2,355 research outputs found
RECOMAC: a cross-layer cooperative network protocol for wireless ad hoc networks
A novel decentralized cross-layer multi-hop cooperative protocol, namely, Routing Enabled Cooperative Medium Access Control (RECOMAC) is proposed for wireless ad hoc networks. The protocol architecture makes use of cooperative
forwarding methods, in which coded packets are forwarded via opportunistically formed cooperative sets within a region, as RECOMAC spans the physical, medium access control (MAC) and routing layers. Randomized coding is exploited at the physical layer to realize cooperative transmissions, and cooperative forwarding is implemented for routing functionality, which is submerged into the MAC layer, while the overhead for MAC and route set up is minimized. RECOMAC is shown to provide dramatic performance improvements of eight times higher throughput and one tenth of end-to-end delay than that of the conventional architecture in practical wireless mesh networks
A Survey of Physical Layer Security Techniques for 5G Wireless Networks and Challenges Ahead
Physical layer security which safeguards data confidentiality based on the
information-theoretic approaches has received significant research interest
recently. The key idea behind physical layer security is to utilize the
intrinsic randomness of the transmission channel to guarantee the security in
physical layer. The evolution towards 5G wireless communications poses new
challenges for physical layer security research. This paper provides a latest
survey of the physical layer security research on various promising 5G
technologies, including physical layer security coding, massive multiple-input
multiple-output, millimeter wave communications, heterogeneous networks,
non-orthogonal multiple access, full duplex technology, etc. Technical
challenges which remain unresolved at the time of writing are summarized and
the future trends of physical layer security in 5G and beyond are discussed.Comment: To appear in IEEE Journal on Selected Areas in Communication
A cross layer multi hop network architecture for wireless Ad Hoc networks
In this paper, a novel decentralized cross-layer multi-hop cooperative network architecture is presented. Our architecture involves the design of a simple yet efficient cooperative flooding scheme,two decentralized opportunistic cooperative forwarding mechanisms as well as the design of Routing
Enabled Cooperative Medium Access Control (RECOMAC) protocol that spans and incorporates the physical, medium access control (MAC) and routing layers for improving the performance of multihop communication. The proposed architecture exploits randomized coding at the physical layer to realize cooperative diversity. Randomized coding alleviates relay selection and actuation mechanisms,and therefore reduces the coordination among the relays. The coded packets are forwarded via opportunistically formed cooperative sets within a region, without communication among the relays and without establishing a prior route. In our architecture, routing layer functionality is submerged into the
MAC layer to provide seamless cooperative communication while the messaging overhead to set up routes, select and actuate relays is minimized. RECOMAC is shown to provide dramatic performance improvements, such as eight times higher throughput and ten times lower end-to-end delay as well as reduced overhead, as compared to networks based on well-known IEEE 802.11 and Ad hoc On Demand
Distance Vector (AODV) protocols
Stability and Distributed Power Control in MANETs with Outages and Retransmissions
In the current work the effects of hop-by-hop packet loss and retransmissions
via ARQ protocols are investigated within a Mobile Ad-hoc NET-work (MANET).
Errors occur due to outages and a success probability function is related to
each link, which can be controlled by power and rate allocation. We first
derive the expression for the network's capacity region, where the success
function plays a critical role. Properties of the latter as well as the related
maximum goodput function are presented and proved. A Network Utility
Maximization problem (NUM) with stability constraints is further formulated
which decomposes into (a) the input rate control problem and (b) the scheduling
problem. Under certain assumptions problem (b) is relaxed to a weighted sum
maximization problem with number of summants equal to the number of nodes. This
further allows the formulation of a non-cooperative game where each node
decides independently over its transmitting power through a chosen link. Use of
supermodular game theory suggests a price based algorithm that converges to a
power allocation satisfying the necessary optimality conditions of (b).
Implementation issues are considered so that minimum information exchange
between interfering nodes is required. Simulations illustrate that the
suggested algorithm brings near optimal results.Comment: 25 pages, 6 figures, 1 table, submitted to the IEEE Trans. on
Communication
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