August 19, 2011Prakash Sangam
It is indeed fun to watch an abstract idea crystallize into a technology and to see it come to life, overcoming the doubts of non-believers, and the objections of naysayers. I experienced this feeling recently, while on the test drive of our over-the-air (OTA), LTE Advanced HetNet test system here in San Diego.
LTE Advanced brings in many dimensions of improvements, be it leveraging very wide bandwidths, or higher orders of MIMO. But from our perspective, the biggest bang for the buck comes from the enhancements of Heterogeneous Networks (or HetNets, as they are often called).
HetNets are a mix of big macro cells, augmented with small pico, femtocells, remote radio heads, relays and others. Well, what is the “big deal?” you may say. “Pico cells have been used in 2G/3G networks for a while, and operators are already deploying femtocells.” In fact, recently the total number of deployed 3G femtocells bypassed that of 3G macrocells.
True, it is a well known fact that these small cells, bring the network closer to the user and provide a leap in performance – very high data rates, very good coverage, increased capacity, etc. But, LTE Advanced can make this leap substantially higher, so that operators get even higher capacity, and users get an exceptionally better mobile broadband experience.
LTE Advanced, together with devices that have advanced receivers, expand the effective coverage of these small cells(Range Expansion), so that they offload more traffic from macro networks — much more than what they would have done otherwise.
I know, the technical intelligentsia out there would want to know how this is done. Well, there are two features really, that make these wonders possible — Adaptive Resource Partitioning (ARP) and device interference cancellation (IC). The former dynamically allocates time and frequency resources between the macro and picocell in accordance to the traffic load each is experiencing. So the cell that has more traffic gets more resource and vice a versa. Device IC cancels the interference from neighboring cells (overhead channels) so the device can decode the picocell, even at a very low-signal level (at the cell-edge for example), in effect extending its coverage.
So, in essence, LTE Advanced realizes the full benefits of HetNets. We showed this via a live demo at this year’s Mobile World Congress. The OTA test system that I mentioned above is a natural outgrowth of the demo, and it utilizes actual macro and pico cells to create a real network.
All of our innovative LTE Advanced algorithms are put to test and being perfected here. Which means, the HetNet benefits that we are vouching for are not just talk, but are vetted in realistic network scenarios.
If you would like to get more insights about the OTA test network, as well as understand LTE Advanced a little better, we invite you to listen to our upcoming webinar on 23rd Aug, 9am PST.
FemtocellHetNetsLTELTE Advanced40August 19, 2011