How to Connect: An Introduction to Access Technologies #1 Victor S. Frost Dan F. Servey Distinguished Professor Electrical Engineering and Computer Science University of Kansas 2335 Irving Hill Dr. Lawrence, Kansas 66045 Phone: (785) 864-4833 FAX:(785) 864-7789 e-mail: [email protected] http://www.ittc.ku.edu/
All material copyright 2006 Victor S. Frost, All Rights Reserved #1 1
Getting Connected
Internet
Access Medium Upstream
Downstream
#1 2 Getting Connected
Internet
Wired Local Loop
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Example
• Digital Subscriber Line: Physical topology
•NID = Network Interface Device •DSLAM= Digital Subscriber Line Access Telephone Lines Multiplexer
Modified from: Tanenbaum, A. Computer Internet Networks, Prentice Hall, 4th ED 2003
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Internet
Coax Cable
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Example
• Hybrid Fiber/Coax (HFC): Network topology
Downstream Upstream
Head end
Internet
#1 6 Getting Connected
Internet
Wireless Local Loop
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Example
• Wireless Local Loop: Physical Topology
Internet
Modified from: Tanenbaum, A. Computer Networks, Prentice Hall, 4th ED 2003 #1 8 Getting Connected
Internet
Wireless Cell Phone
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Example • Cellular Network: Physical Topology Base station • Transmits to users on forward channels • Receives from users on reverse channels Mobile Switching BSS BSS Internet Center MSC HLR STP SS7 • Controls connection VLR Wireline setup within cells & EIR terminal AC PSTN to telephone network AC = authentication center MSC = mobile switching center BSS = base station subsystem PSTN = public switched telephone network EIR = equipment identity register STP = signal transfer point HLR = home location register VLR = visitor location register
Modified from: Leon-Garcia & Widjaja: Communication Networks #1 10 Getting Connected
Internet
Fiber Optic Cable
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Example
• Passive Optical Network (PON): Physical topology
Fiber
• OLT= Optical Line Fiber terminal • ONT = Optical Network Terminal Fiber • ONU=Optical Fiber network Unit • SDU= Single Dwelling Unit •MDU/MTU= Multiple Dwelling/Tenant Unit Internet
Modified from: G. Keiser, FTTX Concepts and Applications, Wiley, 2006 #1 12 Getting Connected
Internet
Powerline
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Example Powerline
• Broadband Powerline Communications: Physical topology • M= Power Meter Unit
Internet
Base/Master Station Home LAN
M In-home power Transformer
Low voltage power network Power Grid
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Internet
Satellite
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Characteristics of Systems
Data Time Bit Error Cost Rate Dynamics rate Twisted Medium Low Medium Medium Pair Wireless Medium High High Low
Coax Medium Low Low Low
Fiber High Low Very Low High
Powerline Low High High Medium
#1 16 Course Assessment
• Homework -> 10% – 4 Assignments, • two before break and two after • Term Paper -> 40% – Turn in paper topic on 22-March – Turn in paper outline and references 1-May – Turn in paper 10-May • Final -> 50%
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Term Paper Topics
• Access Methods for Satellite Networks • Access Methods for Mobile Ad Hoc Networks These are more tutorial so, • Access Methods for RFID (passive or active) nice if include •GPON PowerPoint • Bluetooth • IEEE 802.20 Networks • Wireless Application Protocol • Push to talk services • Access technologies problems for cognitive radios • Role of access techniques in cross layer optimization • Access technologies involved in AT&T’s U-verse, brand name for set of Internet protocol (IP)-enabled services • Access technologies involved in Verizon’s FiOS, the FTTP service offered in the U. S. • Create a simulation of an access technology
#1 18 Course Outline
• Review of basic networking principles • Introduction to network performance metrics – What is ideal? – Application types – Barriers to achieving the ideal –Performance metrics – Network Performance Perspective – What performance can the network guarantee
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Course Outline
• Techniques for coping with access (last hop) impairments – Techniques for coping with noise • Forward error detection/correction coding • Automatic Repeat reQuest (ARQ) • Incremental Redundancy • Co-existence or modifications to end-to-end protocols: End- to-End (TCP) vs ARQ • Case Study: TCP Performance over Multilink PPP in Wireless Networks: Theory and Field Experiences – Techniques for coping with multipath fading • Equalizers •Diversity • RAKE receivers •OFDM
#1 20 Course Outline
• Resource Sharing Principles and Mechanisms for Access Networks – Review general access network topologies – Resource sharing principles • Resource reservation (call) model • Dedicated resources • Shared after reservation •Always-on model • Polling • Access – Asymmetric mechanisms • Assumptions • General descriptions • Scheduling in the downstream • Contention in the upstream
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Course Outline
–Scheduling •What is packet scheduling? • Why is it needed? • What are the requirements for scheduling algorithms? • Specific algorithms –FIFO –RR –WFQ – How scheduling is used in access networks, opportunistic scheduling, e.g., PFQ
#1 22 Course Outline
• Specific systems –DOSCIS – IEEE 802.16/Wi-Max – 3G cellular, WCDMA, HSDPA/HSUPA, EV-DO – Case Study: Mitigating scheduler induced starvation in 3G wireless networks –EPON –Powerline • Wireless access of the future: Cognitive Radio Communications for Dynamic Spectrum Access • Summary of commonalities and differences
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Course Reading List
1. Broadband technology overview. 2005, Corning. p. 1-16. http://www.corning.com/docs/opticalfiber/wp6321.pdf#search=%22broadband%20technology%20overview%22 2. Balakrishnan, H., et al. A comparison of mechanisms for improving TCP performance over wireless links. in ACM Sigcomm August 1996. 1996. Stanford, CA. 3. Bianchi, G., I. Tinnirello, and G. Conigliaro, Design and performance evaluation of an hybrid reservation-polling MAC protocol for power-line communications. International Journal of Communication Systems, 2003. 16(5): p. 427-445. 4. Eklund, C., et al., IEEE standard 802.16: a technical overview of the WirelessMAN air interface for broadband wireless access. Communications Magazine, IEEE, 2002. 40(6): p. 98-107. 5. Fattah, H. and C. Leung, An overview of scheduling algorithms in wireless multimedia networks. Wireless Communications, IEEE, 2002. 9(5): p. 76-83. 6. Fellows, D. and D. Jones, DOCSIS cable modem technology. Communications Magazine, IEEE, 2001. 39(3): p. 202-209. 7. Ghosh, A., et al., Broadband wireless access with WiMax/802.16: current performance benchmarks and future potential. Communications Magazine, IEEE, 2005. 43(2): p. 129-136. 8. Gyasi-Agyei, A. and S.-L. Kim, Cross-layer multiservice opportunistic scheduling for wireless networks. IEEE Communications Magazine, 2006. 44(6): p. 50-57.
#1 24 Course Reading List
9. Haykin, S., Cognitive radio: brain-empowered wireless communications. Selected Areas in Communications, IEEE Journal on, 2005. 23(2): p. 201- 220. 10. Lin, Y.-D., W.-M. Yin, and C.-Y. Huang, An Investigation into HFC MAC Protocols: Mechanisms, Implementation, and Research Issues. IEEE Communications Surveys, 2000. 11. McGarry, M.P., M. Maier, and M. Reisslein, Ethernet PONs: a survey of dynamic bandwidth allocation (DBA) algorithms. Communications Magazine, IEEE, 2004. 42(8): p. S8-15. 12. Parkvall, S., et al., Evolving 3G mobile systems: broadband and broadcast services in WCDMA. Communications Magazine, IEEE, 2006. 44(2): p. 30-36. 13. Pavlidou, N., et al., Power line communications: state of the art and future trends. Communications Magazine, IEEE, 2003. 41(4): p. 34-40. 14. Sarikaya, B., Packet mode in wireless networks: overview of transition to third generation. Communications Magazine, IEEE, 2000. 38(9): p. 164-172. 15. Tian, Y., K. Xu, and N. Ansari, TCP in wireless environments: problems and solutions. IEEE Radio Communications, 2005: p. S27-S32. 16. Zheng, J. and H.T. Mouftah, Media access control for Ethernet passive optical networks: an overview. Communications Magazine, IEEE, 2005. 43(2): p. 145-150.
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