SoftCast: Clean-slate Scalable Wireless Video
Video broadcast and mobile video challenge the conventional wireless design. In broadcast and mobile scenarios the bit rate supported by the channel differs across receivers and varies quickly over time. The conventional design however forces the source to pick a single bit rate and degrades sharply...
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2011
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| Online Access: | http://hdl.handle.net/1721.1/61009 |
| _version_ | 1811085931457806336 |
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| author | Jakubczak, Szymon Katabi, Dina |
| author2 | Dina Katabi |
| author_facet | Dina Katabi Jakubczak, Szymon Katabi, Dina |
| author_sort | Jakubczak, Szymon |
| collection | MIT |
| description | Video broadcast and mobile video challenge the conventional wireless design. In broadcast and mobile scenarios the bit rate supported by the channel differs across receivers and varies quickly over time. The conventional design however forces the source to pick a single bit rate and degrades sharply when the channel cannot not support the chosen bit rate. This paper presents SoftCast, a clean-slate design for wireless video where the source transmits one video stream that each receiver decodes to a video quality commensurate with its specific instantaneous channel quality. To do so, SoftCast ensures the samples of the digital video signal transmitted on the channel are linearly related to the pixels' luminance. Thus, when channel noise perturbs the transmitted signal samples, the perturbation naturally translates into approximation in the original video pixels. Hence, a receiver with a good channel (low noise) obtains a high fidelity video, and a receiver with a bad channel (high noise) obtains a low fidelity video. We implement SoftCast using the GNURadio software and the USRP platform. Results from a 20-node testbed show that SoftCast improves the average video quality (i.e., PSNR) across broadcast receivers in our testbed by up to 5.5dB. Even for a single receiver, it eliminates video glitches caused by mobility and increases robustness to packet loss by an order of magnitude. |
| first_indexed | 2024-09-23T13:17:42Z |
| id | mit-1721.1/61009 |
| institution | Massachusetts Institute of Technology |
| last_indexed | 2024-09-23T13:17:42Z |
| publishDate | 2011 |
| record_format | dspace |
| spelling | mit-1721.1/610092019-04-10T16:17:30Z SoftCast: Clean-slate Scalable Wireless Video Jakubczak, Szymon Katabi, Dina Dina Katabi Networks & Mobile Systems Video broadcast and mobile video challenge the conventional wireless design. In broadcast and mobile scenarios the bit rate supported by the channel differs across receivers and varies quickly over time. The conventional design however forces the source to pick a single bit rate and degrades sharply when the channel cannot not support the chosen bit rate. This paper presents SoftCast, a clean-slate design for wireless video where the source transmits one video stream that each receiver decodes to a video quality commensurate with its specific instantaneous channel quality. To do so, SoftCast ensures the samples of the digital video signal transmitted on the channel are linearly related to the pixels' luminance. Thus, when channel noise perturbs the transmitted signal samples, the perturbation naturally translates into approximation in the original video pixels. Hence, a receiver with a good channel (low noise) obtains a high fidelity video, and a receiver with a bad channel (high noise) obtains a low fidelity video. We implement SoftCast using the GNURadio software and the USRP platform. Results from a 20-node testbed show that SoftCast improves the average video quality (i.e., PSNR) across broadcast receivers in our testbed by up to 5.5dB. Even for a single receiver, it eliminates video glitches caused by mobility and increases robustness to packet loss by an order of magnitude. 2011-02-22T21:30:19Z 2011-02-22T21:30:19Z 2011-02-15 http://hdl.handle.net/1721.1/61009 MIT-CSAIL-TR-2011-008 14 p. application/pdf |
| spellingShingle | Jakubczak, Szymon Katabi, Dina SoftCast: Clean-slate Scalable Wireless Video |
| title | SoftCast: Clean-slate Scalable Wireless Video |
| title_full | SoftCast: Clean-slate Scalable Wireless Video |
| title_fullStr | SoftCast: Clean-slate Scalable Wireless Video |
| title_full_unstemmed | SoftCast: Clean-slate Scalable Wireless Video |
| title_short | SoftCast: Clean-slate Scalable Wireless Video |
| title_sort | softcast clean slate scalable wireless video |
| url | http://hdl.handle.net/1721.1/61009 |
| work_keys_str_mv | AT jakubczakszymon softcastcleanslatescalablewirelessvideo AT katabidina softcastcleanslatescalablewirelessvideo |