There is described a multiple subscriber identity arrangement comprising a modem (10) and a control unit (13) associated with said modem. The modem is capable of receiving and/or transmitting messages related to either one of at least first and second subscriber identities, but not simultaneously. The control unit is configured to, when communication activity associated with the first subscriber identity is being performed (S1) by the modem, cause the modem to send (S3) an indication to a network associated with the first subscriber identity requesting compressed mode. The control unit is further configured to monitor the signalling associated with the second subscriber identity during a compressed mode gap associated with the first subscriber identity.