One of the key elements of the LTE saga is the ability of base stations to configure themselves automatically via self-organizing network (SON) technology. Dr. Mohammad Akhtar, VP of Wireless Networks, Home & Networks Mobility, Motorola Asia Pacific, explains how SON works, how it will benefit operators, and how Moto takes its capabilities beyond 3GPP Release 8.
How does SON work?
In network planning, SON drives into the network elements the determination of neighbor lists, automatic assignment of physical cell IDs (PCI) and RF parameters, and other pre-planned configuration.
SON proposes a streamlined eNodeB deployment model with pre-commissioning of NE and a complete plug & play capability. The Motorola SON solution automates the detection and resolution of PCI allocation and management through unique algorithms to avoid clashes of PCI values between cells. Motorola also created sophisticated algorithms to manage Automatic Neighbor Relationships (ANR) which allows new cells to automatically populate their neighbor lists.
SON manages ongoing optimization through looking at the device parameters to adjust optimization of QoS, neighbor cell, handover parameter, interference control management, and radio parameter (energy savings) from macro networks down to micro and pico cells.
What are the benefits of SON for operators?
The Motorola SON solution reduces OPEX by simplifying the management of the LTE network without disrupting an operator’s current work processes. Operating cost is cut because of reduced error, increased productivity and speed-to-market through automating manual activities. In network planning stage, it rapidly models the optimization of several parameters. When it comes to network deployment, it dramatically reduces the number of manual steps required in provisioning for new network elements expansion. Motorola has analyzed the potential operational savings by comparing the legacy 2G/3G operations workflows with those in a SON-based LTE solution. The SON-based solution showed significant OPEX savings. Motorola anticipates operational efficiency improvements of 65% to 80% in the areas of planning, deployment, operations and optimization.
What management processes are there for operator network engineers to ensure that new BTSs properly optimize themselves (rather than simply trusting it all to software)?
While SON is intended to be an automated solution, it isn’t simply about pushing a button to optimize functions in a network. It’s important to provide operators with functions that enable them to initially review proposed changes before deploying them, thereby helping the operators build trust in the SON algorithms. Motorola SON solution offers an interactive mode that previews proposed changes, allowing operators to approve changes before they are activated. In addition, operators can choose to initially deploy SON in a designated number of cell sites. As operators gain confidence in the SON algorithms and implementation, they can add more capabilities or switch SON to Automatic Mode, where changes are applied locally by the Network Elements (NE) and in real time. In Automatic Mode, the operator can view the changes any time and run reports to view all changes made by the SON algorithms. Operators can also choose the level of automation that suits their needs.
How would SON impact the backend for operators – i.e. OSS/BSS?
When deploying an LTE network, the additional resources needed to manage that LTE network is reduced. Operators will still need to maintain their existing 2G and 3G networks. However, SON limits the additional headcount needed to manage the same functions in an LTE network. Along with this, operations staff can shift their focus on higher order functions, rather than the low-level maintenance tasks of today’s 2G and 3G systems.