Currently, as mobile applications rapidly develop, mobile data traffic increases sharply. Consequently, it is increasingly difficult for a live network to meet a data traffic increase requirement. Therefore, a mobile operator expects to offload partial traffic of the live network to a non-3GPP (non-3rd Generation Partnership Project, non-3rd Generation Partnership Project) network, so as to relieve traffic load of the live network. Therefore, interworking (interworking) between a 3GPP network and a non-3GPP network, for example, interworking between an LTE (Long Term Evolution, Long Term Evolution) network and a WLAN (Wireless Local Area Network, wireless local area network) network, is a current research focus.
There are abundant unlicensed spectrum resources in the WLAN. To fully use the WLAN resources, a manner of interworking between a cellular network and the WLAN is used. On the one hand, the WLAN may still continue to transmit a conventional WLAN service; on the other hand, the cellular network may offload (offload) some services to the WLAN, so as to fully use the WLAN resources and increase a throughput.
In this case, if the WLAN does not distinguish between the conventional WLAN service and a to-be-offloaded service of the cellular network, the conventional WLAN service and the to-be-offloaded service contend for a channel, and more conflicts are introduced. Consequently, channel blocking occurs, and both the to-be-offloaded service of the cellular network and the WLAN service have poor user experience.
Therefore, how to coordinately transmit, in a WLAN, a conventional WLAN service and a to-be-offloaded service of a cellular network becomes an urgent problem to be resolved in interworking between the cellular network and the WLAN.