Page 29 - ITU Journal, Future and evolving technologies - Volume 1 (2020), Issue 1, Inaugural issue

ITU Journal on Future and Evolving Technologies, Volume 1 (2020), Issue 1

in a neighborhood can time multiplex various activities IEEE Circuits and Systems Magazine, vol. 15,
to achieve a network-level power management. Also, ef- no. 3, pp. 6–17, 2015.
fective distributed computing techniques are needed to
address processing limitation issues. [2] N. E. Roberts, K. Craig, A. Shrivastava, S. N.
Wooters, Y. Shakhsheer, B. H. Calhoun, and D. D.
These are quite exciting times of the IoT era. The in- Wentzloff, “A 236nw -56.5 dbm-sensitivity Blue-
vention of tags that can form BTTNs presents a spring- tooth low-energy wakeup receiver with energy har-
board for launching the concept of IoT to new heights. vesting in 65nm CMOS,” in 2016 IEEE Inter-
The possibility for connecting every tagged object in a national Solid-State Circuits Conference (ISSCC).
network that turns into a part of the IoT has finally IEEE, 2016, pp. 450–451.
become a reality.

BTTNs offer a range of research challenges. For exam- [3] J. F. Ensworth and M. S. Reynolds, “BLE-
ple, one of them is in energy harvesting and involves Backscatter: Ultralow-Power IoT Nodes Compat-
the design of an energy harvester with high energy ef- ible With Bluetooth 4.0 Low Energy (BLE) Smart-
ficiency over a wide input power range. Scalability and phones and Tablets,” IEEE Trans. on Microwave
routing discovery in the presence of unidirectional links Theory and Techniques, 2017.
are not trivial routing tasks. Further, in security, future
research should focus on balancing the security needs of [4] P. Zhang, D. Bharadia, K. Joshi, and S. Katti,
BTTNs with limited resource use on the tags. Signal “Hitchhike: Practical backscatter using commod-
processing on the tags is also difficult due to the limited ity WiFi,” in Proceedings of the 14th ACM Con-
computing power of the tags. Future work will reveal ference on Embedded Network Sensor Systems CD-
efficient ways of processing increasing amounts of data ROM, ser. SenSys ’16, New York, NY, USA, 2016,
by the tags and in a cooperative manner. p. 259–271.

The prospects of BTTNs are quite promising, creating a [5] D. Bharadia, K. R. Joshi, M. Kotaru, and S. Katti,
driving force for their further development. The number “Backfi: High throughput WiFi backscatter,”
of BTTN applications is simply staggering. In the near ACM SIGCOMM Computer Communication Re-
future, the hardware and computational aspects of the view, vol. 45, no. 4, pp. 283–296, 2015.
tags will continue to improve. Novel machine learning
methods, possibly designed for the tags only, will be [6] V. Iyer, V. Talla, B. Kellogg, S. Gollakota, and
developed, and more novel techniques in the networking J. Smith, “Inter-technology backscatter: Towards
of the tags will be invented. With all the anticipated internet connectivity for implanted devices,” in
progress, one may argue, the BTTNs will become the Proceedings of the 2016 ACM SIGCOMM Confer-
true backbone of the IoT and will bring to fruition many ence, 2016, pp. 356–369.
of the benefits that have been envisioned by the IoT
paradigm. [7] P. Zhang, C. Josephson, D. Bharadia, and S. Katti,
“Freerider: Backscatter communication using com-
7. CONCLUSIONS modity radios,” in Proceedings of the 13th Interna-
tional Conference on emerging Networking EXper-
In this article, we presented an overview of backscatter- iments and Technologies, 2017, pp. 389–401.
based communication among batteryless tags, the hard-
ware of the tags, the scaling from a single link to a full [8] J. Ryoo, Y. Karimi, A. Athalye, M. Stanaćević,
network, and the signal processing that is carried out S. R. Das, and P. M. Djurić, “BARNET: Towards
by the tags. Further, we listed a number of important activity recognition using passive backscattering
applications with networks composed of such tags. We tag-to-tag network,” in 16th Annual International
also discussed challenges that the tags and the network Conference on Mobile Systems, Applications, and
present, including challenges in energy harvesting, com- Services. ACM, 2018, pp. 414–427.
puting, networking, security, and distributed signal pro-
cessing and decision making. [9] P. V. Nikitin, S. Ramamurthy, R. Martinez, and
K. Rao, “Passive tag-to-tag communication,” in
ACKNOWLEDGEMENT 2012 IEEE International Conference on RFID
The authors are thankful for the support of NSF under (RFID). IEEE, 2012, pp. 177–184.
Awards CNS-1901182, CNS-1763843 and CNS-1763627.
[10] A. Y. Majid, M. Jansen, G. O. Delgado, K. S.
REFERENCES Ytidtnm, and P. Pawetczak, “Multi-hop backscat-
ter tag-to-tag networks,” in IEEE INFOCOM 2019-
[1] J. Blanckenstein, J. Klaue, and H. Karl, “A survey IEEE Conference on Computer Communications.
of low-power transceivers and their applications,” IEEE, 2019, pp. 721–729.

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