Ryan McCaigue Municipal Wireless Architecture Subscribe to Newsletter Tell a Friend Print this Page 03/19/2008 Designing Citywide Wireless? Insist on Maps, Models that Deliver Proven ROI Local-government broadband-wireless networks are capable of supporting a wide range of applications. Each must be considered in the design of the network so that no one application has a negative impact on overall performance. Toward this end, a city or county should begin with a thorough review of the applications it is considering, which involves a great deal of discussion with all the stakeholders likely to use the network, such as: Police Fire Utilities Public Transit Municipal Workers Public Access Telecommunications To assess all your application needs, you'll need to meet with stakeholders to explore the opportunities and costs involved in deploying the network, working to build consensus among various departments and constituents to ensure the broadest possible adoption. Moreover, few cities and counties have the expertise in engineering and RF design staff to facilitate the construction and integration of a wireless network, so finding an experienced partner — a trusted adviser — will be critical to your success. How will the applications impact the network's design? Start with requirements for each application and engineer a solution to meet those requirements. You'll need to find an engineering team or independent design firm that does not sell equipment or profit from the selection of one vendor over another, preferably one that has worked with a wide variety of vendors in the local-government market. Focus on standards-based, cost-effective, reliable, time-tested solutions. Designing a municipal wireless network is more than simply a "Dixie cup" exercise. I’ve seen a number of consultants and vendors doing great disservice to their clients by not doing an appropriate professional, detailed RF design. You can’t simply roll out a map and draw circles on it to predict the propagation of radio frequency energy. You can’t simply say it will take 40 nodes per square mile to provide ubiquitous coverage. Each municipality has its own unique challenges, terrain, trees, buildings, and other sources of RF interference. Each requires a detailed site surveys, interference testing, and propagation modeling for every radio and client. Here is a sample of a network with more than 900 nodes. This heat map shows the propagation of the 4.9-Ghz public-safety mesh across the terrain. The goal of this network was to establish 95% street-level coverage for public safety. Trees in this city play a major role in the ability to establish the required coverage in the north half of the city and buildings in the south. Each network must be designed to fit the unique local conditions. Here is a section of a map showing how water-department and traffic-management divisions have assets covered by a mesh network. It also shows that public safety will have mobile access to the data they need at street level. Here is the propagation of a 5-GHz tower site that is providing capacity to a mesh network in a point-to-multipoint network configuration. Note the impact of the hills on the lower corners and upper center on the coverage. Some 72 locations were considered and modeled before the final selection of 8 locations was made. Without a detailed analysis and plan, cities and counties run the risk of making a large investment in a network that does not meet its goals and needs. These are just a few samples of the types of engineering plans and tools required to plan and deploy a a wide-area mesh network. Before you begin, insist on seeing this type of analysis pre- and post-deployment. It can ensure that you have a complete and reliable network and that you will be able to maximize ROI from the multiple applications you will deploy. Ryan McCaigue is President of Ivy League Consulting LLC. He and his team have engineered, deployed, and manage some of the largest wireless networks in the US. He can be reached at (480) 213-7240. back Related Items: • New York City, Traffic Solution • W2i Finalizes Digital Cities Joint State Briefing Program in Riverside, California • Philly Eyes Options Should EarthLink Pull Out • Los Angeles Catches the Citywide Wi-Fi Wave • OneZone, Toronto Hydro Telecom, Canada • Riverside `08 Comments No records were found. Post new comment: Only registered users can add comments. Please Log-in

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