When it comes to wireless mobile networks, it is a heterogeneous world out there—there are a large number of small cells interspersed with macro cells. HSPA+ and LTE Advanced incorporate many techniques that effectively address the interference generated by such heterogeneous networks (HetNets), some of which are available today.
But the anticipated 1000x mobile data growth takes HetNets to a whole new level, with very dense deployments of small cells—everywhere. Of course, all the existing interference management techniques are needed. Additionally, the industry is working on much smarter ways of managing the interference; one such example with LTE Advanced is “opportunistic small cells.”
Network traffic is very dynamic, continuously changing, even more so in small cell deployments. When you have a hyper-dense network, it is conceivable that not all small cells will have traffic all the time. So, if there is no traffic to carry, why keep those small cells turned “ON” unnecessarily? Exactly! That’s what opportunistic small cells are for! Turn them “OFF” in absence of traffic. This, as you might imagine, reduces the interference from these small cells to surrounding small/macro cells carrying traffic. So, you ask, what if users move toward these small cells that are turned “OFF”? Cha Ching! They only turn off their transmitter, but their receiver stays “ON” listening to the activity in their coverage area. Any time an active user is detected, it comes to life immediately, and the small cell is back in business.
So, in essence, the idea is to selectively turn off a few cells and keep on only those that are necessary. The key is to adaptively identify which ones are necessary and should be kept active. This ensures that unnecessary interference is reduced and thereby network performance is improved. If you would like to see “opportunistic small cells” in action, visit our live over-the-air demonstration at Mobile World Congress 2013. We are utilizing our LTE Advanced small cell test network in San Diego for this demo. If you visit at the right times, you can even chat live with our engineers in the test van in San Diego.