Network management strategies for HetNets

(May 29 2012) 3G , 4G , HetNet , LTE , Wi-Fi

1. The mobile broadband explosion is a cliché that accompanies virtually every industry discussion. This explosion is buoyed by the proliferation of smart phone devices and vast application developer communities. It is expected to drive a twenty to forty fold increase in network capacity demands over the next five years. In response, the mobile industry has availed new radio spectrum resources and developed higher performance technologies, such as LTE – both of which will enable a two to four fold increase in existing network capacity. This capacity enhancement, while important, falls well short of what is needed to meet future mobile broadband demands. To address the capacity short-fall, mobile operators are coming under increasing pressure to embrace small-cells and Wi-Fi network traffic offload solutions. Heterogeneous Network (HetNet) architectures are being standardized by the mobile industry to address the future proliferation of small cells. HetNets anticipate that even as small cells proliferate they will require a variety of configurations, including femto, pico, metro and micro-cells, and umbrella macro-cells to meet coverage and capacity demands. It is this tapestry of different types of cells within the same network that forms the basis of HetNet designs.

   As HetNets proliferate, mobile operators can expect up to a ten-fold or more increase in the number of radio base stations in their networks, with the number of small-cells dwarfing that of macro-cells. This will place mobile operators under tremendous pressure to transform their legacy network design and management philosophies with solutions that enable automation and real-time radio network management and optimization. In particular:

   • Automation is needed to eliminate excessive network deployment costs, which can be tens or hundreds of thousands of dollars for macro-cells. Automation is also necessary for ongoing management and operations so that each technician and engineer can cope with many more radio base stations than they have in the past.
   • Real-time radio management algorithms are needed to ensure optimum resource allocation amongst macro, small-cell and Wi-Fi network layers. This disrupts traditional operational models where manual and semi-automated radio network optimization is a significant operational activity.

   The HetNet standards anticipate the need for automation and real-time radio management algorithms. At the heart of HetNet management are the Self Organizing Network (SON) standards. SON functionality has already been used for indoor pico and femto-cells with automated provisioning and basic radio resource allocation. A variety of enhancements to SON are being developed to enable HetNets to proliferate. In particular:

   • The radio resource management algorithms used in legacy 3G networks (such as soft and softer handover) create significant interference challenges for small-cells when deployed outdoors and in high rise buildings with line-of-sight to macro-cells. The LTE-Advanced standards include a variety of capabilities including inter-cell interference coordination (e-ICIC), real-time parameter optimization, cell load balancing. Since these capabilities are needed, we believe that LTE-Advanced is currently a pre-requisite for large-scale Het-Nets to be reliably deployed.
   • Het-Nets will consist of a tapestry of radio technologies including LTE, 3G and Wi-Fi, over which network traffic must be optimally distributed. A variety of multi-RAT (radio access technology) capabilities are being developed to monitor, manage and optimize traffic flows amongst the various radio technologies.

   As HetNet technologies are developed and new operational models contemplated, we believe that there are several challenges that will linger. In particular:

   • We anticipate that most network operations organizations will resist the advancements and organizational transformations needed to embrace the SON automation and real-time optimization associated with HetNets. While the industry has seen initial success in applying basic SON functionality to femto and pico-cells, it will prove more challenging to apply these SON capabilities in large scale metro, micro and macro-cellular environments.
   • The emerging SON capabilities such as e-ICIC, load balancing and real-time parameter optimization will take time to mature and support the variety of operating scenarios needed, such as adequate feature transparency in multivendor environments and coordination with  legacy 2G and 3G technologies.
   • Significant upgrades to existing network management platforms and planning tools are needed to incorporate HetNet functionality.

   However, given the desperate need for improved network performance and capacity, we believe that mobile operators will be compelled to accelerate their small-cell and HetNet initiatives. These initiatives will catalyze much needed changes in operational regimes and network management platforms.

   By: Phil Marshall, PhD, Tolaga Research

   Bookmark or Share this article

Login to comment