Maximizing the Link Throughput between Smart-meters and Aggregators as Secondary Users under Power and Outage Constraints

摘要

This paper assesses the communication link from smart meters to aggregatorsas (unlicensed) secondary users that transmit their data over the (licensed)primary uplink channel. The proposed scenario assumes: (i) meters' andaggregators' positions are fixed so highly directional antennas are employed,(ii) secondary users transmit with limited power in relation to the primary,(iii) meters' transmissions are coordinated to avoid packet collisions, and(iv) the secondary links' robustness is guaranteed by an outage constraint.Under these assumptions, the interference caused by secondary users in bothprimary (base-stations) and other secondary users can be neglected. Asunlicensed users, however, meter-aggregator links do experience interferencefrom the mobile users of the primary network, whose positions and trafficactivity are unknown. To cope with this uncertainty, we model the mobile usersspatial distribution as a Poisson point process. We then derive a closed-formsolution for the maximum achievable throughput with respect to a referencesecondary link subject to transmit power and outage constraints. Our numericalresults illustrate the effects of such constraints on the optimal throughput,evincing that more frequent outage events improve the system performance in thescenario under study. We also show that relatively high outage probabilitieshave little effect on the reconstruction of the average power demand curve thatis transmitted from the smart-meter to the aggregator.