Table of Contents

Welcome

Chapter 1: Introduction
1.1: Introduction to Current and Upcoming Technologies
1.2: Why Traditional Models Won't Work in Rural Canada
1.3: Overview of the Structure of This Thesis

Chapter 2: Internet Use in Northern Ontario
2.1: Communities and Infrastructure
2.2: Community Based Networks and Their Efforts
2.3: Computer, Internet and Broadband Adoption Statistics
2.4: Outlook for Northern Ontario

Chapter 3: Wired Networks
3.1: Fibre Optic Networks
3.2: DSL
3.3: Cable
3.4: BPL

Chapter 4:Wireless Networks
4.1: WiFi
4.2: Broadband Cellular
4.3: MMDS and LMDS
4.4: Motorola Canopy
4.5: WiMAX

Chapter 5: Satellite Networks
5.1: KU-band and KA-band
5.2: Satellite as a Pipeline

Chapter 6: Broadband Funding Programs
6.1: Government Support for Broadband
6.2: Northern Ontario Heritage Fund Corporation (NOHFC)
6.3: Satellite Internet for Remote Areas (SIRA)
6.4: Federal Funding

Chapter 7: Infrastructure Feasibility Algorithms
7.1: The Need for Algorithms and the Definition of Feasibility
7.2: Reasoning Behind the Algorithms
7.3: Broadband Pipeline Physical Feasibility Algorithm
7.4: Broadband Last Mile Infrastructure Physical Feasibility Algorithm
7.5: Case Study: The Cottage
7.6: Case Study: Village of Hilton Beach
7.7: Afterthoughts on the Algorithms

Chapter 8: Conclusion

Appendix A: List of References
Appendix B: Glossary

3.4: BPL

A heavily debated technology, Broadband over Power Lines (BPL) has been around for a few years and has been tested in many trial installations in Canada and the United States. The electrical grid is easily the most ubiquitous wired network in Canada, so obviously it is worth looking into as a possible medium for distribution of broadband Internet service. The grid could potentially bring broadband Internet and other digital services to any place that has electricity.

The high-voltage power lines that are strung across huge steel towers operate at an extremely high voltage, and this electricity is all over the spectrum and is full of interference [60]. Thus, high-voltage lines are too noisy and cannot be used for BPL. Electrical substations transform these high-voltage lines to medium-voltage networks of power lines that experience less interference. These medium-voltage power lines, the kind running up and down most roads on wooden or steel poles, are used for BPL distribution. On the electrical grid, the electric substation serves the role of network head end for BPL. A device called an injector, which is hooked up to a broadband pipeline, has electrical inductors wrapped around the power lines to create an analog carrier wave on the line [60]. This allows the electricity to still work properly, but a broadband Internet signal is “hidden” (injected) on the power lines. Power lines are bare wire and are not twisted, so these unshielded conductors receive a lot of interference from the surrounding environment. They essentially act like big antennas. Because of this, repeaters are needed about every 300 metres [38] on the power lines to boost the injector's signal and overcome the considerable line noise. They don't simply amplify and relay the signal, however. The BPL repeaters developed by Amperion actually receive the Internet packets fully, disassemble them, correct for noise, then route the packet, and retransmit it down the line [4]. This is to ensure error-free transmission from repeater to repeater, as a quick blast of interference on the line between two repeaters might destroy an attempted transmission.

If the medium voltage power lines are last-mile infrastructure, the last-hundred-feet part of that infrastructure is what connects a home to the BPL-enabled electrical grid. There are two prominent ways to implement this. The first method uses a BPL modem plugged directly into an electrical outlet inside the home or business. To make this possible, an extractor/coupler must be used out on the electrical pole to bypass the transformer, which is problematic for BPL. Like injectors, these couplers use insulated inductive rings around the power lines on both sides of the transformer [4]. The broadband signal that started out at the electrical substation is then available at every electrical outlet in the house or building connected to that transformer. A simple modem, about the size of a large DC adapter, plugs directly into a wall outlet and hooks up to a computer by cat-5 Ethernet cable. The second type of BPL uses an extractor together with a secure WiFi access point on the pole, which completely bypasses the need for transformer couplers and plug-in modems. Subscribers can gain access to the broadband Internet service through a WiFi adapter in their desktop or laptop. This is the preferred version of BPL because of interference issues with the first implementation.

Because outdoor power lines and indoor electrical wiring is not shielded, it is subject to interference from radio transmitters, electric motors, televisions, atmospheric disturbances, the sun, and other sources. Not only does electrical wiring receive interference, but it also causes interference when a BPL network is implemented over it, causing power lines to act like huge antennas. The frequencies used by BPL fall between 1.6 MHz to 30 MHz, which is a high frequency band used for many other purposes, including broadcasting, air and maritime communications, military communications, security services, radio astronomy and amateur radio [13]. Because BPL injectors, repeaters and couplers all transmit with a power of several hundred watts [60], they are not likely to be affected by any interference they receive. They are able to shout above all the noise. Because they are so powerful, however, they inflict crippling interference on the other users of that frequency band. Testing conducted by the BBC [71] and other organizations [76] has shown that the interference heard on these frequencies are so bad, BPL may threaten the very existence of amateur radio and short wave radio. There are also concerns that BPL signals may cause interference to sensitive electronics like those found in hospitals, and that security issues may arise from the fact many customers will be sharing the same unshielded power line. As a result, amateur radio groups like the American Radio Relay League (ARRL) have filed complaints to the FCC and have lobbied against the proliferation of BPL technology with some degree of success. Many BPL trial installations have been ended, possibly due to the complaints or the unpredictable performance of the technology. Martin Wyant, the man behind the BPL trial in Sault Ste. Marie, Ontario, says that the PUC is no longer actively pursuing the technology. Their focus has shifted instead to remote meter reading using an interference-free, low-bandwidth form of BPL [88].

Interference-free, high bandwidth BPL has recently been developed by companies like Corridor Systems and Motorola. Corridor's implementation operates in the unlicensed bands over 800 MHz, and manages to hit impressive speeds of up to 216 Mbps, all for a lower deployment cost. The ARRL has given their system a “clean bill of health” [73] for giving off virtually zero interference. This technology uses several inexpensive and bizarre looking horn-like electromagnetic transceivers branded as “E-Line”, which, in pairs, act as repeaters along the medium voltage power lines. Because Corridor's technology has such high throughput, it may also be effective as an inexpensive pipeline medium, to be used in places where fibre is too expensive to implement. This promising technology hasn't yet been involved in any commercial installations or large tests, however, so it has yet to have been seen if they will stand up to their claims.

While information on the deployment cost of BPL is not readily available, it, like cable and DSL, is based on an existing wired network and needs repeaters and head end hardware with a connection to an Internet pipeline. A reasonable assumption would then be that the deployment cost of cable, DSL and BPL is roughly the same for areas of the same size, in the order of a couple hundred thousand dollars. At an estimated $1000 per repeater, the cost of using BPL as a pipeline is at least $3300 per kilometre. The cost for a plug-in BPL modem would be in the same range as a DSL transceiver or a cable modem, while a standard WiFi card would be at least half that cost. The range of BPL can be as much as a substation's entire primary service area, as long as enough repeaters are used to extend the signal across the grid. A single substation can serve an area of several townships, or a few dozen city blocks. In such a large-scale implementation, however, multiple injectors would be needed. The substation injector would feed several remote, on-pole injectors by fibre or BPL to divide up the load of customers.

Because of the serious interference issues created by Broadband over Power Lines, the first generation of this technology has lost much of the support it had at its peak a year or two ago. The second generation of BPL technologies, especially Corridor Systems' implementation, is promising, but it will likely take at least one or two years of testing before the first widespread deployments are possible. Public Utilities serving rural parts of Canada should investigate and invest in this “new BPL”. Its potential use as an inexpensive pipeline and distribution medium could very well be the answer to the rural broadband problem.

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© Jake Cormier, 2006 [jake (at) stormcloudstudios.com]
Completed as a partial requirement for the degree of Bachelor of Science (specialized)
Department of Computer Science :: Algoma University College :: Sault Ste. Marie, Ontario :: Spring 2006