Ecole d'ingénieur et centre de recherche en Sciences du numérique

The long-term average capacity region per unit energy with application protocols for sensor networks

Tuninetti, Daniela;Caire, Giuseppe

EW 2002, European Wireless 2002, 26-28 February 2002, Firenze, Italy

Best student paper award

We consider a wireless sensor network (WSN) where K sensors must deliver a message within a frame of N time slots by spending a given finite energy. If the message is not transmitted within the required delay then it becomes useless and the residual energy is wasted. The channel is block-fading, with independent fades for each sensor and each slot. Sensors know the fading levels up to the current slot but do not know the future fading levels. The receiver collects the signal on all the slots of the frame and performs joint decoding of all the messages. We characterize the region of long-term average achievable rates and we show that the optimal policy for N = 1coincides with constant power allocation and, as N increases, it tends to waterfilling in time. In this setting, we also characterize the long-term average capacity region per unit energy by showing that the optimal policy is "one-shot", totally decentralized and extremely simple, i.e., every user spends all its available energy on the first slot of the frame whose fading gain is larger than a pre-computed time varying threshold. Since capacity per unit energy is related to the minimum Eb=N0 required for reliable communication, the "one-shot" policy not only makes the most efficient use of the energy but also reduces to the minimum the interference to other users. These characteristics make the "one-shot" policy appealing for systems with severe energy limitation as WSN.

Document Bibtex

Titre:The long-term average capacity region per unit energy with application protocols for sensor networks
Mots Clés:Network protocol; Interference suppression; Rayleigh fading; Multiuser channels; Resource management; Fading channels; Message transmission; Sensor array; Wireless telecommunication;
Type:Conférence
Langue:English
Ville:Firenze
Pays:ITALIE
Date:
Département:Systèmes de Communication
Eurecom ref:801
Copyright: © Wiley. Personal use of this material is permitted. The definitive version of this paper was published in EW 2002, European Wireless 2002, 26-28 February 2002, Firenze, Italy and is available at :
Bibtex: @inproceedings{EURECOM+801, year = {2002}, title = {{T}he long-term average capacity region per unit energy with application protocols for sensor networks}, author = {{T}uninetti, {D}aniela and {C}aire, {G}iuseppe}, booktitle = {{EW} 2002, {E}uropean {W}ireless 2002, 26-28 {F}ebruary 2002, {F}irenze, {I}taly}, address = {{F}irenze, {ITALIE}}, month = {02}, url = {http://www.eurecom.fr/publication/801} }
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