Cache-aided coded content delivery is studied for devices with diverse quality-of-service (QoS) requirements. The network consists of a server, which holds a database of independent contents, and users equipped with local caches of different capacities. User caches are filled by the server during a low traffic period without the knowledge of particular user demands. It is assumed that each user in the system has a distinct QoS requirement, which may be due to the viewing preference of the user, or the display capability of the device. Each user requests a single file from the database to be served at this fixed QoS level, and all the requests are satisfied simultaneously by the server over a shared error-free link. Each file is modeled as a sequence of independently and identically distributed Gaussian samples, and the QoS is measured in terms of the average squared error distortion between the original sequence and the reconstruction. Our goal in this work is to characterize the minimum delivery rate the server needs to transmit over the shared link to satisfy all possible demand combinations, both in the centralized and decentralized settings.
['Qianqian Yang', 'Deniz Gunduz']
Coded Caching and Content Delivery with Heterogeneous Distortion Requirements