cell there is at least one broadcast control channel (bcch) which is constantly available for all mobile radio units and which, in the event of a call, allocates to said mobile radio units one of several slow dedicated control channels (sdcch) on which the transmission parameters for a radio link to be established between the radio network and the mobile station are then exchanged. For the actual communication, use is then made of traffic channels (tch). According to the GSM standard, each frequency channel comprises eight time-slots, each of which can be used as a bcch, sdcch or tch. On the other hand, the bcch, sdcch and tch which are used in a radio cell must not be assigned to the same frequency channel. In the following, the term “channel” is to be interpreted to mean “frequency channel”. Since these frequency channels may be distinctly remote from one another in the frequency spectrum, the invention provides that a parallel transmitting/receiving branch, but preferably several such branches, is/are arranged in the transmitting/receiving device according to the invention.
Depending on the channel structure, of the radio network in question, the slow dedicated control channels and/or the traffic channels may in each instance be combined to form neighbouring groups. In such a case it is possible that the bandwidth of a transmitting/receiving branch comprises not only a single radio channel but several radio channels simultaneously, so that the latter are amplified jointly.
In order that the transmission frequencies of the broadcast control channel, of a slow dedicated control channel and/or of a traffic channel can be adapted arbitrarily so as to conform to the local conditions in the radio cell in question pertaining to the radio network, the transmitting frequencies of different transmitting/receiving branches should be capable of being set independently of one another. This also applies, for example, to transmission branches which are connected in antiparallel manner for bidirectional communication.
On an increasing scale, radio networks are currently being packed by frequency-converting repeaters which, however, with the exception of the frequency conversion, are otherwise transparent. Such repeaters define separate radio cells with transmitting frequencies that are delimited with respect to the neighbouring radio cells and have the characteristic feature that a radio signal with identical content is transmitted on the uplink and downlink sides of the repeater via two different transmitting frequencies, whereby the channel-number that is transmitted on the channel in question for the purpose of identification coincides exclusively with the transmission channel of the radio interface on the downlink side between the frequency-converting repeater and a mobile transmitting station, whereas this channel information for the “internal-network” communication between the actual, stationary transmitting station and the frequency-converting repeater does not coincide with the channel frequency that is used there. Here the invention provides that the transmitting/receiving device according to the invention is operated parallel to such a frequency-converting repeater—that is to say, it is directly coupled on the uplink side to the actual, stationary transmitting station and directly coupled on the downlink side to the mobile transmitting station. In this case the transmitting/receiving device according to the invention has to reproduce the frequency conversion of the repeater, for which purpose it is necessary that the frequencies of the uplink-side and downlink-side radio interfaces of a transmitting/receiving branch are capable of being set independently of one another. By this means, the transmitting/receiving device according to the invention can be operated both in radio cells without frequency conversion and in radio cells with frequency-converting repeaters.
To the extent that the transmitting/receiving device in question is operated in the radio cell of a frequency-converting repeater, the received signals and the signals transmitted further are decoupled from one another in frequency terms, so that it is possible to integrate an uplink-side aerial and a downlink-side aerial
Foster Frank H.
Kremblas, Foster Phillips & Pollick
Littlefeet, Inc.
Vuong Quochien
LandOfFree
Transceiver for amplification between stationary and mobile... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Transceiver for amplification between stationary and mobile..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Transceiver for amplification between stationary and mobile... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3099177