A method of managing a user based input to a portable communication device comprising a primary processor and a secondary processor or to a converged system formed of separate devices comprising a primary processor located in one device and a secondary processor located in the second device, wherein the device or the system comprises: a primary processor configured to control a primary operating system; a secondary processor configured to control a secondary operating system; wherein the device or the system further comprises: a user interface input control operatively coupled to the primary processor, the user interface input control comprising a single button being configured to enable a radio function based on a user input extension entered with the user interface input control; characterized by: the method comprising selectively determining, by the primary processor, processing of the radio function by one of the primary and secondary processors (102, 104) based on activation of the user interface input control in conjunction with the user input interface extension, wherein the user input extension is entered using: a short press time duration of the single physical button to activate a mission critical radio function by the primary processor; and a long press time duration of the single physical button to activate a non-mission critical radio function by the secondary processor. a primary processor configured to control a primary operating system; a secondary processor configured to control a secondary operating system; wherein the device or the system further comprises: a user interface input control operatively coupled to the primary processor, the user interface input control comprising a single button being configured to enable a radio function based on a user input extension entered with the user interface input control; characterized by: the method comprising selectively determining, by the primary processor, processing of the radio function by one of the primary and secondary processors (102, 104) based on activation of the user interface input control in conjunction with the user input interface extension, wherein the user input extension is entered using: a short press time duration of the single physical button to activate a mission critical radio function by the primary processor; and a long press time duration of the single physical button to activate a non-mission critical radio function by the secondary processor. a user interface input control operatively coupled to the primary processor, the user interface input control comprising a single button being configured to enable a radio function based on a user input extension entered with the user interface input control; characterized by: the method comprising selectively determining, by the primary processor, processing of the radio function by one of the primary and secondary processors (102, 104) based on activation of the user interface input control in conjunction with the user input interface extension, wherein the user input extension is entered using: a short press time duration of the single physical button to activate a mission critical radio function by the primary processor; and a long press time duration of the single physical button to activate a non-mission critical radio function by the secondary processor. a short press time duration of the single physical button to activate a mission critical radio function by the primary processor; and a long press time duration of the single physical button to activate a non-mission critical radio function by the secondary processor.