A method of selectively transitioning an operating state of a user equipment, UE within a wireless communications system, comprising: determining, at the UE, to initiate a communication session with at least one other UE to be arbitrated by an application server; determining a size of a call message to be sent by the UE for requesting initiation of the communication session by the application server; selecting a reverse-link channel on which to transmit the call message based upon the determined size of the call message and characterised in that selecting includes: comparing the determined size of the call message with a size threshold wherein the size threshold is smaller than a predefined threshold for triggering state transition for the UE; selecting a first reverse-link channel on which to transmit the call message if the comparison indicates that the determined size is below the size threshold; and selecting a second reverse-link channel on which to transmit the call message if the comparison indicates that the determined size is not below the size threshold; while the UE is in radio resource control connected mode, transitioning the UE to a given operating state that supports transmissions upon the selected reverse-link channel, wherein transitioning comprises configuring a message to request a serving access network to transition the UE to the given state; and transmitting the configured message to the serving access network on a given reverse-link channel, wherein the configured message includes a Traffic Volume Indicator field if the selected reverse link channel is the second reverse-link channel; and transmitting the call message on the selected reverse-link channel after the UE is transitioned to the given operating state. determining, at the UE, to initiate a communication session with at least one other UE to be arbitrated by an application server; determining a size of a call message to be sent by the UE for requesting initiation of the communication session by the application server; selecting a reverse-link channel on which to transmit the call message based upon the determined size of the call message and characterised in that selecting includes: comparing the determined size of the call message with a size threshold wherein the size threshold is smaller than a predefined threshold for triggering state transition for the UE; selecting a first reverse-link channel on which to transmit the call message if the comparison indicates that the determined size is below the size threshold; and selecting a second reverse-link channel on which to transmit the call message if the comparison indicates that the determined size is not below the size threshold; while the UE is in radio resource control connected mode, transitioning the UE to a given operating state that supports transmissions upon the selected reverse-link channel, wherein transitioning comprises configuring a message to request a serving access network to transition the UE to the given state; and transmitting the configured message to the serving access network on a given reverse-link channel, wherein the configured message includes a Traffic Volume Indicator field if the selected reverse link channel is the second reverse-link channel; and transmitting the call message on the selected reverse-link channel after the UE is transitioned to the given operating state. comparing the determined size of the call message with a size threshold wherein the size threshold is smaller than a predefined threshold for triggering state transition for the UE; selecting a first reverse-link channel on which to transmit the call message if the comparison indicates that the determined size is below the size threshold; and selecting a second reverse-link channel on which to transmit the call message if the comparison indicates that the determined size is not below the size threshold; while the UE is in radio resource control connected mode, transitioning the UE to a given operating state that supports transmissions upon the selected reverse-link channel, wherein transitioning comprises configuring a message to request a serving access network to transition the UE to the given state; and transmitting the configured message to the serving access network on a given reverse-link channel, wherein the configured message includes a Traffic Volume Indicator field if the selected reverse link channel is the second reverse-link channel; and transmitting the call message on the selected reverse-link channel after the UE is transitioned to the given operating state.