![](bg6.png)
35 70 105 140 175 210
0
500
1000
1500
2000
2500
Average activity duration [ms]
Mono-canal
35 70 105 140 175 210
Multi-canal
Fixed-length
Adaptive
Maximum reception period length [ms]
Figure 5: Average activity duration within working cycle.
Despite the transitional phase of setting up the net-
work that induces FIFO overflows and slightly longer
end-to-end delays, the data delivery ratios at the sink
are equivalent and sometimes better.
6 CONCLUSION
In this paper, we proposed an adaptive approach based
on a schedule-based MAC protocol, to efficiently uti-
lize the resources of WSNs, especially deployed in
harsh environment and having an unstable topology.
Most of protocols proposed to deal with dynamic
topologies argue on the efficiency of the schedule-
based MAC protocol. They ensure an adequate deliv-
ery ratio while optimizing energy consumption is still
a challenging task. Idle listening, overhearing and
collision are the main sources of energy wasting in
WSNs. The presented approach uses the traffic infor-
mation to right-size the reception period and therefore
to minimize the idle listening. Moreover, it employs
multi-channel scheme to enable parallel transmission
within the network and consequently, it reduces both
collision and overhearing.
The results clearly show that it significantly im-
proves the performance in terms of average activity
duration while providing, at the same time, a good
packet delivery ratio. It also reduces by a half the la-
tency compared to traditional schemes. This meets
the requirements for our target application where the
nodes will communicate over intermittent radio links.
The global solution we are dealing with is able to
withstand the effect of unstable topologies in an in-
teresting energy-saving manner.
REFERENCES
Bizagwira, H., Toussaint, J., and Misson, M. (2014). Ex-
perimental protocols and testbed for radio link quality
evaluation over the freshwater. In 2014 IFIP Wireless
Days (WD), pages 1–4. IEEE.
Chang, L.-W., Huang, Y.-M., and Lin, C.-C. (2013). Per-
formance analysis of s-mac protocol. International
Journal of Communication Systems.
Cui, S., Goldsmith, A. J., et al. (2004). Cross-layer opti-
mization in sensor networks with energy constraints.
IEEE Trans. on Wireless Communications.
Cui, S., Madan, R., Goldsmith, A., and Lall, S. (2005).
Joint routing, mac, and link layer optimization in sen-
sor networks with energy constraints. In IEEE Inter-
national Conference on Communications, 2005. ICC
2005. 2005, volume 2, pages 725–729. IEEE.
Ergen, S. C. and Varaiya, P. (2010). Tdma scheduling al-
gorithms for wireless sensor networks. Wireless Net-
works, 16(4):985–997.
Mahfoudh, S., Chalhoub, G., Minet, P., Misson, M., and
Amdouni, I. (2010). Node coloring and color conflict
detection in wireless sensor networks. Future Internet,
2(4):469–504.
Mode, D. A. (2013). An Advanced Communication System
for Wide-Area Low Power Wireless Applications and
Active RFID. Morgan Hill, CA, USA.
Nour Brinis, Pascale Minet, L. A. S. (2012). Edgm: En-
ergy efficient data gathering with data mules in wire-
less sensor networks. The Sixth International Confer-
ence on Sensor Technologies and Applications.
Pal, P. and Chatterjee, P. (2014). A survey on tdma-based
mac protocols for wireless sensor network. Interna-
tional Journal of Emerging Technology and Advanced
Engineering, 4(6):219–230.
Tseng, Y.-C., Wu, F.-J., and Lai, W.-T. (2013). Oppor-
tunistic data collection for disconnected wireless sen-
sor networks by mobile mules. Ad Hoc Networks,
11(3):1150–1164.
Tuset, P., Adelantado, F., Vilajosana, X., Gallego, F. V., and
Alonso-Zárate, J. (2013). On the use of the 433 mhz
band to improve the energy efficiency of m2m com-
munications. In PIMRC, pages 2813–2818. IEEE.
Tuset-Peiró, P., Anglès-Vazquez, A., López-Vicario, J.,
and Vilajosana-Guillén, X. (2014). On the suitabil-
ity of the 433 mhz band for m2m low-power wire-
less communications: propagation aspects. Transac-
tions on Emerging Telecommunications Technologies,
25(12):1154–1168.
Impact of Time Slot Adjustment on a Multi-hop and Multi-channel Solution for Dynamic WSN Topologies
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