21712 - SCTE Broadband Nov2022 COMPLETE v1

60 Vol. 44 No. 4 - November 2022 Issue technical Correct methods and procedures organised by lifecycle To achieve this Giant Leap for 5G, you need to ensure all these steps are completed and that the data is safely stored in the cloud to speed up future troubleshooting. These steps have been developed from sharing best practices from leading mobile network operators around the world. Get it right first time Reduce OPEX (no second troubleshooting site visits) while increasing QoS, QoE. Increase service up-time and reduce churn. A B C D E F G H I A. Sweep spectrum (site audit) – must use real- time spectrum analysis for looking on site – band clearance What other signals already exist at the chosen site? Will they interfere with or degrade the planned and expected radio performance at this location? Will your site cause interference to other networks or your own signal? B. Antenna Alignment The coverage might not be optimised (e.g. antennae elements pointing in the wrong direction – not as in the RF plan). The slightest error here will cause dropped calls or poor throughput, especially as the site’s traffic ramps up. Leading to very unhappy customers! C. Cable Sweeping If there is a mismatch in impedance with the transmission lines at this site it will become inefficient, drawing more power, which costs money and may ultimately cause damage. This can affect network geographic coverage and also cause dropouts and poor throughput. D. Fibre Connector Inspection Fibre is everywhere these days, even replacing most of the transmission lines. 90% of the faults in fibre networks are caused by dirty connectors affecting the throughput and can be a point of total network failure, perhaps causing a burnout in the remote radio head optics, which would be a costly and timely problem to fix. Inspect Before You Connect (IBYC) is the industry standard practice to optimise FTTA installs. E. Fibre Measurements (Insertion Loss or OTDR) Fibre installation can be very sensitive. Macro/micro bends cause attenuation, which mean the link performance could be dramatically reduced as the laser power is not all transmitted to its destination. This could also be caused by poor splices in the fibres done at installation. Again this could cause drops in throughput to all out failure. Testing is critical to qualify or troubleshoot a link or ensure link loss is within permitted optical budgets. F. Spectrum Measurement – must use real-time spectrum analysis for looking on site – band clearance After radio equipment and antennas are installed at site, RF validation of the installation or upgrade should happen to ensure they are transmitting as expected. If testing wasn’t conducted previously and those test results are not accessible it is very hard for a tech to be certain that their upgrade or repair hasn’t made a problem worse. What is the overall RF Envelope? G. Timing and Synchronisation The 5G Time Division Duplex (TDD) signals are much more susceptible to interference. As a result there are much more stringent requirements for timing and synchronisation. If sync has been lost a tech could spend ages looking for external Interference without realising the fault was from his own network. Verify it’s not an external interferer at site (saving time and money). Potential first problems would be interference, low throughput due to excess latency. Difficulty for 5G devices to attach to radios, frequent call drops, etc. H. 4G/5G RF Analysis It is important to verify that the over-air RF performance is as expected. This is where there have been significant hardware changes from 4G, so there are certain expectations with this, so more measurements are absolutely needed to offer the next level of detail, for example service testing. Also many regulatory bodies are requiring EMF testing to ensure 5G transmitted power remains within safe limits. I. CPRI (Common Public Radio Interface) You can avoid unnecessary climbs by checking the health of the CPRI link to the RRU (Remote Radio Unit) from the bottom of the tower, as well as saving a fortune from SFPs (Small Form- Factor Pluggable transceivers) not being mistakenly destroyed. It is also possible to investigate interference and PIM (Passive Intermodulation) problems, without climbs and while the BTS (Base Transceiver Station (tower)) remains in service. A D D R E S S I N G T H E R I S K S