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In this paper, two novel energy efficient resource allocation schemes are proposed for beyond next generation mobile networks. The schemes take into account the clustering capability of base stations before assigning users to the base stations. A topology management scheme that adjusts the number of active base stations in accordance with the traffic load and also responds to QoS deterioration is...
Cognitive Radio Ad-Hoc Network (CRAHN) is an emerging class of mobile ad hoc networks that provides each network node with a list of available channels. It is expected that the traditional routing approach will not work well in CRAHN, by which its performance may be determined by user and channel interferences, as well as by frequent topology changes. The result is varying connectivity conditions...
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...
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channel state information (CSI) between the secondary transmitter (STx) and the primary receiver (PRx) is assumed to be outdated due to channel feedback latency.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...
Device-to-Device (D2D) communication underlaying cellular network is considered to be a promising resource reuse technique, and it is basically developed for lots of local services. Considering the differences of the quality of services (QoS) between cellular and D2D users, the resource allocation scheme for D2D should flexibly allocate resource for D2D, rather than limiting one D2D user to share...
This paper addresses the power assignment problem in multicarrier code-division multiple-access (MC-CDMA) systems. The problem is formulated as finding the correct transmission power to achieve a desired quality of service (QoS), described by an objective signal-to-interference and noise ratio (SINR). First, the model of the MC-CDMA is described, and by considering a matched filter at the receiver,...
Deploying picocells overlaying Macrocells as the second tier has been regarded as a promising approach to enhance the spectrum efficiency and thus high data rate services, but only if cross-tier interference can be effectively controlled. Since both tiers shall support considerable numbers of users, interference mitigation by centralized/collaborated radio resource allocation among two tiers is infeasible...
In this paper, we study the cross-layer resource allocation for the secondary users (SUs) supporting heterogeneous services in interference-limited spectrum sharing system. Two classes of SUs are considered: delay-tolerant SUs (DT-SUs) and delay- sensitive SUs (DS-SUs). With the queue theory, the delay requirements of DS-SUs are transformed into constant rate requirements. Unlike most previous works,...
Pricing plays a crucial role in trading any resource or service in the existing Broadband Wireless Access system i.e. WiMAX. Through a proper pricing strategy, a wireless service provider would like to achieve the highest revenue, while the end users would like to achieve the highest satisfaction from service usage. In order to make it feasible, in this paper we propose a tradeoff policy between the...
QoS routing protocol has become a hot research spot. However, it is difficult to offer guaranteed QoS, such as bandwidth, delay and delay jitter. To solve this problem, we proposed a Delay-Minimized Routing protocol based on Bandwidth Estimation (DMR-BE) that incorporates an admission control scheme and a route decision scheme to meet the QoS requirement of bandwidth and real-time applications. Bandwidth...
In this work, the distributed power allocation problem in universal mobile telecommunication systems (UMTS) is studied under feedback signal-to-noise ratio (SNR) constraints. The sources of uncertainty are assumed to come from the quantization process and measurement noise in the closed-loop system. The power allocation problem is formulated as a reference tracking problem of a pre-defined signal...
This work studies the power control algorithm proposed by Foschini-Miljanic (1993), standardized for universal mobile telecommunication systems (UMTS). Continuous and discrete time versions of this algorithm are analyzed. First, it is shown that the distributed power allocation scheme can be visualized as a tracking problem of an equivalent power reference that specifies the desired quality-of-service...
Locomotive synchronization operation and control(LSOC) system is a train control system based on LOCOTROL technique and GSM for railway (GSM-R) system for heavy haul railway. The current QoS requirements of GSM-R are designed for train control message transmission (TCMT) service of ETCS, which are not suitable for LSOC service with different characteristic. Therefore, the reasonable QoS requirement...
Delivery of high-quality streaming services over multi-hop wireless mesh networks (WMNs) is a challenging research problem because of quality fluctuation and interference of wireless links in WMNs, as well as strict throughput, delay, and reliability requirements of streaming applications. In this paper, we propose a Network Assisted Peer-to-Peer (NAP2P) system for file-based media streaming services...
Routing in Wireless Mesh Algorithm is concerned with finding “good” source destination paths and has been an active research area since many years. Much of the work is focused on the improvement of global resources, or on the performance of individual transfers. Either case, the routing problem can be casted as a multi-objective with objectives such as load-balancing, end-to-end delay, and path capacity...
In today's wireless communication systems, the design of efficient packet scheduling algorithms at the MAC layer is proven to have significant impact on their overall performances. In the light of this fact, we propose and compare in this paper different scheduling techniques which aim at satisfying the users' requirements in terms of both rates and delays. The considered system is a downlink multi...
This paper proposes a s.c. 2 ms range extension scheme for High Speed Uplink Packet Access (HSUPA) networks to avoid potential coverage problems and usage of multiple TTI lengths. With range extension UEs in poor radio conditions are configured to send bundles of 2 ms TTI transmissions without HARQ feedback to improve their coverage. This paper analyzes the performance of range extension in comparison...
the MAC scheduler is an important and crucial entity of the Long Term Evolution (LTE) and is responsible for efficiently allocating the radio resources among mobile users who have different QoS demands. The scheduler takes different considerations into account such as throughput and fairness when deciding the allocation of the scarce radio resources. LTE is an all IP packet system in which guaranteeing...
Since the radio access of secondary users is typically confined to ensure sufficient operation for primary users in underlay cognitive radio networks (CRNs), the inevitably induced latency and interference pose new challenges on existing routing schemes for Quality-of-Service (QoS) provisioning. Due to stringent accessing and interference constraints, secondary users appeal to exploit multi-path routing...
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