Abstract: Embodiments relate to a method and a device for switching media service channels, which minimize the time required to detect the first I frame for a switch channel by utilizing a caching server when switching channels in an IP-based media service, such as IPTV, and at the same time, minimize the time required for synchronization by changing time information in caching information transmitted from the caching server, such that channel switching between media service channels can be performed more quickly.

Abstract: A content providing service system includes a plurality of UEs configured to request and receive real time contents required to be received in real time or reserved contents reserved in advance from a service device and the service device configured to, when the real time contents or the reserved contents are requested from each of the plurality of UEs at a particular time, first allocate transmission resources to the UEs which request the real time contents and allocate the remaining transmission resources except for the first allocated transmission resources to at least some of the UEs which request the reserved contents.