Multipath

15  Abstrak-Kemacetan terjadi ketika jumlah paket yang ditransmisikan melalui jaringan telah mendekati kapasitas penanganan paket jaringan. Hal ini menjadi faktor utama untuk diketahui lebih dini, guna menghindari adanya kegagalan dalam proses routing. Sebagian besar protokol routing yang digunakan saat ini menggunakan algoritma yang menghasilkan jalur tunggal saja, tanpa memperhatikan permintaan trafik yang bersifat fluktuatif. Penggunaan jalur tunggal dapat menyebabkan terjadinya kemacetan yang berdampak kepada pemborosan sumber daya. Penelitian ini bertujuan untuk melakukan pengendalian kemacetan jaringan dengan mengkombinasikan mekanisme multipath routing dan congestion control pada protokol routing OSPF. Hasil pengujian menunjukkan keunggulan sistem dalam tiga aspek, yaitu kestabilan nilai throughput (100%) sehingga tidak ada packet loss, pengiriman data 50% lebih cepat, dan utilisasi jaringan yang lebih baik.

Information on sea level and its changes are important in connection to global change processes. For centuries sea level has been observed with coastal tide gauges and since some decades with satellite altimetry. Furthermore, during recent years also the application of GNSS reflectometry for sea level observations has been developed. Various methods exist, using ground-based, airborne and space-borne systems, and using different analysis methods. We present results from a dedicated GNSS tide gauge installed at the Onsala Space Observatory at the Swedish west coast. This installation consists of commercially-off-the-shelf GNSS equipment, including geodetic-type choke-ring antennas and geodetic-type receivers. The GNSS tide gauge consists of two antennas mounted on a beam extending in southward direction over the coastline. The antennas are aligned along the local vertical with one antenna facing toward zenith direction and the other facing toward nadir. The zenith-looking antenna is ...

The 1999 AUVFest was held near Gulfport, Mississippi in a shallow-water area with depths between 3 and 8 meters. The acoustic channel was characterized by multipath spanning up to 20 msec and high noise levels from snapping shrimp. Acoustic communication testing was performed with the REMUS AUV transmitting both known test data and realtime status information. In addition, a series of ship-to-ship tests were performed in order to characterize stationary performance at ranges of one to five kilometers. Data rates of 60-5000 bits per second were transmitted and, despite the very shallow water conditions, the communication link was reliable at ranges up to 5 km at all data rates

The conventional routing protocols developed for Mobile ad-hoc network (MANET) show low performance result when they are adapted in Vehicular Ad-hoc Network (VANET) which has more unstable channel features such as short communication time, low packet delivery ratio, frequent link breakage, and rapidly changed topology caused by high mobility. Therefore, applications on VANET environment require a specific routing protocol to

Abstract- MANETs has mobile nodes which are connected through dynamic multi-hop channels. Routing in MANET is a difficult task which has received much attention from researchers. Consistent link failures occur in mobile ad-hoc networks because of node’s mobility and use of fickle wireless channels for data transmission. Because of this, multipath routing protocols arrive with a critical research issue. In this, we propose to implement node-disjoint multipath routing based on AOMDV protocol. The main objective of proposed approach is to obtain all available node-disjoint routes from source-destination with minimum delay and high throughput. With this given approach, as first route for destination is dogged the source starts data transmission. All other backup routes, if available, via the first route are scheduled concurrently with data transmission. In the current work we are proposing the concept of Node Disjoint–Multipath based on the congestion threshold and results will be obtai...

http://airccse.org/journal/jwmn/0510ijwmn08.pdf Channel estimation for LTE Uplink system by Perceptron neural network http://airccse.org/journal/jwmn/0203ijwmn11.pdf LACBER: New Location Aided Routing Protocol For GPS Scarce Manet http://airccse.org/journal/nsa/0809smn02.pdf Performance Analysis of LS and LMMSE Channel Estimation Techniques for LTE Downlink Systems http://airccse.org/journal/jwmn/1011wmn11.pdf Performance Analysis of On-Demand Routing Protocols for Vehicular Ad-Hoc Networks http://airccse.org/journal/jwmn/0811wmn07.pdf An Intelligent Network Selection Strategy Based on MADM Methods in Heterogeneous Networks http://airccse.org/journal/jwmn/0212wmn06.pdf Zigbee Based Voice Controlled Wireless Smart Home System http://airccse.org/journal/jwmn/6114ijwmn04.pdf Vertical Handoff In Wlan-Wimax-Lte Heterogeneous Networks Through Gateway Relocation http://airccse.org/journal/jwmn/0812wmn15.pdf Mobile Agent Based Congestion Control Using AODV Routing Protocol Technique for Mobile Ad-Hoc Network http://airccse.org/journal/jwmn/0412wmn20.pdf Optimization of Energy Consumption for OLSR Routing Protocol in MANET http://airccse.org/journal/jwmn/0212wmn19.pdf

Orthogonal Wavelet Division Multiplexing (OWDM) has been considered as an alternative of Orthogonal Frequency Division Multiplexing (OFDM) in the recent years. OWDM has lower computational complexity and higher flexibility compared to its OFDM counterpart. The core component of OWDM is wavelet. Wavelet has been a much investigated and applied topic in digital image processing for a long time. Recently, it has drawn considerable attention of the researchers working in communication field. In this work we investigate the performances of OWDM under different channel conditions. We consider three channel conditions namely Additive White Gaussian Noise (AWGN), Rayleigh, Ricean, and frequency selective. We consider a number of wavelets namely Haar, Daubechies, Biorthogonal, Reverse Biorthogonal, Coiflets, and Symlets in OWDM design. For system model we choose Digital Video Broadcasting-Terrestrial (DVB-T). Originally DVB-T system was designed based on OFDM. In this work we use OWDM instead. The simulation results show OWDM outperforms OFDM in terms of bit error rate (BER), noise resiliency, and peak-to-average ration. The results also show that the Haar wavelet based OWDM outperforms other wavelets based OWDM system under all three considered three channel conditions.

We propose in this paper a connectivity
-
aware routing algorithm and a set of related theorems. This
algorithm allows nodes in Mobile Adhoc and Sensor Networks (MASNets) to provide the highest
connectivity life time to a specific destination since the issuance of data becomes a necessity for MAS
Nets.
In the proposed Solution, nodes in MASNets are able to specify the disjointness degree of the available
paths allowing the discovery of the optimal set of backup routes and consequently enhance the survivability
of the connectivity. These nodes perfo
rm an on
-
demand discovery and a generation of a set of routes, by
specifying a disjointness threshold, representing the maximal number of nodes shared between any two
paths in the set of k established paths. The proposed multipath routing algorithm, is ada
ptive, secure, and
uses labels to carry the disjointness
-
threshold between nodes during the route discovery. A set of security
mechanisms, based on the Watchdog and the digital signature concepts, is used to protect t
he route
discovery process
.