Femtocell Impact on Broadband Wireless Access Services
Demand for wireless network data services is driven primarily by three factors:
- Device availability so subscribers can consume data
- Service availability for bandwidth intense applications (e.g. Streaming YouTube)
- Flat-rate data plans which makes consumers willing to use their device without the fear of seeing their wireless phone bill get out of control
To deliver these services wireless operators have grown their capacity and used more efficient technologies like HSPA+ or LTE. In any case, the Shannon limit does apply and it comes to a point where a geometric increase in capacity implies a re-thinking of the network architecture such that the site offering service can be geographically close to the demand and where cells are smaller and smaller. In effect, the geometric increase in data capacity is a strong driver for what is typically referred to as “small cells”. With broadband wireless services, the demand will largely be indoor (by approximately one order magnitude more than outdoor). This will further drive the demand for femtocells and indoor cells but operators must be able to understand the economic and technical impact of these solutions.
To assess the impact of large quantities of femtocells or un-managed small cells in a network, the logical solution is a statistical approach whereby distribution hypotheses for the femtocells are made, allowing for a random distribution of these femtocells. After this is accomplished and knowing the technical capabilities (power, etc…) of the equipment it is possible to assess their impact on the overall network. The impact is positive (serving local indoor traffic which would otherwise consume a large amount of capacity from the wireless network) but also negative (injection of interference throughout the service area, leading to a degradation in the CINR and outdoor network capacity). Using different hypotheses in terms of distribution of the femtocells and the services offered to the end-user, an operator can devise a plan that will optimally leverage the right technology for every subscriber. As always, good planning practices lead to better networks.
- Bernard, Mentum Product Management