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This paper presents an adaptive mechanism for improving the content download in wireless environments. The solution is based on the use of the file delivery over unidirectional transport (FLUTE) protocol in multicast networks, which reduce considerably the bandwidth when there are many users interested in the same contents. Specifically, the system proposed reduces the average download time of clients within the coverage area, thus improving the Quality of Experience. To that extent, clients send periodically feedback messages to the server reporting the losses they are experiencing. With this information, the server decides which is the optimum application layer–forward error correction (AL-FEC) code rate that minimizes the average download time, taking into account the channel bandwidth, and starts sending data with that code rate. The system proposed is evaluated in various scenarios, considering different distributions of losses in the coverage area. Results show that the adaptive solution proposed is very suitable in wireless networks with limited bandwidth. [ABSTRACT FROM PUBLISHER]

This paper proposes a multicast content download service based on the use of residual network capacity to push multimedia content to available local storage in personal multimedia devices. The service under study is based on the FLUTE protocol. Specifically, FLUTE packets fill the spare capacity in the IP tunnels reserved for the primary streaming service (opportunistic insertion). The paper also evaluates the use of application layer–forward error correction (AL-FEC) parity to overcome transmission errors, object multiplexing to send the most popular multimedia contents more frequently and cache management policies that consider user preferences to keep in storage the most useful items. The service has been evaluated through simulations and measurements performed with an application prototype based on the DVB-H standards. The results show that AL-FEC enables the use of residual capacity for background content download services. In turn, AL-FEC, as well as object multiplexing, improves the relation between the number of content items and the overall access time. Moreover, results show that high percentages of requests can be served from the local cache of the service, provided that it is possible to estimate the popularity of content items and the user preferences. [ABSTRACT FROM AUTHOR]