A nurse call system that enables a call for a nurse from anywhere in a hospital ward while a patient carries a mobile phone is provided. The nurse call system includes a plurality of patient mobile phones 10 are carried by hospitalized patients and connected to a controller 8 via a base station 12 as with nurse mobile phones 9, and each patient mobile phone 10 has a hospital room ID and a nurse call slave device ID registered therein for recognizing a bed location of the patient carrying the patient mobile phone 10, thus enabling a nurse call operation for transmitting a call signal with the hospital room ID and the slave device ID added thereto, to the nurse call master device 7 and at least one of the nurse mobile phones 9, through a predetermined operation.

A nurse call system that enables a call for a nurse from anywhere in a hospital ward while a patient carries a mobile phone is provided. The nurse call system includes a plurality of patient mobile phones 10 are carried by hospitalized patients and connected to a controller 8 via a base station 12 as with nurse mobile phones 9, and each patient mobile phone 10 has a hospital room ID and a nurse call slave device ID registered therein for recognizing a bed location of the patient carrying the patient mobile phone 10, thus enabling a nurse call operation for transmitting a call signal with the hospital room ID and the slave device ID added thereto, to the nurse call master device 7 and at least one of the nurse mobile phones 9, through a predetermined operation.

Measures for use in operating a network node in a telecommunications network. At a network node located in a second part of the network, signaling messages transmitted between a server and end devices in an at least a first group are monitored. Each monitored signaling message includes a telephone dialing number for a given end device in the at least first group and an extension number for the given end device. On the basis of the monitoring, mapping data is stored which includes mappings between telephone dialing numbers and extension numbers for end devices in the at least first group. In response to detecting a loss of connectivity between a first part of the telecommunications network and the second part of the telecommunications network, extension number dialing request messages received from end devices in the first group are processed according to a detected loss of connectivity operating mode.

Measures for use in operating a network node in a telecommunications network. At a network node located in a second part of the network, signaling messages transmitted between a server and end devices in an at least a first group are monitored. Each monitored signaling message includes a telephone dialing number for a given end device in the at least first group and an extension number for the given end device. On the basis of the monitoring, mapping data is stored which includes mappings between telephone dialing numbers and extension numbers for end devices in the at least first group. In response to detecting a loss of connectivity between a first part of the telecommunications network and the second part of the telecommunications network, extension number dialing request messages received from end devices in the first group are processed according to a detected loss of connectivity operating mode.