Hybrid automatic repeat request method of a downlink tunnel

A hybrid automatic repeat request method of a downlink tunnel, comprising the following steps:

• a base station transmitting tunnel data that comprise protocol data units of multiple mobile stations to an access relay station via a tunnel link;
• (a) the access relay station determining its own reception of the tunnel data that comprise protocol data units of multiple mobile stations, and transmitting feedback to the base station via the tunnel link;
• or
• (b) the access relay station receiving feedback from each of the mobile stations about reception of a corresponding protocol data unit which is sent via an access link, and according to the feedback from each of the mobile stations, applying for bandwidth for retransmission or concentratedly transmitting the feedback from each of the mobile stations to the base station via the tunnel link, wherein
• the access relay station extracting the protocol data unit of each of the mobile stations after successfully receiving the tunnel data that comprise protocol data units of multiple mobile stations, and transmitting the protocol data unit of each of the mobile stations to each of the mobile stations via the access link,
• the tunnel link being made up of multi-hop relay stations, the relay station accessing the base station being the 1st hop relay station, and the relay station accessing the mobile station being the nth hop relay station, wherein, the 1st hop, the 2nd hop, . . . , the (n−1)th hop relay station not transmitting feedback immediately to the base station after receiving the tunnel data.