Secondary subscriber line override system and method

#1. Field of the Invention

#The present invention is directed to a method and system of utilizing a secondary telephone line service, and in one embodiment encompasses analyzing a dialing sequence to convert from utilizing the secondary telephone line service to utilizing a primary telephone line service without the use of a manual override.

#2. Discussion of the Background

#A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:

#FIG. 1 is a block diagram of a secondary telephone line service box according to the present invention; and

#FIG. 2 is flow of a dialed digit processor that determines the destination telephone line of the call.

#As secondary telephone line services become more prevalent, users are going to utilize those services as if they were POTS services. That means that cordless telephones will be connected to such services and users will expect to be able walk around with the cordless phone without thinking about the fact that the cordless phone base station is connected to a non-POTS connection. According, in the case of an emergency (e.g., the cordless phone user falls and is injured), the user is unlikely to think about pressing a manual override button to switch from a secondary line to the primary line. In fact, if a user has the cordless phone handset, that user is likely to be very far from the base station where such an override button might exist. Similarly, non-residents of the house or guests of the company would likely be unaware of the existence of the manual override and would be unable to utilize the phone for emergency services. There is, therefore, a need for an automatic switching system converts from utilizing a secondary telephone line service to the POTS network without the need for user intervention.

#Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, FIG. 1 is a schematic illustration of a secondary telephone line service box 100 according to the present invention. A telephone line from a wall mounted telephone or a cordless telephone base station is connected to the telephone line connector 110. When a user takes the phone off-hook, the call processor 120 monitors the DTMF tones generated by the phone handset and determines if the number dialed corresponds to a telephone entry that should be directed to the POTS network or the secondary line network.

#As shown in FIG. 2, the call processor 120 collects digits as dialed, and determines if the digits so far constitute a match of any number in the database of the box 100. If a total match occurs (e.g., the user has dialed all three digits of 911 in order), then the call processor 120 switches the outgoing call to the POTS interface 130 and re-dials the captured digits (thereby connecting the call to the desired service). The call processor can optionally temporarily block the return sound path to the user so that the user does not hear the digits being redial, which may otherwise confuse the user.