AU2000258008B2

AU2000258008B2 - Method for the assembly of a mobile radio network base station and connection of the base station to the network

Info

Publication number: AU2000258008B2
Application number: AU2000258008A
Authority: AU
Inventors: Rudolf Ritter
Original assignee: Swisscom Mobile AG
Current assignee: Swisscom Mobile AG
Priority date: 2000-07-26
Filing date: 2000-07-26
Publication date: 2005-09-01
Anticipated expiration: 2020-07-26
Also published as: AU5800800A; CN1454436A; ES2228554T3; ATE276628T1; AU2000258008A1; EP1304005A1; JP2004505526A; WO2002009462A1; CN1199494C; DE50007826D1; EP1304005B1

Abstract

The invention relates to a method for the assembly of a mobile radio network base station comprising a mobile service switching centre (MSC) and one or more base station controllers (BSC) each with one or more base stations (BTS). The invention in particular comprises a method for the assembly of a base station of a public mobile radio network (PLMN), the connection of the base station with the public mobile radio network and the arrangement of a corresponding mobile radio network. The base stations are installed in existing constructions on public, open ground, said constructions having a mains electrical supply. The signal transmission of the radio frequency transmission occurs bi-directionally between base station and the base station controller by means of the mains electrical supply.

Description

Method for Setting up a Base Station of a Mobile Radio Network and Connection of the Base Station to the Mobile Radio Network The present invention relates to a method for setting up a base station of a mobile radio network and connection of the base station to the mobile radio network. The mobile radio network comprises a mobile-services switching center (MSC) and one or more base station controllers (BSC) each with one or more base stations (BTS), which mobile radio network is connected to the public switched telephone network via the MSC. The base station controllers are connected to the mobile-services switching center, while in each case one io or more of the base stations are connected to a common assigned base station controller. The base stations comprise means of receiving and transmitting radio frequency signals with mobile radio devices. In particular, the present invention encompasses a method for setting up a base station of a public mobile radio network (PLMN) and the connection of the base station to the public mobile radio network as well as the system of a corresponding mobile radio network.

Public mobile radio networks (PLMN: Public Land Mobile Network) enable the users to access the most various mobile telecommunication services. Such a mobile radio network can be considered an extension of the public fixed network (PSTN: Public Switched Telephone Network). It is typically composed of different reception and transmission areas (as described e.g. in Digital Cellular Telecommunications System; Network Architecture: GSM (Global System for Mobile communications); Technical Specification, European Telecommunications Standards Institute (ETSI), TS/SMG-030302Q), which are assigned to a so-called mobile-services switching center (MSC), the areas having a destination code and a common routing plan. An MSC forms the functional interface between the fixed network and the mobile radio network.

The MSCs provide all necessary functions for calls from and to a mobile radio device. In order to obtain area coverage of the reception and transmission areas in a particular geographic region, in the normal case, a plurality of base station systems (BSS: Base Station System) are necessary, i.e. each MSC is thus an interface to a plurality of base station systems. On the other hand, in the normal case, a plurality of MSCs are needed in order to cover an entire country. A BSS consists of a base station controller (BSC) and one or more base stations (BTS: Base Transceiver Station). A base station covers a so-called reception/transmission cell. The base station system comprises all necessary technical means (transceivers, controllers, etc.), so that the MSC can communicate with a particular mobile radio device in a particular cell. A BSC is a network component of the mobile radio network for speaking to one or more base stations.

In the last few years, mobile telecommunication over such abovedescribed public mobile radio networks has been able to show tremendous growth in all sectors by means of a wide variety of new and improved offers both in the technological area as well as in services. One of the factors which has contributed to this growth is that a user of such a mobile radio network would be in reach everywhere at all times. Despite great efforts, this aim has not been achieved everywhere by the industry, however, because of the high costs, among other things, for the installation of an antenna network, with blanket coverage, with base stations. In overcrowded areas, however, it has been observed that a multiple coverage of the same area can result from telecommunications companies competing with each other. An unnecessarily great burden on the population in these areas in the radio frequency field thereby results (electrosmog). Load peaks in such areas can be reduced in particular by structure-related screens being reduced or circumvented by more localized receiving and transmitting stations. The search for new, costtolerable solutions with as small as possible, but still sufficiently large, receiving and transmitting capacities in this field seems to be more important today then ever.

It is an aspect of this invention to propose a mobile radio network and a new corresponding method for setting up a base station of such a mobile radio network and for connecting the base station to such a mobile radio network which do not have the above-mentioned drawbacks. In particular it should be a solution that makes it possible to expand transmitting and receiving areas quickly and economically.

According to an aspect of the present invention, there is provided a method for setting up a base station of a mobile radio network and for connecting the base station to the mobile radio network, which mobile radio network includes at least one mobile-service switching center, with a transmission/reception area assigned to the mobile-service switching W:\SASKIM~atent Spec\200258008.doc center, and one or more base station controllers each with one or more base stations, the mobile radio network being connected via the mobileservice switching center to the public switched telephone network, the base station controllers being connected to the mobile-service switching center and including monitoring and control functions for the base stations, one or more of the base stations in each case being connected to a common assigned base station controller, and the base stations each including means for exchange of radio frequency signals with mobile radio devices, wherein at least one of the base stations is installed in an existing facility on exposed public ground, which facility is supplied by a power supply system, the at least one of the base stations is coupled to the power supply system with a first transceiver module, a second transceiver module is likewise coupled to the power supply system at another location, whereby the transmission of electrical signals corresponding to the radio frequency signals is made possible bidirectionally over the power supply system between the transceiver modules by means of the transceiver modules, and the second transceiver module is connected to the base station controller assigned to the at least one last-mentioned base station, so that communication to one another between the at least one base station and the base station controller assigned to it is made possible via the power supply system.

The invention has the advantage, inter alia, that a minimum of new installations is required to expand the network, use being made of existing infrastructure. This relates not only to the cost expenditure, but also to the time expenditure required for the construction of a comparable standard installation of base stations. Another advantage is that the transmitting capacity of the base stations can be kept small through the relatively small cell sizes in the mostly very local installations. With the constantly increasing state regulation, this can be correspondingly important.

In one embodiment variant, the transceiver modules use for transmission a transmitting signal, a receiving signal as well as a separate control signal.

W:\SASKIA\Patent Specr200258008.doc This embodiment variant has in particular the advantage that it corresponds to GSM requirements.

In another embodiment variant, used as the public facilities for installation of the base stations are street illumination devices of the road network, such as e.g. street lights or other illuminating elements of public and private facilities, etc. This embodiment variant has inter alia the advantage that it is makes use of easily accessible and widespread public facilities.

In a further embodiment variant, used as the public facilities for installation of the base stations are the power supply system with the installation devices necessary therefor of public transportation. This embodiment variant has the same advantages as the preceding embodiment variant.

In an embodiment variant, the base station controllers and the base stations connected thereto each have a control processor with a modem, which control processor is coupled e.g. to a frequency triplexer/triplex filter by means of which control processor and modem the radio frequency signals are transmittable through two transmitting signals and a control signal in a separate frequency range. This embodiment variant has in particular the advantage that it corresponds to GSM requirements.

In another embodiment variant, the transceiver modules use frequency shift keying (FSK) as the frequency modulation technique for the transmission.

This embodiment variant has in particular the advantage that the transmission security is increased.

In a further embodiment variant the transceiver modules use FDMA (Frequency Division Multiple Access) and/or TDMA (Time Division Multiple Access) or CDMA (Code DivisionMultiple Access) as the frequency modulation technique for transmission. This embodiment variant has in particular the advantage that the combination of TDMA and FDMA corresponds to the GSM standard, and broad-band CDMA with a transmission rate of up to 2Mbit/second corresponds to the UMTS standard.

In another embodiment variant the transceiver modules use a transmission frequency range between 100 MHz and 500 MHz for transmission of the radio frequency signals over the power supply system. This has inter alia the advantage that this frequency range is particularly suitable for transmission over the power supply network.

In a further embodiment variant, two or more different reception/ transmission cells with different cell group identity are covered with at least one of the base stations.

According to another aspect of the present invention, there is provided a mobile radio network which includes at least one mobileservice switching center, with a transmission/reception area assigned to the mobile-service switching center, and one or more base station controllers each with one or more base stations, the mobile radio network being connected via the mobile switching center to the public switched telephone network, the base station controllers being connected to the mobile service switching center and including monitoring and controlling functions for the base stations, in each case one or more of the base stations being connected to a common, assigned base station controller, and the base stations each including means for exchange of radio frequency signals with mobile radio devices, wherein at least one of the base stations is installed in a previously existing facility on exposed public ground, which facility is supplied via a power supply system, the at least one last-mentioned base station includes a first transceiver module which is coupled to the power supply system, and the assigned base station controller includes a second transceiver module which is likewise coupled to the power supply system so that electrical signals corresponding to the radio frequency signals are transmittable bidirectionally over the power supply system between the transceiver modules.

Embodiment variants of the present invention will be described in the following with reference to examples. The examples of the embodiments are illustrated by the following attached figures: W:\SASKIA\Patent Spec\200258008.doc Figure 1 shows a block diagram which illustrates schematically an embodiment example of a mobile radio network according to the present invention in which street illumination devices of the public road network are used.

Figure 2 shows a block diagram which illustrates schematically an embodiment example of a base station installed in a street illumination device as well as the transceiver module for connection to the base station controller.

Figure 3 shows a block diagram which illustrates schematically another embodiment example of a base station installed in a street illumination device as well as the transceiver module for connection to the base station controller.

Figure 4 shows a block diagram which illustrates in more detail an embodiment example of a base station installed in a street illumination device and the transceiver module assigned to it.

Figure 5 shows a block diagram which illustrates in more detail an embodiment example of a transceiver module assigned to a base station controller.

W:\SASKIAMPatent Spec\200258008.doc Figure 6 shows a block diagram which illustrates schematically an embodiment example of a mobile radio network analogous to Figure 1, a transceiver module, assigned to a base station controller (BSC), communicating with a plurality of transceiver modules of different base stations at the same time.

Figure 7 shows a block diagram which illustrates schematically an embodiment example of a base station installed in a street illumination device, the base station covering two different reception/transmission cells with different cell group identity.

Figure 8 shows a block diagram which illustrates schematically an embodiment example of a coupling element of a transceiver module for bidirectional transmission on the power supply system of electrical signals corresponding to the radio frequency signals.

Figure 9 shows a block diagram which illustrates schematically an embodiment example of a mobile radio network analogous to the embodiment example of Figure 1, the bidirectional transmission of the radio frequency signals from one transceiver module to another transceiver module and vice versa taking place over a three-phase power supply system.

Figure 1 illustrates an architecture which can be used for achieving the invention. In this embodiment example, a mobile radio network comprises at least one mobile-services switching center MSC with a transmission/ reception area assigned to the mobile-services switching center MSC and one or more base station controllers BSC1/ BSC2 each with one or more base stations (BTS: Base Transceiver Station) 10. The structure of the mobile radio network and its components could take place e.g. according to the GSM standard (Global System for Mobile Communication) of the ETSI (European Telecommunications Standards Institute) or the UMTS standard (Universal Mobile Telephone System). The mobile radio network can be e.g. a public mobile radio network (PLMN: Public Land Mobile Network). The mobile radio network is connected, for instance, to the public switched telephone network (PSTN: Public Switched Telephone Network) 40 via the mobile-services switching center MSC. The mobile-services switching center comprises switching and signaling functions for the management of mobile radio devices.

The base station controllers BSC1/BSC2 are connected to the mobile-services switching center MSC, and comprise monitoring and control functions for the base stations 10. In each case one or more of the base stations 10 are connected to a common, assigned base station controller BSC, and comprise in each case means for exchange of radio frequency signals with mobile radio devices, which mobile radio devices lie within the transmission/reception area, a so-called transmission/reception cell C 1

C

5 covered by a base station The base stations 10 are installed in existing facilities 11 on exposed, public ground, which facilities 11 are supplied via a power supply system 20/21 or i0 have a power supply system connection. Understood by "existing" facilities are facilities which are also used or could be used for purposes other than the installation of base stations 10. Understood here as "public ground" are in particular places from which the base stations 10 cover exposed territory

C

1

C

5 with radio frequency signals. The places can very well be situated on private grounds. For example such already existing infrastructures on exposed public ground are street illumination devices such as street lamps, street lights, etc., flood lights for sports facilities, stadiums among other things, devices for power supply of public transportation means, such as e.g. street cars or railways, but can also be such devices in a broader sense such as ski lift installations, funicular installations, etc. Shown in this embodiment example as facilities 11 are street illumination devices 12 of the public road network The numeral 13 designates the antenna 13 of a base station 10. The base stations 10 are each coupled to the power supply system 20 with a first transceiver module 60. A second transceiver module 61 in each case is likewise coupled to the power supply system 20 at another location. The transmission over the power supply system 20 of the electrical signals corresponding to the radio frequency signals is thereby made possible bidirectionally between the transceiver modules 60/61 by means of the transceiver modules 60/61. The transceiver modules 60/61 are connected with the base station controller BSC1/BSC2 assigned to the respective base station so that communication between the base stations 10 and the base stations controllers BSC1/BSC2 assigned to them can take place over the power supply system 20 and the connection 30. Power Line Communication PLC, i.e. the transmission over the power supply system of electrical signals corresponding to the radio frequency signals is known in the state of the art in various embodiment variants. Examples of such configurations can be found in the patent publication W098/06188 "Power Line Communications" or in the patent publication US 5,977,650 "Transmitting Communications Signals Over A Power Line Network." The connection 30 between the transceiver modules 61 and the base station controllers BSC1/BSC2 can take place e.g. via a coaxial cable, an optical cable/glass fiber cable or via a twisted pair cable. Neighboring transmission/reception cells of base stations of conventional mobile radio networks are typically between 2 and 20 km in size. Mostly short range (low power) base stations are thereby used. In the present invention the cell sizes io of individual cells C 1 C can be much smaller, however, for instance only 50 m in size. This can be the case in particular with the installation of base stations in street illumination devices 12 as in this embodiment example. The handover with such microcells C 1

C

5 i.e. the transfer of the connection of a mobile radio device of a moving user from the base station 10 of a cell C to the base station of the next following cell C 1 respectively C.- 1 must be able to be carried out very quickly owing to the size of the microcells C 1

C

5 and is known and described in the state of the art in various embodiment variants. An example of such a procedure is described in the patent publication US 5,189,734 "Cellular Radio System." Figures 2 and 3 illustrate two embodiment examples of a mobile radio network analogous to the embodiment example 1 of base stations 10 installed in public street illumination devices 12. Figures 4 and 5 show moreover the transceiver modules 60/61 in more detail. As in the previous embodiment example, the radio frequency signal is transmitted in each case bidirectionally between the base stations 10 and base station controllers BSC by means of two transceiver modules 60/61 via the power supply system 20. A transformer module 70 can be connected in series to the transceiver module 61, which transformer module can transform, if necessary, the electrical voltage of the supply line 21 11 kV(k volt)) to the voltage needed by the street illumination devices 12 of e.g. 230 V, or respectively 400 V. The transceiver modules 60/61 each consist of a coupling element 62 by means of which the transceiver modules 60/61 are coupled to the power supply system, as well as a modem module 63, which modulates, or respectively demodulates, the radio frequency signals corresponding to the power supply system. The modem module 63 of the base stations 10 comprises in particular the function of converting radio frequency signals of the frequency range bidirectionally, which frequency range is suitable for transmitting and receiving in open space (i.e.

between the antenna 13 of the base station and the mobile radio devices located in the assigned transmission/reception cell, e.g. 900/1800 MHz) to the frequency range suitable for transmission of the signals over the power supply system between 100 MHz and 500 MHz). On the other hand, the modem module 63 assigned to the base station controller BSC comprises the function of converting the transmission frequency range of the signals on the power supply system 20 bidirectionally into a frequency range suitable for the io transmission to the base station controller BSC, e.g. via glass fiber cable or coaxial cable. The transceiver modules 60/61 can use as the frequency modulation technique for the transmission e.g. Frequency Shift Keying, Frequency Hopping, FDMA (Frequency Division Multiple Access), TDMA (Time Division Multiple Access: GSM uses a combination of TDMA and FDMA) or CDMA (Code Division Multiple Access, especially for UMTS, which achieves with broadband CDMA a transmission rate of up to 2 Mbit/second). Other modulation techniques are also conceivable, however, such as ASK (Amplitude Shift Keying) or PSK (Phase Shift Keying). The transmission frequency range can lie e.g. between 50 MHz and 500 MHz, but also e.g. under 400 kHz. Low frequency signals can normally be transmitted better over the power supply system. It has been shown, however, that radio frequency signals in a radio frequency range between 100 MHz and 500 MHz result in most cases in a reasonable relationship between transmitting distance and random noise. The frequency range between 400 kHz and 50 MHz is less suitable for transmission in most cases since it has large spectral noise components, whereas with transmission frequencies over 500 MHz the radio frequency signal usually weakens too quickly for the power supply system still to be useful as a transmission medium. The transceiver modules 60/61 can use e.g. three separate signals for transmission, for instance a transmitting signal Tx, a receiving signal R, and a control signal C. The control signal C, comprises e.g. set-up and alert information for or from the base station 10. The transceiver modules 60/61 comprise, for example, a control processor with modem. The control processor is coupled to a frequency triplexer/triplex filter, the two transmission signals T, and R, and the control signal C, being transmittable in a separate frequency range. As mentioned, with UMTS a channel can amount to up to 2 Mbps, which means up to 4 Mbps with the two signals R, and T. Thus the frequency range under 400 kHz is usually unsuitable for transmitting the two channels R, and However, the frequency range under 400kHz can be used, for example, for transmission of the control signal C.

Figure 6 shows an embodiment example of a mobile radio network analogous to the embodiment example of Figure 1, in which mobile radio network however a plurality of the existing facilities 11 hang on the same electrical line with the same voltage without these facilities 11 being separated io from one another through transformer modules 70. In such an embodiment example a transceiver module 61 assigned to a base station controller (BSC) can also communicate with a plurality of transceiver modules 60 of different base stations 10, as illustrated in Figure 6.

Figure 7 is an embodiment example with a mobile radio network analogous to the embodiment example of Figure 1. In this embodiment example, covered by at least one of the base stations 10 installed in existing facilities 11 are two or more different reception/transmission cells C6...7 with differing cell group identity. This can be achieved e.g. with use of the directional characteristic of the antennas. The embodiment example of Figure 7 corresponds to the installation of two or more base stations 10 according to the number of reception/transmission cells C 6 7 Each reception/transmission cell C 67 has its own channel(s), so that a handover takes place if a mobile radio device is moved from the one reception/transmission cell to the other reception/transmission cell.

Figure 8 illustrates an architecture as can be used for achieving the coupling element 62 in a transceiver module analogous to the embodiment examples of Figures 4 and 5. The coupling element 62 is coupled to the power supply system via a connection 20, i.e. an electrical conductor. The power supply of the existing facilities can take place as in this embodiment example e.g. with 230 V and 50 Hz at max. 100OA. The coupling element 62 comprises a primary inductance 621 of e.g. 50 [H to 200 H depending upon the required signal characteristic. The inductance 621 of the power supply system 20 is coupled to the signal input/output connection 627 via two coupling capacitors 6231624. The connection 627 connects the coupling element 62 to the modem module, which modulates signals to be transmitted from the base station controller to the base station and vice versa in the frequency range suitable for the transmission. The two coupling capacitors 623/624 can have e.g. a capacity of 0.01 F to 0.5 iF. The second coupling capacitor 624 generates together with the first coupling capacitor 623 a further attenuation in that it is connected to ground 628. The signal input/ output connection 627 comprises a secondary inductance 622, e.g. of minimally 250 H. The two coupling capacitors 623/624 can be additionally supplemented by two fuses 625/626, l0 e.g. safety fuses. If in this case the two coupling capacitors 623/624 fail for any reason, the inductance 622 for the electrical main current is connected to ground and the fuse 626 is destroyed. This can thus serve as additional security. It is to be mentioned that with the coupling capacitor 62 both inductive coupling through a coupling transformer for high frequencies) and capacitive coupling or a combination of the two can be used. Coupling elements of the functionality described here can be found in various embodiment variants in the state of the art.

Figure 9 illustrates an architecture which can be used to achieve transceiver modules 60/61 of a mobile radio network analogous to the embodiment example of Figure 1 with a base station 10 installed in one of the said existing facilities. In this embodiment example a transformer module 70 is connected via the electrical conductor 21 to a polyphase main network with e.g.

11 kV. The transformer module 70 transforms the electrical voltage to the voltage required by the said existing facility (in this embodiment example a street illumination device 12). In this embodiment example, the voltage is transformed to the 400 V of a three-phase power supply system r/s/t. Each of the phases rlslt can supply e.g. only a single such facility or the facilities can be supplied by all 3 phases r/s/t, if this is necessary; such as e.g. with various flood light devices, etc. Reference numeral 628 is also the ground or earth in this embodiment example. The mobile-service switching center MSC is also connected, as in the previous embodiment examples, to the public switched telephone network (PSTN) 40, and the mobile-service switching center MSC, for its part, to the base station controller BSC. The radio frequency signals are transmitted bidirectionally between base station 10 and base station controller BSC by means of two transceiver modules 60/61 over the power supply system This takes place in that the modem module 63 modulates the signals to be transmitted in a way analogous to the preceding embodiment example and transmits them to the coupling elements 62. The input/output signals Cx, Rx, Tx can be transmitted on one phase only, on a plurality of phases, or on all possible, available phases. Since the phases r/slt couple capacitively in the power supply system the input/output signals even if the signals are transmitted on one phase only-- can be taken over at the opposite transceiver module by any one of the coupling elements 62 or likewise taken separately.

The coupling elements 62 can comprise a low pass filter, among other things, in order to separate the signals. The street illumination facility 12 is likewise connected to the power network It is to be added that the modem modules 63 in the embodiment example of Figure 9 can comprise a 3-way splitter element. The three phases of the power supply system 20 are each coupled to the power supply system 21 via a separate current bar in the transformer module 70. The three coupling elements 62 of the transceiver module 60/61 can also comprise more complex high pass filter elements. The coupling elements 62 are also referred to, among other things, as radio frequency "jumpers", which usually comprise an AC blocker and a radio frequency coupling element (capacitive and/or inductive). The filter elements 62 serve to let through only signals in the radio frequency range which are used for transmission of the telecommunications signals and thereby to prevent the electrical main current of the power supply system 20 from reaching the base station controller BSC or respectively the base station 10. The telecommunications signals are transmitted between transceiver modules 60/61 in both directions, in the direction of the base station as Well as in the direction of the base station controller BSC. If the radio frequency signals are transmitted from the base station controller BSC to the base station 10, they are transmitted via antenna to the receiving/transmitting cell assigned to the base station 10. In the reverse direction, radio frequency signals are received by the mobile radio devices via antenna 13 in the receiving/transmitting cell assigned to a base station 10 and are transmitted to the base station controller BSC via the transceiver modules 60/61 and the power supply system 20. The most various embodiment examples of power line communication (PLC) can be found in the state of the art. Furthermore it is to be pointed out that the present invention must not be limited to radio frequency signals of mobile radio networks (PLMN: Public Land Mobile Network). Also transmitted with the present invention can be radio frequency signals of personal communication systems, broadcast video, broadcast audio, paging, two-way or direct satellite broadcasting, wireless networks, in particular MAN (wireless Metropolitan Area Network) and/or radio frequency telemetry as well as WLL (Wireless Local Loop).

Claims

1. A method for setting up a base station of a mobile radio network and for connecting the base station to the mobile radio network, which mobile radio network includes at least one mobile-service switching center, with a transmission/reception area assigned to the mobile-service switching center, and one or more base station controllers each with one or more base stations, the mobile radio network being connected via the mobile-service switching center to the public switched telephone network, the base station controllers being connected to the mobile-service switching center and including monitoring and control functions for the base stations, one or more of the base stations in each case being connected to a common assigned base station controller, and the base stations each including means for exchange of radio frequency signals with mobile radio devices, wherein at least one of the base stations is installed in an existing facility on exposed public ground, which facility is supplied by a power supply system, the at least one of the base stations is coupled to the power supply system with a first transceiver module, a second transceiver module is likewise coupled to the power supply system at another location, whereby the transmission of electrical signals corresponding to the radio frequency signals is made possible bidirectionally over the power supply system between the transceiver modules by means of the transceiver modules, and the second transceiver module is connected to the base station controller assigned to the at least one last-mentioned base station, so that communication to one another between the at least one base station and the base station controller assigned to it is made possible via the power supply system.

2. A method according to claim 1, wherein the transceiver modules use for transmission a transmitting signal, a receiving signal, and a separate control signal.

3. A method according to claim 1 or 2, wherein used as public facilities for installation of the at least one base station are street illumination installations of the road network. WASASKIAMPatent Spec\200258008.doc

4. A method according to claim 1 or 2, wherein used as public facilities for installation of the at least one base station are power supply systems of public transportation means.

5. A method according to any one of claims 1 to 4, wherein the base station controller and the base stations connected to it each include a control processor with modem by means of which the radio frequency signals are transmittable through two transmission signals and a control signal in a separate frequency range.

6. A method according to any one of claims 1 to 5, wherein used as the frequency modulation technique for the transmission in the case of the transceiver modules is frequency shift keying.

7. A method according to any one of claims 1 to 5, wherein used as the frequency modulation technique for the transmission in the case of the transceiver modules is frequency division multiple access and/or time division multiple access or code division multiple access.

8. A method according to any one of claims 1 to 7, wherein used in the case of the transceiver modules is a transmission frequency range of between 100 MHz and 500 MHz for the transmission of the radio frequency signals over the power supply system.

9. A method according to any one of claims 1 to 8, wherein at least one of the base stations covers two different reception/transmission cells with differing cell group identity.

A mobile radio network which includes at least one mobile-service switching center, with a transmission/reception area assigned to the mobile-service switching center, and one or more base station controllers each with one or more base stations, the mobile radio network being connected via the mobile switching center to the public switched telephone network, the base station controllers being connected to the mobile service switching center and including monitoring and controlling functions for the *base stations, in each case one or more of the base stations being connected to a common, assigned base station controller, and the base stations each including means for exchange of radio frequency signals with mobile radio devices, wherein at least one of the base stations is installed in a previously existing facility on exposed public ground, which facility is supplied via a power W:\SASKIAPatent Spec\200258008.doc supply system, the at least one last-mentioned base station includes a first transceiver module which is coupled to the power supply system, and the assigned base station controller includes a second transceiver module which is likewise coupled to the power supply system so that electrical signals corresponding to the radio frequency signals are transmittable bidirectionally over the power supply system between the transceiver modules.

11. A mobile radio network according to claim 10, wherein the transceiver modules use for transmission a transmitting signal, a receiving signal and a separate control signal.

12. A mobile radio network according to claim 10 or 11, wherein the said facilities are street illumination installations of the road network.

13. A mobile radio network according to claim 10 or 11, wherein the said facilities are power supply systems of public transportation means.

14. A mobile radio network according to any one of claims 10 to 13, wherein the transceiver modules each include a control processor with modem, which control processor is coupled to a frequency triplexer I triplex filter by means of which the radio frequency signals are transmittable through two transmission signals and a control signal in a separate frequency range.

A mobile radio network according to any one of claims 10 to 14, wherein the transceiver modules use frequency shift keying as the frequency modulation technique for the transmission.

16. A mobile radio network according to any one of claims 10 to 14, wherein the transceiver modules use frequency division multiple access and/or time division multiple access or code division multiple access as the frequency modulation technique for the transmission.

17. A mobile radio network according to any one of claims 10 to 16, wherein the transceiver modules use a transmission frequency range of between 100 MHz and 500 MHz for transmission of the radio frequency signals over the power supply system. WASASKIA\Patent Spec\20025808.doc

18. A mobile radio network according to any one of claims 10 to 17, wherein two or more different reception/transmission cells with differing cell group identity are able to be covered with at least one of the base stations.

19. A method for setting up a base station of a mobile radio network and for connecting the base station to the mobile radio network substantially as hereinbefore described with reference to any one of the embodiments shown in the drawings. A mobile radio network substantially as hereinbefore described with reference to any one of the embodiments shown in the drawings. DATED: 5 July, 2004 PHILLIPS ORMONDE FITZPATRICK Attorneys For: a a SWISSCOM MOBILE A W:\SASKIA\Patent Spec200258008.doc