Current Issue : January - March Volume : 2017 Issue Number : 1 Articles : 5 Articles
The Transmission Control Protocol (TCP) is one of the main communication protocols in the Internet, and it has been\ndesigned to provide an efficient reaction to packet loss events which are due to network congestion. Congestion is the\nmain cause of losses in wired networks, but in today heterogeneous networks, loss events can also be introduced due\nto higher error rates on wireless channels, host mobility, and frequent handovers. Unfortunately, all packet losses are\ninterpreted by TCP as a sign of congestion, triggering an inappropriate reaction which reduces its transmission rate\nand leads to performance degradation. In order to avoid this problem, it is important for TCP to correctly understand\nwhether the reason of a packet loss is due to congestion or to a problem in the wireless link. This paper presents an\ninnovative jitter-based cross-layer TCP algorithm, named XJTCP. It adopts the jitter ratio as loss predictor, joined with a\nlayer two notification, in order to correctly infer the nature of a loss event. Performance evaluation and comparison\nwith other common TCP implementations shows how XJTCP can be an interesting solution in the presence of wireless\nenvironments....
Access security is the key obstacle of the rapid popularization of wireless mesh network (WMN). We suggest the proxy\ngroup signature scheme based on identity in this paper. This scheme is combined with proxy group signature and\nidentity-based group signature, based on designated hierarchical proxy architecture for WMN. An anonymous mutual\nauthentication scheme is thus achieved, which not only simplifies the complex management of PKI but also\nguarantees anonymous authentication and owns high handover authentication efficiency. Performance and security\nanalysis show that the scheme in this paper is efficient and resilient to a series of security and anonymity attacks....
The centralized processing in cloud radio access network enables cooperation between baseband processing units (BBUs)\nlike inter-cell interference (ICI) cancellation on the basis of coordinated multipoint (CoMP). Large amounts of the sharing\ndata will be transmitted through fronthaul transport network. In the paper, both integer non-linear programming (INLP)\noptimization model and adaptive genetic algorithm (GA) are explored to release the capacity pressure of the fronthaul\ntransport network when CoMP is introduced. We also consider the resource allocation problem of the passive optical\nfronthaul network. The proposed algorithm tries to reduce the downlink bandwidth and improve the optical resource\nallocation efficiency of the optical fronthaul with minimal influence on the fronthaul topology. During the simulations,\nthree critical factors are considered: (1) the number of cell edge users, (2) the average traffic demand of cell edge users,\n(3) the size of cell cluster used to enable the CoMP. The simulation results show that the most efficient bandwidth saving\nand optical resource allocation can be achieved with INLP, while the proposed adaptive GA nearly has the same\nperformance with low computational complexity and fast convergence, which is more applicable for the large-scale\nfronthaul network. Furthermore, the load difference of the fronthaul transport network can be further reduced....
With the substantial progress in self-interference (SI) cancelation, the full-duplex (FD) technique, which allows the\ncommunication user to transmit and receive signals over the same frequency band simultaneously, enables a\nsignificant enhancement of spectral efficiency (SE) in comparison with the traditional half-duplex (HD) technique.\nRecently, relay-assisted device-to-device (D2D) communications underlaying cellular networks have aroused a great\ndeal of research interests due to its high SE. For the new meaningful paradigm of the combination of the FD and\nthe amplify-and-forward (AF) relay-assisted D2D communications, analyzing the SE and energy efficiency (EE) is\ncrucial, which have not been investigated in the existing works. In this paper, we focus on the EE of the FD twoway\n(FDTW) relay-assisted D2D communications with uplink channel reuse by considering the residual SI at the\nD2D users and compare it with the HD counterpart. Our goal is to find the optimal transmission powers and\namplification gain to maximize the system EE while guaranteeing SE requirements and maximum transmission\npower constraints. A new two-tier alternative iteration optimization algorithm is proposed to solve the optimization\nproblem. Simulation results show that (1) the results obtained by the proposed algorithm is very close to those\nobtained by the exclusive searching method, (2) smaller residual power of SI leads to better performance of EE and\nSE, (3) the SE obtained by FDTW relay-assisted D2D networks is higher than the SE obtained by the HD counterpart,\nand (4) the EE comparison of FDTW relay-assisted D2D networks and its HD counterpart depends on the residual\npower of SI. The EE obtained by FDTW relay-assisted D2D is higher than the EE obtained by HD counterpart only\nwhen the residual power of SI is sufficiently small....
K-connectivity-based topology control can improve fault-tolerant performance of multi-hop wireless networks.\nExisting algorithms mainly focused on preserving the same k-connectivity between any two nodes. However, in\npractical network deployments, the algorithms enforcing k-connectivity degrade network performance, when the\ntopology requires heterogeneous nodal fault-tolerant requirements. In this paper, we aim to develop interferenceaware\ntopology control based on the different kij connectivities between any two nodes and propose a fault-toleranceand-\ninterference-aware topology control (FICTC) algorithm. It can be proved that FICTC can meet different\nfault-tolerant requirements between any two nodes, and is the optimum solution for min-max network\ninterference. Simulation results show that FICTC not only leads to weaker interference, but also achieves\nhigher throughput and lower end-to-end (E2E) delay than existing fault-tolerant topology control schemes....
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