FI107101B - Connecting a Computer to a Radiotelephone - Google Patents

Description

107101

The present invention relates to an interface arrangement between a radiotelephone and a computer, according to the preamble of claim 1.

The increasing use of radiotelephones, particularly mobile telephones, has brought with it the need for so-called. to connect mobile office equipment. For example, users want to connect their laptop computer via a radio connection established by a radiotelephone to another computer for data transfer between them. The connection between the radiotelephone and the computer 15 must take into account two essential points.

First, the modem to be installed on the computer is normally configured to be connected to a telephone network (PSTN) bi-wire, and this PSTN interface must be fitted to the radiotelephone. Secondly, some form of control of the outbound connection of the radiotelephone must be provided for establishing, maintaining and disconnecting and responding to the incoming connection so that the communication program on the computer can control the connection.

25 For this purpose, a matching device has been developed for use between a computer and a radiotelephone, for example, called a "teleadapter". One such known arrangement is simplified as shown in Figure 1. Figure 1 shows the modem 4 and the adapter 20 (TA) via a two-wire "PSTN" connection 17. The function of the adapter 20 is to perform the conversion between the two-wire modem connection and the audio connection 16 of the mobile phone 1 and with the control channel 15. The advantage of such a solution is that the software (SW) of the computer 3 does not need to be converted for use with a cellular telephone, but can be used with some standard commercial communication program that controls the connection through the modem. The adapter 20 picks up control signals from the cable 17 and converts them to the necessary control signals of the radio telephone 2 107101 via channel 15. On the other hand,

A disadvantage of the above solution is that the signal processing of the control channel in the adapter requires control logic, e.g., a microprocessor. Such a solution significantly increases the overall cost of the interconnection system.

A variant of the adapter described above is disclosed in WO 90/03076 (Method and Apparatus for Controlling Transmission of Voice and Data Signals). The "teleadapter", described in neutral terms, can also be placed, for example, inside a computer on its own module and even somehow connected to a modem. However, this does not eliminate the above-mentioned disadvantages of the prior art.

It is an object of the invention to provide an interface arrangement by which the above-mentioned drawbacks can be substantially eliminated. This problem is solved according to the symbols of claim 1 · · f.

* · * T ··· '25 Thus, the inventive idea is to divide the connection arrangement into two: on the one hand, adjusting the levels of the connection cables is done in the adapter part of the radiotelephone (Cradle / connector: e.g. . in the car) and on the other hand all the control logic has been adapted for this purpose. *. 3 0 by the extended communication software of the computer • ·. ·; ·. office. Physically, the connection arrangement according to the invention / # comprises a serial communication bus for control, a dual · · · '·' · wired PSTN connection cable and a radio telephone adapter: ...: the circuits in which the signal levels ·: ·. for radiotelephone internal communications.

* * • · ·

The solution according to the invention does not require significant equipment. The required level matching circuits of the adapter part are very simple in construction and hence inexpensive. On the other hand, the communication program on the computer requires two blocks, one controlling the modem and the other via a serial connection to establish a radio connection 5 of the radiotelephone and to answer an incoming call if necessary. Thus, the application program must be able to control two physical interfaces, the serial port and the modem bus interface. Duplication of programming will incur some costs, but additional unit costs will not arise for the electronics themselves.

In the connection arrangement according to the invention, the electrical and physical structure of the serial communication bus, e.g. RS232, may be known per se, and the logical signaling on the bus is determined by the signaling used by the internal control bus of the radio telephone in question.

In the connection arrangement of the invention, the signals transmitted on the audio channel of the modem and the radiotelephone are known per se and are signals of a telephone network. The computer modem may be an external box modem known per se or an internal modem. card modem, with or without auto-dial. The invention; however, the modem does not use the modem: · 'any connectivity features, such as auto-dial, but only the useful data transfer functions. The modem may also be a · · · • '/ · fax modem or equivalent signal converter.

: *. \ 30 The invention is advantageously applied to cellular phones.

• · «• · *. *: In the following, the invention will be explained in more detail with reference to the accompanying figures, in which »: 35: 1 illustrates a radiotelephone-to-computer technology. an ankle attachment arrangement; and Figure 2 schematically illustrates a connection arrangement according to the invention.

4,107,101

Figure 1 in the drawing was already discussed above. Figure 2 is a simplified example of an embodiment of a connection arrangement according to the invention. The cellular telephone 1, i.e. the handset operating in the cellular network, is provided with an adapter part 5 having e.g. the external audio signal and the control signal connections 6 and 5, respectively. The computer 3 is provided with software, in particular a communication program (SW). The computer which in this example is a Personal Computer 3 (PC) also has an Internal Card Modem 4 (MODEM). The computer has a serial port, RS232, which connects a communication bus 5 for controlling the mobile phone 1, while the modem 4 is connected to the mobile phone via a two-wire connection 6, which transmits signals conforming to sig-15 signals transmitted over a standard telephone line (PSTN). shown) in a manner known in the art.

The matching part 2 of the mobile phone 1 is provided with matching circuits (not shown) for matching the signal levels 20 of the wires 5 and 6 to the internal levels of the mobile phone: the level of the two-wire 6 (The mobile phone is processor-controlled in a manner known per se.) The physical dimensioning of the matching circuits depends on the structure of the particular mobile phone being used and more specifically on its interface specifications:: **. As such, upon receipt of such specifications, one of ordinary skill in the art will be able to design these adapter circuits in a simple manner, which may be accomplished by simple circuit solutions, e.g. · With the idea.

5,107,101 to describe a program that extracts control signals generated by a communication program and converts them into signals used on the internal control bus of the mobile phone (and, accordingly, receives signals from the internal control bus 5 of the mobile phone and modifies them into a format understood by the communication program). Thus, the signals transmitted on the communication bus 5 include, for example, call initiation / notification of an incoming call; call type (data, speech); address (phone number to call); acknowledgments; symbols; 10 call termination, etc.

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Claims (7)

6 107101 An interface for a radiotelephone and a computer, wherein the interface of the radiotelephone comprises an external audio signal and a control signal, wherein the computer has a serial port 5 and a modem connected to the computer; , characterized in that the serial port of the road 10 is connected via a communication bus (5) to the control signal connection of the radiotelephone, the first block of the computer traffic program being adapted via the serial port connection to control the various that the modem (4) is in turn connected to the mobile phone via a two-wire connection (6), and that in addition the part includes the level control circuits of the audio signals as well as the physical control bus and the communication bus matching circuit of the radiotelephone. 20 An interface arrangement according to claim 1, characterized in that the computer is a portable personal computer. • · '-Ϊ- * 25 An interface arrangement according to claim 1 or claim 2, characterized in that the radiotelephone is a cellular telephone used in a cellular network. • · · · · · · · · · An interface arrangement according to any one of the preceding claims, characterized in that the modem is an internal modem connected to the parallel bus of a computer. • · «{I An interface arrangement according to any one of the preceding claims, characterized in that the serial port is a communication bus 35 RS232 bus. « An interface arrangement according to any one of the preceding claims, characterized in that the modem is a fax modem. 7 107101