The vision of self-organizing networks (SON), which is in line with the views of 3GPP (3rd Generation Partnership Project) and the NGMN (Next Generation Mobile Networks) group, is that future radio access networks needs to be easier to plan, configure, manage, optimize and heal compared to how it used to be.
SON has been codified by the 3GPP Release 8 specifications in a series of standards including 36.902,[1] as well as public white papers outlining use cases from the NGMN.[2] The first technology making use of SON features will be UMTS Long Term Evolution. The LTE specification inherently supports SON features like Automatic Neighbor Relation (ANR) detection, which is the 3GPP LTE Rel. 8 flagship feature.[3]
Newly added base stations should be self-configured in line with a ‘plug-and-play’ paradigm, while all operational base stations will regularly self-optimize parameters and algorithmic behavior in response to observed network performance and radio conditions. Furthermore, self-healing mechanisms can be triggered to temporarily compensate for a detected equipment outage, while awaiting a more permanent solution.
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Self-Organizing Networks are commonly divided into three subareas:
Self-configuration strives towards the 'plug-and-play' paradigm in the way that new base stations shall automatically be configured and integrated into the network. This means both connectivity establishment, and download of configuration parameters and software.
The base station parameters can be regularly adjusted, based on both base station and mobile station observations. One of the first SON features establishes neighbor relations automatically (ANR), while others optimize random access parameters or mobility robustness in terms of handover oscillations.
When some nodes in the network becomes inoperative, self-healing mechanisms aims at reducing the impacts from the failure, for example by adjusting parameters and algorithms in adjacent cells so that other nodes can support the users that were supported by the failing node.
Self-organizing Networks features are expected to be introduced gradually with the arrival of new 4G systems in radio access networks, allowing for the impact of potential ‘teething troubles’ to be limited and gradually increasing confidence. Self-optimization mechanisms in mobile radio access networks can be seen to have some similarities to automated trading algorithms in financial markets.
The Mobile World Congress trade conference in 2009 saw the first major announcements of SON functionality for LTE mobile networks, with Optimi, Actix[4], Alcatel-Lucent[5], Motorola and Nortel[6] all making announcements and demonstrations of early stage products. First deployments are expected in Japan and USA during 2009/10[7].
On 2 February 2010 Actix Limited announced a contract [8] to supply centralized SON for LTE networks to NEC Corporation of Japan.
The first commercial live test of one of the official 3GPP SON functions was held 12 November by TeliaSonera and Ericsson[9]. It verified the Automatic Neighbor Relations (ANR) feature in parts of a commercially deployed network in Sweden, using a mobile for a commercial chipset vendor. ANR automatically sets up neighbor relations based on actual radio conditions. The most complete set of SON features is provided by Nokia Siemens Networks
C. Brunner, D. Flore: Generation of Pathloss and Interference Maps as SON Enabler in Deployed UMTS Networks. In: Proceedings of IEEE Vehicular Technology Conf. (VTC Spring '09). Barcelona, Spain, April 2009