Lucent aims for real-time optimisation of cellular networks

Stuart Corner
Sunday, 09 April 2006 16:10

Business IT - Technology

Lucent technologies has unveiled a means of optimising the performance of CDMA networks in response to fluctuating usage patterns, developed in conjunction with Telecom NZ.
Lucent revealed that its New Zealand arm has been working with Telecom NZ over the last two years to trial "a unique new approach to optimising the coverage and capacity of mobile networks".

Testing is taking place in the Lower Hutt, Taranaki, Bay of Plenty and Mt Eden regions. Lucent built the mobile network and currently manages it for Telecom NZ.

Currently cellular network parameters are effectively static - they are set up once and then re-tuned on a monthly or yearly basis at best. According to Mike Flanagan, Bell Labs technical manager, who is overseeing the testing. "Traditionally, communications networks are designed around a static scenario based on peak usage patterns. But of course traffic patterns are always changing. In the evenings the majority of mobile device use is at the home, during the day it is in the office area, and during rush hours along the major traffic arteries. By creating a network that can optimise itself dynamically to adjust to the changing network needs throughout the day we can enable service providers to improve quality of service related to the delivery of mobile voice and data services."

The technique uses Bell Labs' Ocelot software combined with real-time technologies that "measure usage patterns and performance conditions across an entire network at any given time of day". Armed with this information, Ocelot is used to find the best network parameters to achieve optimal capacity and coverage. These network parameters include base station transmit power levels as well as antenna orientation.

Adjustments are presently not made in real-time in response to observed usage patterns and performance levels. Rather, these parameters are monitored, patterns identified and the power levels and antenna settings programmed to change during the day and the week accordingly.

The next phase of theresearch is to implement real-time dynamic optimisation - where the network will continually monitor network traffic usage and be able to optimise itself in short time intervals.

"Pattern modelling is very useful and a major step, but users don't always conform to those patterns," said Flanagan. "For example, when there is a specific event like a traffic jam or a big rugby game there is a big spike in mobile phone calls in a concentrated area. Traditional network design can't cope with those changes in network usage very well."

Kevin Kenrick, Telecom NZ's general manager mobile, said: "We have already seen real benefits such as significant reductions in dropped calls and increases in network availability. We've also seen an improvement in the capacity of the network to deal with increased traffic at specific times of the day, helping us maximise our infrastructure investment."

Bell Labs is working with KMW Communications which has supplied programmable base station antennas that provide adjustable pan/tilt functionality. By changing the pan, tilt and power output of each antenna, the system can remotely modify the network coverage topology, modifying each base station's coverage area.  To shift traffic from congested base stations to under-utilised ones.