Soft Delivery: Survey on A New Paradigm for Wireless and Mobile Multimedia Streaming

TL;DR

This paper surveys soft delivery schemes for wireless multimedia streaming, a new paradigm that enables graceful quality degradation and avoids cliff effects by directly transmitting frequency-domain coefficients without digital coding.

Contribution

It provides a comprehensive overview of soft delivery schemes, highlighting their advantages over traditional digital-based methods in wireless video streaming.

Findings

Soft delivery enables graceful quality degradation in fluctuating channels.

It avoids cliff and leveling effects common in digital schemes.

The survey summarizes various soft delivery techniques and their benefits.

Abstract

The increasing demand for video streaming services is the key driver of modern wireless and mobile communications. For robust and high-quality delivery of video content over wireless and mobile networks, the main challenge is sending image and video signals to single and multiple users over unstable and diverse channel environments. To this end, many studies have designed digital-based video delivery schemes, which mainly consist of a sequence of digital-based coding and transmission schemes. Although digital-based schemes perform well when the channel characteristics are known in advance, significant quality degradation, known as cliff and leveling effects, often occurs owing to the fluctuating channel characteristics. To prevent cliff and leveling effects irrespective of the channel characteristics of each user, a new paradigm for wireless and mobile video streaming has been proposed. Soft delivery schemes skip the digital operations of quantization and entropy and channel coding while directly mapping the power-assigned frequency--domain coefficients onto the transmission symbols. This modification is based on the fact that the pixel distortion due to communication noise is proportional to the magnitude of the noise, resulting in graceful quality improvement, wherein quality is improved gradually, according to the wireless channel quality without any cliff and leveling effects. Herein, we present a comprehensive summary of soft delivery schemes.