5 research outputs found
Network-Level Cooperation in Energy Harvesting Wireless Networks
International audienceWe consider a two-hop communication network consisted of a source node, a relay and a destination node in which the source and the relay node have external traffic arrivals. The relay forwards a fraction of the source node's traffic to the destination and the cooperation is performed at the network level. In addition, both source and relay nodes have energy harvesting capabilities and an unlimited battery to store the harvested energy. We study the impact of the energy constraints on the stability region. Specifically, we provide inner and outer bounds on the stability region of the two-hop network with energy harvesting source and relay
Effect of Energy Harvesting on Stable Throughput in Cooperative Relay Systems
In this paper, the impact of energy constraints on a two-hop network with a
source, a relay and a destination under random medium access is studied. A
collision channel with erasures is considered, and the source and the relay
nodes have energy harvesting capabilities and an unlimited battery to store the
harvested energy. Additionally, the source and the relay node have external
traffic arrivals and the relay forwards a fraction of the source node's traffic
to the destination; the cooperation is performed at the network level. An inner
and an outer bound of the stability region for a given transmission probability
vector are obtained. Then, the closure of the inner and the outer bound is
obtained separately and they turn out to be identical. This work is not only a
step in connecting information theory and networking, by studying the maximum
stable throughput region metric but also it taps the relatively unexplored and
important domain of energy harvesting and assesses the effect of that on this
important measure.Comment: 20 pages, 4 figure
Wireless Network-Level Partial Relay Cooperation: A Stable Throughput Analysis
In this work, we study the benefit of partial relay cooperation. We consider
a two-node system consisting of one source and one relay node transmitting
information to a common destination. The source and the relay have external
traffic and in addition, the relay is equipped with a flow controller to
regulate the incoming traffic from the source node. The cooperation is
performed at the network level. A collision channel with erasures is
considered. We provide an exact characterization of the stability region of the
system and we also prove that the system with partial cooperation is always
better or at least equal to the system without the flow controller.Comment: Submitted for journal publication. arXiv admin note: text overlap
with arXiv:1502.0113
Relay-assisted Multiple Access with Full-duplex Multi-Packet Reception
The effect of full-duplex cooperative relaying in a random access multiuser
network is investigated here. First, we model the self-interference incurred
due to full-duplex operation, assuming multi-packet reception capabilities for
both the relay and the destination node. Traffic at the source nodes is
considered saturated and the cooperative relay, which does not have packets of
its own, stores a source packet that it receives successfully in its queue when
the transmission to the destination has failed. We obtain analytical
expressions for key performance metrics at the relay, such as arrival and
service rates, stability conditions, and average queue length, as functions of
the transmission probabilities, the self interference coefficient, and the
links' outage probabilities. Furthermore, we study the impact of the relay node
and the self-interference coefficient on the per-user and aggregate throughput,
and the average delay per packet. We show that perfect self-interference
cancelation plays a crucial role when the SINR threshold is small, since it may
result to worse performance in throughput and delay comparing with the
half-duplex case. This is because perfect self-interference cancelation can
cause an unstable queue at the relay under some conditions.Comment: Accepted for publication in the IEEE Transactions on Wireless
Communication
Network-Level Performance Evaluation of a Two-Relay Cooperative Random Access Wireless System
In wireless networks relay nodes can be used to assist the users'
transmissions to reach their destination. Work on relay cooperation, from a
physical layer perspective, has up to now yielded well-known results. This
paper takes a different stance focusing on network-level cooperation. Extending
previous results for a single relay, we investigate here the benefits from the
deployment of a second one. We assume that the two relays do not generate
packets of their own and the system employs random access to the medium; we
further consider slotted time and that the users have saturated queues. We
obtain analytical expressions for the arrival and service rates of the queues
of the two relays and the stability conditions. We investigate a model of the
system, in which the users are divided into clusters, each being served by one
relay, and show its advantages in terms of aggregate and throughput per user.
We quantify the above, analytically for the case of the collision channel and
through simulations for the case of Multi-Packet Reception (MPR), and we
provide insight on when the deployment of a second relay in the system can
yield significant advantages.Comment: Submitted for journal publicatio