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Published 05 December 2017 in Research
Tags: 5G, fixed wireless, UK Enterprise Broadband Index, Ofcom

Dr John Naylon, CTO and founder, CBNL

CBNL was recently joined by leading experts in the field of 5G for a roundtable chaired by Emeka Obiodu (Strategy Director at the GSMA) to explore the status and future of UK enterprise broadband. 

With me on the panel were: Jonathan Dann (Managing Director of Telecom Research at RBC Capital Markets), Mischa Dohler (Professor of Wireless Communications at King’s College London) and Nick Lane (Chief Analyst at Mobilesquared).

Meeting in London, we discussed today’s connectivity landscape, the evolution of operator business models, and the role of new technology in the evolving pre-5G ecosystem. 

Supplementing the panel was the announcement of the ‘UK Enterprise Broadband Index.’ 

The survey, commissioned by CBNL, revealed that all UK businesses have experienced some issues with poor broadband services in the last two years. 

The most significant of these pertain to slow, or slower-than-advertised, broadband speeds, and substantial periods of network downtime. 

However, more than half of these businesses have not acted on these problems, instead choosing to remain with the same broadband provider.

With 89% of companies stating they would consider moving to wireless broadband, the research highlights the changing market perceptions towards this technology. 

In all likelihood, this is driven by the universal reliance of people upon mobile broadband, and their generally good experiences with it.

This striking statistic, and others within the index, provided a framework for a discussion of the current challenges facing the UK enterprise broadband market. 

The very high acceptance of wireless technology highlights the potential for disruptive wireless service providers to reconcile the digital divide and shape the future of connectivity.

The market status of UK enterprise broadband

The burgeoning demand for increased connectivity in the UK and the simultaneous acceptance of poor connectivity was a paradox my co-panelists unanimously acknowledged, and most had experienced directly.

This anecdotal evidence is supported by CBNL’s survey, which indicated that whilst 83% of businesses surveyed said that their connectivity requirements were being met by their broadband provider, 47% admit they are not receiving the broadband speeds advertised, 35% have been negatively impacted by slow broadband speeds, and 34% have experienced significant periods of downtime. 

With penetration of fixed wireless in the UK below many comparable regions of the globe, it’s plausible that a lack of exposure to alternative broadband solutions is contributing to the UK market’s acceptance of poor connectivity. 

To facilitate economic growth, the UK should seek to augment the range of technologies available to consumers with an emphasis on scalable solutions which can effectively meet growing demand.

The evolution of operator business models

Quickly moving from problem to opportunity, we proceeded to discuss the market opportunities for disruptive carriers seeking to leverage alternative solutions, such as fixed wireless.

Despite businesses looking for faster and more reliable broadband, when asked why they were opting to remain with their current provider, 32% of survey participants said they wanted to avoid disruption. 

Reflecting on this, Nick Lane commented: 

“The rapid deployment of fixed wireless solutions will be fundamental to improving the connectivity ecosystem, and as such needs to be a key focus for investment.”

“Operators leveraging these wireless solutions for enterprise can also benefit from their efficiency to build a more attractive business case to meet consumer demand, which at times is outpacing the capabilities of some of today’s legacy broadband services.”

Significant advances in millimetre wave have also meant that modern high-capacity wireless technologies have a clear path to quickly scale networks to multi-gigabit speeds, a capability that appears increasingly attractive for under-served UK businesses.

With such a clear and attractive business case, fixed wireless is presenting operators with a lucrative prospect for investment and establishing itself as a vital part of a diversified connectivity ecosystem.

New technology and the future of UK connectivity

Looking to the future, it is clear that recent advances in wireless sit alongside a significant market opportunity for operators.

Although fixed wireless is not as prevalent in the UK as fixed line, there was no dispute amongst us that the market’s perceptions of new technology is growing warmer. 

Underpinning this, the CBNL Enterprise Broadband Index revealed that 89% of businesses would consider moving to wireless services if the speed and reliability was comparable to, or greater than, their existing broadband.

Ofcom’s recent call for inputs to inform their programme of work to make millimeter wave spectrum bands available for 5G is also a significant indication of the value of high-capacity wireless in the UK market.

Increasing availability of millimetre wave, such as the 26GHz band, will be vital to unlock investment in enterprise broadband, allowing operators to benefit from the full potential of high band spectrum and catalyse the regeneration of a more diverse marketplace.

With the potential of these new technologies uncapped, panellist opinion was unified in its agreement that wireless innovation can bridge the gaps in the UK broadband market and pave the way for the next generation of connectivity.

Dr John Naylon, Chief Technology Officer, CBNL

M2M communications are transforming the world into one where everything and everyone is networked and connected.

The GSMA and Machina Research predict that the number of connected devices is set to double over the next eight years to 50 billion globally.

If that’s correct communication between these connected devices will explode.

But what does this mean for the operator and the consumer?

How will the proliferation of machine-to-machine (M2M) communications affect mobile data traffic and how can operators develop the next generation networks which will ensure that they are ready for the connected device explosion?

Debate in the industry has been centred on whether mobile operators and their network infrastructure can actually cope with the data demand that is expected with a critical mass of M2M applications.

Despite migration to 3G and LTE base stations, the proliferation of mobile connected devices continue to drive demand on networks and is challenging operators’ strategies to increase capacity and connectivity.

However, from an operator’s perspective, M2M communications is just another step in the inevitable modernisation of next generation networks.

It is imperative that operators deliver every bit of data at the lowest possible cost to not only increase capacities but to lower TCO and maintain profitability.

The best strategy to achieve this requirement is not always so clear.

Innovative next generation solutions such as small cells are the types of technologies that operators need to be considering to meet this challenge.

As always, the cost of mobile backhaul is a paramount consideration in running and launching new services, and indeed small cell backhaul equipment is forecast to expand very dramatically.

Whilst the challenge of providing high-capacity, carrier-grade backhaul to outdoor small cells has been much discussed, it is no longer seen as a barrier by forward thinking operators.

A range of efficient and flexible wireless technologies, including point-to-multipoint (PMP), is providing more cost-effective carrier-grade networks for operators than traditional backhaul techniques. 

For instance, PMP saves spectral resources and equipment through aggregating backhaul traffic from multiple cell sites.

This innovative use of wireless technology creates up to 50% TCO savings whilst delivering guaranteed quality of service over licensed spectrum.

Ultimately, M2M communications are designed to enable products and services that powerfully enrich peoples’ lives.

Current operator networks, built for voice and data transport, are already creaking under the weight of mobile data traffic and that’s even before your car checks the traffic along your route and uploads its maintenance data!

However the rate of innovation in architecture and technology in all parts of the mobile network is truly remarkable.

With wireless technologies coming to the fore, consumers can look forward to a more intelligent and connected world with networks that live up to their demands.

Dr John Naylon, Chief Technology Officer, CBNL

One of the most common questions we’re asked by new customers is,

“How do I decide when to deploy point-to-multipoint (PMP) and when to deploy point-to-point (PTP) for my backhaul?”

This is a great question, because the two technologies are very complementary to each other. 

An engineering perspective

From an engineering perspective, in making the choice between PMP and PTP for a given link, we are seeking to maximise efficiency and utilisation of the equipment and the RF channel while satisfying a set of requirements for throughput, latency and link availability. 

In economic terms, this translates into choosing the technology which gives the lowest total cost of ownership while satisfying those requirements.

Traffic characteristics

An excellent way to make the choice between PMP and PTP is to look at the characteristics of the data traffic we want to carry. 

I’m going to consider mobile broadband backhaul traffic here, because that’s what the majority of our customers use our technology for today. 

In a future post I will talk about small cell backhaul traffic.

As ever, the NGMN has some useful information we can use, in the whitepaper Guidelines for LTE Backhaul Traffic Estimation.

This paper describes (§2.2) the initially counter-intuitive result that the peak throughput for an eNodeB actually occurs, not during busy hour, but during quiet time. This is because:

“During busy times, there are many UEs being served by each cell. The UEs have a range of spectrum efficiencies, depending on the quality of their radio links. Since there are many UEs, it is unlikely that they will all be good or all be bad, so the cell average spectral efficiency (and hence cell throughput) will be somewhere in the middle.

During quiet times however, there may only be one UE served by the cell. The cell spectrum efficiency (and throughput) will depend entirely on that of the served UE, and there may be significant variations … the scenario under which the highest UE and cell throughputs occur [is]: One UE with a good link has the entire cell’s spectrum to itself. This is the condition which represents the ‘headline’ figures for peak data rate”.

Figure 4, reproduced here, illustrates this point:

Illustration of cell throughput during busy and quiet times

The paper goes on to give the following peak and mean traffic figures for a number of LTE configurations:

Figure 5: Mean and peak (95%-ile) user plane traffic per cell for different LTE configurations

Understanding the peak-to-mean ratio

What we can immediately see from this figure is that the peak-to-mean ratios of the traffic in the dominant, downlink, direction are very large, ranging from about 4:1 to almost 6:1. 

This agrees well with measurements we see from real networks. 

For example, the following from a very busy HSPA+ network show the peak-to-mean ratio of the backhaul traffic for each node B (on the y-axis) plotted against the peak backhaul demand for that node B on the x-axis.

Peak Backhaul Demand (Mbps)

When traffic has a high peak-to-mean ratio like this, we call it “bursty”, as opposed to “smooth” when the peak-to-mean ratio is close to 1. 

Data traffic in general, for example on LANs and residential internet access connections as well as mobile networks, is bursty; and this presents a difficulty in carrying it efficiently on PTP links, as shown here:

Bursty traffic is hard to carry effeciently

The problem here is that a PTP link with a single traffic source (a ‘tail link’ in the backhaul network) needs to be dimensioned to carry the peak traffic, but there is only a single source of offered load. 

Therefore the utilisation of the link (or efficiency) is equal to the mean offered load divided by the capacity, or in other words the reciprocal of the peak-to-mean ratio of the traffic. 

So if my traffic has a peak-to-mean ratio of 4:1, the maximum utilisation of a PTP link carrying that traffic is ¼, or 25%. 

In the chart above, you can visualise this as all the white space below the red line being wasted bandwidth, which is provisioned but unused.

It’s important to say that this is not a failing in PTP systems in any way – it is simply that the characteristics of the traffic are not well suited to the static bandwidth provisioning that PTP provides.

The advantage of a PMP system is that it can serve multiple sources of offered load simultaneously. 

The bandwidth of the shared RF channel is dynamically allocated to different sources as required. 

Conceptually, then, the peaks and troughs from different traffic sources ‘cancel out’ to some extent, as we illustrate in the following live network example showing eight nodeBs being backhauled by a single VectaStar Gigabit sector.

Multipoint backhaul packet switched not circuit switched

Here we are also relying on another property of the traffic, namely that peak demands for different nodeBs do not occur at exactly the same time. 

We discuss this at greater length in The Effect of System Architecture on Net Spectral Efficiency for Fixed Services.

Liberating spectrum to meet growing capacity demands

A useful analogy here is to think about a bank with deposit accounts.

Banks operate a fractional reserve system, meaning that they are only able to repay a defined fraction of the total of deposits at any given time.

This therefore relies on the observation that, statistically, not everybody goes to the bank and withdraws all their savings at the same time.

When this assumption breaks down, there is a ‘run on the bank’.

In a similar way, we rely on the observation that, statistically, not every node B requires its theoretical peak backhaul throughput at the same time.

When this assumption breaks down, things are a bit less dramatic however – we simply discard some low priority traffic.

This is perceived (if at all) by users as a temporary reduction in internet browsing speed.

Crucially, we can dimension the system in such a way as to set the probability that this occurs to a value of our choosing.

The advantage of fractional reserve banking is that it liberates dormant capital for further investment and lending.

Likewise, the more efficient use of RF channels in PMP systems liberates dormant electromagnetic spectrum (provisioned but unused, as in the example above) for use addressing the ever-growing capacity demands of modern mobile networks.

Conclusion

In conclusion, then, some brief rules of thumb for when to deploy PTP and when to deploy PMP are as follows:

Deploy PTP…
… when traffic is smooth (voice dominated)
… when traffic has already been aggregated
… in the middle mile of backhaul
… for long distance links
… when spectrum is uncongested or inexpensive
Deploy PMP…
… when traffic is bursty (data dominated)
… to create an on-air traffic aggregation
… for tail links (last mile)
… for dense deployments
… when spectrum is congested or expensive

 

Julius Robson, Wireless Technology Specialist, CBNL

I was recently pondering on the amount of spectrum available for the different types of small cell backhaul, when I came across a table of the UK spectrum allocations in the "Frequency Band Review for Fixed Wireless Service" for Ofcom.

Plotting the available bandwidths on a graph alongside sub-6GHz allocations for mobile access makes for an interesting comparison:

 

Starting at the bottom, we see that around 1.5GHz - a quarter of all spectrum below 6GHz - is available for mobile access of one sort or another.

This includes licenced cellular 2G, 3G and the forthcoming LTE allocations, as well as the 2.4 and 5GHz unlicensed bands for Wi-Fi etc.

In comparison, allocations for ‘microwave’ links between 6 and 60GHz are over ten times the size, with over 16GHz available.

Adding to this the 18GHz or so available for ‘millimetre wave’ between 60 and 80GHz, we see an enormous potential for high capacity transport.

Not only is there more spectral bandwidth, but the spectral efficiency is generally much higher for fixed Line-of-Sight (LoS) microwave links than for Non-Line-of-Sight (NLoS) mobile access.

The end result is significantly more capacity for microwave.

This analysis helps quantify the scarcity of NLoS spectrum below 6GHz and the need to reserve it for mobile access.

On the other hand, LoS spectrum above 6GHz is relatively abundant and is well suited to fixed backhaul links.

For small cell backhaul, we see microwave and millimetre wave LoS links doing the heavy lifting and backhauling the bulk of the capacity, whilst the NLoS solutions will address special situations that cannot be reached any other way.

Published 24 May 2012 in Backhaul, Research
Tags: Wireless, Fibre, LTE, 3G, 4G, Capacity, Cost, White Paper, Economics

Chris Wright, Marketing Manager, CBNL

Our latest white paper examines how mobile operators planning to move to fibre backhaul can significantly lower costs by using wireless now, and investing in fibre later.Our latest white paper examines how mobile operators planning to move to fibre backhaul can significantly lower costs by using wireless now, and investing in fibre later.

This strategy uses wireless as an interim solution for operators that need to increase backhaul capacity, but cannot move to fibre today.

The paper shows that over ten years, operators can reduce the Net Present Value (NPV) of their backhaul upgrade by:
 

  • 7% in developed markets and 31% in emerging markets compared with leased fibre
  • 14% in developed markets and 27% in emerging markets compared with built fibre.

Fibre: a complex journey

The transition to fibre backhaul is often complex, expensive, and time consuming.

Building a fibre network requires a huge initial investment and a long deployment time, with permitting and negotiation of right-of-way access rights often taking longer than installation itself.

If an operator chooses to lease fibre but does not have a privileged relationship with a fibre provider that ensures affordable pricing, it may find high rental costs in some areas, especially in emerging markets.

However, a hybrid approach can ease the pressure of transitioning to fibre, upgrading networks and making the necessary investments.

Why panic?

The white paper outlines that there is plenty of breathing space to be had by not jumping straight in to a full-on fibre commitment.

It provides new financial analysis on the implications for operators choosing from different backhaul solutions - wireless, leased fibre, and built fibre - and compares these choices to the adoption of wireless backhaul as an interim solution in both developed and emerging markets.

If they have access to spectrum, operators may save money by initially deploying a wireless backhaul solution that is paid off in a short period, and moving to fibre gradually at a later time, when and where it becomes available or cost effective, or when the operator is ready to deploy it.

The overall cost savings of the wireless-to-fibre solution are due to the combined effect of the lower cost of ownership of wireless backhaul and the financial benefits tied to postponing fibre investment.

Get your free copy

Download a FREE copy of our latest white paper - 'Wireless backhaul can ease transition to fibre'