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Dual decomposition coupled with the subgradient method has found application to optimal resource management in communication networks, as it can lead to distributed and scalable algorithms. Network entities—nodes or functional layers—exchange Lagrange multipliers and primal minimizers of the Lagrangian function towards optimizing a network-wide performance metric. It is of interest to study the performance...
This paper discusses the development of a discrete-event simulation model for an integrated emergency post. This post is a collaboration between a general practitioners post and an emergency department within a hospital. We present a generalized and flexible simulation model, which can easily be adapted to several emergency departments as well as to other departments within the hospital, as we demonstrate...
LTE has been proposed as a possible wide area communications network for the Smart Grid. We analyze the performance of the LTE TDD mode when the uplink traffic (such as AMI meter readings and sensor data) is significantly higher than downlink traffic. We derive theoretical best case mean uplink latency figures for the relevant subset of LTE TDD uplink/downlink configurations (0, 1 and 6) and validate...
The cloud-based multimedia applications have been increasingly adopted in recent years. The key challenge for the application providers is how to optimally reconfigure resources to cope with the time-varying workload. In this paper, we study the optimal resource reconfiguration for cloud-based multimedia applications to minimize the average round-trip-time (RTT). Specifically, we propose the optimal...
Content delivery networks have been widely used for many years providing service for millions of users. Lately, many of these networks are migrating to the cloud for its numerous advantages such as lower costs, increased performance, availability and flexibility in installing new resources. This paper introduces a new approach towards load balancing as well as power reduction in cloud-based content...
In this paper, we conceive an energy-efficient power and subcarrier allocation scheme for downlink OFDMA systems under average delay constraints. The services associated with multi-users have different packet arrivals and delay requirements. The problem of dynamic power and subcarrier allocation is formulated as a constrained Markov decision process (CMDP) with control actions based on the joint states...
In this paper, we propose relay transmission protocol based on SoQ(Satisfaction of QoS) for QoS enhancement and analyze the performance of the proposed method in Wireless USB Networks. In the proposed protocol, Wireless USB host executes the Satisfaction of QoS (SoQ) time slot allocation algorithm. And, in order to give devices with scarce resource another chance to improve QoS, the proposed relay...
In this paper, we present design and implementation aspects of a network resource provisioning module proposed for the Polish Initiative of Future Internet called System IIP (being currently one of major European projects aimed at designing the Internet of the Future). In particular, we introduce novel LP optimization models of network resource provisioning designed to minimize the resource consumption,...
In this paper, we propose a fast, dynamic slot assignment scheme to reduce timeslot access delay for newly arrived nodes in tactical ad hoc networks. As there is no central coordinator in distributed networks, a newly arrived node in conventional schemes must negotiate separately with each of its neighbors for timeslot allocation. However, it is not necessary to negotiate with all the neighboring...
In this paper, we analyse the delay performance of a point-to-multipoint cognitive radio network which is sharing the spectrum with a point-to-multipoint primary network. The channel is assumed to be independent but not identically distributed and has Nakagami-m fading. A constraint on the peak transmit power of the secondary user transmitter (SU-Tx) is also considered in addition to the peak interference...
To deal with problems that queuing information is not included in cognitive information when performing Resource Allocation (RA), a dynamic cross-layer scheme is proposed for the multimedia cognitive radio (CR) system with Orthogonal Frequency Division Multiplexing (OFDM). In this scheme, we consider that several crucial factors influence the RA decision, including channel state information, interference...
In this paper, we investigate the video stream distributed transmission problem for the emergency communication over heterogeneous wireless networks. The key issue of the transmission problem is how to guarantee the quality of service, when the video stream is transmitted by multiple wireless access networks. According to observed available bit rate (ABR) and round trip time (RTT) over each access...
In the times of increased global competition, software companies are forced to search for more effective development practices and often team up with onshore and offshore partners to develop faster and better products. In this paper we empirically explore a highly distributed onshore development project with a complex coordination structure. Our findings demonstrate that onshore development projects...
Inter-cell Interference (ICI) in the uplink of modern cellular communication systems with high frequency reuse is hard to predict, as fast scheduling and link adaptation lead to a high interference fluctuation. This fluctuation poses a big challenge for link adaptation algorithms that need an accurate SINR estimate to assign suitable modulation and coding schemes for transmission. To enable ICI prediction...
With the popularity of cloud computing, high volume data needs to be processed in real-time. Therefore, many distributed stream processing systems have risen to deal with this requirement. One kind of distributed stream processing applications contains several PEs which are connected together to implement the application logic. As data is in the form of streams and it needs to be processed in real-time,...
Coordinated multi-point (CoMP) transmission is considered as an efficient technique to improve cell-edge performance as well as system spectrum efficiency. In CoMP-enabled systems, a cluster of coordinated base stations (BSs) are typically assumed to be connected to a control unit (CU) via backhaul links, and the provided performance gain relies heavily on the quality of the channel state information...
This paper introduces Adaptive Backpressure, a novel scheme that improves the utilization of dynamically managed router input buffers by continuously adjusting the stiffness of the flow control feedback loop in response to observed traffic conditions. Through a simple extension to the router's flow control mechanism, the proposed scheme heuristically limits the number of credits available to individual...
In this paper, we investigate resource allocation in the OFDMA cooperative networks with Best effort (BE) services and Real time (RT) services. Both Amplify-and-forward (AF) and Decode-and-forward (DF) schemes are considered adaptively in the two-hop relay transmission. We resolve the relay node, relay strategy selection combined subcarrier and power allocation in mixed services resource allocation...
Resource allocation is a critically important issue for cognitive networks, because it needs to not only meet the quality-of-service (QoS) requirements for the secondary users (SU), but also protect the QoS of primary users (PU) from degradation. In this paper, we develop the optimal power allocation scheme for the cognitive network, which can satisfy the QoS requirements of SUs and PUs simultaneously...
This paper studies a spectrum sharing cognitive radio (CR) network coexisting with a primary network. In particular, the channel state information (CSI) between the secondary transmitter (STx) and the primary receiver (PRx) is assumed to be outdated due to channel feedback latency. We assume that the secondary user (SU) shall satisfy a given delay quality-of-service (QoS) constraint as well as the...
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