QoS challenges in the NFV/5G networks

Posted by Sandeep Raina on Jun 28, 2017 11:00:00 AM

NFV-core based 5G networks have already caught the fancy of the Telco Cloud service provider. The reasons for this are its promise of high QoS.

High speed/throughput, high reliability, low latency, high capacity, high availability, high connectivity and dynamic bandwidth allocation are the key QoS benefits that Telco Cloud service providers can expect from the 5G Cloud RAN and the NFV core networks. These QoS attributes will be consumed by - and will characterise - the 5G services that they serve:

  • eMBB (enhanced mobile broadband): These services require high capacity, high speed and dynamic bandwidth allocation. While high speed helps to upload and download video-based content faster and in gigabyte sizes, bandwidth can be allocated on demand for UHD video, Virtual Reality, Augmented Reality, etc.
  • uRLLC (ultra-reliable and low-latency communications): These services require high reliability, high availability and low latency. High reliability supports mission-critical services such as connected robotic factories and remote surgery, while low latency makes delay-critical services such as autonomous cars and remote-controlled drones a reality.
  • mMTC (massive machine-type communications): High capacity, high speed, dynamic bandwidth allocation characterise this class of services. It is most suited for IoT services like smart cities, serving billions of ‘things’ and ‘devices’ up to a density 1 million per square kilometre

Here is a quick round-up on the promised values of the 5G QoS parameters:

  • Speed/throughput of 10 Gbps, and a target of 20Gbps
  • End-to-end latency reduced to a range of 1-10 ms and to 0.5 ms for the physical network
  • Network availability stretched to 100%
  • Reliability parameters like Block Error Ratio (BLER) for 5G expected to be 0.00001 in a 1 ms period, compared to 0.01 in 4G
  • Jitter brought down to 10-100 microseconds
  • Bandwidth from 100 Kbps for small sensored devices to several hundred Mbps for industrial robotic cameras

To achieve these ambitious QoS values there is tremendous work being done on 5G MIMO antennas, 5G Cloud RAN and the NFV core network. However, as we know from experience, physical radio access and air interface pose the real challenge and will continue to remain an obstacle for faster propagation and transmission. Efforts are being made to reduce packet size, transmission time and propagation time to as low as possible.

As exabyte-scale data generated by the 5G services traverses the 5G network and/or its complementary 4G and WiFi networks, it needs to be monitored in real-time for associated QoS guarantees at all points of time. A technique which is unique to 5G helps in achieving the QoS guarantees to a large extent: slicing of 5G network functions (RAN and Core) so that network and service resources can be dedicated and negotiated (scaling in, scaling out) dynamically.

Even as these QoS challenges are being worked on, the responsibility lies with the 5G CSP to assure latency, reliability and connectivity on a 24/7 basis to prevent any degradation of these critical QoS parameters. Assurance systems are needed to extend assurance to 5G slices and sub-slices, not just to the entire network. A sliced, secure always-available network with built-in redundancy will allow seamless data handovers between 5G, LTE and WiFi networks, thus assuring mobility continuity, coordination and availability.

It is important to note that many 5G services, if not offered with guaranteed QoS, will land the Telco Cloud service providers in serious commercial and legal problems. Imagine a drone dropping, a driverless car veering off the motorway, a stalled robot in the production line or a video frame freezing in the middle of a remote surgery.

Telco Cloud service providers are conscious that delay-critical services are highly dependent on the 5G network QoS and the management of its network slices. They know that it requires redoubled effort on the 5G CSP’s part to analyse and action network/service data quickly to keep capacity, latency, reliability, availability and connectivity under close surveillance and offer proactive remediation. Through the use of key Assurance techniques such as proactive closed-loop automation, service assurance and service orchestration as well as automated root cause analysis amongst others, Telco Cloud service providers can begin to offer the challenging QoS values that 5G promises.

Topics: 5G, NFV, Network Function Virtualization, Telco Cloud, CSP Digital Transformation

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