Data recovery schemes in mobile broadcasting services

The mobile broadcasting services such as mobile television (TV) and interactive social TV become more popular in wireless broadcasting networks and attract a lot of research attention in pervasive computing. However, due to the error-prone nature of wireless broadcast, how to efficiently recover packet loss at mobile devices is a big challenge. To solve this problem, many research efforts suggest adopting another IP-based wireless network to handle packet recovery. In particular, mobile devices are equipped with two interfaces: one for the broadcast network and the other for such a recovery network. Mobile devices will continually receive the broadcasting content from the broadcast network. When packets are lost in the broadcast network, these mobile devices will ask the recovery network for data retransmissions. In this way, the broadcast network can incur less computation complexity because it does not need to simultaneously deal with the regular broadcasting and the retransmission jobs. Taking the digital video braodcasting-handheld (DVB-H) system as an example, this chapter introduces three types of data recovery schemes for mobile broadcasting services. First, the DVB-H system is integrated with a cellular network, where the parity data are transmitted through either the DVB-H channel or the cellular channel for data recovery. Second, a WiMAX network is adopted to support both the request submission sent fromthe mobile devices and the packet retransmission to these mobile devices. Third, mobile devices will organize a wireless ad hoc network to exchange the lost DVB-H packets to realize data recovery through peer-to-peer communications.