Patent ID: 8611278

Claim:
A mobile device for a wireless network system, the wireless network system comprising the mobile device, a plurality of base stations (BSs) and a backhaul network device, each of the BSs is connected to the backhaul network device, the mobile device working in a low-duty mode periodically comprising a preconfigured available interval and a preconfigured unavailable interval, the mobile device comprising: a communication module, being configured to receive BS information of each of the BSs, the BS information of each of the BSs comprising a service loading condition; and a process module, being electrically connected to the communication module, and configured to select a primary BS and a backup BS from the BSs according to the BS information of each of the BSs, wherein the communication module is configured to perform a data transmission procedure with the primary BS during the preconfigured available interval to communicate with the backhaul network device via the primary BS, and perform a connection keeping procedure with the backup BS during the preconfigured unavailable interval; and wherein when the communication module communicates with the backhaul network device via the primary BS, the process module is further configured to determine that the data transmission procedure fails and enable the communication module to perform a data transmission recovery procedure with the backup BS so that the communication module continuously communicates with the backhaul network device via the backup BS.