A good analogy I’ve heard used to describe the heterogeneous network
(HetNet) is a layer cake
. A layer cake consists of separate dessert cakes that are frosted and placed on top of each other to form a single dessert. The cakes are separate but combined
into one, and an effective wireless HetNet needs to be the same way.
The main layers of HetNet consist of the macro network sites and all the other “small cell” sites are the layers. In this sense, the small cells are basically everything that is not a macro site—namely, distributed antenna systems (DAS), Wi-Fi, pico- and femtocells.
These small cells are separate from macro cells and can have their own unique requirements. For example, acquiring sites to deploy them can be challenging. When sites are acquired, concealing equipment in unobtrusive, aesthetically pleasing ways is often required. Bringing power and backhaul are also concerns.
Macro sites have their unique challenges as well. Legacy wireless networks exist and must be protected while newer network technologies are rolled out. Space limitations often restrict the amount and weight of equipment that can be deployed. Ensuring optimal performance in the midst of other RF signals is critical.
Taken together though, the two layers of macro sites and small cells need to make for one delicious dessert, or in this case one robust, user-satisfying wireless network. Handoffs between layers are important here, as are containing RF signals to limit an overall raising of the noise floor. LTE is a noise-limited technology, and small cell deployments need to account for the impact to the surrounding macro layer.
I speak about these topics in this video that was shot at the 2014 PCIA Wireless Infrastructure Show. A number of people at that event were talking about how to better integrate macro sites and small cells. What do you think? What else needs to be done to ensure a fantastic macro/small cell dessert?