A person shared to the author: “Once, it took 36 hours from a user complaint to the normal restoration of the network.” Just imagine if it was after the 5G application was fully popularized that the Internet was not available for 36 hours, it would be a problem for businesses and individuals. What kind of loss did it cause? What kind of blow has been brought to the brand reputation of operators?
In this regard, industry insiders are even more vividly expressing that this is like the increase in car ownership, road expansion, and traffic signal facilities during the morning and evening rush hours in Beijing. At this time, the traditional traffic management model obviously cannot adapt to changes. 5G networks also face such problems.
In the face of increasingly complex traffic management problems, the emergence of smart transportation has solved the problem. Similarly, today's 5G networks also require efficient operation and maintenance methods.
It is precisely this demand that both operators and equipment manufacturers are actively exploring ways to improve operation and maintenance efficiency, hoping that with the help of new technologies, problems can be detected early and hidden dangers can be eliminated.
5G fronthaul network operation and maintenance encounter challenges
If the improvement of 5G network operation and maintenance efficiency is compared to system engineering, the improvement of fronthaul network operation and maintenance efficiency is the most important part. Perhaps many people do not agree with this view. Don't worry, when the author finishes talking about the prequel network, you may change your opinion.
In order to reduce network delay and realize edge computing, the 5G network evolves the BBU and RRU two-level structure of the 4G network to the three-level structure of CU, DU and AAU. Among them, CU is responsible for processing non-real-time protocols and services; DU is responsible for processing physical layer protocols and real-time services; AAU is the active antenna processing unit, which is the part that we see hanging on the 5G base station pole.
The fronthaul network is the part that connects the AAU and the DU, and is the transmission link closest to the AAU antenna in the 5G network. 5G AAU antennas have high requirements for fronthaul networks: On the one hand, more and more 5G base stations use Massive MIMO as the core antenna technology, and the antenna elements inside 5G AAU have been significantly upgraded compared with 4G; on the other hand, the number of 5G base stations is huge. This has led to a huge scale of the 5G fronthaul network, which makes the operation and maintenance and deployment costs of the 5G fronthaul network very sensitive. As of the end of 2020, my country's three major operators have all opened more than 718,000 5G base stations. In 2021, my country will build more than 600,000 5G base stations.
Therefore, the 5G fronthaul network can be described as a bridge connecting user terminals and the 5G core network. If the bridge is "sick", the 5G network cannot be peaceful. If the fronthaul network cannot improve efficiency in terms of operation and maintenance, no matter how good the core network is, it will be futile. This is like, no matter how well you build the expressway, the entrance to the expressway is not only narrow, but the road is uneven, and vehicles will be blocked at the entrance.
Speaking of this, you must have discovered the great value of 5G fronthaul network to the improvement of 5G network operation and maintenance efficiency. Previously, operators’ plans to deploy fronthaul networks mainly included the following:
Optical fiber direct drive, each AAU and DU are directly connected to the network by optical fiber point-to-point;
Passive WDM mode, through passive combiner/demultiplexer, transmit optical signals of different center wavelengths in the same optical fiber, saving deployment costs;
Active WDM mode, corresponding WDM/OTN/SPN equipment is configured in the AAU site and DU computer room, and multiple fronthaul signals share optical fiber resources through WDM technology;