ad hoc wireless networks lecture notes

... multi-hop wireless ad hoc networks,” in Ad Hoc Networking, pp 139–172, Addison-Wesley, Reading, Mass, USA, 2001 [3] T Camp, J Boleng, and V Davies, “A survey of mobility mod-els for ad hoc network ... connectivity probability of a wireless ad hoc network,” in Proceedings of the International Workshop on Wireless Ad-Hoc Networks, pp 120–124, June 2004 [5] F Bai, N Sadagopan, and A Helmy, “Important: ... from performance degradation in high-speed conditions 1 Introduction Research has gained a significant advance in the develop-ment of routing protocols for wireless ad hoc networks [1, 2] The

Ngày tải lên: 21/06/2014, 11:20

... Although often used in practical implementations of mobile ad hoc networks, IEEE 802.11 presents several drawbacks in the context of ad hoc networks, one of them being its poor throughput performance ... control (MAC) protocols for ad hoc networks has been dominated by the IEEE 802.11 standard, which was initially implemented in the context of single-hop wireless local area networks (WLANs) Although ... Exponential Fade Duration. We assume arbitrary distributions for both nonfade and fade durations As a special case, we consider fixedl for nonfade duration and exponentially distributed fade duration

Ngày tải lên: 21/06/2014, 22:20

... INTRODUCTION An ad hoc wireless network is a special type of wireless net- work that does not have a wired infrastructure to support communication among the wireless nodes. In multi-hop ad hoc networks, ... Krunz, “CDMA-based MAC protocol for wireless ad hoc networks,” in Proceedings of the 4th ACM In- terational Symposium on Mobile Ad Hoc Networking and Com- puting (MobiHoc ’03), pp. 153–164, Annapolis, ... mentioned above as- sume the homogenous environment of wireless networks. There are a lot more works on energy-efficient communi- cation in ad hoc wireless networks, such as in [15, 16]. Sing et al. studied

Ngày tải lên: 22/06/2014, 22:20

... Trang 1Wireless NetworksLecture 28Mobile Ad hoc Network Dr Ghalib A Shah Trang 2► Expected Properties of Ad-hoc Routing Protocols► A taxonomy for routing protocols in Mobile ad ► Some common ... Trang 6The characteristic of ad hoc networksTrang 7► one hop(uplink or downlink)► PCF(pointed coordination function) Trang 10Expected Properties of Routing Ideally an ad hoc network routing protocol ... range of each other via the wireless media. ► an independent basic service set Trang 5 Mobile distributed multi-hop wireless network (manet) ► a group of mobile, wireless nodes which cooperatively

Ngày tải lên: 05/07/2022, 13:18

... Revised 15 April 2005 Wireless ad hoc sensor networks differ from wireless ad hoc networks from the following perspectives: low energ y, lightweight routing protocols, and adaptive communication ... routing in ad hoc sensor networks. A lot of development has been seen in ad hoc routing since the introduction of highly dynamic destination-sequenced distance-vector routing (DSDV) [1]. Ad hoc on-demand ... in ad hoc wireless networks,” in Mobile Computing, vol. 353, chap- ter 5, pp. 153–181, Kluwer Academic, Boston, Mass, USA, 1996. [4] G. Kunito, K. Yamazaki, H. Morikawa, and T. Aoyama, “An ad-hoc

Ngày tải lên: 23/06/2014, 00:20

... Trang 1Wireless Ad Hoc & Sensor NetworksMedium Access Control Application Transport Protocol WS 2010/2011Network ... Demand Assigned Multiple Access – PRMA : Packet Reservation Multiple Access Trang 2Wireless Ad Hoc & Sensor NetworksMedium Access Control Application Transport Protocol WS 2010/2011Network ... Demand Assigned Multiple Access – PRMA : Packet Reservation Multiple Access Trang 3Wireless Ad Hoc & Sensor NetworksMedium Access Control Application Transport Protocol WS 2010/2011Network

Ngày tải lên: 09/07/2014, 08:13

... these papers are designed for mobile ad hoc networks but not sensor networks Unlike sensor networks, bat-tery constraint is not a major issue of mobile ad hoc networks Therefore, only few papers ... applications, wireless sensor networks still face a number of challenges due to their particular characteristics that other wireless networks, like cellular networks or mobile ad hoc net-works ... mobile ad hoc networks, data is transmitted continu-ously and randomly so mobile device has to wake up to listen to the channel Therefore, unlike mobile ad hoc networks, the MAC design for sensor networks

Ngày tải lên: 14/12/2017, 17:47

... Abstract: Broadcasting is a common and basic operation used to support various network protocols in wireless networks To achieve energy-efficient broadcasting is especially important for ad hoc wireless ... In addition, broadcast operations in wireless sensor networks are generally different from those in wired networks because multiple nodes can be reached by a single transmission without any additional ... nodes in the networks Trang 2Keywords: wireless sensor networks; minimum connected dominating set; minimum-energy broadcast problem; network lifetime maximization 1 Introduction Recent advances

Ngày tải lên: 02/11/2022, 09:22

... Basics of wireless communication ► Evolution of modern wireless communication systems ► Wireless Networks ► Research issues in emerging wireless networks ► Adequate knowledge of wireless networks ... Trang 1Wireless NetworksLecture 1 Introduction to Wireless Communication Dr Ghalib A Shah Trang 2Data Communication and Networks1 Wireless Communication and Networks, 2 nd Ed., W Stalling. 2 Wireless ... domains of wireless networks Trang 4Course Syllabus Introduction to wireless communication  Evolution of wireless communication systems  Medium access techniques Trang 5Introduction to Wireless

Ngày tải lên: 05/07/2022, 13:04

... Trang 1Wireless NetworksLecture 2 Introduction to Wireless Communication Dr Ghalib A Shah Trang 3Last Lecture ReviewTrang 4Trans mis s ion in Wireles ... Trang 23 Noise consists of all undesired radio signals, whether manmade or natural  Noise makes the reception of useful information difficult  The radio signal’s strength is of little use, if ... carrier signal: In radio frequency systems an analog signal is always used as the main airborne signal  Information Signal: On top of this signal another signal, analog or digital, is added that carries

Ngày tải lên: 05/07/2022, 13:05

... Trang 1Wireless Networks Lecture 3 Introduction to Wireless Communication Dr Ghalib A Shah Trang 5Multiplexing Trang 7 Time­division multiplexing (TDM)► Takes advantage of the fact that the achievable bit rate of  ... shape in between the Trang 29Multipath Propagation Trang 32Fading channel Additive white Gaussian noise (AWGN) channel ► Signal is degraded only by thermal noise ► Accurate for space communication ... noise (solar, galactic, atmospheric) and manmade ► Above 10 GHz, higher attenuation due to atmospheric Trang 18Ground Wave PropagationTrang 19► AM radioTrang 20Sky Wave PropagationTrang 22Line­of­Sight PropagationTrang

Ngày tải lên: 05/07/2022, 13:05

... Trang 1Wireless Networks Lecture 4 Error Detecting and Correcting Techniques Dr Ghalib A Shah Trang 2 Review of previous lecture #3  Transmission Errors  Summary of today’s lecture Trang ... Q X P X D X k n k n Trang 18Wireless Transmission Errors Error detection requires retransmission  Detection inadequate for wireless applications ► Error rate on wireless link can be high, results ... or forward correction codes (FEC) ► Designed to detect and correct errors ► Widely used in wireless networks  Automatic repeat request (ARQ) protocols ► Used in combination with error detection/correction

Ngày tải lên: 05/07/2022, 13:05

... Trang 1Wireless NetworksLecture Multiple Access Techniques Dr Ghalib A Shah Trang 3Last Lecture ReviewTrang 4Multiple Access Techniques Frequency ... planning - all users on a CDMA system use the same radio frequency spectrum ► Random Walsh codes enhance user privacy; a spread-spectrum advantage ► Precise power control increases talk time ... collisions occur only in reservation slots  advantages: ► higher throughput under heavy loads ► max throughput up to 80% of channel capacity  disadvantages: ► more demanding on users as they

Ngày tải lên: 05/07/2022, 13:06

... Trang 1Wireless NetworksLecture 7 CSMA and Spread Spectrum Dr Ghalib A Shah Trang 2 Review of previous lecture #6Trang 3Last Lecture ReviewTrang 4Carrier Sens e Multiple Acces s  (CSMA) Dis advantages ... bandwidth Trang 11Spread SpectrumTrang 12 Types of spreading:► direct s equence s pread s pectrum (DSSS) ► frequency hopping s pread s pectrum (FHSS) Trang 15Frequency Hoping Spread SpectrumTrang ... 8ExampleTrang 9► spread narrow band signal into a broad band signal using a special code ► initially developed for military in order to combat jamming and interception ► power of spread signal is the

Ngày tải lên: 05/07/2022, 13:07

... Trang 1Wireless NetworksLecture 8 Evolution of Wireless Networks Dr Ghalib A Shah Trang 2 Review of previous lecture #7 1G wireless cellular networks ► NMT ► AMPS ► TACS ... 3Last Lecture Review► Versions of CSMA ► CSMA/CA ► Example ► Frequency Hoping ► Direct Sequence Trang 4Evolution of Wireless Systems The worldwide success of cellular telephone has lead to ... placed in the same amount of space This was also made possible by cell towers and related equipment Trang 132G Advantages The lower powered radio signals require less battery power, so phones

Ngày tải lên: 05/07/2022, 13:07

... Trang 1Wireless NetworksLecture 9 Evolution of Wireless Networks (Part II) Dr Ghalib A Shah Trang 2Outlines  Review of last lecture #8 ► HSCSD ► GPRS ► EDGE ► IS-95B ... GPRS ► EDGE ► IS-95B ► UMTS/W-CDMA ► CDMA2000  Summary of today’s lecture Trang 3Review of last lecture #8 1G wireless cellular networks ► NMT ► AMPS ► TACS  2G cellular systems ► GSM ► IS-136 ... service (GPRS) ► Enhanced Data rates for GSM Evolution (EDGE)  IS-95B upgrade for IS-95 Trang 6Wireless Networks Upgrade Paths IS-95 GSM IS-136 &PDC Cdma2000-1xRTT Cdma2000-1xEV DVDO Cdma2000-3xRTT

Ngày tải lên: 05/07/2022, 13:07

... Trang 1Wireless NetworksLecture 11 Fundamentals of Cellular Networks (Part I) Dr Ghalib A Shah Trang 3Review of last lectureTrang 4 Early mobile system objective ... with reduced transmission power  Thereby providing additional capacity with no addition to spectrum  This is the foundation of for all modern wireless communication systems Trang 7AMPS ArchitectureTrang ... actual radio coverage is known as the footprint and is determined from field measurement, propagation prediction models ► However a regular shape is needed for systematic system design and adaptation

Ngày tải lên: 05/07/2022, 13:08

... Trang 1Wireless Networks Lecture 12Fundamentals of Cellular Networks (Part II) Dr Ghalib A Shah Trang 2► Guard channels concept► ... pass through a cell in a matter Trang 17 Additional capacity is provided through addition of new cell sites,  Difficult to obtain new cell sites  Install additional channels and BS at same location ... by MSC due to high traffic load ► ∆ is set too small for handoff time ► No channels are available on any of nearby BS ► Drop in signal level is not due to momentary fading ► Mobile is actually

Ngày tải lên: 05/07/2022, 13:08

... Trang 1Wireless NetworksLecture 13Fundamentals of Cellular Networks (Part III) Dr Ghalib A Shah Trang 2 Last lecture review  Interference and system capacity ... capacity ► Co-channel interference and capacity ► Adjacent channel interference and capacity  Channel Planning for Wireless System Trang 3Last lecture review Channel Assignment Strategies ► Guard ... Breathing cell can lead to abrupt dropped calls  Hence, the engineer must make difficult decision of Trang 18Adjacent channel interference Interference resulting from signals which are adjacent in

Ngày tải lên: 05/07/2022, 13:08

... Trang 1Wireless NetworksLecture 14 Fundamentals of Cellular Networks (Part IV) Dr Ghalib A Shah Trang 2 Trunking and Grade of Service ► Measuring Traffic Intensity ... Concept Trang 3Last lecture review Interference and system capacity ► Co-channel interference and capacity ► Adjacent channel interference and capacity  Channel Planning for Wireless System Trang ... one call-hour per hour or one call-minute per minute • 0.5 Erlang: Radio channel occupied 30 minutes during 1 hour Trang 6Grade of Service GOS is a benchmark used to define performance of a particular

Ngày tải lên: 05/07/2022, 13:09