4.4: Motorola Canopy

One of the most exciting wireless broadband systems on the market today is Figure 30: Motorola Canopy Logo [44]a proprietary Motorola technology called Canopy. This flexible, extensible and simple solution consists of three main pieces of infrastructure: the access point (AP), subscriber module (SM), and backhaul module (BH) [44]. An access point module is an integrated antenna and transceiver with a 60-degree directional beam width, so these APs are usually mounted in a cluster of six to provide 360-degree coverage. A cluster is mounted an a tower or tall building along with a cluster management module (CMM) to manage the subscribers' access to the network. The CMM also needs to be connected to a high-speed Internet pipeline, the bandwidth from which will be shared between the access point's subscribers. What makes Canopy such an attractive solution is the fact that an expensive fibre optic or other wired pipeline is not needed; Canopy's backhaul infrastructure can fill this role. A 5.7 GHz backhaul parabolic or panel module can have a throughput of up to 300 Mbps over an incredible line-of-sight distance of 200km, or 10km where no line of sight is available [44]. For an access point to use a point-to-point backhaul link as a pipeline, one backhaul module would be installed on the same tower or building as the access point, and connected to the cluster management module. The other backhaul module would be installed on a tower or building at some remote location where a high-capacity backbone or pipeline already exists. This backhaul link would effectively bridge the Canopy access point to some preexisting pipeline up to 200km away (but probably a lot closer). Subscribers need to install an integrated antenna/transceiver outdoors, with a clear line of sight to the nearest access point if possible. A standard Ethernet cat-5 cable runs from the subscriber module to the computer, thereby connecting that computer to the Canopy network.

Figure 31: Canopy Infrastructure [48]

Canopy infrastructure comes in six different versions, operating in six different unlicensed frequency bands: 900 MHz, 2.4 GHz, 5.1 GHz, 5.2 GHz, 5.4 GHz, and 5.7 GHz [49]. The lowest frequency version, 900 MHz, has a throughput of about 4 Mbps and a line-of-sight range of 64km. It will operate with an unclear line of sight, but with a reduced range of under 10km. The 2.4 GHz version has a throughput of 7 Mbps and a line-of-sight range of 8km. Operational range will be significantly reduced as more obstacles impede a clear line of sight. The 5.1+ GHz versions of Canopy have a throughput of 7 Mbps and a range of 3km, and absolutely require a clear line of sight. Why have Canopy equipment for six different frequency bands when the 900 MHz version clearly is most flexible option? Since these six bands are unlicensed, they are prone to interference from other wireless devices that operate on the same frequencies. Each location will have different interference obstacles, which should be investigated before a Canopy solution is chosen. For a Canopy system or other wireless network to provide the most reliable service, it should be implemented on a frequency band where there is a minimum of interference. Portable phones, pagers, security systems, WiFi networks and other devices share the 900 MHz and 2.4 GHz bands, so the 5.1+ GHz versions of Canopy may be the best choice for deployment in a city where a lot of these other devices exist. In rural areas, however, this is probably not going to be an issue.

Given the simplicity and flexibility of the Canopy platform, its surprisingly affordable deployment cost may come as a shock. Backhaul modules have throughputs from 10 Mbps to 300 Mbps, and prices range from $1000 to $10,000 respectively [50]. A pipeline running at 60 Mbps is probably sufficient for most access points. A two-sided (point-to-point) 5.7 GHz backhaul pipeline running at 60 Mbps would cost about $10,000, while a 300 Mbps link would cost $20,000. The 900 MHz version of the last-mile infrastructure (access points and subscriber modules) is the most attractive solution for rural areas thanks to its high speed and its 64km range. An access point, consisting of six AP modules and a cluster management module, would cost about $14,000 plus the costs associated with placing the equipment on a tower or building [50]. Hence a single 900 MHz access point cluster with a 60 Mbps backhaul could blanket an area of 200 square kilometres with broadband Internet service for an infrastructure cost of under $30,000. Subscriber modules, the only equipment needed on the customer's end other than a computer and Ethernet card, cost several hundred dollars but many Canopy service providers like Xplornet inexpensively rent them out to customers.

Figure 32: Canopy Last Mile Infrastructure [39]

The foremost Canopy provider in Canada is Barrett Xplornet, which is based in New Brunswick but serves the entire country through a network of contract technicians. Xplornet operates Canopy networks in about 20 communities in Ontario, including the Northern Ontario communities of Hornepayne, Dubreuilville, and Wawa, for about the price of DSL or cable Internet service. They primarily use the 900 MHz and 2.4 GHz technology, but they do also offer the 5.2 GHz and 5.7 GHz versions. In fact, Xplornet usually installs both 2.4 GHz and 900 MHz AP modules on a tower, using the less expensive 2.4 GHz subscriber modules for nearby customers and using the 900 MHz modules when a customer is further away [86]. Xplornet is intending on rolling out several more Canopy networks this summer after acquiring $30 million in capital funding from an American investment firm this past year [12]. If a community can gather at least 100 signatures of people willing to subscribe to the service, Xplornet will seriously consider installing a Canopy network and offering broadband Internet service there. In order for a network to be installed and serviced in a community, Xplornet needs to have a technician in the area. If they don't have a local technician, anyone with some kind of technical experience can apply to take a course to become the local Xplornet installer. There is an exciting business opportunity here: an entrepreneurial person with some computer science or engineering experience (and no fear of heights) located in a community lacking broadband Internet service could circulate a petition to collect 100 signatures for an Xplornet Canopy network, then apply to become the sole installer and service person for that very same network.

There is no doubt that Motorola Canopy could solve the rural broadband problem. It is a flexible, extensible and reliable platform that operates at speeds that rival DSL and cable, plus it covers a large geographic area for a low infrastructure cost. Hence, it is quite economically feasible for rural areas and small communities. Canopy has been around for a couple of years, but isn't as widespread as it should be. This could be attributed to next to nonexistent marketing; ask anyone what Canopy is and they won't be able to give you an answer. There may not be a chance for Canopy to gain any momentum or widespread recognition, however, with new the new WiMAX standard aiming to take over the Wireless MAN market.

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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