Deploying a fixed broadband wireless link used to require the network operator to perform radio route design, check for a clear line of sight and complete the necessary link-budget calculations to ensure reliable communications between two end points. Those early systems were pre-engineered for their specific environment: They had preselected static parameters to optimize the link for that environment.
Although the process worked well at the time, the point-to-point links simply could not scale for mass-market deployments serving thousands of subscribers. Point-to-multipoint systems were developed to address the broadband-access market, bridge the last mile and provide multimegabit capacity to subscribers. Because sub-11-GHz spectrum is well-suited to address mass-market demand, service providers began to look for 2.5-, 3.5- and 5-GHz solutions to address their needs.
However, the enhanced first-generation point-to-multipoint broadband wireless systems still relied on a set of static parameters for all end-points-the lowest common denominator for all environmental conditions -- they were unable to deal with real-world challenges of multiple subscribers in different locations, with differing path characteristics, within the same service area. The approach fell short in terms of capacity, coverage and the resulting business model equation.