| 摘要 |
<p>A communications system is capable of knowing presence status of mobile communications devices such as cellular transceivers. An access gateway such as, for example, a PDSN access gateway or home agent access gateway, manages access to a mobile communications device. The access gateway knows the presence status of the mobile communications device and reports it to a presence server. The access gateway can know the presence status using attributes obtained during management of system operation by the access gateway.</p> |
