A system may include obtaining first and second mode ranking based on categorical attributes of a first item and on payment mode use constraints and transmitting an indication of a first payment mode responsive to the first or the second mode ranking. Signals received by each of the plurality of antenna configurations are combined in a combiner and passed to a rake receiver that can be configured to combine the signals received by each of the plurality of antenna configurations for further processing. An onscreen function execution method of the present invention includes mapping active regions of the touchscreen to functions of at least one application, displaying an application screen in response to an application activation command and executing, if a tap is detected on one of the active regions, a function mapped to the application activation command. Each network element that receives the loop back message modifies the message in a predetermined manner. , if difference value is 3 or more, 8 is subtracted, and if difference value is less than \u22124, 8 is added to thereby transform two difference values where difference therebetween is 8 into the same value.