All materials on our website are shared by users. If you have any questions about copyright issues, please report us to resolve them. We are always happy to assist you.

Share

Description

An Analysis of the Throughput of Packet Radio Networks. André Stranne Licentiate thesis presentation Lund, 16/5 – 2003. Outline. Introduction and background System model Packet collision analysis Interfering energy analysis Approximations Summary. Introduction and background.

Transcript

An Analysis of the Throughput of Packet Radio Networks André Stranne Licentiate thesis presentation Lund, 16/5 – 2003 Outline Introduction and background System model Packet collision analysis Interfering energy analysis Approximations Summary Introduction and background An Analysis of the Throughput of Packet Radio Networks Wireline Wireless Internet IR Radio Sound An Analysis of the Throughput ofPacket Radio Networks Data communications 1011010010110 Fixed phone ADSL Ethernet GSM Bluetooth 3G Circuit switched Packet switched 1110 101 011 An Analysis of the Throughput of Packet Radio Networks Radio networks 1011010010110 Phone calls Internet data GSM (3G) Bluetooth GPRS (3G) Throughput 011 01 An Analysis of the Throughput ofPacket Radio Networks ? OK OK OK 0 101 1110 An Analysis of the Throughput of Packet Radio Networks - What data rates can be expected in packet radio networks? Analysis: How to do it? Analyze real packet radio networks Realistic but not very convenient Create mathematical models of packet radio networks Outline Introduction and background System model Packet collision analysis Interfering energy analysis Approximations Summary Main features Networks, units Packet transmissions Packet-based slow frequency hopping Different packet lengths Interference System model System Networks Units Packet transmissions Frequency channels Packet-based frequency hopping Transmitted data Network Throughput Lost data Performance measure Throughput = achieved data rate Packet reception models What is the cause of packet losses in the networks? Packet collision analysis: Interfering energy analysis: Collisions Interfering energy Outline Introduction and background System model Packet collision analysis Interfering energy analysis Approximations Summary Collision analysis Packet reception model Packet losses from packet collisions ? Collision analysis Packet reception model Packet losses from packet collisions Collision analysis Probability of collision? Probability of successful packet reception? Throughput? Calculation outline Calculate how probable n collisions are with packets transmitted from a single interferer j, Hard to find that expression Details in the thesis Convolutions of PDFs (probability distribution functions) Calculation outline Calculate how probable n collisions are with packets transmitted by all interferers Assumption: independent packet transmissions Calculation outline Sum the probabilities for the number of collisions that can be tolerated for successful packet reception If no collisions can be tolerated: 625 μs Bluetooth example System of Bluetooth ”piconets” 79 frequency channels No collisions Single interferer! 79 channels 1 collision 2 collisions Bluetooth example Prob. of number of collisions from single interferer Low collision probability! 20 interferers 40 interferers 60 interferers 80 interferers 100 interferers Bluetooth example Prob. of total number of collisions Medium size packet type All interferers! No interferers More interferers 50 % 26 Bluetooth example Network throughput More collisions More lost packets Reduced data rate Decreasing system throughput Maximum system throughput Increasing system throughput Bluetooth example System throughput Total throughput for all piconets in the system Outline Introduction and background System model Packet collision analysis Interfering energy analysis Approximations Summary no collision collision collision Energy analysis Collision-based packet reception model Energy analysis New packet reception model More detailed The collision analysis does not account for the duration of the packet overlaps in the collisions the strength of the received interfering signals Interfering energy 1 2 3 3 Single frequency channel 1 2 Energy analysis Interfering energy Time 1 Length of overlap Signal strength Energy analysis Interfering energy Time 2 Energy analysis Interfering energy 1 Time 3 Energy analysis Interfering energy 1 2 Time Energy analysis Interfering energy Calculation outline Basically the same as for the collision analysis Variables for number of collisions Variables for amount of interfering energy Bluetooth example Link budget Distance between interferers and reference nodes Increasing interference Bluetooth example Network throughput Bluetooth example System throughput Outline Introduction and background System model Packet collision analysis Interfering energy analysis Approximations Summary Complexity issues Exact expressions complicated Simple approximations needed For the collision-based analysis, we have such an approximation Approximation of energy-based analysis is beyond the scope of this thesis Approximation Full expression / approximation Accurate enough? 10 channels Bluetooth 79 channels 30 channels Approximation error (Bluetooth example) Outline Introduction and background System model Packet collision analysis Interfering energy analysis Approximations Summary Contributions Probabilistic framework for analysis of PRNs that transmit packets of different lengths Exact expressions for the throughput Approximate expression which can be used for strongly interfering networks Publications F. Florén, A. Stranne and O. Edfors, Analysis of Slow Frequency Hopping Networks, NRS 01, Sweden, 2001 F. Florén, A. Stranne, O. Edfors and B.-A. Molin, Throughput Analysis of Strongly Interfering Slow Frequency-Hopping Wireless Networks, VTC Spring 2001, Greece, 2001 A. Stranne, F. Florén and O. Edfors, Evaluating a Performance Analysis of Slow FH Systems by Simulations, RVK 02, Sweden, 2002 A. Stranne, F. Florén, O. Edfors and B.-A. Molin, Throughput of IEEE 802.11 FHSS Networks in the Presence of Strongly Interfering Bluetooth Networks, PIMRC 2002, Portugal, 2002 Publications A. Stranne, F. Florén, O. Edfors and B.-A. Molin, Throughput of Strongly Interfering Slow Frequency-Hopping Networks, submitted to IEEE Transactions on Communications, 2003 A. Stranne, F. Florén, O. Edfors and B.-A. Molin, Analysis of Strongly Interfering Slow Frequency-Hopping Systems, Technical Report, Department of Electroscience, Lund University, 2003 Future work Approximations Development of system model Applications of the results Special thanks to

Related Search

Previous Document

Next Document

Related Documents

We Need Your Support

Thank you for visiting our website and your interest in our free products and services. We are nonprofit website to share and download documents. To the running of this website, we need your help to support us.

Thanks to everyone for your continued support.

No, Thanks