5Qs on 5G: With Accedian Networks

Scott Sumner, VP Solutions of Development and Marketing

Accedian Networks certainly has a few things to say on the subject of 5G as it looks to maintain its reputation for service provider SDN, mobile backhaul and small cells moving into the next-generation. Scott Sumner, VP Solutions of Development and Marketing, is realistic about 5G, and speaks about what he sees as a strictly evolutionary network.

What can Accedian contribute to 5G?

5G networks will be increasingly dynamic, crowded with competing applications, and will require exceptional QoS. Coordinated multipoint access will require sophisticated traffic delivery over multiple backhaul paths.

“The path to 5G relies on optimizing latency and increasing network capacity”

The path to 5G relies on optimising latency and increasing network capacity, while allowing the assured coexistence of applications as diverse as the Internet of Things (IoT), security, streaming 8K video, and multi-caller voice over LTE (VoLTE) sessions.

The Software Defined Networking (SDN) controllers required to support multi-carrier aggregation, dynamic traffic engineering, and performance optimisation will require a real-time feed of network performance to optimise quality of experience (QoE).

Accedian diagram

Distributed Network Functions Virtualization (NFV) is required to locate latency-critical network functions close to the ‘users’. Hand-offs between carriers will impact latency. Performance must be assured between NFV infrastructure (NFVI) hosting related functions to ensure end-to-end QoE is maintained.

“a real-time feedback loop to SDN and self organising network (SON) controllers”

Accedian solutions measure performance at all layers, slices, services and applications to provide a real-time feedback loop to SDN and self organising network (SON) controllers. This allows the multiple 5G services and use cases to coexist and be simultaneously performance-optimised, while also providing a method to best use existing backhaul capacity.

“Accedian solutions cover the full service introduction and maintenance lifecycle”

This level of network performance assurance has some specific requirements:

– Performance Assurance Attributes – real-time, adaptive, directional, ubiquitous, embedded, open, standards-based, microsecond (µs) precise delay metrics.

– Monitoring Metrics – per-flow bandwidth utilisation, available capacity, packet loss, latency, delay variation, QoS / QoE KPIs for VoLTE and applications.

– Network Visibility – needs to be ubiquitous, covering all locations and layers, with “resolution on demand” to avoid drowning in the data lake of big analytics.

Accedian solutions cover the full service introduction and maintenance lifecycle: from assessing network readiness, to deployment validation, to ongoing monitoring, trending and troubleshooting, using network embedded instrumentation that employs capabilities of existing, standards-based infrastructure.

2. What are the main challenges for 5G for Accedian and the industry as a whole?

The main challenges centre around dramatically reduced latency limits for real-time applications, while also providing increased bandwidth to media-rich services, as well as ubiquitous, connectionless access for chatty IoT deployment.

“networks need to be completely redesigned”

For ultra-low latency to be realised, networks need to be completely redesigned to allow network functions to be hosted very close to the end-users (Virtual Network Functions, or VNFs, need to be as close as possible to the cell sites serving the user equipment). Because services typically chain multiple VNFs, the principles of distributed NFV (D-NFV) will need to be standardised and proven out in real networks, to achieve latency objectives.

Backhaul will be required to use all available paths to meet bandwidth capacity requirements, especially in coordinated multipoint (CoMP) installations where data may need to be replicated over multiple paths to allow seamless aggregation at the handset, while accounting for reliability requirements.

“Instrumentation is critical for such an evolving network”

The necessity of using HetNets and widely deployed small cells to meet RAN capacity requirements increases the number of endpoints served by the backhaul network, while reducing the financial contribution of each. Instrumentation is critical for such an evolving network with many more endpoints, but at the same time, cost pressure demands much more efficient methods to meet the 5G business case.

Accedian solutions are being virtualised to allow much greater cost efficiency (up to 80% reduction), power consumption (up to 90% less), and higher degree of centralised control scalability in commercial off-the-shelf (COTS) NFVI. Maintaining the measurement precision and multi-flow monitoring capabilities of standalone instrumentation is a challenge, but is being overcome by using miniaturised test endpoints such as programmable smart SFPs and compact GbE hardware modules.

3. What are your timescales in terms of investments in R&D in 5G specifically as well as potential deployment?

Accedian has been investing in its NFV-based instrumentation for over three years, and recently launched (March 2015) the VCX Controller as the first commercially available virtualised instrumentation platform. Working with the Nano smart SFP and the ant GbE modules as remote test points, it has already been adopted in large-scale networks by four Tier-1 mobile operators, two cable MSOs, and a national U.S. telecom provider.

” In 2016, Accedian will develop new and innovative testing methods”

Accedian will focus its investment on this 5G-ready solution over the coming years, as it supplants traditional monitoring architectures. All the features available in Accedian’s existing network interface device (NID) solutions will be available in the VCX virtualised version by year-end. In 2016, Accedian will develop new and innovative testing methods that combine the capabilities of standard-based and open source virtual network function components (VNFCs) with QoE (Level 5-7) analytics and synchronisation testing to create a new breed of total visibility monitoring solution.

4. Will 5G be an evolution or a revolution in terms of networking?

Evolutionary! Proposed 5G requirements like 100% coverage, 99.999% availability, and 90% reduction in network energy usage should be achievable with existing technology ; these shortcomings are constrained by economics more than technology.

Certainly, there are plenty of opportunities to profitably improve 4G/LTE and these are the things much more likely to happen in the next five years than building out a completely new system.

“LTE-A networks can approach 5G performance with proper optimisation”

For example, operators are already making progress increasing data speeds of existing networks using dual-carrier LTE-A, capable theoretically of up to 300 Mbps downlink speeds. This represents a big opportunity for operators to develop profitable 4G services and meet mobile broadband demand for several more years.

With network-embedded instrumentation, LTE-A networks can approach 5G performance with proper optimisation:

1. Assess network readiness for incremental capacity and service upgrades.

2. Localise performance pinch points to focus upgrades and optimisation efforts.

3. Monitor utilisation trends and variation, and tune the network with real-time feedback to get the most out of existing infrastructure.

4. Monitor performance over the migration phase to NFV / SDN for troubleshooting and to optimise network configuration as traffic load increases.

5. What will the main uses cases of 5G be and can one network meet the needs of these?

On the most practical level, as described by GSMA, as of now there are really only four plausible 5G applications not achievable with LTE, LTE-A, and other 4G improvements:

1. Augmented reality

2. Virtual reality

3. Tactile internet

4. Autonomous driving

Grouped together, the first three of those could involve purposes both fun (like gaming) and practical (like manufacturing or medicine). VR/AR systems are in their infancy, and their success will be dependent not only on high bandwidth/low latency networks beyond what LTE-A can deliver, but also other in-development technologies like motion sensors and heads up display (HUD).

None of these services will come about unless operators and service providers invest in them, and that depends on being pretty certain the services will be profitable. In other words, enough customers will pay for them to make the investment worthwhile.

In reality, the main applications that must coexist efficiently in a practical 5G view would be:

1. High-bandwidth media-centric applications (VoLTE / ViLTE / wireless-connected office)

2. Low-latency, transactional grade applications (security, health, signaling/control plane for rapid hand-offs/roaming)

3. Low-performance IoT applications where volume of endpoints compete for network resources, but are unlikely to require high amounts of bandwidth or low-latency: thermostats, appliances, industrial monitoring, etc.

“dynamic performance optimization (DPO) will be an essential part of the SDN networks”

One network can meet all of these needs if traffic from each application is routed carefully to respect the overall network capacity, as well as the individual services’ performance needs. As an example, IoT traffic should not be sent along premium, low-latency backhaul paths if it will interfere with applications requiring these attributes. In this light, dynamic performance optimization (DPO) will be an essential part of the SDN networks that will ‘spin up’ these network slices for individual applications, and manage their on-demand performance requirements.

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