World Cup mobile coverage passes the test

Maracanã Stadium is an icon of soccer in Brazil, and it received a facelift to house 82,000 fans for the final game of 2014 FIFA World Cup Brazil. Mobile coverage at this stadium is a matter of national pride and the Brazilian Agency of Telecommunications (ANATEL) is supervising the work of ensuring top network performance.

As part of this effort, several contractors worked on different parts of various operator networks. Both Ericsson and Alcatel-Lucent (ALU) worked with ANATEL and mobile phone providers TIM, Oi and Claro to provide the best customer experience possible.

After struggling for some time with inadequate signal coverage, poor voice quality on calls and unreliable data connections, ALU purchased handheld indoor drive-test units from JDSU to find the real causes behind these issues.

The variety of stakeholders in this project complicated matters significantly; each used their own management system with no neutral reference as a baseline. Tests were performed for both voice and data to verify the quality of various call lengths and to ensure proper handovers. Not all tests were satisfactory, making further investigation necessary.

With the JDSU RANAdvisor Handheld TrueSite installed on popular handheld phones, ALU identified coverage issues to be a result of incorrect physical cell identities (PCI) at some locations. This was caused by the failure of small cells installed inside the stadium. Some of the cells were found to radiate with low power when they should have been outputting a greater power level.

Following a structured methodology to establish root problem causes, TrueSite identified the offending issues. The JDSU CellAdvisor Base Station Analyser provided additional data not only to further diagnose the problem, but also to resolve it.

RF testing let JDSU identify and solve problems and test several aspects of the distributed antenna system (DAS) installation. First up was testing over-the-air (OTA) power levels and LTE/UMTS radio power conformance. The local ALU integration partner had some doubts about the signal power sent from the ALU radios to the DAS system. OTA power tests made with the RANAdvisor Handheld reported very low signal levels but proper transmission power level at radios was reported with a CellAdvisor. This excluded the radios as the possible cause of the problem.

High VSWR was reported with the CellAdvisor, indicating impairments in the cabling system. ALU located and replaced the reflection source at the connectors of the DAS system, solving this problem. CellAdvisor also performed LTE ID scans and UMTS scramble scans, verifying that all the cell sites were properly assigned their identifier and were transmitting at correct power levels.

Finally, the unit performed insertion loss measurements, verifying the proper signal response of RF attenuators across the transmitted frequency band of 2.6 GHz LTE. This test did not identify any issues with the attenuators, certifying their performance.

After all issues were identified and solved, another indoor test was performed with TrueSite to verify that correct PCIs for LTE were radiating the correct signal levels and that voice and data services performed well for a large audience during games.

“I would like to thank the excellent support of JDSU at the Maracanã Stadium,” said Alcatel-Lucent’s Pedro Oliveira. “They provided a series of very important tests such as the verification of the transmission power of our remote radio heads and VSWR reflection tests of the RF cables, validating the proper levels of RF power in our distributed antenna system. This let us quickly resolve service issues with a single quality-assurance supplier.”