A method, in a cellular network for paging a mobile set (3) in a paging group (1) comprising the steps of:

- organizing cells (8) of said paging group (1) into a paging sequence (6) comprising ordered sets (7) comprising said cells (8),

- paging said paging sequence (6) by successively paging each set (7), one set (7) at a time, in order of appearance in said paging sequence (6), until said mobile set (3) is found,

where said organizing cells step comprises:

- computing a ranking value for each cell (8) pertaining to said paging sequence (6),

- ordering said cells (8) after said ranking value in descending order,

- grouping contiguous ordered cells (8) into sets (7).

For controlling the traffic balance between the paging upon incoming calls and the location registration according to the traffic at the time of transmitting and receiving packets, to realize efficient battery conservation in a mobile station, the present invention provides a system constituted by a plurality of base stations, a plurality of mobile stations, and a management server for location information of each mobile station and the like, in which a set of respective cells formed by the base stations constitutes a first area group, whereas each mobile station shifts to a mode periodically receiving signals from the base stations if no signals are transmitted and received for a predetermined period. Each base station forms second to n-th area groups (n ≥ 2), each having an area smaller than that of the first area, to be included in the first area group used when the mobile stations are in idle state. Each mobile station selects the area group to register according to the period in which no packet is received and transmitted in the above-mentioned mode, and registers its location while specifying an area within this area group with respect to the server.

In a mobile communication system having plural cells for presenting plural types of communication service to plural mobile stations, information of allowance of delay of call connection is attached to a call to the mobile station, and when delay of call connection is not allowed as seen from this information of allowance, the mobile station is paged simultaneously through all cells in the location registration area, and when delay of call connection is allowed, the mobile station is paged sequentially in the unit of certain cells in the location registration area. Accordingly, the control traffic required for location registration and paging can be decreased.

In a cordless key telephone system where adjacent service zones (Z1, Z3; Z2, Z4) having the same control channel are overlapped, forming an unavoidable interference-affected overlapping zone (Z13, Z24), a main unit (1) initially selects an access unit (21-28) from each service zone in response to an incoming call from a network and transmits a first alert signal to that unit where it is broadcast to elicit an acknowledgment (ACK) signal from cordless stations. On receiving it, the access unit selects a speech channel, broadcasts a first channel assignment signal on the control channel, and then a first ringing signal on the selected speech channel. The main unit determines whether there is a cordless station (36) failing to respond to the first alert signal. If such a station exists, the main unit selects a first, idle access unit (22; 28) which is located in one of the adjacent service zones. A second alert signal is then broadcast on a control channel from the first access unit. Following receipt of an ACK signal from a cordless station (36), a second channel assignment signal is broadcast from the first access unit (28), signalling the identification of a speech channel (S3) previously selected by a second, initially selected access unit (27) located in the adjacent service zones. A second ringing signal is broadcast from the second access unit (27) on the previously selected speech channel (S3).

A mobile communications network is presented, wherein the mobile communications network includes a user equipment UE, an access node of an access network, and a control plane function, wherein a method in the mobile communications network comprises the following steps: moving the UE from a connected state into a connected inactive state in the access network while maintaining an active control plane connection associated with the UE between the access node and the control plane function; generating at the access node a UE context; receiving at the access node from a core network downlink data destined to the UE; if failing to resume an access network connection between the access node and the UE, generating by the access node a downlink data notification based on the UE context; sending the downlink data notification through the active control plane connection.

This disclosure relates to a 5G or pre-5G communication system for supporting a higher data transfer rate after a 4G communication system such as LTE. In one embodiment for paging a terminal, a base station identifies information on a coverage enhancement (CE) level of the terminal and transmits a message including the information on the CE level of the terminal to a mobility management entity (MME). When a paging message including the information on the CE level from the MME is received, the base station transmits a paging signal to the terminal, based on the CE level of the terminal.