577 research outputs found
Finite Horizon Online Lazy Scheduling with Energy Harvesting Transmitters over Fading Channels
Lazy scheduling, i.e. setting transmit power and rate in response to data
traffic as low as possible so as to satisfy delay constraints, is a known
method for energy efficient transmission.This paper addresses an online lazy
scheduling problem over finite time-slotted transmission window and introduces
low-complexity heuristics which attain near-optimal performance.Particularly,
this paper generalizes lazy scheduling problem for energy harvesting systems to
deal with packet arrival, energy harvesting and time-varying channel processes
simultaneously. The time-slotted formulation of the problem and depiction of
its offline optimal solution provide explicit expressions allowing to derive
good online policies and algorithms
Eligible earliest deadline first:Server-based scheduling for master-slave industrial wireless networks
Industrial automation and control systems are increasingly deployed using wireless networks in master-slave, star-type configurations that employ a slotted timeline schedule. In this paper, the scheduling of (re)transmissions to meet real-time constraints in the presence of non-uniform interference in such networks is considered. As packet losses often occur in correlated bursts, it is often useful to insert gaps before attempting retransmissions. In this paper, a quantum Earliest Deadline First (EDF) scheduling framework entitled ‘Eligible EDF’ is suggested for assigning (re)transmissions to available timeline slots by the master node. A simple but effective server strategy is introduced to reclaim unused channel utilization and replenish failed slave transmissions, a strategy which prevents cascading failures and naturally introduces retransmission gaps. Analysis and examples illustrate the effectiveness of the proposed method. Specifically, the proposed framework gives a timely throughput of 99.81% of the timely throughput that is optimally achievable using a clairvoyant scheduler
Optimal Packet Scheduling on an Energy Harvesting Broadcast Link
The minimization of transmission completion time for a given number of bits
per user in an energy harvesting communication system, where energy harvesting
instants are known in an offline manner is considered. An achievable rate
region with structural properties satisfied by the 2-user AWGN Broadcast
Channel capacity region is assumed. It is shown that even though all data are
available at the beginning, a non-negative amount of energy from each energy
harvest is deferred for later use such that the transmit power starts at its
lowest value and rises as time progresses. The optimal scheduler ends the
transmission to both users at the same time. Exploiting the special structure
in the problem, the iterative offline algorithm, FlowRight, from earlier
literature, is adapted and proved to solve this problem. The solution has
polynomial complexity in the number of harvests used, and is observed to
converge quickly on numerical examples.Comment: 25 pages, 6 figures, added lemma and theorems, added reference,
corrected typo
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