Energy-Efficiency and Reliability Trade-Off in Wireless Sensor Networks

U ovoj disertaciji je kvantitativno određen odnosa energetske efikasnosti i pouzdanosti u bežičnim senzorskim mrežama na fizičkom sloju i sloju kontrole pristupa medijumu. Pronađene su optimalne vrednosti ovog odnosa u smislu višeciljne optimizacije sa Pareto pristupom, bez preferenci.In this dissertation we quantify energy-efficiency and reliability trade-off in wireless sensor networks at physical and medium access control layers. We find the trade-off optimal solutions in the sense of multi-objective Pareto optimality, without preferences

On the Delay-Energy Tradeoff in Multiuser Fading Channels

We consider the delay-energy tradeoff on a fading channel with multiuser diversity. For fixed arbitrary rates of the users, the total transmitted energy is minimized subject to a delay constraint. To achieve this goal we propose a scheme which schedules a subset of all users simultaneously. The scheduled users are allocated power to guarantee successful separation at the detector by successive decoding. In this way, we can benefit from both multiuser diversity and the near-far situation via scheduling and simultaneous transmission, respectively. We analytically show that when the number of users goes to infinity the energy required to guarantee the required user rates can be made as small as required at the cost of a higher delay “delay-energy tradeoff”. We explicitly compute the delay under the proposed scheduling policy and discuss how delay differentiation can be achieved. We extend the results to multiband multiaccess channel. Finally, all the results can be generalized in a straightforward fashion to broadcast channel due to the Gaussian multiaccess-broadcast channel duality

On the Delay-Energy Tradeoff in Multiuser Fading Channels

We consider the delay-energy tradeoff on a fading channel with multiuser diversity. For fixed arbitrary rates of the users, the total transmitted energy is minimized subject to a delay constraint. To achieve this goal we propose a scheme which schedules a subset of all users simultaneously. The scheduled users are allocated power to guarantee successful separation at the detector by successive decoding. In this way, we can benefit from both multiuser diversity and the near-far situation via scheduling and simultaneous transmission, respectively. We analytically show that when the number of users goes to infinity the energy required to guarantee the required user rates can be made as small as required at the cost of a higher delay "delay-energy tradeoff". We explicitly compute the delay under the proposed scheduling policy and discuss how delay differentiation can be achieved. We extend the results to multiband multiaccess channel. Finally, all the results can be generalized in a straightforward fashion to broadcast channel due to the Gaussian multiaccess-broadcast channel duality.</p