# Enhancement of VoIP over IEEE WLANs by Adapting Transmitting Interval

Save this PDF as:

Size: px
Start display at page:

## Transcription

3 Therefore, if we use Equations (1) and (11) to calculate B avl, the Equation (9) should be modified as We can simplify N as N = N = B avl/.9 2 B req. (12) p s T p B avg/.9 p s T s + p c T c + p i T i R codec 2. (13) Thus, given the parameters of the codec and the network, if we let n equals to N, we can obtain the maximum number of calls network can support by solving Equations (2), (1), (11) and (13). Take Codec G.729a and network parameters shown in Table I as an example. For Codec G.729a, the bit rate of codec R codec is 8 kbps (8 bits for 1 ms frames). If we choose 2 frames per packet to transmit which represents 2 ms interval to transmit 2 bytes. Using Equations (4) () and (6), we can obtain that T suc = = 772µs, T col = = 828µs, T p = 8µs, T i = 2µs. Then, we can obtain the maximum number of calls network can support N is Table II summaries the maximum number of VoIP calls for different number of frames per packet. In these calculations, network parameters are as shown in Table I and we use codec G.729a. We can see from Table I that the larger number of frames per packet is, the more VoIP calls are allowed in the network since the required bandwidth is lower, while larger number of frames per packet means larger delay, for example, 4 frames per packet means 4 ms more codec delays. If the number of frames per packet is too large, it will not satisfy the quality of VoIP showed in the next subsection. TABLE II MAXIMUM NUMBER OF VOIP CALLS FOR G.729A Frames/Packet Required Bandwidth Number of Calls kbps kbps kbps kbps kbps kbps kbps kbps kbps kbps B. Voice Quality Measures Before obtaining the maximum number of VoIP calls experimentally, we should define our measurement of voice quality in engineering. We use a metric proposed in [2], which takes into account mouth to ear delay, loss rate, and the type of the encoder. The quality of voice is defined by the R-score where R = d 11 4log(1 + 1e).11(d 177.3)H(d 177.3), (14) d = d codec +d jitterbuffer +d network is the total mouth to ear delay comprising vocoder delay which includes ms look-ahead delay, 1ms coding delay per frame, delay in the de-jitter buffer and network delay. The network delay includes delay in sending buffer and retransmission. e = e network + (1 e network )e jitter is the total loss including network and jitter losses. H(x) is the Heaviside function { 1 if x > H(x) = otherwise. the parameters used are specific to the G.729a encoder with uniformly distributed loss. The R-score greater than 7 is considered as acceptable quality. We can calculate from Equation (14) that the total delay should be no larger than 244 ms, which means the delay in the network should be less than 22 ms even there is no loss in the network and jitter. In general situation, to ensure the quality of VoIP in WLAN, the network delay should not be larger than 1 ms and the network loss rate should be less than 3%. C. Maximum Number of VoIP Connecting Experimentally In this subsection, we will show the maximum number of VoIP calls in ns-2 [8] simulations with the network parameters shown in Table I and Codec 729.a with 2 frames per packet which means 2 bytes per 2 ms. The VoIP calls join the network one by one every 2 seconds. We can see from Figure 1 that when the eleventh call joins the network, the quality of all VoIP calls in the network becomes bad, and the throughput of the network drops slightly. It indicates that the maximum number of VoIP calls is ten, which accurately matches the value N in the subsection A. To identify the reason why the eleventh call makes the network into poor situation, we plot Figure 2 to analyze the average collision probability of the network and the average idle time of the network. We find that before the eleventh call comes, the average collision probability p c increases slightly from to.3. The average idle time drops quickly at beginning because when the number of calls increases, the idle time due to no packet to be sent decreases quickly, and it drops slightly when there are more calls in the network, since at that time, most of network idle time is due to backoff process and DIFS time. When the eleventh call comes into the network, the average collision probability p c increases quickly to.1 from.3 and then jumps to.23, and the average network idle time decreases from 2 us to 1 us slightly. This means in Equation (1) the parameter T col becomes much larger and the average system idle time T idle becomes smaller, thus the available bandwidth B avl becomes lower. Therefore, we can

6 Numver of calls supportted Transmitting interval (ms) (a) CW min = 1 Analytical 2M Simulation 2M Analytical 11M Simulation 11M Numver of calls supportted Analytical 2M Simulation 2M Analytical 11M Simulation 11M Transmitting interval (ms) (b) CW min = 31 Numver of calls supportted Analytical 2M Simulation 2M Analytical 11M Simulation 11M Transmitting interval (ms) (c) CW min = 63 Fig. 4. Maximum number of calls supported with transmitting interval increasing. Average thoughput (bits/s) 3.k With ATICAC No CAC With normal CAC 2.k 2.k 1.k 1.k.k. (a) Average throughput of network Average dealy (ms) With ATICAC No CAC With normal CAC (b) Average delay of calls Average loss rate (%) (c) With ATICAC No CAC With normal CAC Average loss rate of calls Fig.. Call quality statistics with the number of calls increasing. Average thoughput (bits/s) 3.k 2.k 2.k 1.k 1.k.k. (a) Data traffic with no CAC Voice calls with no CAC Data traffic with ATICAC Voice calls with ATICAC Average throughput of network Average dealy (ms) Data traffic with no CAC Voice calls with no CAC Data traffic with ATICAC Voice calls with ATICAC (b) Average delay of network Average loss rate (%) Data traffic with no CAC Voice calls with no CAC Data traffic with ATICAC Voice calls with ATICAC (c) Average loss rate of network Fig. 6. Network statistics with the number of calls increasing. C. Performance Evaluation To evaluate the performance of ATICAC, we consider a scenario that VoIP calls join the network one by one every 2 seconds from 12 second. All the calls in the simulation use fixed 2 ms transmitting interval which is wildly used for VoIP calls [17] except for ATICAC. In Figure, the line with legend star represents the network performance when there is no call admission control. After the eleventh call joins the network at the time 122 second, the network falls into saturate mode, the average throughput decreases slightly and the average delay and average loss rate increase dramatically in Figure -(b) and (c). The line with legend triangle represents the network performance using normal call admission control. When the number of existing calls in the network attains the maximum value, i.e., 1 calls, the base station will reject new arriving calls until one existing call finishes. The normal call

### PROVIDING STATISTICAL QOS GUARANTEE FOR VOICE OVER IP IN THE IEEE 802.11 WIRELESS LANS

V OICE OVER WIRELESS LOCAL AREA N ETWORK PROVIDING STATISTICAL QOS GUARANTEE FOR VOICE OVER IP IN THE IEEE 82.11 WIRELESS LANS HONGQIANG ZHAI, JIANFENG WANG, AND YUGUANG FANG, UNIVERSITY OF FLORIDA The

### then, we require that, in order to support the offered load, (1)

Capacity of an IEEE 802.11b Wireless LAN supporting VoIP To appear in Proc. IEEE Int. Conference on Communications (ICC) 2004 David P. Hole and Fouad A. Tobagi Dept. of Electrical Engineering, Stanford

### Adaptive DCF of MAC for VoIP services using IEEE 802.11 networks

Adaptive DCF of MAC for VoIP services using IEEE 802.11 networks 1 Mr. Praveen S Patil, 2 Mr. Rabinarayan Panda, 3 Mr. Sunil Kumar R D 1,2,3 Asst. Professor, Department of MCA, The Oxford College of Engineering,

### Attenuation (amplitude of the wave loses strength thereby the signal power) Refraction Reflection Shadowing Scattering Diffraction

Wireless Physical Layer Q1. Is it possible to transmit a digital signal, e.g., coded as square wave as used inside a computer, using radio transmission without any loss? Why? It is not possible to transmit

### Can I add a VoIP call?

Can I add a VoIP call? Sachin Garg Avaya Labs Basking Ridge, NJ 07920 Email: sgarg@avaya.com Martin Kappes Avaya Labs Basking Ridge, NJ 07920 Email: mkappes@avaya.com Abstract In this paper, we study the

### An Experimental Study of Throughput for UDP and VoIP Traffic in IEEE 802.11b Networks

An Experimental Study of Throughput for UDP and VoIP Traffic in IEEE 82.11b Networks Sachin Garg sgarg@avaya.com Avaya Labs Research Basking Ridge, NJ USA Martin Kappes mkappes@avaya.com Avaya Labs Research

### A TCP-like Adaptive Contention Window Scheme for WLAN

A TCP-like Adaptive Contention Window Scheme for WLAN Qixiang Pang, Soung Chang Liew, Jack Y. B. Lee, Department of Information Engineering The Chinese University of Hong Kong Hong Kong S.-H. Gary Chan

### Introduction VOIP in an 802.11 Network VOIP 3

Solutions to Performance Problems in VOIP over 802.11 Wireless LAN Wei Wang, Soung C. Liew Presented By Syed Zaidi 1 Outline Introduction VOIP background Problems faced in 802.11 Low VOIP capacity in 802.11

### Admission Control for VoIP Traffic in IEEE 802.11 Networks

Admission Control for VoIP Traffic in IEEE 802.11 Networks Sachin Garg Avaya Labs Basking Ridge, NJ 07920 Email: sgarg@avaya.com Martin Kappes Avaya Labs Basking Ridge, NJ 07920 Email: mkappes@avaya.com

### Voice Service Support over Cognitive Radio Networks

Voice Service Support over Cognitive Radio Networks Ping Wang, Dusit Niyato, and Hai Jiang Centre For Multimedia And Network Technology (CeMNeT), School of Computer Engineering, Nanyang Technological University,

### DUE to the high performance versus price ratio, IEEE

Improving WLAN VoIP Capacity Through Service Differentiation Deyun Gao, Member, IEEE, Jianfei Cai, Senior Member, IEEE, Chuan Heng Foh, Member, IEEE, Chiew-Tong Lau, Member, IEEE, and King Ngi Ngan, Fellow,

### Enhancing WLAN MAC Protocol performance using Differentiated VOIP and Data Services Strategy

IJCSNS International Journal of Computer Science and Network Security, VOL.9 No.12, December 2009 89 Enhancing WLAN MAC Protocol performance using Differentiated VOIP and Data Services Strategy S.Vijay

### VoIP in 802.11. Mika Nupponen. S-72.333 Postgraduate Course in Radio Communications 06/04/2004 1

VoIP in 802.11 Mika Nupponen S-72.333 Postgraduate Course in Radio Communications 06/04/2004 1 Contents Introduction VoIP & WLAN Admission Control for VoIP Traffic in WLAN Voice services in IEEE 802.11

### Express Forwarding : A Distributed QoS MAC Protocol for Wireless Mesh

Express Forwarding : A Distributed QoS MAC Protocol for Wireless Mesh, Ph.D. benveniste@ieee.org Mesh 2008, Cap Esterel, France 1 Abstract Abundant hidden node collisions and correlated channel access

### Fast Retransmission Mechanism for VoIP in IEEE 802.11e wireless LANs

Fast Mechanism for VoIP in IEEE 802.11e wireless LANs Gyung-Ho Hwang and Dong-Ho Cho Division of Electrical Engineering, Department of Electrical Engineering and Computer Science, KAIST, 373-1 Guseong-dong

### Enhanced Power Saving for IEEE 802.11 WLAN with Dynamic Slot Allocation

Enhanced Power Saving for IEEE 802.11 WLAN with Dynamic Slot Allocation Changsu Suh, Young-Bae Ko, and Jai-Hoon Kim Graduate School of Information and Communication, Ajou University, Republic of Korea

### Performance Evaluation of VoIP Services using Different CODECs over a UMTS Network

Performance Evaluation of VoIP Services using Different CODECs over a UMTS Network Jianguo Cao School of Electrical and Computer Engineering RMIT University Melbourne, VIC 3000 Australia Email: j.cao@student.rmit.edu.au

### CSMA/CA. Information Networks p. 1

Information Networks p. 1 CSMA/CA IEEE 802.11 standard for WLAN defines a distributed coordination function (DCF) for sharing access to the medium based on the CSMA/CA protocol Collision detection is not

### Modeling and Simulation of Quality of Service in VoIP Wireless LAN

Journal of Computing and Information Technology - CIT 16, 2008, 2, 131 142 doi:10.2498/cit.1001022 131 Modeling and Simulation of Quality of Service in VoIP Wireless LAN A. Al-Naamany, H. Bourdoucen and

### Performance Comparison of Dual Queue and EDCA for VoIP over IEEE 802.11 WLAN

Performance Comparison of Dual Queue and for VoIP over IEEE 8. WLAN Jeonggyun Yu and Sunghyun Choi Multimedia & Wireless Networking Laboratory (MWNL), School of Electrical Engineering, Seoul National University,

### Throughput Modeling in IEEE 802.11 WLAN-based Wireless Networks

Throughput Modeling in IEEE 82.11 WLAN-based Wireless Networks Kirill Ermolov Aalto University Espoo, Finland kirill.ermolov@aalto.fi Abstract Wireless Local Area Networks (WLANs) are nowadays the most

### ECE 358: Computer Networks. Homework #3. Chapter 5 and 6 Review Questions 1

ECE 358: Computer Networks Homework #3 Chapter 5 and 6 Review Questions 1 Chapter 5: The Link Layer P26. Let's consider the operation of a learning switch in the context of a network in which 6 nodes labeled

### Improving Throughput Performance of the IEEE 802.11 MAC Layer Using Congestion Control Methods

Improving Throughput Performance of the IEEE 802.11 MAC Layer Using Congestion Control Methods Song Ci CS Department University of Michigan-Flint Flint, MI48502 cisong@umich.edu Guevara Noubir College

### VoIP Session Capacity Expansion with Packet Transmission Suppression Control in Wireless LAN

1144 PAPER Special Section on Internet Technology and its Architecture for Ambient Information Systems VoIP Session Capacity Expansion with Packet Transmission Suppression Control in Wireless LAN Yasufumi

### Performance Evaluation of AODV, OLSR Routing Protocol in VOIP Over Ad Hoc

(International Journal of Computer Science & Management Studies) Vol. 17, Issue 01 Performance Evaluation of AODV, OLSR Routing Protocol in VOIP Over Ad Hoc Dr. Khalid Hamid Bilal Khartoum, Sudan dr.khalidbilal@hotmail.com

### Virtual PCF: Improving VoIP over WLAN performance with legacy clients

Virtual PCF: Improving VoIP over WLAN performance with legacy clients by Usman Ismail A thesis presented to the University of Waterloo in fulfillment of the thesis requirement for the degree of Master

Balancing Uplink and Downlink Delay of VoIP in WLANs using Adaptive Priority Control (APC) Sangho Shin Columbia University Dept of Computer Science New York, USA sangho@cs.columbia.edu Henning Schulzrinne

### CS263: Wireless Communications and Sensor Networks

CS263: Wireless Communications and Sensor Networks Matt Welsh Lecture 4: Medium Access Control October 5, 2004 2004 Matt Welsh Harvard University 1 Today's Lecture Medium Access Control Schemes: FDMA TDMA

### TCP in Wireless Networks

Outline Lecture 10 TCP Performance and QoS in Wireless s TCP Performance in wireless networks TCP performance in asymmetric networks WAP Kurose-Ross: Chapter 3, 6.8 On-line: TCP over Wireless Systems Problems

### II. IEEE802.11e EDCA OVERVIEW

The 18th Annual IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC'7) CACITY IMPROVEMENT OF WIRELESS LAN VOIP USING DISTRIBUTED TRANSMISSION SCHEDULING Kei Igarashi,

### Mobile Communications Exercise: Satellite Systems and Wireless LANs. Georg von Zengen, IBR, TU Braunschweig, www.ibr.cs.tu-bs.de

Mobile Communications Exercise: Satellite Systems and Wireless LANs N 1 Please define the terms inclination and elevation using the following two figures. How do these parameters influence the usefulness

### Adapting WLAN MAC Parameters to Enhance VoIP Call Capacity

Adapting WLAN MAC Parameters to Enhance VoIP Call Capacity Gráinne Hanley, Seán Murphy and Liam Murphy Dept. of Computer Science, University College Dublin Belfield, Dublin 4, Ireland hanleyg@gmail.com,

### Comparative call Capacity analysis of VOIP in IEEE802.11b WLAN Environment

Comparative call Capacity analysis of VOIP in IEEE802.11b WLAN Environment Jitendra Jakhar 1, Sankit R Kassa 2, Tejpal 3 PG Student, Electronics & Communication Engineering Department, SBCET, Jaipur, Rajasthan,

### An Efficient Transmission Scheme for Short Message Service in IEEE 802.16 Systems

An Efficient Transmission Scheme for Short Message Service in IEEE 802.16 Systems Sung-Min Oh* and Jae-Hyun Kim* *Ajou University, School of Electrical and Computer Engineering smallb01@ajou.ac.kr and

### No Ack in IEEE 802.11e Single-Hop Ad-Hoc VoIP Networks

No Ack in IEEE 802.11e Single-Hop Ad-Hoc VoIP Networks Jaume Barceló, Boris Bellalta, Anna Sfairopoulou, Cristina Cano, Miquel Oliver Abstract This paper analyzes the impact of the No Ack policy in VoIP

### Performance Analysis of the IEEE 802.11 Wireless LAN Standard 1

Performance Analysis of the IEEE. Wireless LAN Standard C. Sweet Performance Analysis of the IEEE. Wireless LAN Standard Craig Sweet and Deepinder Sidhu Maryland Center for Telecommunications Research

### ENSC 427: Communication Networks. Analysis of Voice over IP performance on Wi-Fi networks

ENSC 427: Communication Networks Spring 2010 OPNET Final Project Analysis of Voice over IP performance on Wi-Fi networks Group 14 members: Farzad Abasi (faa6@sfu.ca) Ehsan Arman (eaa14@sfu.ca) http://www.sfu.ca/~faa6

### CS6956: Wireless and Mobile Networks Lecture Notes: 2/11/2015. IEEE 802.11 Wireless Local Area Networks (WLANs)

CS6956: Wireless and Mobile Networks Lecture Notes: //05 IEEE 80. Wireless Local Area Networks (WLANs) CSMA/CD Carrier Sense Multi Access/Collision Detection detects collision and retransmits, no acknowledgement,

### Analysis of QoS parameters of VOIP calls over Wireless Local Area Networks

Analysis of QoS parameters of VOIP calls over Wireless Local Area Networks Ayman Wazwaz, Computer Engineering Department, Palestine Polytechnic University, Hebron, Palestine, aymanw@ppu.edu Duaa sweity

### A Policy-Based Admission Control Scheme for Voice over IP Networks

Journal of Computer Science 5 (11): 817-821, 2009 ISSN 1549-3636 2009 Science Publications A Policy-Based Admission Control Scheme for Voice over IP Networks Sami Alwakeel and Agung Prasetijo Department

### IEEE 802.11E ENHANCEMENT FOR VOICE SERVICE

V OICE OVER WIRELESS LOCAL AREA N ETWORK IEEE 802.11E ENHANCEMENT FOR VOICE SERVICE PING WANG, HAI JIANG, AND WEIHUA ZHUANG, UNIVERSITY OF WATERLOO Wired network IP phone Gateway router Access point Motivated

### Enhancement of VoIP over IEEE 802.11 WLAN via Dual Queue Strategy

Enhancement of VoIP over IEEE 802.11 WLAN via Dual Queue Strategy + Multimedia & Wireless Networking Laboratory School of Electrical Engineering Seoul National University jgyu@mwnl.snu.ac.kr, schoi@snu.ac.kr

### ... neither PCF nor CA used in practice

IEEE 802.11 MAC CSMA/CA with exponential backoff almost like CSMA/CD drop CD CSMA with explicit ACK frame added optional feature: CA (collision avoidance) Two modes for MAC operation: Distributed coordination

### A study of Skype over IEEE 802.16 networks: voice quality and bandwidth usage

Iowa State University Digital Repository @ Iowa State University Graduate Theses and Dissertations Graduate College 2011 A study of Skype over IEEE 802.16 networks: voice quality and bandwidth usage Kuan-yu

### ANALYSIS OF LONG DISTANCE 3-WAY CONFERENCE CALLING WITH VOIP

ENSC 427: Communication Networks ANALYSIS OF LONG DISTANCE 3-WAY CONFERENCE CALLING WITH VOIP Spring 2010 Final Project Group #6: Gurpal Singh Sandhu Sasan Naderi Claret Ramos (gss7@sfu.ca) (sna14@sfu.ca)

### Supporting VoIP in IEEE802.11 Distributed WLANs

Supporting VoIP in IEEE802.11 Distributed WLANs Zuo Liu Supervisor: Dr. Nick Filer July 2012 1 Voice VoIP Applications Constant Streaming Traffic Packetize interval usually 10-30 ms 8 160 bytes each packet

### Real-Time Traffic Support in Heterogeneous Mobile Networks

Real-Time Traffic Support in Heterogeneous Mobile Networks Yuan Sun Elizabeth M. Belding-Royer Department of Computer Science University of California, Santa Barbara {suny, ebelding}@cs.ucsb.edu Xia Gao

### Capacity Evaluation of VoIP in IEEE 802.11e WLAN Environment

Capacity Evaluation of VoIP in IEEE 802.11e WLAN Environment Abdelbasset Trad, Farukh Munir INIA, Planete Project 4 oute des Lucioles, BP-93 06902 Sophia-Antipolis, France Email: {atrad, mfmunir}@sophia.inria.fr

### Enhanced TXOP scheme for efficiency improvement of WLAN IEEE 802.11e

Enhanced TXOP scheme for efficiency improvement of WLAN IEEE 802.11e Jakub Majkowski, Ferran Casadevall Palacio Dept. of Signal Theory and Communications Universitat Politècnica de Catalunya (UPC) C/ Jordi

### Seamless Congestion Control over Wired and Wireless IEEE 802.11 Networks

Seamless Congestion Control over Wired and Wireless IEEE 802.11 Networks Vasilios A. Siris and Despina Triantafyllidou Institute of Computer Science (ICS) Foundation for Research and Technology - Hellas

### Multiple Access Techniques PROF. MICHAEL TSAI 2011/12/8

Multiple Access Techniques PROF. MICHAEL TSAI 2011/12/8 Multiple Access Scheme Allow many users to share simultaneously a finite amount of radio spectrum Need to be done without severe degradation of the

### IEEE 802.11 Ad Hoc Networks: Performance Measurements

IEEE 8. Ad Hoc Networks: Performance Measurements G. Anastasi Dept. of Information Engineering University of Pisa Via Diotisalvi - 56 Pisa, Italy Email: g.anastasi@iet.unipi.it E. Borgia, M. Conti, E.

### 802.11. Markku Renfors. Partly based on student presentation by: Lukasz Kondrad Tomasz Augustynowicz Jaroslaw Lacki Jakub Jakubiak

802.11 Markku Renfors Partly based on student presentation by: Lukasz Kondrad Tomasz Augustynowicz Jaroslaw Lacki Jakub Jakubiak Contents 802.11 Overview & Architecture 802.11 MAC 802.11 Overview and Architecture

### Performance Evaluation of Wired and Wireless Local Area Networks

International Journal of Engineering Research and Development ISSN: 2278-067X, Volume 1, Issue 11 (July 2012), PP.43-48 www.ijerd.com Performance Evaluation of Wired and Wireless Local Area Networks Prof.

### Simulative Investigation of QoS parameters for VoIP over WiMAX networks

www.ijcsi.org 288 Simulative Investigation of QoS parameters for VoIP over WiMAX networks Priyanka 1, Jyoteesh Malhotra 2, Kuldeep Sharma 3 1,3 Department of Electronics, Ramgarhia Institue of Engineering

### EECS 122: Introduction to Computer Networks Multiaccess Protocols. ISO OSI Reference Model for Layers

EECS 122: Introduction to Computer Networks Multiaccess Protocols Computer Science Division Department of Electrical Engineering and Computer Sciences University of California, Berkeley Berkeley, CA 94720-1776

### Railway Freight Dispatching Telephone System Based on VoIP in Wireless Networks

International Conference on Computer, Communications and Information Technology (CCIT 2014) Railway Freight Dispatching Telephone System Based on VoIP in Wireless Networks Jun Xiao1, Feng Liu1, 2 1 2 School

Frame aggregations in the wireless LANs: A review paper Presented by: Anwar Saif Asia-Pacific Advanced Network Wireless communication 2009 Abstract The overhead induced by the IEEE 802.11 PHY and MAC layer

### Nov doc.: IEEE / aa QoS Tutorial. Date: Authors: Submission. Graham Smith, DSP Group

Authors: 802.11 QoS Tutorial Date: 2008-11-10 Slide 1 Abstract The channel access schemes for 802.11 are outlined and the two QoS schemes, introduce in 802.11e, described in more detail. The major differences

### A Neighborhood Awareness Method for Handoff Assistance in 802.11 Wireless Networks

A Neighborhood Awareness Method for Handoff Assistance in 802.11 Wireless Networks Gurpal Singh *, Ajay Pal Singh Atwal ** and B.S. Sohi *** * Deptt of CSE & IT, BBSBEC, Fatehgarh Sahib, Punjab, India,

### Efficient MAC Protocol for Heterogeneous Cellular Networks (HC-MAC)

Vol.2, Issue.2, Mar-Apr 2012 pp-078-083 ISSN: 2249-6645 Efficient MAC Protocol for Heterogeneous Cellular Networks (HC-MAC) 1 Y V Adi Satyanarayana, 2 Dr. K Padma Raju 1 Y V Adi Satyanarayana, Assoc. Professor,

### A Slow-sTart Exponential and Linear Algorithm for Energy Saving in Wireless Networks

1 A Slow-sTart Exponential and Linear Algorithm for Energy Saving in Wireless Networks Yang Song, Bogdan Ciubotaru, Member, IEEE, and Gabriel-Miro Muntean, Member, IEEE Abstract Limited battery capacity

### Improving WLAN VoIP Capacity through Service Differentiation

IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, VOL. X, NO. XX 1 Improving WLAN VoIP Capacity through Service Differentiation Deyun Gao, Member, IEEE, Jianfei Ca Member, IEEE, Chuan Heng Foh, Member, IEEE,

### A Short Look on Power Saving Mechanisms in the Wireless LAN Standard Draft IEEE 802.11

A Short Look on Power Saving Mechanisms in the Wireless LAN Standard Draft IEEE 802.11 Christian Röhl, Hagen Woesner, Adam Wolisz * Technical University Berlin Telecommunication Networks Group {roehl,

### A Comparative Study of Video Transfer over Bluetooth and 802.11 Wireless MAC

A Comparative Study of Video Transfer over Bluetooth and 802.11 Wireless MAC Aravind Iyer and U. B. Desai SPANN Laboratory Department of Electrical Engineering IIT Bombay, INDIA - 400076 Abstract In this

TCP Fairness for Uplink and Downlink Flows in WLANs Juho Ha and Chong-Ho Choi School of Electrical Engineering and Computer Science, and ASRI Seoul National University, Seoul, Korea. {hazo,chchoi}@csl.snu.ac.kr

### A Full Duplex MAC Protocol for Efficient Asymmetric Transmission in WLAN

A Full Duplex MAC Protocol for Efficient Asymmetric Transmission in WLAN Chulmin Kim, Cheeha Kim Department of Computer Science and Engineering Pohang University of Science and Technology(POSTECH) Pohang,

### OPTIMIZING VOIP USING A CROSS LAYER CALL ADMISSION CONTROL SCHEME

OPTIMIZING VOIP USING A CROSS LAYER CALL ADMISSION CONTROL SCHEME Mumtaz AL-Mukhtar and Huda Abdulwahed Department of Information Engineering, AL-Nahrain University, Baghdad, Iraq almukhtar@fulbrightmail.org

### Measuring Data and VoIP Traffic in WiMAX Networks

JOURNAL OF TELECOMMUNICATIONS, VOLUME 2, ISSUE 1, APRIL 2010 Measuring Data and VoIP Traffic in WiMAX Networks 1 Iwan Adhicandra Abstract Due to its large coverage area, low cost of deployment and high

### Comparative Study of VoIP over WiMax and WiFi

www.ijcsi.org 433 Comparative Study of VoIP over WiMax and WiFi M. Atif Qureshi* 1, Arjumand Younus* 2, Muhammad Saeed #3, Farhan Ahmed Sidiqui #4, Nasir Touheed* 5, and M. Shahid Qureshi* 6 * Faculty

### Applying Active Queue Management to Link Layer Buffers for Real-time Traffic over Third Generation Wireless Networks

Applying Active Queue Management to Link Layer Buffers for Real-time Traffic over Third Generation Wireless Networks Jian Chen and Victor C.M. Leung Department of Electrical and Computer Engineering The

### Dynamic Packet Aggregation to Solve Performance Anomaly in 802.11 Wireless Networks

Dynamic Packet Aggregation to Solve Performance Anomaly in Wireless Networks ABSTRACT Tahiry Razafindralambo - Isabelle Guérin Lassous CITI lab.- Project INRIA ARES Bt L. De Vinci - 21 av. Jean Capelle

### APPENDIX 1 USER LEVEL IMPLEMENTATION OF PPATPAN IN LINUX SYSTEM

152 APPENDIX 1 USER LEVEL IMPLEMENTATION OF PPATPAN IN LINUX SYSTEM A1.1 INTRODUCTION PPATPAN is implemented in a test bed with five Linux system arranged in a multihop topology. The system is implemented

### Throughput Analysis of WEP Security in Ad Hoc Sensor Networks

Throughput Analysis of WEP Security in Ad Hoc Sensor Networks Mohammad Saleh and Iyad Al Khatib iitc Stockholm, Sweden {mohsaleh, iyad}@iitc.se ABSTRACT This paper presents a performance investigation

### PLUS-DAC: A Distributed Admission Control Scheme for IEEE 802.11e WLANs

-DAC: A Distributed Admission Control Scheme for IEEE 8.e WLANs Kiran Kumar Gavini, Varsha Apte and Sridhar Iyer Kanwal Rekhi School of Information Technology Indian Institute of Technology Bombay, Powai,

### TCOM 370 NOTES 99-12 LOCAL AREA NETWORKS AND THE ALOHA PROTOCOL

1. Local Area Networks TCOM 370 NOTES 99-12 LOCAL AREA NETWORKS AND THE ALOHA PROTOCOL These are networks spanning relatively short distances (e.g. within one building) for local point-to-point and point-to-multipoint

### Quality of Service Analysis of Video Conferencing over WiFi and Ethernet Networks

ENSC 427: Communication Network Quality of Service Analysis of Video Conferencing over WiFi and Ethernet Networks Simon Fraser University - Spring 2012 Claire Liu Alan Fang Linda Zhao Team 3 csl12 at sfu.ca

### A Cross Layer Solution for VoIP over IEEE802.11

A Cross Layer Solution for VoIP over IEEE82. F. De Pellegrini, F. Maguolo, A. Zanella and M. Zorzi. depe,maguolof,zanella,zorzi @dei.unipd.it.it Department of Information Engineering, University of Padova,

### Extended-rtPS Algorithm for VoIP Services in IEEE 802.16 systems

Extended-rtPS Algorithm for VoIP Services in IEEE 802.16 systems Howon Lee, Taesoo Kwon and Dong-Ho Cho Department of Electrical Engineering and Computer Science Korea Advanced Institute of Science and

### IEEE 802.11e WLANs / WMM. S.Rajesh (rajeshsweb@gmail.com) AU-KBC Research Centre, BroVis Wireless Networks, smartbridges Pte Ltd.

IEEE 802.11e WLANs / WMM S.Rajesh (rajeshsweb@gmail.com) AU-KBC Research Centre, BroVis Wireless Networks, smartbridges Pte Ltd. Outline A short review of 802.11 MAC Drawbacks of 802.11 MAC Application

### An End-to-End Measurement-Based Admission Control Policy for VoIP over Wireless Networks

An End-to-End Measurement-Based Admission Control Policy for VoIP over Wireless Networks Ala Khalifeh Department of EECS University of California, Irvine [akhalife]@uci.edu Abstract in this paper, we present

### VoIP codec adaptation algorithm in multirate 802.11 WLANs : distributed vs centralized performance comparison

VoIP codec adaptation algorithm in multirate 82.11 WLANs : distributed vs centralized performance comparison Anna Sfairopoulou, Carlos Macián, Boris Bellalta Network Technologies and Strategies (NeTS)

### An Experimental Performance Analysis of MAC Multicast in 802.11b Networks for VoIP Traffic

An Experimental Performance Analysis of MAC Multicast in 82.11b Networks for VoIP Traffic Martin Kappes DoCoMo Euro-Labs Landsberger Str. 312, 8687 Munich, Germany kappes@docomolab-euro.com Keywords: IEEE

### PERFORMANCE OF THE GPRS RLC/MAC PROTOCOLS WITH VOIP TRAFFIC

PERFORMANCE OF THE GPRS RLC/MAC PROTOCOLS WITH VOIP TRAFFIC Boris Bellalta 1, Miquel Oliver 1, David Rincón 2 1 Universitat Pompeu Fabra, Psg. Circumval lació 8, 83 - Barcelona, Spain, boris.bellalta,

### Bluetooth voice and data performance in 802.11 DS WLAN environment

1 (1) Bluetooth voice and data performance in 802.11 DS WLAN environment Abstract In this document, the impact of a 20dBm 802.11 Direct-Sequence WLAN system on a 0dBm Bluetooth link is studied. A typical

### Solutions to Performance Problems in VoIP over 802.11 Wireless LAN 1

1 Solutions to Performance Problems in VoIP over 802.11 Wireless LAN 1 Wei Wang, Soung C. Liew Department of Information Engineering The Chinese University of Hong Kong Victor O. K. Li Department of Electrical

### Performance Evaluation of the IEEE 802.11p WAVE Communication Standard

Performance Evaluation of the IEEE 8.p WAVE Communication Standard Stephan Eichler (s.eichler@tum.de), Institute of Communication Networks, Technische Universität München Abstract In order to provide Dedicated

### Collision of wireless signals. The MAC layer in wireless networks. Wireless MAC protocols classification. Evolutionary perspective of distributed MAC

The MAC layer in wireless networks The wireless MAC layer roles Access control to shared channel(s) Natural broadcast of wireless transmission Collision of signal: a /space problem Who transmits when?

### Handover Management based on the Number of Retries for VoIP on WLANs

Handover Management based on the Number of Retries for VoIP on WLANs Shigeru Kashihara Yuji Oie Department of Computer Science and Electronics, Kyushu Institute of Technology Kawazu 68-4, Iizuka, 82-852

### Aspects of Coexistence Between WiFi and HSDPA

(Cross-layer design and network planning for B3G systems) Aspects of Coexistence Between WiFi and HSDPA Orlando Cabral Valdemar Monteiro 2005, it - instituto de telecomunicações. Todos os direitos reservados.

### A Multiplex-Multicast Scheme that Improves System Capacity of Voice-over-IP on Wireless LAN by 100% *

A Multiplex-Multicast Scheme that Improves System Capacity of Voice-over-IP on Wireless LAN by 100% * Wei Wang, Soung C. Liew, Qixiang Pang Department of Information Engineering The Chinese University

### Adaptive Bandwidth Management and QoS Provisioning in Large Scale Ad Hoc Networks

Adaptive Bandwidth Management and QoS Provisioning in Large Scale Ad Hoc Networks Kaixin Xu, Ken Tang, Rajive Bagrodia Scalable Network Technologies, Inc. {xkx, ktang,rlb}@scalable-networks.com Mario Gerla

### PERFORMANCE ANALYSIS OF WLAN STANDARDS FOR VIDEO CONFERENCING APPLICATIONS

PERFORMANCE ANALYSIS OF WLAN STANDARDS FOR VIDEO CONFERENCING APPLICATIONS Lachhman Das Dhomeja 1, Shazia Abbasi 1, Asad Ali Shaikh 1, Yasir Arfat Malkani 2 1 Institute of Information and Communication

### Techniques to reduce the IEEE 802.11b handoff time

Techniques to reduce the IEEE 802.11b handoff time Héctor Velayos and Gunnar Karlsson Dept. of Microelectronics and Information Technology KTH, Royal Institute of Technology Stockholm, Sweden {hvelayos,gk}@imit.kth.se

### Scheduling Video Stream Transmissions for Distributed Playback over Mobile Cellular Networks

Scheduling Video Stream Transmissions for Distributed Playback over Mobile Cellular Networks Kam-Yiu Lam 1, Joe Yuen 1, Sang H. Son 2 and Edward Chan 1 Department of Computer Science 1 City University

### Controlled Random Access Methods

Helsinki University of Technology S-72.333 Postgraduate Seminar on Radio Communications Controlled Random Access Methods Er Liu liuer@cc.hut.fi Communications Laboratory 09.03.2004 Content of Presentation

### Dynamic Traffic Prioritization in 802.11e Networks

1 Dynamic Traffic Prioritization in 802.11e Networks William Spearman, James Martin, James Westall Abstract The IEEE 802.11 family of standards defines a collection of widely used local wireless network