Modeling the fair co-existence of LAA and Wi-Fi

By Julie Bradford

More often than not, the debate around the use of licence-exempt spectrum is driven by passion rather than analysis. After all, this is a debate whose impact goes beyond the technology choice, or financial impact; which technology is selected will set an important precedent for how unlicensed spectrum should be used.

It’s for this reason that we at Real Wireless were delighted that Cisco asked us to simulate and assess options for the co-existence of LAA-LTE and Wi-Fi, helping to redress the balance of the debate by introducing some cold, hard, technical data into the narrative.

At the heart of Wi-Fi’s success is the premise of fair co-existence, enabling multiple Wi-Fi system owners to deploy Wi-Fi access points in the same unlicensed spectrum in an unmanaged fashion. Service providers increasingly wish to also make more use of unlicensed spectrum in order to contribute to mobile system capacity, with one of several means of achieving this being Licensed Assisted Access (LAA-LTE).

Our work for Cisco was presented at the recent CEEC 2015 conference and forms part of their LAA-LTE contributions to 3GPP. Cisco’s contribution turns on a feature called listen before talk (LBT), of which there are a variety of different schemes available.

For this analysis, we used one of Real Wireless’s own, custom-developed tools – in this case, the Wi-Fi and LTE (WaLT) system simulator. Using this tool, we modelled co-existence performance between LAA-LTE and Wi-Fi when set up to use a variety of candidate LBT schemes. These interactions are highly complex, therefore a sophisticated simulator was required, the product of our collective experience and knowledge of modeling techniques.

The results of our simulations clearly demonstrate that the details of the choice of LBT scheme and settings of that scheme matter significantly to achieving fair coexistence.

This was a great project to be involved with, particularly as it gave Real Wireless and Cisco the opportunity to add a much more scientific voice to a hotly contested issue.

Download Fair Co-Existence of Licensed Assisted Access LTE (LAA-LTE) and Wi-Fi in Unlicensed Spectrum

Download Fair Co-Existence of LAA and Wi-Fi presentation »

Key considerations in the development of 5G

I recently gave a talk at a Westminster eForum event, discussing the challenges that 5G development faces.

This was part of a wider discussion about the future of networks, devices and 5G, with speakers from YouGov, Vodafone, Qualcomm and Analysys Mason participating in the conversation. Together we left no stone unturned, examining the latest trends, regulatory perspectives, what 5G will actually look like — and much more.

One clear point that came out of the talks was that, despite recent statements to the contrary, there remains a lot still be decided about 5G. As a result, it’s important we look carefully at who will be using the 5G standard and what implications that may have, not just the technology side of the equation.

5G — enabling new applications
5G isn’t just about doing things faster; it will be the first generation to explicitly target the needs of multiple vertical industries. The graph below is designed to illustrate the challenge at hand. The grey area denotes the applications whose needs LTE cannot currently meet, and these are where 5G could demonstrate real added value over LTE.


Addressing the Internet of Things and multimedia
One of the key conflicts that embodies the challenge of 5G is between the demands being placed on it by the Internet of Things and multimedia applications.

These each have a vastly different set of requirements, with IoT emphasising low power and reliability, and multimedia content a need for high capacity and data rates.

The diagram below demonstrates the different factors that need careful consideration where 5G is concerned, and how the two applications differ:



Rather than rushing out the next generation of cellular technology to meet arbitrary deadlines, time needs to be spent now thinking about how 5G can serve the wider societal and industrial needs — not just smartphones and tablets. Much thought also needs to go into the compact between investment and competition, the answers to which could come from network architecture.

At the same time, we need to avoid the real risk of overhyping 5G in the next few years, creating a much larger headache for the industry later on. For the time being, users are only just starting to come to terms with 4G, therefore we need to ensure we take the time to consider the next generation — squeezing out the maximum value we can out of the current generation in the meantime.

For more information on the considerations for 5G, take a look at the slides I presented in full here:

For more information on Real Wireless’s work in 5G, read our recent blog post.

Public Wi-Fi presents a great opportunity for Virgin

Last month, Virgin announced a major expansion of its Wi-Fi hotspot network, with the investment intended to challenge BT’s dominance of the Wi-Fi space. In this blog post, Real Wireless Expert Ade Ajibulu looks at how Virgin could be taking advantage of the latest Wi-Fi technologies to offer a game-changing service.

With BT boasting more than five million hotspots, most of them via home routers, Virgin has some catching up to do. Cost is certainly a key part of the decision, with network capacity only getting more expensive at the same time as mobile data use goes through the roof.Public WiFi

This move could however be a complete game-changer, opening up new revenue streams taking multi-play offers to the next level, disrupting the plans of the traditional MNOs and maintaining customer loyalty in the face of competition from disruptive players such as Sky and TalkTalk.

The key is in taking advantage of cloud-based Wi-Fi cellular integration tools coming to the market, which promise to deliver cellular-like quality of experience on hybrid networks and which, unlike bespoke software solutions, scale with the size of the Wi-Fi network.

Video services are an integral part of the offering, and any expanded Wi-Fi network will need to deliver the same quality of experience and reliability as the cellular network.

For this to work, the network requires performance optimisation and automated fault recovery techniques, plus seamless handover and full integration between cellular and Wi-Fi. This means that subscribers can experience the same content and services over any device, regardless of location and on the move, and that it is immaterial whether a user is on the cellular or Wi-Fi hotspot network.

Up until now this has been technically difficult and expensive.

However, with emerging technologies such as Hotspot2.0/Passpoint, this is set to change. These can support seamless handover along with a new generation of cloud based services, providing a full range of cellular and Wi-Fi integration and performance management techniques.XCellAir is one of a number of companies currently providing such a service.

It would reduce reliance on the EE network, without having to acquire spectrum or having to acquire all the mobile network engineering expertise to operate carrier grade networks. It would also bring significant revenue opportunities at a time when a number of issues are being thrown up by BT’s proposed acquisition of EE.

In order to make the most of the proposed move, now is the time for Virgin to be considering these services.