Ubiquisys Unveils Further Details of Self-Organising Femtocells

Femtocell developer, Ubiquisys has released details of a new self-organising femtocell system. Originally developed to meet the requirements of a specific mobile operator customer, the system consists of modular femtocells providing "lego blocks" of 3G coverage that automatically work together to serve any size or shape of building.

The main advantage of the system, claims the company, is a dramatic cut in the cost of ownership compared to traditional DAS, microcell or picocell systems. This is partly because the system is based on low-cost mass-produced femtocell hardware, running at a low transmission power of up to 20dBm and with a call capacity set at between 8 and 16 simultaneous calls. But the main reason is that unlike traditional systems, the femtocell grid is designed to be self-installed by the customer's IT staff. This eliminates the costly radio planning and specialist installation that has relegated traditional systems to niche markets.

Self-organising grid mitigates interference risk

The reason that the Ubiquisys femtocell system can be self-installed, and why it is completely self-managing in operation, is because the femtocells individually use cognitive radio to form themselves into a self-organising grid. The femtocells continuously sense both surrounding macro cells and their femtocell neighbours, and then configure power, frequency and scrambling codes between them to provide an optimum service according to the operator's policy. Coverage overlap is a key feature of the grid. The femtocells use sophisticated selection algorithms to ensure maximum spatial diversity between the scrambling codes used in the grid. This ensures that service is not affected by interference in the areas where femtocell coverage overlaps. And if there are changes to the macro network, or if femtocells are moved, added or removed, then the femtocells adapt instantly. The result is a robust grid of continuous service throughout the building, where every femtocell provides full HSPA data capacity.

New options for enterprise convergence Each femtocell configures its own 'neighbour list' to provide seamless mobility for users as they move around the building. The user is passed from the macro network to a femtocell as they arrive, passed from femtocell to femtocell as they move around the building, and are passed back to the macro network when they leave. The service is seamless and continuous. The system also has the option to support local offload of voice and data, which cuts down on an operator's core network costs and opens up IP-PBX integration opportunities.

"Our business femtocell system builds on the unique self-organising capabilities of the Ubiquisys femtocell," said Chris Gilbert, CEO Ubiquisys. "It enables operators to reach vast numbers of SMEs with a cost effective solution for the first time, but it also scales to provide flexible, modular coverage for organisations of any size. The system promises to be a catalyst for the next generation of converged business communications."

Ubiquisys is currently inviting mobile operators to see the system in action at business premises in the UK.

Posted to the site on 8th May 2009