5G is here, and we’re all moving to the “edge”

Almost imperceptibly, 5G has become a reality. There is no need to peruse those market research reports; a simple glance at the 5G icons on mobile phone advertisements all around gives us sufficient proof.

However, the impact of 5G on our lives is far more profound than simply “switching to a new mobile phone.” As the backbone of networks in the future interconnected world, 5G’s far-reaching aim is to cover “all scenarios” of wireless interconnection needs within our imagination in the three following categories:

• eMBB: Enhanced mobile broadband, that is, high-speed data transmission can be achieved at a rate of 1Gbps;
• uRLLC: Ultra-high reliability and low-latency communication, providing a bit error rate as low as 10-5 orders of magnitude, and latency of less than 1 millisecond;
• mMTC: Massive machine type communications, capable of supporting up to 1 million connections per square kilometer, and used to cover low-speed and low-power IoT applications

Figure 1: 5G application scenarios and required network bearing capacity         (Source: IMT-2020 (5G) Promotion

But while “all scenarios” coverage is indeed appealing, but there are quite a number of challenges that must be overcome to realize this goal--when the massive data formed on the network terminal is transmitted through the network to the cloud server for processing, and then back when the terminal completes the closed-loop services, this will inevitably cause problems such as network congestion, increased latency, and lower connection success rate. A user experience hampered by these deficiencies is far from what is expected of 5G.

From the perspective of telecom operators, this level of bandwidth consumption will cause huge transmission pressure on the backhaul network and service center. At the same time, the three application scenarios require different levels of network performance, and it is not easy to adapt a single network architecture to such diversified service needs. And the bottom line behind all of this is immense cost.

Therefore, in order to realize the 5G vision, it is necessary to completely transform existing wireless communication network architecture. The focus of this transformation is "edge computing."

In traditional cellular mobile network architectures from 2G to 4G, the processing of information is mainly done by the data center of the core network; that is to say, all information needs to be transmitted from the edge of the network to the core network for processing and then back to the edge. As can be imagined, this model poses a challenge to the economy and flexibility of network deployment and operation. The concept of “edge computing” that has been become indispensable in the field of network cloud computing is the perfect solution to this issue.

Specifically, in the 5G transmission network, gateways, servers and other equipment are deployed in the server rooms close to the access side (edge end), moving the computing power originally concentrated in the central server room to the edge of the network. This actually entails building a small-scale data center established on the edge of the network to directly process the information and data from the edge devices without having to "turn in" every bit to the central server room for processing. This model is referred to as Mobile Edge Computing (MEC).

Figure 2: MEC architecture in 5G    (Source: Wireless Deep Sea)

The benefits of MEC are obvious：

• as there is no need to send data back to the core network, latency is greatly reduced.
   
• Localized, low-value data can be processed in the edge computing center. If necessary, the "finished" data can be transmitted to the core network, thus greatly reducing the pressure on network bandwidth and the resources of the central server.
   
• The edge data center can flexibly define the functions of the edge network according to the application scenarios covered, improve the efficiency of content and service distribution, and enhance user experience. This is greatly conducive to the emergence of new business models.

To be more specific, the deployment of MEC will provide strong support for the three major application scenarios of 5G.

The first type of scenario entails eMBB applications, which comprise primarily high-definition video, VR/AR and other application scenarios that require a huge network bandwidth. Traditional network data processing methods have long transmission paths, large bandwidth demands, and high network latency. Following the deployment of MEC, video caching can be configured using MEC to process VR/AR data, enhancing user experience by accelerating network speed and reducing latency. Operators and users can also use MEC to create specialized services for enterprises, shopping malls, schools and other personnel and data-intensive sites, such as VR shopping guides, indoor navigation and other services in large shopping malls, thus highlighting the value of 5G.

In terms of uRLLC high-reliability applications, as MEC is closer to the edge of the network, time-sensitive data can be directly processed in MEC, thus ensuring that millisecond-level latency can be achieved. This is extremely critical in automotive, industrial and other applications.

In mMTC, it is necessary to connect to a large number of IoT terminals and collect the data generated by them. For the core network, these unprocessed raw data are extremely cumbersome. If data is transmitted to the MEC, they will be analyzed using MEC and key information will be extracted and reported to the core network after processing, thereby optimizing both data quality and quantity.

Of course, there are still many factors that need to be carefully considered in the actual deployment of MEC. After all, even though MEC offers a wide range of benefits, efforts to utilize it will be dampened and enthusiasm will wane if it fails to bring operators real profit. In reality, different choices have different effects. In summary, operators have three options to choose from in terms of MEC deployment:

• Site server room deployment: This method is closest to the end user and can cover a range of about 1 kilometer (≤5 base stations). It is small in scale and high in cost but may still be a viable solution in areas with high user density (such as commercial districts).

• Integrated access server room deployment: Covering a radius of 5-10 kilometers (about 20 base stations), the scale of service is a little in-between, and the return on investment is not significant; therefore, operators generally do not opt for this deployment method.

• Edge data center deployment: Covering 50-100 kilometers (more than 100 base stations), operators generally believe that the deployment of MEC at this level is the most conducive to balancing the relationship between costs and benefits, and this is also where most MECs are deployed at present.

Figure 3: Different deployment methods of MEC         (Source: Wireless Deep Sea)

Ultimately, the specific method of deployment requires detailed analysis of specific issues. Fortunately, MEC itself provides this flexibility in deployment, allowing operators to explore and experiment before finally finding the best solution for each demand scenario.

As 5G is simply too lucrative, many stakeholders in the industry are actively pushing the wide utilization of "5G edge computing." In addition to traditional telecom operators, some Internet companies have joined the ranks and proposed experimental solutions. Active industry organizations are also discussing whether they can extract the common needs of MEC and build a common network. This standardization attempt will also be highly conducive to the future development of MEC.

Figure 4: Tencent Cloud's 5G edge computing center can be deployed with just a flat piece of ground, electricity, and the Internet        (Source: Leiphone)

In short, all our efforts tell us that 5G is truly something out of the ordinary. To maximize the powers of 5G, it is evident that we must adopt the strategy of introducing edge computing and staying close to the "edge." This is a challenge but also an opportunity.