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The proliferation of cloud services makes virtualization technology more important. One important feature of virtualization is live Virtual Machine (VM) migration, which can be employed to facilitate load balancing, fault management and server maintenance etc. Two main metrics of evaluating a live VM migration mechanism are total migration time and downtime. The existing literature on live VM migration...
Ethernet Passive Optical Network (EPON) is one of the most promising technologies for FTTX deployed by service providers at the access network. Dynamic Bandwidth Allocation (DBA) for the upstream traffic can help optimize the network bandwidth utilization. This paper discusses a centralized DBA called as Universal DBA (UDBA) algorithm that supports quality of service (QoS) of the upstream traffic...
Passive Optical Networks (PONs) are attractive fiber-based access systems providing broadband access solutions at a low cost. A hybrid Wavelength Division Multiplexing (WDM) — Time Division Multiple Access (TDMA) PON is a favorite PON configuration, in which the researchers have drawn much attention. We have analysed and proposed several protocols for dynamic wavelength allocation in a WDM-TDMA PON,...
In next generation wireless networks like WiMAX, a dynamic Call Admission Control (CAC) plays an important role to ensure Quality of Service (QoS) of existing users and to efficiently utilize network resources. We propose a predictive CAC namely Wireless Fair Intelligent Admission Control (WFIAC) that admits or rejects a new incoming connection base on resource availability and load in the network...
This paper considers the IEEE 802.11g network behavior in different situations and topologies for video transmission. They were precisely chosen with the focus put on gathering as much information about the network as possible. Speaking of measuring the network, the parameters as bandwidth, delay, jitter and packet loss, were obtained as results of simulations performed in NS-2 (Network Simulator...
This paper presents a two-path design of quadrature band-pass modulators and discusses the architectural level implementation issues for power reduction. The methodology uses an architecture which locks IF frequencies to the sampling frequency. The basic delay based solution is converted into integrator based solution for the implementation. Robustness of the structure against the mismatch...
MPLS-Traffic Engineering (MPLS-TE) provides many recovery mechanisms such as rerouting and protection. Existing one-to-one backup and path-based backup schemes are not resource efficient. We propose Common Protection Path (CPP), a novel protection scheme which selects a common protection path for traffic demands having the same ingress and egress routers. CPP also factors in path failure probability...
Data centers are used to host computation-intensive distributed applications. Since all the applications are distributed in nature, their performance is significantly affected by the communication network. These applications generally create two kinds of flows: large data flows that require high throughput and small control flows that require low delay. These two contradictory requirements are not...
Cluster-based logic blocks from most commercial FPGA products do not have an input bandwidth constraint, i.e., limiting the number of signals going from routing channels into the block. We show that high quality packing for such logic blocks can be easily achieved based on k-way partitioning. We implemented 2 such packing tools: PPack (routability-only) and its timing driven version TPPack. Experimental...
In WiMAX architecture to avoid congestion at the base station, a mechanism namely WiMAX Fair Intelligent Congestion Control (WFICC) was proposed in [11]. WFICC ensures that the traffic is scheduled in such a way that the base station output buffer operates around a target operating point, without violating the Quality of Service (QoS) requirements of connections. However, only preliminary results...
Implications of implementing a local storage within Passive Optical Networks to enhance Video-on-Demand delivery are critically examined in this work. We conduct packet level simulations in order to study enhancements of Quality of Service attributes. Two architectures where the Passive Optical Network is equipped with and without a local storage server are simulated to study the behavior of packet...
The constant frequency pulse trains of Radar can produce the high peak sidelobes. Stepped frequency signal is used to reduce these lobes with wider overall bandwidth while having small instantaneous bandwidth. For uniform frequency stepped pulse trains, there can be undesirable peaks of the autocorrelation function, known as grating lobes, around the main lobe. In this paper we address this issue,...
The Double Estimation Technique (DET) is a GNSS signal-tracking concept. DET has the capability to produce reliable unambiguous, full-precision delay estimates from the Binary Offset Carrier (BOC) signals which have been adopted by the modernized and new GNSS, including the European Galileo constellation. DET is robust, being able to function under conditions of low C/N0, strong multipath and filtering...
SCIS is the State Company for Internet Services in Iraq that works as the main Internet Service Provider (ISP). After 2003 war in Iraq, there is extremely high demand for Internet service due to very long period of sanctions enforced on Iraq. However, satisfying such high demand is a challenging task; as the cost, number of subscribers and Quality of Service (QoS) are important factors that need to...
A dynamic method to trigger the handover algorithm in LTE networks is proposed. The method utilizes Doppler frequency estimation in the downlink for adjustment. This method is beneficial for high speed mobiles in micro cells, where the cell radius is small and needs a dynamic algorithm to respond in a timely manner. Comparison to the practical handover triggering method, which is currently implemented...
The Long Term Evolution (LTE) defined by 3rdGeneration Partnership Project (3GPP) is a dominant cellular wireless technology which is currently being commercialized worldwide. In this paper, we evaluate the performance of self-healing schemes for LTE Evolved Packet Core (EPC) network elements failures in different architectural configurations. We also analyze message overhead and bandwidth requirements...
While optimization models for traffic engineering in multi-service networks are known, survivability is a key issue not introduced so far in consideration in such models. In this paper, the novelty and contribution is that new optimization models that address the off-line survivability-supported Traffic Engineering (TE) problem in multi-service networks are presented. In such networks traffic demands...
In this paper a new cross-layer connection admission control (CAC) algorithm in WiMAX networks is proposed. The CAC algorithm makes the decisions whether accept or not the new connections based on the quality of channel communications. Moreover, the proposed CAC works together with an uplink scheduling mechanism which allocates the network resources in accordance with the information about the quality...
The wireless access in vehicular environment system is developed for enhancing the driving safety and comfort of automotive users. However, such system suffers from quality of service degradation for safety applications caused by the channel congestion in scenarios with high vehicle density. The present work is a congestion control mechanism in vehicular ad-hoc network. It supports the communication...
Video-on-demand (VoD) is a rapidly growing method for viewing and sharing video content over the Internet. However, video on demand consumes a significant amount of bandwidth, forcing content publishers and content delivery networks to examine approaches such as the use of peer-to-peer (P2P) technologies to assist in video distribution. We study the performance impact of a peer localization strategy...
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