TY - GEN
T1 - Hermes
T2 - 16th Annual Conference on Mobile Computing and Networking, MobiCom 2010
AU - Dhananjay, Aditya
AU - Sharma, Ashlesh
AU - Paik, Michael
AU - Chen, Jay
AU - Kuppusamy, Trishank Karthik
AU - Li, Jinyang
AU - Subramanian, Lakshminarayanan
PY - 2010
Y1 - 2010
N2 - While the cellular revolution has made voice connectivity ubiquitous in the developing world, data services are largely absent or are prohibitively expensive. In this paper, we present Hermes 1, a point-to-point data connectivity solution that works by modulating data onto acoustic signals that are sent over a cellular voice call. The main challenge is that most voice codecs greatly distort signals that are not voice-like; furthermore, the backhaul can be highly heterogeneous and of low quality, thereby introducing unpredictable distortions. Hermes modulates data over the extremely narrow-band (approximately 3kHz bandwidth) acoustic carrier, while being severely constrained by the requirement that the resulting sound signals are voice-like, as far as the voice codecs are concerned. Hermes uses a robust data transcoding and modulation scheme to detect and correct errors in the face of bit flips, insertions and deletions; it also adapts the modulation parameters to the observed bit error rate on the actual voice channel. Through real-world experiments, we show that Hermes achieves approximately 1.2 kbps goodput which when compared to SMS, improves throughput by a factor of 5× and reduces the cost-per-byte by over a factor of 50×.
AB - While the cellular revolution has made voice connectivity ubiquitous in the developing world, data services are largely absent or are prohibitively expensive. In this paper, we present Hermes 1, a point-to-point data connectivity solution that works by modulating data onto acoustic signals that are sent over a cellular voice call. The main challenge is that most voice codecs greatly distort signals that are not voice-like; furthermore, the backhaul can be highly heterogeneous and of low quality, thereby introducing unpredictable distortions. Hermes modulates data over the extremely narrow-band (approximately 3kHz bandwidth) acoustic carrier, while being severely constrained by the requirement that the resulting sound signals are voice-like, as far as the voice codecs are concerned. Hermes uses a robust data transcoding and modulation scheme to detect and correct errors in the face of bit flips, insertions and deletions; it also adapts the modulation parameters to the observed bit error rate on the actual voice channel. Through real-world experiments, we show that Hermes achieves approximately 1.2 kbps goodput which when compared to SMS, improves throughput by a factor of 5× and reduces the cost-per-byte by over a factor of 50×.
UR - http://www.scopus.com/inward/record.url?scp=78649238279&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=78649238279&partnerID=8YFLogxK
U2 - 10.1145/1859995.1860010
DO - 10.1145/1859995.1860010
M3 - Conference contribution
AN - SCOPUS:78649238279
SN - 9781450301817
T3 - Proceedings of the Annual International Conference on Mobile Computing and Networking, MOBICOM
SP - 113
EP - 124
BT - MobiCom'10 and MobiHoc'10 - Proceedings of the 16th Annual International Conference on Mobile Computing and Networking and 11th ACM International Symposium on Mobile Ad Hoc Networking and Computing
PB - Association for Computing Machinery
Y2 - 20 September 2010 through 24 September 2010
ER -