quency relief: The low capacity microwave radios are normally operated in 10, 11.5, 18, 23, and 38 GHz bands to backhaul cellular traffic. These are mainly TDM-based, have smaller channel bandwidths as compared to gigabit radios and thus can't carry large amount of traffic. Many operators often face shortage of such frequencies and utilize many channels at transmission hubs to support traffic backhauling of various individual cell sites. MMW radios can thus be used to free up some traditional microwave frequencies at high capacity sites. Extending fiber backbone: Fiber may not be required to cover sites which are at boundaries of the city. MMW radio links, on the other hand, cannot cover longer distances due to higher losses associated with such higher frequencies. However, this limitation can often be mitigated by the use of hybrid fiber and wireless links. Extending distances with hybrid links: The license-free microwave radios can be used in rural and remote areas since the presence of license-free Wi-Fi radios is almost negligible in these areas of many Next Generation Mobile Communications Ecosystem emerging and developing nations and secondly these radios can cover longer distances. However, these cannot be used in urban areas due to interference issues. Thus, a combination of MMW and license-free radios can be used to extend the coverage from urban to rural and vice versa. Miscellaneous: Some other areas where MMW can be used are as follows [7]: Millimeter-wave radar can work in fog and then will play a key role for the safety driving if a low cost millimeter-wave radar is used. Many car and electronics manufacturers for example, Toyota, Honda, Mitsubishi, OKI and SO on, are developing the car radar systems. MMW RFID (radio frequency identification) tag has a high potentiality if small size antenna can be fabricated in the millimeter-wave band. 7.3.3 Backhaul via License-free Microwave Radios PtP and PMP backhaul solutions are available in the ISM (Industrial Scientific and Medical) license-free band. Thes