Further to the Telecomistan commitment of knowledge sharing in the telecom domain, here is a short report on a new feature called DFCA (Dynamic Frequency and Channel Allocation) by NSN. The enhanced feature allows operators to double the GSM voice capacity using the Orthogonal Sub Channel (OSC).

GSM operators worldwide will now be able to get more from limited spectrum and improve their overall Quality of Service (QoS). Nokia Siemens Networks has launched a unique Dynamic Frequency and Channel Allocation (DFCA) feature that can double GSM network capacity within existing spectrum. The feature supports growth, while maintaining service quality and controlling costs.

GSM operators in emerging markets are adding millions of subscribers every month. However, spectrum limitations prevent operators from adding new subscribers to their existing networks without building more base stations sites.

“DFCA has immense potential to help operators address the challenge of ever increasing voice and data traffic,” said Prashant Agnihotri, head of GSM/EDGE product management, Nokia Siemens Networks. “It helps operators squeeze voice calls into less bandwidth, so it can be alternatively used for data, either through Enhanced Data Rates for GSM Evolution (EDGE) or by re-farming the spectrum to Wideband Code Division Multiple Access/Long Term Evolution (WCDMA/LTE). It brings a substantial increase for operators in terms of potential earnings per base station site.”

Dynamic Frequency and Channel Allocation (DFCA) excels at pairing and allocating two users in the optimal channel, and can further improve spectral and hardware efficiency.

Nokia Siemens Networks’ DFCA feature helps operators to continue acquiring new subscribers while overcoming current spectrum bottlenecks. Using a combination of software features, it increases the traffic carrying capacity of existing sites, while improving network quality. This, in turn, minimizes the immediate investment in additional sites, reducing the total cost of ownership. An added benefit is a huge increase in energy efficiency per subscriber.

Minimize Site Density by up to 50%

In the past, mobile operators seeking to extend capacity to satisfy growing traffic demand generally augmented BTS hardware at cell sites with antenna combiners to add more transceivers. Wideband transmitter combiners, for example, introduce about 3.5dB loss. Compensating for the decrease in coverage may necessitate new sites. The OSC, in turn, maintains the coverage area in capacity extensions. This can cut the site count by up to 50%, and the operator’s costs accordingly. The OSC offers an efficient method of adding channel capacity while leaving the site hardware configuration untouched.