1. Wireless: Solution for high-speed Internet access in regional Queensland Presenter: Mr. Huan Pham (PhD student) Supervised by Dr. Bill Lavery James Cook University

2. Internet Access Platforms Twisted pair Coax/Fibre Optical Fibre Wireless Cable modem Tel modem ISDN xDSL FTTH Fibre ring MMDS LMDS Satellite

3. Internet xDSL modem ISDN adapter Telephone modem Exchange ISP Twisted Pair

4. Twisted Pair Capacity ä Telephone modem l < 64 Kbit/s (for download, lower for upload) ä ISDN Basic l 128 Kbit/s, (bi-directional) ä xDSL l Symmetrical or Asymmetrical l Maximum download rate from 1.5 Mbit/s to 50 Mbit/s depending on the technology and distance. Upload rate for asymmetrical case: dozens Kbit/s l Distance limit: < 5 km from CO or Remote access terminal l Access capacity not shared by other users.

5. Coax/Fibre cable Internet Cable Modem ISP NIU Fibre Node Cable Modem NIU Fibre Node Coaxial Cable Optical Fibre

6. Coax/Fibre Capacity l Downstream up to 30 Mbit/s l Upload up to 10 Mbit/s l Bit rate is shared among subscribers passed by coax cable. --> bit rate/user is lower

7. Wireline advantages/disadvantages ä Advantages l Potentially offer very high bit rate l More reliable (less affected by noise, interference, weather conditions) ä Disadvantages l High up-front investment in cabling, environment issues, permission to lay cable... l Much higher cost per user in low population density areas l Higher deployment time l Monopoly by cabling companies

8. Wireless Options ä MMDS (and other WLL operating at 2 - 5 MHz) ä LMDS (Local Multipoint Distribution Services) ä Satellite ä Mobile

9. MMDSMMDS Main transmitter Repeater Internet Point of Presence

10. MMDSMMDS ä Frequency 2.1 GHz, 2.3 GHz (in Australia) ä Line of sight transmission ä Not vulnerable to rain ä Maximum coverage distance = 50 km ä Normally one way - telephone cable return ä Two-way MMDS is more costly and limited by available bandwidth ä Bandwidth is shared among all (online) users ä Frequency reuse can be made by using n-sector antennas, and/or cellular layout (the latter is subject to ACA regulation)

11. MMDS Capacity Assumptions: MMDS Channel:6MHz Modulation scheme:QAM-64 Customer peak offered rate:400 (Kbit/s) Statistical multiplexing gain:5 User time online:20% Capacity: Number of users (one sector): Number of users (four sectors): 4 x 2000 = 8000 30Mbit/s

12. Other Frequency Options ä 2 x 150 MHz frequency at 3.4 GHz band. (this is to be auctioned later this year) ä Unlicensed frequency band at 2.4 GHz and 5GHz

13. LMDSLMDS ä Frequency: 28 GHz ä Strict line-of-sight transmission ä Signal absorbed by rain ( See Signal in Rain graph )Signal in Rain graph ä Cellular layout. Cell size (<5 km) mainly depends on: l transmitter power l modulation scheme l rain rate l required availability ä Frequency reuse made possible by l n-sector antennas l cellular layout l cross-polarisation transmission

14. LMDS Capability Assumptions Bandwidth2x75 (MHz) Modulation schemeQAM-16 Frequency reuse factor/cell: 4 Cell size (square):5(km) x 5(km) Capacity Bit rate / cell:400 (Mbit/s) (able to support about 1000s online users, peak rate a couple of Mbit/s) Bit rate / km 2 :16 Mbit/s/km 2 ~100 Mbit/s each way

15. LMDS Hexagon layout Frequency reuse factor = 4 Frequency reuse factor = 3

16. LMDS Square Layout Frequency reuse factor = 1 Frequency reuse factor = 2 Frequency reuse factor = 4

17. SatelliteSatellite Web server Internet Satellite ISP

18. Satellite Capability ä Satellite operates at C-band (4-8GHz) or Ku-band (12- 18GHz) which is affected by weather condition. ä Large coverage areas, virtually anywhere. ä It’s difficult to apply frequency reuse. Thus it offers limited bit rate/user. ä Commonly available with one-way Internet access, return via telephone modem. Typically 400Kbit/s download ä Suits non real-time applications l Suitable for areas where other options are not available

19. SummarySummary ä Advantages of Wireless over Wireline l Scalability l Lower up-front investment l Fast deployment time l Ability to bypass the incumbent Telco. ä Limitations l Limited bandwidth l Affected by noise, interference, weather conditions l Latency of satellite systems limit real-time applications ä The advantages make them suitable for low density population areas in regional Queensland such as Townsville & Carne.

20. Current Research Current Research ä Performance of TCP over wireless and... ä How to facilitate QoS (Quality of Service) over wireless link

21. Questions?Questions?

22. Thank you! The End

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