Method and apparatus for transmitting a UPnP Byebye message

摘要

A method and apparatus for transmitting a Byebye message (171) when an operation of a controlled device (200) is abnormally terminated are provided. A new field is added to discovery and Event messages defined in the UPnP standard. These messages are exchanged to allow a control point (300) to monitor the controlled device (200). When the operation of the controlled device (200) is abnormally terminated, the control point (300) monitoring the operation of the controlled device (200) determines whether or not the operation of the controlled device (200) is abnormally terminated according to the presence or absence of a response to a Subscription Renewal message (560). The control point (300) multicasts the Byebye message (171) over the network instead of the controlled device (200) abnormally terminated. It is possible to notify all control points in a network that the operation of the controlled device (200) is abnormally terminated without increasing the load on the network and compatibility problems with existing UPnP devices.