CALL ORIGINATION IN A MOBILE TELEPHONE APPARATUS

Abstract: There is described a phone, particularly a mobile phone, which allows a user to set one of two modes of operation. In one mode, dialled numbers are treated as private numbering plan numbers unless one specific character, such as a particular digit, is dialled, while, in another mode, numbers are treated as external numbers, unless another specific character is dialled.

Description: CALL ORIGINATION IN A MOBILE TELEPHONE APPARATUS TECHNICAL FIELD OF THE INVENTION This invention relates to a telephone apparatus, and in particular to a mobile telephone which may be used in situations where there exists the possibility of using a private numbering plan. BACKGROUND OF THE INVENTION Existing mobile phone standards allow for the use of so-called private numbering plans, in which a group of subscribers can contact each other by dialling abbreviated numbers. The necessary interactions over the radio interface are defined in the GSM standard, for example, at GSM 04.08 Section 10.5.4.7. This standard defines the required format of a number to be sent over the radio interface, to allow access to a private numbering plan number. The problem remains as to how to convert a number, dialled by a user, into a number which appropriately accesses the radio interface. Of course, the phone must also be able to handle calls to numbers which are not part of the same numbering plan. SUMMARY OF THE INVENTION In accordance with aspects of the invention, the phone has two modes of operation. In a first mode, dialled digit sequences are interpreted as numbers of a first type, unless they include a specified prefix digit. In a second mode of operation, dialled digit sequences are interpreted as numbers of the second type, unless they include a specified prefix character. Thus, for example, when a user expects mainly to be making calls to numbers within a private numbering plan, he can set the phone into a mode of operation in which dialled numbers are normally interpreted by the phone as numbers in a private numbering plan, and handled accordingly, while a prefix digit would need to be dialled to allow access to external numbers not forming part of that private numbering plan. When a user expects mainly to be making calls to numbers outside the private numbering plan, he can set the phone into a mode of operation in which dialled numbers are normally interpreted by the phone as external numbers, and handled accordingly, while a prefix character would need to be dialled to allow access to numbers forming part of the private numbering plan. BRIEF DESCRIPTION OF DRAWINGS Figure 1 is a schematic block diagram of a mobile phone in accordance with the first aspect of the invention . Figure 2 is a flow diagram showing a method in accordance with a second aspect of the invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Figure 1 is a schematic block diagram of a telephone in accordance with a first aspect of the invention. As is conventional, the phone 2 includes a man-machine interface (MMI) 4, including a keypad for digit entry by a user, and a display, for example in the form of a LCD. Also, the phone 2 includes a transceiver (TX) 6, for converting signals into a form suitable for transmission over a radio interface, and for converting signals received over the radio interface into a form suitable for processing within the phone. Further, the phone 2 includes an interface 8 for a SIM card, which, as is well known, stores information specific to a particular user. Other components of the phone 2, not shown, are also conventional . In accordance with the invention, the phone incorporates, for example within its software- controlled processor, a number conversion module 10, which includes two switches 12, 14, which are jointly controlled by a processing unit of the phone, on the basis of inputs supplied by the user via the MMI 4. It will be appreciated that the switches may be physical switches or, perhaps more conveniently, may be "virtual switches", illustrating the way in which different input data may be processed in different ways in software depending on various user inputs . Depending on the position of the switch 12, inputs from the MMI 4 may be supplied to one of two number processing units 16, 18 while, depending upon the position of the switch 14, numbers input to the block 10 may be decoded in one of two decoding units 20, 22. Figure 2 is a flowchart, showing the different operations of the two number processing units 16, 18. As indicated above, it will be appreciated that these may be realised in different hardware blocks or, as suggested by Figure 2, an alternative processing path in a software processing unit. The process starts at step 40, when a user of the phone dials a number using the MMI 4. At step 42, it is determined whether the phone is in PNP (Private Numbering Plan) mode. In this embodiment of the invention, the phone may be set into a PNP mode, which is most useful when the user expects most outgoing calls to be to other numbers within a common private numbering plan, or to an external mode, which is most useful when a user expects most outgoing calls to be to external numbers (for example, the user may not be a member of a private numbering plan) . The mode of operation of the phone may be selected by the user, for example from a menu appearing on the MMI 4. Alternatively, the mode might be set by entering a specific code from the keypad of the phone. If, in step 42 of the process shown in Figure 2, it is determined that the phone is in the PNP mode, the number is handled at step 48 in the number processing block 18. In this mode of operation, the next step, step 50 in Figure 2, is to examine the dialled number, to determine whether a specific escape digit has been entered as the first digit. If not, then, at step 52, the number processing block 18 converts the number into the correct form, for example formatted according to GSM 04.08, for transmission to the transceiver 6, as if it is a PNP number. On the other hand, if the user has dialled a specific escape digit as the first digit of the dialled number, this is used by the number processing block 18 as an indication that the remainder of the dialled number is to be converted, at step 54 in Figure 2, as if it is an external number. Preferably, the user is able to define a specific escape digit for his own use, again through the MMI 4 on the phone. (Alternatively, the escape digit may be a digit sequence or may include a multiple keypress or a long duration keypress) . For example, if the user knows that none of the numbers in his Private Numbering Plan, which he wishes to dial, will begin with the digit "9", he may choose to define that as the relevant escape digit. Then, in order to dial an external (or network dialling plan) number, he must dial 9xxxx. On the other hand, to dial a private numbering plan number, he simply dials that number yyyy, with no preliminary escape digit. If the phone is in the external mode, that is, the answer to the question at step 42 is NO, the method passes to step 44, at which the number is received, for example by number processing block 16 in Figure 1. In this mode of operation, the next step, step 70 in Figure 2, is to examine the dialled number, to determine whether a specific prefix character has been entered as the first digit. If it has, then, at step 72, the number processing block 18 converts the number into a suitable form for transmission to the transceiver 6, as if it is a PNP number. On the other hand, if the user has not dialled the specific escape digit as the first digit of the dialled number, this is used by the number processing block 18 as an indication that the dialled number is to be converted, at step 74 in Figure 2, as if it is an external number. In this case, although the prefix character may be selectable to be a digit, it may not be possible to determine any particular digit which will never be the first digit of an external number, and hence which can be used as the prefix character, referred to hereinafter as "p" . Therefore, the phone preferably recognises a specific keypress operation as the required prefix character p. For example, this specific keypress operation may involve pressing multiple keys simultaneously or in a particular sequence, or it may involve a long duration keypress of a specific key or keys. Then, in order to dial a PNP (or private numbering plan) number, he must dial pxxxx. On the other hand, to dial an external (or network dialling plan) number, he simply dials that number yyyy, with no prefix character . The invention also relates to decoding blocks 20, 22 which, again, can be set into different modes. In conventional mobile phones, the user may have a smart card, a SIM card, which he may use to store frequently- dialled numbers. Alternatively, the numbers may be stored in non-volatile memory in the phone itself. In the case of storage on the SIM card, one mode of operation of the SIM card allows the user to enter a short code to access the relevant number, which is then displayed on the MMI 4, for dialling by the user. Typically, these numbers are stored in the same format used for transmission to the transceiver mentioned above . In a phone in accordance with the invention, the number which the user must dial depends on the mode in which the phone is operating. Thus, Figure 1 shows a switch 14 which, as described above with reference to the switch 12, may be in hardware, or may simply represent a means for deciding in software which processing steps are to be taken, and which determines whether numbers retrieved from the SIM card 8 are sent to a decoding block 20, or a decoding block 22. Thus, numbers are stored on the SIM card 8 along with the type of number and numbering plan identification. The decoding blocks 20, 22 decode the stored numbers in the same way, but present the decoded numbers differently to the display of the MMI 4, such that the number as displayed is the number which must be dialled in the associated mode of operation of the phone. Thus, depending on whether the phone is in a PNP mode or an external mode, the number which is displayed on the MMI 4 may include an escape digit or prefix character which the user must dial to access that number, or may omit any such digit or character. There is thus described a mobile phone which allows easy abbreviated dialling, for example when a private numbering plan is in operation.

Claims: CLAIMS 1. A mobile phone, having: a first mode of operation in which dialled digit sequences including a first specified prefix character are interpreted as numbers of a first type, and dialled digit sequences not including the first specified prefix digit are interpreted as numbers of a second type ; and a second mode of operation in which dialled digit sequences including a second specified prefix character are interpreted as numbers of the second type, and dialled digit sequences not including the second specified prefix digit are interpreted as numbers of the first type . 2. A mobile phone as claimed in claim 1, wherein numbers of the first type are private numbering plan numbers, and numbers of the second type are external numbers . 3. A mobile phone as claimed in claim 2, wherein the first specified prefix character is a digit from a keypad of the phone. 4. A mobile phone as claimed in claim 2, wherein the first specified prefix character is defined by a multiple keypress operation. 5. A mobile phone as claimed in claim 2, wherein the first specified prefix character is defined by a long duration keypress. 6. A mobile phone as claimed in claim 3, 4 or 5 , wherein the first specified prefix character is selectable by a user. 7. A mobile phone as claimed in claim 2, wherein the second specified prefix character is a digit from a keypad of the phone. 8. A mobile phone as claimed in claim 2, wherein the second specified prefix character is defined by a multiple keypress operation. 9. A mobile phone as claimed in claim 2, wherein the second specified prefix character is defined by a long duration keypress . 10. A mobile phone as claimed in claim 7, 8 or 9, wherein the second specified prefix character is selectable by a user. 11. A mobile phone as claimed in claim 1, wherein the mode of operation thereof is selectable by a user from a menu on a display of the phone. 12. A mobile phone as claimed in claim 1, wherein the mode of operation thereof is selectable by a user by inputting a code on a keypad of the phone. 13. A mobile phone as claimed in any preceding claim, comprising means for decoding stored numbers and means for displaying the decoded stored numbers, the means for displaying operating in accordance with the first or second mode of operation of the phone, such that the displayed number is the number to be dialled in that mode of operation.

Inventors: DARBY MICHAEL, FENTON ANDREW MARK, DARBY, MICHAEL, FENTON, ANDREW, MARK
Applicants: DARBY MICHAEL, ERICSSON TELEFON AB L M, FENTON ANDREW MARK, DARBY, MICHAEL, FENTON, ANDREW, MARK, TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
Application year: 1999
Main classification: H04M1
IPC codes: H04M1, H04Q7