Design Inset Fed Microstrip Patch Antenna for L-Band Applications

Present paper focuses on design and simulation of an inset fed rectangular microstrip patch antenna for GPS applications. The proposed antenna is designed at frequency 1.9 GHz which comes in L-Band region and simulated using Electromagnetic Simulator such as HFSS simulation software with three different dielectric substrates and comparing their performance characteristics such as gain, bandwidth, beam width, VSWR and return loss. The simulation results shows that the maximum bandwidth is obtained with FR4 substrate and the minimum bandwidth is found with Arlon AD320 substrate, where as the maximum gain obtained with air (vaccum) substrate. The proposed antenna has been designed for the range of 1.9 GHz and which is highly suitable for GPS applications.

Ford-fulkerson and genetic algorithm application for optimal distribution of network resources under financial constraints

The article is devoted to finding the optimal network resources distribution in the network represented by anundirected complete connected planar uplifted graph. It is assumed that the weight of the edge of the graph is determined by the minimum bandwidth(traffic) of the router at its nodes. The functional is the sum of the bandwidth (maximal flow) of the routers on all nodes under the restrictions on their total cost. The complexity of the problem lies in the fact that there are two types of uncertainty in it: the first – the type of router in each network node is not initially determined, the second – the path between the nodes on which the maximum traffic is realized is not defined. The first uncertainty is solved by using the Genetic Algorithm and the second uncertainty is solved by using the Ford Fulkerson algorithm. An example of calculation for a fragment of a network of a real Internet Service Provider (ISP) is presentedin this article.

Penggunaan Virtual Machine untuk Mengoptimalkan Server pada Cloud Gaming dengan GamingAnywhere

The development of the game industry is increasingly advanced until the emergence of cloud gaming network technology. Cloud gaming allows low-spec clients to play high-spec games. An open-source cloud gaming platform is GamingAnywhere. In this study, we will implement a cloud gaming server using GamingAnywhere and combine it with a virtual machine. The virtual machines that will be used are VirtualBox and VMware. This research is aimed at providing information about resource usage on servers and clients as well as Quality of Service (QoS) and Frames Per Second (FPS) from GamingAnywhere running on virtual machines. From the results of server measurements it only takes 12-21% CPU usage, 5-7% GPU usage, and 75-77% memory usage for VirtualBox and 17-26% CPU usage, 26-35% GPU usage, and 64-65% memory usage for VMware. From the FPS measurement results obtained on the client, it has an average of more than 59 fps for the three test games when GamingAnywhere is running on VirtualBox, VMware, and without using a virtual machine. From the measurement results, to get optimal QoS in accessing games with GamingAnywhere, a minimum bandwidth of 5 Mbps is needed and the distance between the client and the router is a maximum of 7 meters. If the bandwidth is less than 5 Mbps, the system experiences a delay of ± 0.003 seconds and the packet loss is more than 10%.

Nxt-Freedom: Considering VDC-Based Fairness in Enforcing Bandwidth Guarantees in Cloud Datacenter

In the cloud datacenter, for the multi-tenant model, network resources should be fairly allocated among VDCs (virtual datacenters). Conventionally, the allocation of cloud network resources is on a best-effort basis, so the specific information of network resource allocation is unclear. Previous research has either aimed to provide minimum bandwidth guarantee, or focused on realizing work conservation according to the VM-to-VM (virtual machine to virtual machine) flow policy or per-source policy, or both policies. However, they failed to consider allocating redundant bandwidth among VDCs in a fair way. This paper presents a bandwidth that guarantees enforcement framework NXT-Freedom, and this framework allocates the network resources on the basis of per-VDC fairness, which can achieve work conservation. In order to guarantee per-VDC fair allocation, a hierarchical max–min fairness algorithm is put forward in this paper. In order to ensure that the framework can be applied to non-congestion-free network core and achieve scalability, NXT-Freedom decouples the computation of per-VDC allocation from the execution of allocation, but it brings some CPU overheads resulting from bandwidth enforcement. We observe that there is no need to enforce the non-blocking virtual network. Leveraging this observation, we distinguish the virtual network type of VDC to eliminate part of the CPU overheads. The evaluation results of a prototype prove that NXT-Freedom can achieve the isolation of per-VDC performance, which also shows fast adaption to flow variation in cloud datacenter.

Design of a Programmable Gain Amplifier (PGA) for Bluetooth Low Energy (BLE) in 0.13 um CMOS

Programmable Gain Amplifiers (PGA's) are circuits capable of conveniently changing their gain to address various levels of amplification. Knowing this, the topology proposed in this work takes a source degenerated first stage, a common-source with resistive load second stage, and a gm boosting circuit interface to realize a PGA that has low power consumption and low area. The design developed was able to achieve a maximum power dissipation of 103.1 uW, a minimum bandwidth of 5.59 MHz, a maximum noise of 32.01 nV/sqrt(Hz), and a gain range of 2.31 - 19.84 dB. Each differential output of the circuit is loaded with 700 fF, which is the estimated load for the hypothetical following block, the Analog-to-Digital Converter (ADC). Furthermore, the supply voltage of the circuit is 1 V and the design was undertaken on Global Foundrie's 130 nm technology. The phase margin of the core circuit is no greater than 100.3˚ and no less than 49˚ . The circuit which design is described in this work is intended to be within the receiver (RX) sub-domain of a Bluetooth Low-Energy (BLE) system, which finds applications on the IoT and healthcare industries, for instance.

Analisis Throughput Video Live Streaming pada Pengguna Layanan Internet Indihome dengan Resolusi Layar Berbeda

Throughput yang diperoleh pada pengguna layanan internet, berpengaruh dengan kualitas layanan internet dalam hal transfer data, terutama pada layanan video streaming yang sangat bergantung dengan throughput yang cukup besar. Pada penelitian ini dilakukan pengukuran throughput terhadap layanan video streaming, pada sisi client jaringan, selama satu minggu. Pengukuran dilakukan pada layanan Indihome PT. Telkom Kota Lhokseumawe. Layanan video streaming yang diukur adalah video dengan resolusi layar 360p, 480p, 720p, dan 1080p, pada website lk21.org. Jumlah client saat pengukuran adalah 4 client yang mengakses website secara serentak. Throughput diukur menggunakan software wireshark. Hasil pengukuran menunjukkan bahwa throughput rata-rata per client dalam kategori baik saat mengakses video streaming dengan resolusi video 360p, 480p, dan 720p, karena throughput rata-rata masing-masing video tersebut masih di atas kebutuhan bandwidth minimum masing-masing tipe video. Sementara untuk resolusi video 1080p dalam kategori buruk, kecuali hanya satu client saja yang mengakses video streaming, sehingga throughput yang diperoleh akan berada di atas kebutuhan minimum bandwidth tipe video 1080p.

Optimizing the Directionality and Minimizing the Reflections using Lenses

In antenna propagation waves should be guided from leakages and directionality which has became more essential now a days due to number of hurdles which scatters the signal. In this paper we design a leaky lens antenna of UWB frequency and simulate that using CST tool in parallel plate waveguide that works efficiently in high frequency range of 6-30GHz. This approach is totally based on propagation of leaky waves by focusing on the lenses properties. Eventually we increase the gap between the lens and slot for optimal directivity in antenna and then for optimizing the transmission coefficient and minimizing the reflection we use the Matching layer in it. As a result directional radiation will be obtained which is much more achieved than any other antenna of Ultra Wide Band Range and the minimum bandwidth is required which is less than -10dB for radiation