Document Actions
Site Survey
Before any equipment is deployed, there must be a site survey to
determine what is needed in order to have a successful wireless
operation. By understanding the dynamics of the market where the
deployment will take place and planning accordingly, the service
provider can ensure success on Day One of operations.
Link Budget
Figure 17: The link budget determines the success or failure of a wireless operation
The figure above illustrates a link budget. It is the equation of the power of a signal transmitted minus detractions between the transmitter and receiver (rain, interference from other broadcasters, vegetation, gain at the antennas ate either end) and what signal is received at the receiver.
Frequency Plan
Part of the site survey process is to determine a viable frequency plan. The wireless op-erator must make maximum use of limited spectrum assets. How does one do that?
Figure 18: By reusing frequencies at different base stations, a WiMAX operator can avoid interference from their own network
The diagram above illustrates how a wireless operator (cellular, WiMAX, etc) uses their limited spectrum allocation to deliver the best service possible while avoiding interfer-ence between their base stations. Note there are nine different base stations with three different frequencies but no similarly shaded circle touches another. If they did touch, there would be interference between base stations because they would be operating on the same frequency.
Its about windows, not roof tops
Traditional wireless thinking dictated that a radio and its associated antenna should be at the highest point possible with a line of sight to a majority of the service area (note mountain tops and the Empire State Building). This is not necessarily so with WiMAX. As indoor subscriber units mature, the value of antenna placement is not necessarily in height above subscribers, but in achieving as short and direct a line of sight possible be-tween base station and subscriber's CPE.
Figure 19: Imagine each window or floor paying $500 per month in WiMAX services
Next Section
Link Budget
Figure 17: The link budget determines the success or failure of a wireless operation
The figure above illustrates a link budget. It is the equation of the power of a signal transmitted minus detractions between the transmitter and receiver (rain, interference from other broadcasters, vegetation, gain at the antennas ate either end) and what signal is received at the receiver.
Frequency Plan
Part of the site survey process is to determine a viable frequency plan. The wireless op-erator must make maximum use of limited spectrum assets. How does one do that?
Figure 18: By reusing frequencies at different base stations, a WiMAX operator can avoid interference from their own network
The diagram above illustrates how a wireless operator (cellular, WiMAX, etc) uses their limited spectrum allocation to deliver the best service possible while avoiding interfer-ence between their base stations. Note there are nine different base stations with three different frequencies but no similarly shaded circle touches another. If they did touch, there would be interference between base stations because they would be operating on the same frequency.
Its about windows, not roof tops
Traditional wireless thinking dictated that a radio and its associated antenna should be at the highest point possible with a line of sight to a majority of the service area (note mountain tops and the Empire State Building). This is not necessarily so with WiMAX. As indoor subscriber units mature, the value of antenna placement is not necessarily in height above subscribers, but in achieving as short and direct a line of sight possible be-tween base station and subscriber's CPE.
Figure 19: Imagine each window or floor paying $500 per month in WiMAX services
Next Section
