Overview of the regulatory aspects for the deployment line-of-sight MIMO for fixed links

This paper addresses regulatory issues regarding the deployment of MIMO for fixed microwave links. The concept of Line-of-Sight MIMO uses the spatial separation of radio antennas to create different propagation paths between the same locations and thus allows multiple transmissions over the same radio channel. Combining different antenna schemes provides certain flexibility in designing the system in the “controlled” environment, which makes LOS MIMO a great method for increasing the achievable link capacity within the same frequency channel. Hence it provides great advantages for the operators and significant spectrum efficiency increase. However, there are still some open regulatory issues that are currently under discussion. Some of the possible implications of the LOS MIMO concept deployment on the regulatory framework (in terms of frequency planning, licensing, fees etc.) have been presented in this paper.