A compressive coding device converts three color components of pixel data from the RGB presentation to the YCbCr presentation according to a mapping rule. Particularly, there are broadly contemplated herein, in accordance with at least one presently preferred embodiment of the present invention, methods and arrangements for facilitating determinations of suitable times for enabling system updates andor downloads. The group call may then be initiated over the established eMBMS bearer using network group identifiers associated with the call originator and one or more group members present in the selected geographic area and unicast service with a dedicated link to group members located outside the selected geographic area may be established to include such group members in the group call.