ISCO International is a pacesetting wireless communications solutions provider and global supplier of radio frequency management & spectrum conditioning, as well as AIM products & solutions.. Our employees are experts in radio frequency (RF), network noise sources, and interference mitigation. Driven by customer focus and technical innovation, ISCO increases the value of customers' wireless networks.

Marine RF Interference Mitigation

The Situation
A mobile operator in the 850MHz UMTS B-Band was challenged by watercraft of all sizes utilizing bi-directional amplifiers (BDA's) for communication system signals. These devices created unwanted interference throughout the carrier's coastal cell sites. Large vessels would dock for a period of time and monopolize these BDAs. Additional interferers include analog devices (security devices, television amplifier devices, etc), and other local RF sources that are not properly filtered or optimized.

These interferers created a double whammy - an increase in the noise floor and additional mobile transmit power resulting in higher dropped call rates and incomplete call attempts. The net result is that quality of service was impacted and higher rates of customer complaints.

The Resolution
ISCO provided its dANF (digital Adaptive Notch Filter) for an evaluation to solve the interference issues. Initially, activities included an evaluation of the dANF working with the Ericsson BTS to "notch" out interferers in a lab environment. The tests were successful.

The next step was to place the dANF into one of the sites for a live trial. The resolution of the problem was immediately seen. We could see multiple interferers large and small occurring and the dANF immediately applyed notches to mitigate the interference. The ISCO dANF can apply up to three notches simultaneously.

Infrastructure Details
The dANF is designed to be installed into networks experiencing in-band & co-channel interference and using various BTS's from different equipment manufacturers; ISCO has a special installation kit for each vendor's BTS.Once installed, ISCO can demonstrate successful interference mitigation as shown below:

Actual results with the dANF in use
 

Impairment at an unprotected site
 

Impairment at a protected site
 

 
 

Additional dANF 850 & 1900MHz Applications

There are many examples of situations which result in unacceptable interference and noise in wireless networks:

•  Marine - Personal watercraft, Oil Rigs, Freightliners, etc.

•  Border Cell - Use along Canada or Mexico Border to prevent interference from bordering cites which may not be regulated as tightly.

•  Special Event Sites - Typically used in sites where unknown interferers may be introduced. COW, COLT, or at an installed site where events are occurring, such as NASCAR, PGA/LPGA golf tournaments, Super Bowl, political conventions and trade shows, horse races, Olympic competitions, to name a few.

•  Dense Urban - In major metropolitan areas where other operators or unknown RF devices could be used and interfere.

•  Spectrum Re-Mining.

An ISCO dANF can be deployed in just six weeks in any wireless market to start reducing interference problems. To learn more or start a trial, please contact us at sales@iscointl.com.