Network Technology and the HetNet
Most operators see the heterogeneous network, or HetNet, as the best way to address coverage and capacity needs for next-gen networks. These networks will be comprised of both micro and macro sites utilizing the same core equipment. But what kind of network technology is required to successfully manage the HetNet?
Small cells function like macro cells in many ways, so a lot of the network technology is the same. “Additional Pico gateways may need to be added for management reasons, but they function exactly the same as a Macro BTS.” explained Tony Goodman. Looking to the future, the consensus is that self-optimizing, monitoring, and adapting technology is the path forward. In a sense, we're talking about a smart network.
David Swift, Director of Smallcell Solution Marketing, Alcatel Lucent, defined the key enablement of the HetNet as, “Self-Optimizing Networks (SON) technology, developed by Bell Labs, which continually monitors the small cells performance, the traffic type and source, and then adapting itself automatically to achieve optimal performance as part of the cellular network. Looking forward, SON is a key part of HetNet which expands interworking between small cells and macro cells to the next level.”
Amir Makleff agreed, adding, “The backhaul solutions for small cells will need to be self-optimized (SON) and include service aware Ethernet switch technologies such as QoS and VLAN along with the high capacity capabilities that allow for ring, mesh, and daisy-chain topologies.”
Upsides and Downsides
It almost a pre-drawn conclusion that small cells can provide considerable savings for operators, but what kind of numbers are we talking about? David Swift says a small cell deployment, “provides a savings of over 30% compared to a traditional macro upgrade.” Additionally, Swift continued, “Metro small cell delivers more that financial savings to an operator, bringing large improvements in overall throughput and customer satisfaction: a key differentiator to any network.”
The size of small cells allows them to be deployed in areas that are unreachable by macro sites, like in underground train tunnels, or between narrow buildings in dense urban areas. Small cells have a lower power requirement, and sometimes face fewer municipal regulatory restrictions.
There are also spectral benefits. “With the spectral limitation carriers face, small cell represents a way to add additional sectors without adding additional spectrum,” said Tony Goodman.
No solution is without challenges, though. Here is a basic bullet list of some of the challenges operators face when deploying arrays of small cells:
- Backhaul: The traditional method of pulling fiber to towers will not work with small cell
- Complexity: Managing the large number of small cells
- Distance: Lower powered sites have shorter coverage distance
- Availability: Small cells have yet to be implemented en masse
- Equipment: Managing the large number of deployed small cells requires additional core equipment
