Patent ID: 6885665

Claim:
A method for identifying an end point terminal within a service group of end point terminals as a to-be-used terminal, where each of said terminals is characterized by an ID comprising the steps of: sending a message to said end point terminals, specifying a response criterion, requesting idle end point terminals that meet said response criterion to respond; receiving one or more responses from said idle end point terminals that meet said response criterion; based on a selected one of said responses, modifying said response criterion to form a changed response criterion; and based on information related to said response criterion either selecting the end point terminal that supplied the selected one of said responses as the to-be-used terminal, or returning to said step of sending a message, where the specified response criterion being said changed response criterion, wherein said response criterion specifies an end point terminal IDs range by providing an x value and a y value of, so that either only end point terminals that are included in said range send a response message, if they are idle, or only idle end point terminals determine whether they are included in said range and are thus enabled to send a response message each of said end point terminals, in determining whether its ID is within range of end point terminal IDs, compares its ID to said x value and to said y value, in the process subtracting from it's ID a value related to a constant supplied in said message, where the subtraction is performed in modulus arithmetic.