Radio terminal using a hybrid coax-fibre broadband network

The invention relates to a wireless subscriber using a hybrid fiber coaxial cable broadband access network according to the preamble of claim 1.

Wireless local loops, such as those offered by incumbent operators that have an infrastructure for the conventional connection of telephone terminals, making use of existing two-wire copper lines, with a U-interface for the transmission of ISDN information passing between radio base stations and concentrating units from which a transmission path arranged on a central, preferably at the place of a conventional telephone exchange radio control unit consists. The air interface of such a radio access network between the aforementioned radio base stations and either cordless subscriber terminals are connected directly or between the radio base stations and subscriber-side interfaces, which represent a communication outlet to which telephone terminals or entire PBXs.

In particular, non-conventional providers have access networks that are constructed using optical waveguides, which as originally intended to serve not only distribution services, but also for interactive services, ie for the provision of telephone traffic are equipped. Here, the optical waveguide, so the fiber optic lines, as near as practicable to the subscriber, where a transition to a coaxial cable network takes place at the Koaxialkabelstrecken subscriber terminals, are turned on, inter alia ISDN subscriber terminals via respective interface circuits.

This is therefore to hybrid fiber coaxial cable broadband access networks.

The object of the invention is now to provide a wireless local loop, the mitausnutzt such a hybrid fiber coaxial cable broadband access network.

This object is achieved by the features specified in the characterizing part of claim 1.

Accordingly, the radio base stations for the mobile subscriber, such as interface circuits for ISDN subscribers connected to the branches of Koaxialkabelstrecken the hybrid access network. In the data transfer device DFR which is part of a exchange-side interface unit of the hybrid network, the 16kBit / s D-channels are combined in accordance with the ISDN transmission protocol of multiple radio base stations to a 64 kbit / s signaling channel. This summarized signaling channel is combined with several connected with radio base stations 64kBit / s B channels and supplied to at least one PCM30 line. This at least one PCM30 line is connected to a central radio control unit RDU and is treated there function the same as in a radio local loop radio access network (RLL) connected to a central radio controller lines coming from remote concentrating units of this radio access network.

In such type of connection on the one hand in a large scale parts of the hybrid network for the mobile subscriber terminal, particularly the transmission paths, utilized, and can be used in the technology of RLL-radio access networks in the specific for the radio subscriber connection parts.

The latter circumstance also that a connecting line at least be shared for the inventive mobile subscriber terminal and an optionally parallel-operated in the catchment area of ​​the same exchange RLL radio access network, according to another in claim 2 mentioned embodiment of the invention the central radio control unit and connects with the central office performs can.

Further embodiments of the invention are specified in the remaining sub-claims.

In the embodiment according to claim 3 of the transport of the transfer protocols of the wireless terminal above that layer of protocol which is used by the data transfer device of the hybrid network with the result that for the wireless local loop and for the original connected to the Koaxialstrecken the hybrid network participants have the same data transfer device can be used is carried out.

Alternatively, there is provided a separate data transfer device for the wireless subscriber terminal according to claim 4, which also transports the transfer protocols of the wireless local loop.

Further embodiments of the invention according to claims 5 and 6 relate to the implementation of interfaces between the radio base stations and the branches of the Koaxialkabelstrecken of the hybrid network, namely, in one case, while maintaining a radio base station in the technology of the RLL radio access network and using a special interface circuit which under other in adjustment to the operation of such a radio base station a U-interface implemented and are incorporated in the other case in the form of a unit, wherein the interface circuit and radio base station.

according to claim 7 the Koaxialkabelstrecken for the remote supply of such an integrated interface radio base unit are mitausgenutzt.

The invention by way of example with reference will be explained in greater detail to a drawing.

In the drawings:<ul><li>Figure 1 is a hybrid fiber coaxial cable broadband access network, as it is inventively mitausgenutzt for a radio subscriber.</li><li>Figure 2 is a wireless subscriber terminal according to the invention, which also provided according to another invention, parallel operation of RLL radio access network is shown.</li><li>Figures 3 and 4 port versions of the interfaces for the connection of the mobile subscriber to the Koaxialstrecken the hybrid network.</li></ul>

The hybrid fiber-Koaxilkabel broadband access network according to Figure 1 is used for subscriber access to a telephone exchange LE.

In subscriber-side region has this access network as connecting cables Coaxial Coaxial, which are connected to a unit stroke in which a conversion of the electrical signals from the coaxial cable takes place on optical signals for transmission on fiber optic cable through a central electro-optical converter. The subscriber to this coaxial cable is done at intersections thereof via subscriber-specific interface circuits, such as the interface circuit CIU-a / b and for the connection of an analog telephone terminal and possibly a television, the connection circuit CIU-SO for the individual subscriber terminal ISDN terminals and also a television in the form of interface circuit MDU, which is intended for larger residential unit and the terminal is in each case a plurality of both conventional telephone terminals and ISDN terminals and television receivers.

The signal transmission between the device hub and switching-related institutions is via an optical fiber line connecting said electro-optical converter with a central Electro-optical converter which is created by pooling several decentralized converters by means of electrical combiner / splitter C / S. This combiner / splitter are also used for coupling and decoupling of the signals for other services, such as interactive television.

As exchange-end device, the unit HIU provides the switching and signaling functions performs for the subscribers connected via the coaxial cable. It is connected through a copper line to the exchange LE. As part of this interface circuitry is to say, a data transfer device DRF (Data Frame Relay), which serves as a multiplexer for the signaling channels of the connected ISDN subscriber.

As Figure 2 shows, are connected to a coaxial coax a hybrid fiber coaxial cable broadband access network of the kind radio subscriber Fu described. This connection is made through units DIU-RBS, in each of which a radio base station and an interface unit are integrated.

The radio base station of a radio terminal includes all the facilities necessary to send and receive wireless information and signaling information from and to the wireless subscriber terminal.

The interface portion of the units DIU-RBS provides a U interface, ie, that the radio base stations as ISDN subscribers are connected to the branches of the coaxial cable coax.

As further to the parts of the hybrid access network with respect to the radio terminal unit coming a central radio control unit RDU to mention. The serving for the signaling between the wireless subscriber terminals Fu and the central office or the aforementioned central radio controller 16kBit / s D-channels are combined the functional unit HIU the hybrid network to a 64 kbit / s signaling channel in the unit DFR. This signaling channel is used together with a number of leading to the radio base stations 64 kbit / s B-channels are combined for transmission on at least one PCM30 PCM30 line connecting the functional unit HIU with the central radio control unit RDU. There these PCM30 line is functionally identical operated for switching functions as in a RLL-radio access network connected to the central radio control unit coming from remote concentrating units lines. As mentioned above, the appropriate technology can be taken over by RLL access networks due to this type of treatment, on the other hand it is thus possible to operate the wireless subscriber terminal according to the invention at a central radio control unit together with a RLL-access network.

In the figure, such a parallel operation is shown, although not a requirement for the application of the invention. At such RLL access network subscriber side include subscriber units RNT, to which a plurality of subscriber terminals are connected subscriber, and radio base stations RBS. is the radio link between the subscriber connection units RNT and the radio base stations RBS. The radio base stations are connected via a two-wire cable and a U interface U to concentrating decentralized units RBC and this over a PCM30 the signal to a radio control unit RDU, which may be about to see the same one for the radio subscriber Fu that at the hybrid access network are connected, shall prevail.

The operation of the wireless local loop and the RLL access network preferably obey the DECT standard. Alternatively, also comes to the PACS standard, which is used in USA, is used.

As already indicated, in the illustrated embodiment, the radio base stations with interface circuits are integrated for connection to the coaxial cable and make the units DIU-RBS. These units then have a configuration as shown in Figure 4, that contain both the components to realize the transition from and to the coaxial cable as well as those for realizing the functions of the radio base station. In the former case, this is a modulator / demodulator M / D, here denoted by A coax ASIC and a radio frequency device RF1. In the two said cases, this is also a radio frequency device RF2, a microprocessor uP and under the condition of operation of the radio terminal according to the DECT standard, a DECT controller DC.

The connection of radio subscribers can also be implemented in such a way that radio base stations are used, as are also used in RLL access networks using and between these and the branches of the coaxial cable, an interface module is connected, by the radio base station as an ISDN subscriber to the coaxial cable can be connected.

This solution is indicated in Figure 3, as well as having a radio base station RBS in RLL access networks use an interface module MCIU shows that in addition to a interface unit UP control CTR, a modulator / demodulator unit M / D and a radio frequency unit RF.

According to a further embodiment, the coaxial cable for the remote supply of the radio base stations can be used in the case of the integrated terminal solution, without this being explicitly depicted in Figure 2, is in this case expediently to proceed such that only the main line of the coaxial cable is also utilized and that of to the interface circuits separate feed lines are routed to the branches of this main line.

The synchronization of radio frames transmitted from the Funkbasisstaionen carried out by the functional unit HIU that this corresponding timestamps and control information on the coax fiber link coax / fiber to the terminal units DIU-RBS sends. The control information is used, among other things, adjust to take account of transit time differences, an offset of the start time of the radio frame. The reason for this, and an indication of the offset value can be carried out by an operating system OS-ML from.