Indoor coverage is a challenge and WiMAX is no exception. Even with WiMAX we are talking about using complementary indoor technologies like WiFi. 3G operators are looking to solve the issue with Femtocells indoors. Some of the WiMAX providers have been asked in the past to address the problem by increasing the density of macro and micro cells.
WiMAX vendor Redline’s pitch is that increasing cell density can be avoided for a while. They are pushing an interim solution, an unconventional approach. Redline believes that the optimal approach is to build a macro base station that delivers high power (4 to 10 Watts depending on frequency), then add on Matrix A and Matrix B MIMO support to provide statistical power enhancement of 6 – 10 dB for coverage and capacity and finally further enhance the system with beamforming to create an adaptive macro WiMAX base station solution.
So in Phase I you use high power macro base station. Later in Phase II the operator underlays the network with pico base stations in capacity hotspots or coverage holes as required and in Phase III Beamforming and Femtocells are used to further enhance the coverage model as required by the operator. The rationale behind this sequence is to minimize the technology risk along the development path spread over several years.