تحقیق در مورد شبکه ارتباطی Telecommunication Networks

لینک پرداخت و دانلود *پایین مطلب *   فرمت فایل :Word ( قابل ویرایش و آماده پرینت )    تعداد صفحه30   شبکه ارتباطی: Telecommunication Networks ایجاد ارتباط: Voice- Voic Network (Telephone Network) Text- Text Network (Telex Network) Data- Data Network                  کابل مسی فیزیکی             نوری                     رادیو رادیویی            ماهواره   Voice انتقال صدا از محلی به محل دیگر در Voice  ترمینال        تلفن در Text ترمینا ...

دانلود پایان نامه تحلیل شبکه های نامتقارن Analysis Unbalance Networks

دانلود پایان نامه تحلیل شبکه های نامتقارن Analysis Unbalance Networks مبحث تلفات انرژی الکتریکی بعلت صدها میلیارد ریال زیان سالیانه به صنعت برق چند سالی است در کانون توجه وزارت نیرو و متخصصان برق قرار دارد و تبعات و آثار زیان بار آن در شبکه چه از لحاظ فنی چه از لحاظ بار مالی ایجاب می کند بطور گسترده ای مورد تجزیه و تحلیل قرار گرفته و راههای عملی کاهش آن مشخص می گردد. یکی از معضلات در شبکه های توزیع که باعث ایجاد عوارض و اثرات نامطلوبی در سیستم می گردد نا متعادلی بار می باشد . در واقع امرو ...

دانلود مقاله AN ANALYSIS OF VARIOUS PARAMETERS IN WIRELESS SENSOR NETWORKS USING ADAPTIVE FEC TECHNIQUE

M.R.Ebenezar jebarani1and T.Jayanthy2 ABSTRACTIn Wireless sensor network, since the media is wireless there will be burst errors which leads tohigh bit error rate that affect the throughput. Wireless sensor networks drop the packets due to propagationerrors that lead to retransmission traffic. This paper evaluates the effect of adaptive FEC in Wirelesssensor networks. Adaptive FEC technique improves the throughput by dynamically tuning FEC dependingupon the wireless channel loss. The main ...

دانلود مقاله Forward Error Correction in Sensor Networks

Jaein Jeong and Cheng Tien EeDepartment of Electrical Engineering and Computer ScienceUniversity of California, BerkeleyMay 16, 2003 AbstractIn any network, there are two basic methods to recover errorneous packets. One way is to useAutomatic Repeat Request (ARQ), and another is Forward Error Correction (FEC). Since, in sen-sor networks, power is scarce and is primarily consumed by wireless transmission and reception,we would prefer to use FEC rather than ARQ. In this paper we determine empirica ...

دانلود مقاله Datalink Streaming in Wireless Sensor Networks

Raghu K. Ganti, Praveen Jayachandran ∗,Haiyun Luo, and Tarek F. Abdelzaher AbstractDatalink layer framing in wireless sensor networks usuallyfaces a trade-off between large frame sizes for highchannel bandwidth utilization and small frame sizes for effectiveerror recovery. Given the high error rates of intermotecommunications, TinyOS opts in favor of small framesizes at the cost of extremely low channel bandwidth utilization.In this paper, we describe Seda: a streaming datalinklaye ...

دانلود مقاله Cross-Layer Analysis of Error Control in Wireless Sensor Networks

Mehmet C. Vuran Ian F. Akyildiz Abstract—Severe energy constraints and hence the low powercommunication requirements amplify the significance of theenergy efficient and preferably cross-layer error control mechanismsin Wireless Sensor Networks (WSN). In this paper, a crosslayermethodology for the analysis of error control schemes inWSNs is presented such that the effects of multi-hop routing andthe broadcast nature of the wireless channel are investigated.More specifically, the cross-layer ...

دانلود مقاله Performance Evaluation of Network Coding in IEEE 802.11 Wireless Ad Hoc Networks - انتشار 2014

Ad Hoc Networks Volume 16, May 2014, Pages 131–141 Kyu-Hwan Lee, Sunghyun Cho, Jae-Hyun Kim AbstractWe evaluate the practical network coding (NC) gain in a wireless ad hoc networks.First, we introduce how network coding can be applied to IEEE 802.11ad hoc networks. Next, we find obstructive factors by which the NC gainmay decrease as compared with the theoretical NC gain. Finally, throughthe performance evaluation, we analyze why a performance difference occursbetween practical and ...

دانلود مقاله Attacks on Mobile Adhoc Networks: A Survey - انتشار 2014

International Journal of Research in Advent Technology, Vol.2, No.5, May 2014E-ISSN: 2321-9637 Er. Nitin Aggarwal1, Ms. Kanta Dhankhar2 Abstract-Due to recent developments in technology and uniquely distinct characteristics of MANETs, theapplicability of MANETs have become pervasive. As the applications are increasing, the vulnerability of thesenetworks against various attacks has been exposed. MANETs have not clearly and explicitly stated defensemechanisms, so attacker node can easily di ...

دانلود مقاله A Survey of QoS Based Routing Protocols for Wireless Sensor Networks

J Inf Process Syst, Vol.8, No.4, December 2012 R.Sumathi* and M.G.Srinivas** Abstract—With the increasing demand for real time applications in the Wireless SenorNetwork (WSN), real time critical events anticipate an efficient quality-of-service (QoS)based routing for data delivery from the network infrastructure. Designing such QoSbased routing protocol to meet the reliability and delay guarantee of critical events whilepreserving the energy efficiency is a challenging task. Considerable r ...

دانلود مقاله PPR: Partial Packet Recovery for Wireless Networks

PPR: Partial Packet Recovery for Wireless NetworksKyle Jamieson and Hari BalakrishnanMIT Computer Science and Artificial Intelligence Lab{jamieson, hari}@csail.mit.edu AbstractBit errors occur over wireless channels when the signal isn’t strong enough toovercome the effects of interference and noise. Current wireless protocols may useforward error correction (FEC) to correct for some (small) number of bit errors,but generally retransmit the whole packet if the FEC is insufficie ...