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Abstract — In this paper we present a novel mechanism (Wireless Data Sharing, WDS) to share popular contents among second-level proxies connected to a parent proxy through a bandwidth-limited, wireless, broadcast channel. The idea is to publish the transmission of a content requested by a second-level proxy so as to make all the other ones able to capture such a content during the reliable unicast transmission from the parent towards the requesting second-level proxy over the broadcast channel. This would allow users served by these proxies to decrease the time to access contents, without any additional bandwidth consumption. In addition, such an approach would increase channel efficiency and decrease central server load. We provide a detailed description of the architecture and functions of the WDS system, with explicit reference to the prototype we have implemented. Such a prototype has enabled us to evaluate the performance of the data sharing mechanism from both user and network viewpoints. In more detail, we have carried out a measurement campaign in an IEEE 802.11 environment to get quantitative results about: (i) bandwidth saving, (ii) content access latency, and (iii) signaling overhead. Index Terms — cache pre-fetching, popular contents, broadcast and bandwidth-limited channel, reliable transport. I