An apparatus employed in a user equipment, UE (101, 102), the apparatus comprising: one or more processors configured to: receive a paging message (414, 512) corresponding to a mobile terminating service in a packet-switched, PS, domain of a network, wherein the paging message (414, 512); distinguish the mobile terminating service from among a plurality of different mobile terminating services based on a paging cause parameter of the paging message (414, 512); and a radio frequency interface configured to receive the paging message (414, 512) over a radio interface (104, 105); characterized in that the one or more processors are further configured to: receive a PS paging category support indication indicating a supported level of granularity of PS paging categories during an attach procedure or a tracking area update, TAU, procedure; determine a level of granularity of distinguishing the mobile terminating services from among the plurality of mobile terminating services based on the PS paging category support indication; wherein the PS paging category support indication indicates the plurality of service categories of said mobile terminating services comprising: - a category for each of an internet protocol, IP, multimedia subsystem, IMS, related service and a non-IMS related service, or - a category for each of an IMS voice / video call, an IMS short message service, another IMS service, and a non-IMS service. receive a paging message (414, 512) corresponding to a mobile terminating service in a packet-switched, PS, domain of a network, wherein the paging message (414, 512); distinguish the mobile terminating service from among a plurality of different mobile terminating services based on a paging cause parameter of the paging message (414, 512); and a radio frequency interface configured to receive the paging message (414, 512) over a radio interface (104, 105); characterized in that the one or more processors are further configured to: receive a PS paging category support indication indicating a supported level of granularity of PS paging categories during an attach procedure or a tracking area update, TAU, procedure; determine a level of granularity of distinguishing the mobile terminating services from among the plurality of mobile terminating services based on the PS paging category support indication; wherein the PS paging category support indication indicates the plurality of service categories of said mobile terminating services comprising: - a category for each of an internet protocol, IP, multimedia subsystem, IMS, related service and a non-IMS related service, or - a category for each of an IMS voice / video call, an IMS short message service, another IMS service, and a non-IMS service. receive a PS paging category support indication indicating a supported level of granularity of PS paging categories during an attach procedure or a tracking area update, TAU, procedure; determine a level of granularity of distinguishing the mobile terminating services from among the plurality of mobile terminating services based on the PS paging category support indication; wherein the PS paging category support indication indicates the plurality of service categories of said mobile terminating services comprising: - a category for each of an internet protocol, IP, multimedia subsystem, IMS, related service and a non-IMS related service, or - a category for each of an IMS voice / video call, an IMS short message service, another IMS service, and a non-IMS service. - a category for each of an internet protocol, IP, multimedia subsystem, IMS, related service and a non-IMS related service, or - a category for each of an IMS voice / video call, an IMS short message service, another IMS service, and a non-IMS service.