Patent Publication Number: US-2003223557-A1

Title: Method and apparatus for handset exclusion control

Description:
BACKGROUND OF THE INVENTION  
       [0001] Typical modems are connectable both to a telephone line and to a telephone handset, so that when a modem session (data, fax or voice or a combination thereof) is not being handled, the telephone line may be easily accessed through the handset for regular voice telephone calls.  
       [0002] During handling of a modem session, certain activities, such as picking up the handset, dialing and hook on/off of the handset, may cause serious, sometimes irrecoverable, disturbance to the modem session. Therefore, it is common to exclude the handset connection during handling of a modem session. Typically, the handset exclusion is implemented as a logical NOT of the modem hook state. In other words, when there is a modem session in progress, the handset is excluded, and when a modem session is not in progress, the handset is enabled.  
       [0003] The International Telecommunication Union (ITU) V.92 standard enables the coexistence of modem sessions and regular voice telephone calls. For example, a modem session may be put “on hold” in order to accept an incoming regular voice telephone call. In another example, a modem session may be put “on hold” in order to initiate an outgoing regular telephone call.  
       [0004] Accordingly, it will be necessary to implement handset exclusion in a different manner than that described hereinabove.  
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0005] The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to organization and method of operation, together with objects, features and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanied drawings in which:  
     [0006]FIGS. 1, 2 and  3  are simplified illustrations of modem cards in accordance with some embodiments of the present invention;  
     [0007]FIG. 4 is a simplified flowchart illustration of a method of activating and deactivating handset exclusion, in accordance with an embodiment of the present invention;  
     [0008]FIG. 5 is an exemplary timing diagram, in accordance with an embodiment of the present invention;  
     [0009]FIG. 6 is a simplified flowchart illustration of a method of activating and deactivating handset exclusion, in accordance with another embodiment of the present invention; and  
     [0010]FIG. 7 is an exemplary timing diagram, in accordance with an embodiment of the present invention. 
    
    
     [0011] It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements.  
     DETAILED DESCRIPTION OF THE INVENTION  
     [0012] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However it will be understood by those of ordinary skill in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures and components have not been described in detail so as not to obscure the present invention.  
     [0013] Reference is now made to FIGS. 1, 2 and  3 , which are simplified illustrations of modem cards in accordance with some embodiments of the present invention. In FIG. 1, a modem card  100  may comprise a “LINE IN” modem jack  102  and a “TELEPHONE IN” handset jack  104 . Handset jack  104  is able to be connected to a telephone  106 , while modem jack  102  is able to be connected to a wall outlet of a telephone line (not shown). Modem card  100  may also comprise a hardware modem controller  108  and a data access arrangement (DAA)  110 . Modem card  100  may also comprise additional components, but these are not shown in FIG. 1 in order not to obscure the description of embodiments of the present invention. A software modem control  109  is shown in FIGS. 1, 2 and  3 , and will be described hereinbelow.  
     [0014] The individual wires of two-wire analog lines connecting telephony devices to the near central office of the telephony network are known as the “Tip” wire and the “Ring” wire. Modem jack  102  may be coupled to DAA  110  via a Tip wire  112  and a Ring wire  114 . Similarly, handset jack  104  may be coupled to DAA  110  via a Tip wire  116  and a Ring wire  118 .  
     [0015] Hardware modem controller  108  may comprise a general purpose input output (GPIO) pin (not shown). Modem card  100  may comprise a relay  120  controlled by the GPIO signal which may connect or disconnect Tip wire  116 .  
     [0016] A modem card  200  according to another embodiment of the present invention is shown in FIG. 2. It is similar to modem card  100  of FIG. 1, and reference numerals may be repeated among the figures to indicate corresponding or analogous elements. Modem card  200  may comprise a relay  220  controlled by the GPIO signal which may connect or disconnect Ring wire  118 .  
     [0017] A modem card  300  according to a further embodiment of the present invention is shown in FIG. 3. It is similar to modem card  100  of FIG. 1, and reference numerals may be repeated among the figures to indicate corresponding or analogous elements. Modem card  300  may comprise a relay  320  controlled by the GPIO signal which may simultaneously connect or disconnect Tip wire  116  and Ring wire  118 .  
     [0018] Hardware modem controller  108  is a physical unit on the modem card which may provide, among other things, the control pins for the modem card components (such as, for example, the codec clock, control signals for the modem hook, a control signal for handset exclusion, a bridge to the communication port or computer bus). Software modem control  109  is a software module which may contain, among other things, the logic and state machines for control signals of hardware modem controller  108 . Additionally, software modem control  109  is responsible for the operation of hardware modem controller  108  throughout the modem session.  
     [0019] Software modem control  109  may be, for example, a software module stored in memory on the host computer (not shown) and running on the central processing unit of the host computer, or may be, for example, software resident on memory (not shown) on modem card  100 , running on a microprocessor (not shown) or a digital signal processing chip (not shown) on modem card  100 . Control of the handset exclusion is control of the GPIO signal of hardware modem controller  108 . Throughout the specification and the claims, the term “modem controller” is used to mean a logical unit comprising a hardware modem controller and a software modem control. The GPIO signal and methods of its control will now be described.  
     [0020] Reference is now made to FIG. 4, which is a simplified flowchart illustration of a method of activating and deactivating handset exclusion, in accordance with an embodiment of the present invention. Reference is made additionally to FIG. 5, which is an exemplary timing diagram for the GPIO signal, in accordance with an embodiment of the present invention. To aid in understanding this embodiment, an exemplary timing diagram for the modem hook is also shown. In the exemplary timing diagram of FIG. 5, a GPIO value of 1 activates handset exclusion (by opening the switch in relay  120 ,  220  or  320 ), while a GPIO value of 0 deactivates handset exclusion (by closing the switch in relay  120 ,  220  or  320 ). Clearly any two values may be used for the GPIO signal instead of 1 and 0.  
     [0021] A modem session is in progress (block  400 ) and data  500  is being received and/or transmitted. The modem is “hook off”. The GPIO signal has a value of 1 and handset exclusion is active. The modem may detect a call waiting signal  502  or may receive a request  502  to initiate an outgoing voice call while putting the modem session on hold (block  402 ). Modem on hold negotiation  504  may be conducted (block  404 ). If the “on hold” negotiation is not successful, then the modem session may continue as is (block  400 ). If, however, “on hold” is negotiated successfully, the modem may perform “flash”  506  to switch to the voice call (block  406 ) and deactivate the handset exclusion (block  408 ). A “flash” or a “flash switchhook” is a quick “hook on”—“hook off” sequence, such as, for example, a quick hanging up and picking up of the handset, where the period of time of the “hook on” is defined on a country basis according to the communication regulations of that country. During flash, the modem is “hook on”.  
     [0022] The change in the value of the GPIO signal from 1 (handset exclusion active) to 0 (handset exclusion inactive) may occur right after the call waiting signal or voice outgoing call request is received and before “flash”  506  is performed, or during “flash”  506 , or after “flash”  506 . In other words, it may occur any time between arrows  508 . Once “flash”  506  has been completed, the modem is “on hold”  510 , and the modem is “hook off”.  
     [0023] Although it is not illustrated in FIG. 5, when the modem is “on hold”  510 , the modem may detect the end of the voice call (block  410 ). The modem may activate the handset exclusion (block  412 ), may perform a training sequence and may resume the modem session (block  400 ).  
     [0024] Although the modem does not detect the end of the voice call, perhaps, for example, because the voice call has not yet ended, the modem may receive a request  512  to restore the data connection (block  414 ). The modem may activate the handset exclusion (block  416 ) and perform “flash”  514  to switch to the data call (block  418 ). During flash, the modem is “hook on”.  
     [0025] The change in the value of the GPIO signal from 0 (handset exclusion inactive) to 1 (handset exclusion active) may occur right after the data connection restoration request is received and before “flash”  514  is performed, or during “flash”  514 , or after “flash”  514 . In other words, it may occur any time between arrows  516 . Once “flash”  514  has been completed, the modem session that was previously “on hold” is in progress (block  400 ). The modem may perform a training sequence  518  and may begin receiving and/or transmitting data  520 .  
     [0026] Reference is now made to FIG. 6, which is a simplified flowchart illustration of a method of activating and deactivating handset exclusion, in accordance with another embodiment of the present invention. Reference is made additionally to FIG. 7, which is an exemplary timing diagram for the GPIO signal, in accordance with another embodiment of the present invention. To aid in understanding this embodiment, an exemplary timing diagram for the modern hook is also shown. In tie exemplary timing diagram of FIG. 7, a GPIO value of 1 activates handset exclusion (by opening the switch in relay  120 ,  220  or  320 ), while a GPIO value of 0 deactivates handset exclusion (by closing the switch in relay  120 ,  220  or  320 ). Clearly any two values may be used for the GPIO signal instead of 1 and 0.  
     [0027] A modem session is requested  702  (block  600 ), and the modem may switch to “hook off”, while maintaining handset exclusion deactivated (block  602 ). The GPIO signal has a value of 0 and handset exclusion is inactive. The modem may detect whether a parallel voice call is in progress (block  604 ). Although it is not illustrated in FIG. 7, if no parallel voice call is in progress, then the modem may activate handset exclusion (block  605 ) and perform the requested call (block  606 ).  
     [0028] If, however, the modem senses that a parallel voice call is in progress  704 , then a request  706  to the voice call parties to initiate a modem session may optionally be made (block  608 ). If the request is denied (block  610 ), then the voice call may continue (block  612 ).  
     [0029] If the request is approved  706 , or alternatively, if no request is made, then the modem may activate the handset exclusion (block  614 ) and perform “flash”  708  to switch to the data call (block  616 ). The change in the value of the GPIO signal from 0 (handset exclusion inactive) to 1 (handset exclusion active) may occur before “flash”  708  is performed, or during “flash”  708 , or after “flash”  708 . In other words, it may occur any time between arrows  709 . Once “flash”  708  has been completed, the modem is active and the requested modem session may be initiated, with data  710  being transmitted and/or received (block  618 ).  
     [0030] Once the modem session is over, the modem may perform “flash”  712  to switch to the voice call (block  620 ) and deactivate the handset exclusion (block  622 ). The change in the value of the GPIO signal from 1 handset exclusion active) to 0 (handset exclusion inactive) may occur before “flash”  712  is performed, or during “flash”  712 , or after “flash”  712 . In other words, it may occur any time between arrows  711 . Once “flash”  712  has been completed, an indication  714  to the voice call parties that the voice call may continue may be made (block  624 ). Then the modem session ends  716 , and the voice call may then continue (block  612 ).  
     [0031] While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will now occur to those of ordinary skill in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.