| 摘要 |
A presence service can be provided by an access point (101, figure 1) serving a small cell 100 by rejecting a request for registration 204 from a user equipment (103) after acquiring its IMSI 203 and sending the IMSI 204 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 205. If 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 207. The presence service can therefore be notified of subscribers who linger in a particular area or return to that area at regular intervals. In a second embodiment a UE determines (306, figure 3) if a cell is a presence cell by processing the received presence cell identifier message which is broadcast by the small cell 100. In a third embodiment the UE determines (405, figure 4) if a cell is a presence cell by analysis of the cause code value in the registration reject message. |
