Wireless operators bring it up in almost all operator-vendor dialogues: “Does your SON work in a closed-loop fashion?”. Closed-loop SON is one of the main promises of automated centralized SON (C-SON) solutions and is sometimes a mandatory requirement from operators, making it essential in any solid SON offering.
In most cases, when the vendor simply answers “of course!”, have they truly understood the full intent of what the operators are asking, or is closed-loop SON missing a critical aspect?
The foundation
A closed-loop SON has the ability to automatically receive parameter network sets, run optimization, then provision parameter set adjustments back onto the network – automatically and faultlessly. This loop part of a C-SON integration with vendor OSS is the basic foundation of any C-SON solution, ensuring the automation of coordinated SON activities.
But does this accurately define all aspects of closed-loop SON?
The bigger picture
The true meaning of closed-loop SON is much broader. It isn’t just the configured connections that allow for the closed-loop data transfers, but rather a wider network-centric approach which continuously seeks anomalies in network performance. Closed-loop SON can only be completed by utilizing corrective C-SON techniques, which consider the current level of network performance degradation while comparing it against normal traffic pattern behavior.
Parameter changes have a direct impact on network performance. Any C-SON parameter adjustment applied on the network will affect network performance for the sector and its surroundings, eith positively or in some cases negatively. In order to carry out the next phase of successful optimization and avoid negative impact to the network, C-SON is first requested to verify the positive effects of the latest parameter changes by analyzing the network health, usually through network KPIs.
A C-SON solution must recover from a degraded network performance situation automatically. It can do this by either reverting back to a healthy network snapshot or applying corrective SON activities.