DECEMBER 2020
Telecom Network And Network Testing Madhukar Tripathi
T&M FEATURE
Head - MARCOM &OPTICAL PRODUCTS, ANRITSU INDIA PVT.LTD
Test and Measurement: Network Test Network testing is very broad subject. In this article I am covering telecom (mobile) network testing. Telecom network can be divided into 2 major category- wired network and wireless network from installation and operation point of view. Telecom network is hybrid (combination of Wired and wireless network). Wired and Wireless network are essential and important part of all telecom network. Due to 5G network deployment worldwide this article covers network testing having 5G network as focus. Wired Network Measurement
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Figure -1: 5G Mobile Network
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CU- Central Unit DU- Distributed Unit RU- Remote Unit eCPRI- Ethernet Common Public Radio Interface RoE- Radio Over Ethernet MEC Mobile Edge Computing GM/GMC- Grand Master Clock Transport Measurements required by 5G Mobile Network I&M (Installation and Maintenance) contain following measurements: • 5G Mobile Network eCPRI/RoE Measurements • 5G Mobile Network Latency Measurements • 5G Mobile Network Time Synchronization Measurements
5G Mobile Network eCPRI/RoE Measurements
Common Public Radio Interface (CPRI) compliant interface equipment has been used for 3G and LTE systems to convert the mobile fronthaul wireless signal to the optical signal. CPRI is commonly said to need to be about 16 times faster than the radio transmission speed to perform digital conversion of radio signals. Since 5G transmission speeds are about 100 times faster than LTE, a new eCPRI/RoE technology based on market mainstream Ethernet is being adopted. With 5G featuring high speeds and large capacity, maintaining mobile fronthaul communications quality requires communications and latency tests measuring either CPRI or RoE frame bit errors and latency with high accuracy. The 1914.3 (RoE) and eCPRI frame formats both use Ethernet in their lower layers, allowing timing areas to be tested using standard Ethernet timing methods. Areas such as latency, routing, switchover time, and BER over the 1914.3 and eCPRI frame formats must also be tested.
5G Mobile Network Latency Measurements
Since maintaining minimum assured communication speeds is generally impossible using Ethernet, latency times of the entire network including the 5G mobile fronthaul must be managed strictly. To suppress latency times between the mobile fronthaul 5G antenna and Core/Metro network, it is important to minimize the latency of the network equipment as much as possible. Implementing the 5G low-latency feature requires using two testers to accurately measure one-way delay between two distant separate points.
