Challenges to Bearer Networks from New Demands in MBB
New Trends and Requirements
The popularization of LTE has enabled widespread rollouts in mobile video services. According to data from OVUM, video represented 55% of all wireless network traffic in Q1 2015 and that percentage is expected to grow to over 70% in 2017 as definitions continue to graduate to even higher levels (720P→1080P→2K). The higher resolutions lead to ever-increasing amounts of data traffic over mobile networks. OVUM further predicts that the number of paid video users worldwide will reach 1.5 billion in 2020, among which over 40% of LTE users are expected to subscribe to enhanced-experience HD video services. Adding to the burdens, MBB connections between things will increase, even more so than that between people and between people and things. Machine-to-machine (M2M) communication places heightened demands on network coverage and requires ultra-low latency (less than 5 ms in aircraft controls, for example), not to mention the zero-interruption and real-time interconnection support for such applications as industrial robots.
Challenges to Bearer Networks
Traffic bursts are frequently encountered in data-intensive video services, especially when video content is being buffered for the first time. Insufficient performance of equipment on bearer networks leads to packet loss and decreases in throughput, which in turn degrades the user experience. To ensure a good experience, the bearer network must be able to provide high throughput from one end to the other. Considering these influences on subscriber satisfaction, operators must revamp their bearer networks to handle the demands from video services if they hope to have longevity in this revenue stream. The rebuilds should first consider how to simplify the network hierarchy, reduce the convergence ratio, create more CDNs in closer-proximity to consumers, and implement real-time adjustments to service paths based on the level of network congestion. The second area of focus is obtaining the ability to perceive the viewing experience in real time to guarantee a service experience featuring swift response and top-notch quality. Most existing quality-of-experience systems have defects, such as a lack of real-time measurement capabilities (such as the time needed to buffer videos or measuring the frozen frame count) and slow responsiveness in locating performance bottlenecks on the network (including RAN, bearer, and core network segments in addition to the Internet egress).
In the 4.5G/5G era, M2M connectivity will become a major service requirement, which will entail further simplification of the bearer network architecture, such as reducing the hops in the IP+Optical segments, while moving EPCs closer to the user side. Network latency must also be reduced while supporting a massive 100-fold increase in terminals accessing the network. Meanwhile, communication between people, M2M services, and human-machine interactions will all be based over the same physical bearer network, which means each service type will likely have an influence over the quality of the others unless precise quality-of-service assurances can be implemented. For example, data-intensive video service packets may go after the bandwidth of mission-critical service packets transmitted to aircraft control systems that require ultra-low latency. These and other types of interferences require network virtualization capabilities be implemented on the bearer network, a task well suited to SDN technologies that can take a physical network and separate it into multiple dedicated networks virtualized into service-priority types (such as M2M networks, common-user networks, dedicated-line networks, and so forth). Utilizing SDN will ensure the quality-of-service level will meet the requirements of the application, especially in the case of mission-critical applications.