Learn how to pinpoint uplink interference while reducing tower climbs and saving money
Interference can make or break a cell site commissioning. From the macro tower layer to indoor small cell deployments, interference costs time and money while creating the potential for customer churn based on poor quality of experience.
But with the vast and complex nature of global telecommunications networks, interference is going to happen. Given that reality, it’s important to equip tower technicians with the tools they need to find and eliminate interference quickly and correctly the first time.
Let’s focus on uplink interference. While download throughput is essential to mobile applications like web browsing, mobile banking and exchanging emails, poor uplink speeds impede important consumer activities like file sharing or social media use.
To help highlight the importance of mitigating uplink interference, consider an Indian service provider in the process of launching VoLTE services. Ahead of the launch, technicians found acute uplink interference causing up to 25% total capacity degradation at multiple sites particularly around the mountainous border with Nepal where the Himalayas begin.
The process of identifying and recording uplink interference required field techs to climb more than 150 feet in some cases to reach directional antennas. Coupled with foggy, winter conditions and low visibility, the work proved time consuming, filled with errors and, based on the less than favorable environmental conditions, quite risky.
To simplify the process, the service provider brought in experts from Viavi to help simplify the process and ensure a smooth VoLTE launch. The Viavi team conducted numerous tests and analyzed uplink spectrum, RSSI and spectrograms to identify the uplink interference as coming from nearby radar as well as what looked like a WiMAX transmission originating from Nepalese towers. And that was accomplished in a cost-effective manner that minimized tower climbs.
So how did Viavi do it?
The antennas in this situation used CPRI uplink cables to connect to the baseband unit (BBU). Instead of climbing the tower to test the CPRI connection, a fiber tap was put in at ground level. The RFoCPRI, as well as RFoOBSAI, functionalities come with Viavi’s CellAdvisor Base Station Analyzer, which performs a wide range of test functions in one unit. The CellAdvisor tools feature spectrum analysis up to 8 GHz and support all wireless technologies from 2G to 4G, along with LTE-A carrier aggregation, MIMO 4×4, PIM detection, MBMS analysis, and interference analysis and Layer-2 term and monitoring for CPRI fronthaul.
The Viavi techs also used AntennaAdvisor, the handheld companion to CellAdvisor, which allows users to follow along on a map to locate interference.
In sum, the right tools can enable service providers to easily identify, isolate and eliminate interference quickly, which is an imperative for service providers looking to retain existing customers and win new customers by providing optimal quality of experience.
