Small cell maturity raises management issues

Femtocells have grown up and left home, according to ip.access founder and CTO Nick Johnson, commenting on the news Wednesday that the Femto Forum had rebranded as the Small Cell Forum. Johnson was unveiling the firm’s first 4G small cell – an event that highlights the growing maturing of the sector – yet brings with it some interesting network planning considerations.

The firm’s E-100 is an LTE access point built on Freescale’s QorlQ Qonverge base-station-on-a-chip unit, and is capable of supporting 64 LTE users and 32 3G users simultaneously, with an additional interface for a wifi module. The device will be sent out to operator labs later this year with field trials to start in early 2013.

But with potentially tens of thousands of small cells appearing in the network topology, there’s a real danger that the SON (self organising network) elements will be overwhelmed by the requests.

A SON implementation is designed to allow the network to automatically and continually self optimise by passing instructions back to the basestations telling them to reconfigure certain parameters. Eventually, implementations will go so far as to allow the network to ‘self heal’.

However, Andy Tiller, SVP of product management at ip.access, pointed out that the small cell layer could quite easily hog the SON functionality due to the sheer number of small cells present. As a result, ip.access has devised a sort of aggregation layer which sits in between the SON and the small cell layer and called it the NOS (network orchestration system).

The NOS allows clusters of small cells to be managed in the context of the whole network, passing down KPI-based optimisations directed by the SON, and sidestepping a network management headache.