In this kind of environment, subscribers are usually in LoS of a
central tower. Therefore, for this kind of application, networks using the SC-PHY standard,
which uses spectrum below 11 GHz but is based on a single-carrier technique,
would be ideally suited. Alternately, an SC-PHY-based solution (when the BS coverage
area is small and LOS is viable) or an OFDM-PHY-based solution (when the BS coverage
area is large or LOS is not viable) are both suitable for this application.
Urban Fixed and Mobile Broadband Services
In the previous section, we discussed the limitations of wired broadband services such
as DSL and cable modems in urban environments. However, their limitations are not
Figure 15.3 WiFi backhaul with WiMAX technology
Wired backhaul
WiMAX BS
(OFDM)
Internet cafe
Muni-WiFi
Accesspoint
Hotel with
WiFi HotSpot
Base station coverage area
490 Chapter 15
confined to rural environments alone. Cable TV networks are neither ubiquitous nor
have been upgraded in all areas to enable broadband services. Telephone networks,
which are ubiquitous in developed nations, neither have the sufficient reach nor have
been upgraded everywhere to enable broadband services ubiquitously.
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