Arrangement for using a mobile terminal in a radio switching system with different transmission standards

The invention relates to an arrangement for operating a mobile Terminal, for example, optionally via a cordless system Landlines to the DECT (Digital European Cordless Telecommunications) standard, or via a cellular Mobile radio system according to the GSM (Global System for Mobile Communication) standard. Increasingly there for many Participants want from any location, both in a demarcated premises that of a cordless system is supplied to have the phone in the car. Typically, a node uses on the premises a cordless telephone set according to the DECT standard operates, in the car and a car telephone, which according to the GSM standard is working. To use two different telephone sets to avoid, it is known, a two systems handset, engl. to use dual-mode phone, which both DECT and Send GSM signals and can receive. See DE 43 44 702 A1. Of the Radio contact with the DECT system is preferably as in DECT systems for technical reasons, the voice quality is better than in GSM systems. Although an implementation of the Two systems-handset possible, but is a significant Effort required to meet the diverse requirements of Standards, such as speech coding, encryption, Handover procedure and authentication of the mobile terminal, together adapt. To meet this requirement, it is known each DECT control station a so-called. Interworking Unit to you, see. radio show, Issue 3, 1996, page 24, Franzis Verlag GmbH, Feldkirchen.

The GB-A-2241850 describes a DECT phone that can access via a (mobile) relay station to a GSM base station. Different communication standards are provided (ie, DECT and GSM) for the transmission between the phone and relay station and between the relay station and base station. WO 95/23485 discloses a multimode communication system with a base station that can be controlled by different wired or wireless devices to process different transmission standards.

With the invention, the object is now resolved, a low-cost indicate arrangement in which a mobile terminal in Cordless systems or used in cellular mobile radio systems can be, without interfering with the network infrastructure to make have to.

This object is described with the first claim Assembly dissolved.

The essence of the invention is that via an interface between the mobile terminal and a fixed Assembly, access to the cordless system or the cellular Mobile radio system has all the necessary data is transferred independently of standard that required for human-machine communication. In the event of a phone is the language, the content of the display and the information on each confirmed button.

The operation of the invention will be at a Embodiment explains. The accompanying drawing shows a figure with an interface arrangement between a GSM device and a DECT device.

In a first application will access a cordless Telephone according to the DECT standard short DECT phone, the GSM network described.

For this, a permanently in the vehicle installed adapter for a GSM phone, for example, with a Infrared interface circuit equipped. Likewise, the DECT phone equipped with an infrared interface circuit, so with the DECT phone both intended to DECT network and via the infrared interface on the GSM network can be accessed. The GSM phone may then present Case omitted.

In a second application case, the GSM-telephone and a DECT base station, each with an infrared interface circuit equipped. In this case, it is possible to use a GSM telephone access the DECT network.

According figure, the interface device from a Interface circuit 1 in a GSM adapter and a Interface circuit 2 in a DECT telephone. There are Figure represented only the modules that are essential for the Explanation of the invention. With the interface circuits 1, 2 is a duplex-capable devices through infrared path 3 produced. Each interface circuit 1, 2 consists in essentially of an infrared transceiver 1.1, 2.1, a digital signal processor 1.2, 2.2 and a Codec 1.3, 2.3.

When a connection request of a subscriber with a DECT device must first via the GSM network, the transmitter of the infrared transceiver 2.1 enabled. This is done either by pressing a in DECT device located button or automatically sequential polling the interface arrangement, so-called. polling whether information for transmission is present. The of the keyboard DECT device triggered dialing information and commands of the digital signal processor 2.2 as processed data via a bidirectional data line 2.4, the infrared transceiver 2.1 and the infrared path 3 to the transceiver 1.1 of the GSM unit supplied from the bidirectional data line 1.4 to the digital signal processor 1.2 of the GSM unit performs, with the Dialing information and instructions on the DECT device further processed so are as if the dialing information and commands from a GSM phone comes. Once connected, the language or example, in facsimile transmission, the data from DECT unit via the Codec 2.3 in PCM or ADPCM format and a bidirectional line 2.5 to about 2.1 transceiver and thence the infrared path 3 to the transceiver 1.1 via a bidirectional Line 1.5 transferred to the codec 1.3 of the GSM unit.

The simple and thus inexpensive interface arrangement it is possible for the subscriber, depending on the location with only one mobile terminal either the GSM network or the DECT network to use and thus the benefits of different exploit tariff structures. The availability of the subscriber as by exploiting a known network performance characteristics Rufweiterschalten no reply of the participant ensured so that the subscriber is always reachable on the same number. The Infrared interface proves to be particularly favorable, since no Interference with the appropriate radio part occur and the Component costs for infrared interfaces are low. But it is also possible, existing interfaces, for example for data transmission via GSM equipment, for the purpose described exploit. In this case, a cable connection would be between GSM device and DECT device required. The invention Interface system is far less expensive than the cost for known dual-mode devices. The simple Circuit structure, it is possible with the devices designed equip interface assembly or already in operation contained units with the interface arrangement to expand.