[UPDATE 2] Open Source, Open Architecture, Muni-Wireless Costs. AKA -- How Non-Proprietary Wireless is More Cost Effective.

More and more I've been receiving inquiries about the costs per square mile for a CUWiN-based mesh wireless system. Interest in this number really took off with the announcement by Tropos that it would cost $68,000 to wireless one square mile using their gear. At the time, I found this number extremely strange -- more plucked from thin air than empirically derived to suite the multitude of different geographies and topologies. Due to large increase in the number of inquires I was receiving, I wrote up this quick numbers-crunching on CUWiN networking costs.

Which brings me to today -- I just read a piece by Eric Griffith where he gets this information from Bert Williams, vice president of marketing for Tropos Networks:

"We usually talk in terms of $75,000 per square mile for our gear," says Williams, who estimates that the Tropos hardware accounts for about 60 to 70 percent of the total cost of installation. Adding the ongoing costs for backhaul and system management, he believes the number to be closer to $100,000 per square mile.

Now wait a second -- first $68,000? Then $75,000?? Then $100,000??? This is why I'm skeptical about the firmness of numbers when they're provided. A critical consumer of municipal networks needs to be extremely careful about the total costs of their network. So, to add to the debate, and provide a counterpoint to proprietary systems -- here's some estimates for what the total cost is to build a CUWiN-based network (which is a non-proprietary, open source software and open architecture hardware system) in five easy steps:

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• First, one needs to estimate the density of nodes needed per square mile. Click here for information on how I computed my node density numbers. This number will let you estimate how many nodes you'd need to cover a specific geographical area.

   

• Second, nail down your up-front, per-node networking costs. Here are estimates for a CUWiN-based system they are purposefully at the high end of the range (e.g., one can buy nodes for under $350, hourly wages are set at $50/hour, one doesn't need any server equipment on the network -- though why not throw in Intranet services and applications instead of just focusing on Internet Service Provision?):
  • $350 -- Per Node Cost of Hardware & Software
  • $250 -- Setup, Construction, & Installation (5hrs/per node@$50/hour)
  • $5,000 -- Server Equipment (per network)
  • $60 -- Node Upkeep Costs (10% Node Failure Rate Equivalent)
  • $15 -- Electricity for One Year
  • $600 -- Bandwidth for one year (per 10 nodes)

   

• Third, identify your network size (square mileage/node density) and your start-up costs for the network (i.e., your first year costs) -- here's some quick benchmarks for variously sized wireless networks for quick reference:

  25 Nodes

  • $8,750 -- Node Costs of Hardware & Software
  • $6,250 -- Setup, Construction, & Installation (5hrs/per node @ $50/hour)
  • $5,000 -- Server Equipment (per network)
  • $750 -- Node Upkeep Costs (10% Node Failure Rate Equivalent)
  • $375 -- Electricity for One Year
  • $1500 -- Bandwidth for one year
  • TOTAL: $22,625

  50 Nodes

  • $17,500 -- Node Costs of Hardware & Software
  • $12,500 -- Setup, Construction, & Installation (5hrs/per node @ $50/hour)
  • $5,000 -- Server Equipment (per network)
  • $1500 -- Node Upkeep Costs (10% Node Failure Rate Equivalent)
  • $750 -- Electricity for One Year
  • $3000 -- Bandwidth for one year
  • TOTAL: $40,250

  100 Nodes

  • $35,000 -- Node Costs of Hardware & Software
  • $25,000 -- Setup, Construction, & Installation (5hrs/per node @ $50/hour)
  • $5,000 -- Server Equipment (per network)
  • $3000 -- Node Upkeep Costs (10% Node Failure Rate Equivalent)
  • $1500 -- Electricity for One Year
  • $6000 -- Bandwidth for one year
  • TOTAL: $75,500

  250 Nodes

  • $87,500 -- Node Costs of Hardware & Software
  • $62,500 -- Setup, Construction, & Installation (5hrs/per node @ $50/hour)
  • $5,000 -- Server Equipment (per network)
  • $7,500 -- Node Upkeep Costs (10% Node Failure Rate Equivalent)
  • $3,750 -- Electricity for One Year
  • $15,000 -- Bandwidth for one year
  • TOTAL: $181,250

  1000 Nodes

  • $350,000 -- Node Costs of Hardware & Software
  • $250,000 -- Setup, Construction, & Installation (5hrs/per node @ $50/hour)
  • $5,000 -- Server Equipment (per network)
  • $30,000 -- Node Upkeep Costs (10% Node Failure Rate Equivalent)
  • $15,000 -- Electricity for One Year
  • $60,000 -- Bandwidth for one year
  • TOTAL: $710,000

   

• Fourth, estimate your yearly maintenance and upkeep (recurring) costs for your network:

  Estimated at $50/year per node + 10% upkeep cost + electrical cost:

  • $3,875/year -- 25 Node Network
  • $7,750/year -- 50 Node Network
  • $15,500/year -- 100 Node Network
  • $38,750/year -- 250 Node Network
  • $155,000/year -- 1000 Node Network

   

• Fifth, estimate monthly costs per node/house based on different network sizes and break-even points:

  25 Node Network

  • $33.75 -- Over 3 Years
  • $25.42 -- Over 5 Years
  • $19.17 -- Over 10 years

  50 Node Network

  • $30.97 -- Over 3 Years
  • $23.75 -- Over 5 Years
  • $18.33 -- Over 10 years

  100 Node Network

  • $29.58 -- Over 3 Years
  • $22.92 -- Over 5 Years
  • $17.92 -- Over 10 years

  250 Node Network

  • $28.75 -- Over 3 Years
  • $22.42 -- Over 5 Years
  • $17.67 -- Over 10 years

  1000 Node Network

  • $28.33 -- Over 3 Years
  • $22.17 -- Over 5 Years
  • $17.54 -- Over 10 years

These are high estimates for this type of network -- if one can get nodes for under $350, or labor for under $50/hour, one can bring down the costs substantially. But clearly, the costs are far cheaper for an open source, open architecture system than are currently being estimated for proprietary networks.

I have endeavored to break down each of the expenses to it's basic components and hope that this will enable potential community wireless networkers to make more informed decisions about the options available. Clearly, this level of detail should be available to (and demanded by) any organization, business, or municipality interested in deploying these types of networks. I hope that this information will help move the "wireless network costs" debate forward and will be a catalyst for more transparency in the underlying assumptions being used to generate municipal wireless cost estimates.

Download this attachment for all of this information in a handy 1-page spreadsheet -- allowing anyone to change any of the difference parameters to instantly get new estimates. A useful tool for everyone thinking of building wireless networks.

[UPDATE 2] Thanks to everyone who's e-mailed me thoughts, ideas, methodological tweaks, etc. Please remember that this piece provides a heuristic that people can use to generate wireless networking cost estimates. As such, this is not an all-encompassing algorithm for measuring deployment costs and node densities (which would need to take into account a great number of additional variables -- such as spectrum congestion levels, multipath interference, antenna height, the non-circularity of wireless coverage patterns, etc. etc. etc.). The numbers provided are based on real-world implementations, and will prove relatively accurate most of the time. As always, I encourage everyone to remain a critical consumer of any cost estimates you see, especially ones that are given without any context and without being broken down into their constituent parts.

A special thanks to Andrew from www.funferal.org who tracked down this article on optimal circle-packing density which quite indulged the geekier side of me.