A presence service can be provided by an access point 101 serving a small cell 100 by rejecting a request for registration from a user equipment 103 after acquiring its IMSI and sending the IMSI to a presence database 105. The user equipment determines if the cell is a presence cell by comparing the cell's location area code (LAC) with LACs stored in a list and looking for a match. It the cell is a presence cell then the user equipment, rather than placing the LAC in a forbidden list, re-tries registration again but only after a pre-set time period of 5-10 minutes has elapsed. This has the advantage that a presence service can be notified of subscribers who linger in a particular area or return to that area at regular intervals.