We’re back to talking HetNets

Users buy experiences. And in today’s continually connected world, connectivity is an experience we seek out and cannot do without. We want instant access to online information and services, whether at home, out and about or on the move.

Connectivity is increasingly heterogeneous, but we treat it as a single experience. Users might connect to home Wi-Fi, 4G or 5G in a town, mmWave 5G in an urban city centre or a private network at their workplace. Regardless of the device connection, the expectation is a frictionless service with speeds matched to the need. Anything that interferes with this leaves a bad taste in the mouth. In reality, everyone has a ‘bad connectivity’ story to tell; using a poor mobile network when Wi-Fi would be stronger or struggling with patchy Wi-Fi when the 4G signal would offer better connectivity.

But it is not only about good coverage; the networks available to us need to be optimised and work together in delivering that experience. Network selection needs to be matched to the environment and task in hand. Some non-real-time applications will tolerate network interruptions and can recover gracefully, whereas others such as video calling will frustrate the user or at worst completely fail.

The better option is to assess, measure, select and use multiple networks concurrently to the best of their respective abilities. The objective – to provide an experience closer to the holy grail; a truly converged and superior connectivity experience and one that is network-aware, uses the best connections automatically, follows the user’s preferences but does not require any user intervention. As a concept, this is something which has been evolving and improving over time. An Apple or Android handset no longer blindly switches between Wi-Fi and cellular networks. These devices are continually checking the quality of the available networks to make network selection decisions, trying to provide the best user experience they can. Databases of connection quality history are kept to aid in that process. However, it is mostly a binary decision – one network or another.

Why does this matter? Historically, public Wi-Fi has been deployed by a wide range of entities, with widely varying experience in deploying radio networks. Some networks deliver a good customer experience, and others fall short. Slow-to-load web pages and calls dropping as a device switches from one option to another all contribute to a poor user experience. In a commercial environment such as a shopping centre, entertainment venue or stadium, this falls far short of the user expectation.

Implementations to date have mostly leaned towards the binary use of one network or another – with the effort focussed on selecting the right network at the right time. Using a mix of connectivity is always going to provide the best experience, and since iOS 7, Apple have been combining network paths. Using an IETF standard called multipath TCP (MPTCP), connections can be split into subflows and sent over separate networks for recombination at a capable endpoint. Apple originally introduced this for Siri – sending the request over both Wi-Fi and mobile connections and using the fastest response to give Siri a snappier feel.

It expanded the use of this to Apple Music, Maps and Siri – ensuring a resilient and responsive service while on the move. And if Apple is using a technology for a specific goal – i.e., maintaining and improving connectivity on the go – you can be assured that it’s a user experience led technology. It’s a commercial move too for Apple. Every small user experience enhancement contributes to delighted customers and increased interest in their products, so investing in this area of technology is clearly a good business decision.

As an important technology to manage HetNets, it is no surprise that the standardisation bodies have introduced convergence technologies into the latest releases. MPTCP has been standardised within IETF for some time and newer multipath standards are now in preparation such as QUIC and MP-QUIC. 3GPP have adopted convergence in Release 16 where they define the Access Traffic Steering, Switching, Splitting function (ATSSS) to incorporate and manage MPTCP (and most probably QUIC within R17). More recently the Broadband Forum have collaborated with 3GPP to create convergence specifications for Fixed Mobile Convergence (FMC).  The 5G core network is truly convergent – but convergence functions are not mandatory. However, it’s clear that they are going to be strategically crucial for operators to be able to provide better network experiences in a HetNet and FMC world.

As nations release licence exempt bands in the 6 GHz spectrum, the need for convergence is going to increase. These high frequencies will enable technologies such as Wi-Fi 6E to deliver huge data rates, but the high frequencies will also limit propagation creating a greater need for user devices to consider and utilise all available network options whether licensed or exempt.

During the current pandemic, video streaming has exploded. Zoom’s revenues had quadrupled by September 2020, and Microsoft recently reported a 50% increase in daily active users. This new reliance on video streaming for corporate users is not going to disappear anytime soon. While lockdowns and curbs on interacting will drop, predictions suggest remote working will retain much of the uplift instigated by the pandemic.

New streaming media platforms will emerge, and existing platforms moving to HTTP3 will need an alternative to TCP. While lots of research is ongoing in this sector, the 3GPP ATSSS and broadband forum convergence platforms are looking like strong contenders. On the enterprise side, the pandemic has also increased the use of Software Defined WAN (SD-WAN) which in its more mature form, implements a full converged network solutions (rather than just simple failover).

But while establishing new network models is a question of supply versus demand, understanding how users interact with connected services remains an area for improvement. Real Wireless has seen an increase in demand for intelligent network design and deployment scenarios to combat just this issue.

Taking stadia as an example, users will want strong connectivity in the car parks, conference rooms, stadium seats and around food and retail outlets. Deploying a network in accordance with a set of ground rules around signal level and coverage areas is one thing, but as devices make so many internal network selection and usage decisions, a deeper device understanding is now needed. Only by gathering device logs and understanding the device-level decisions made to select and converge networks can a true user experience be evaluated.

A stadium environment is clearly a complex one, and any complex environment will have pitfalls such as the overuse of customer data. Leveraging Real Wireless’s expertise and deep understanding of Wi-Fi, 5G and private 5G in particular will help to future proof public networks and ensure that the experience on offer is as closely matched to the user expectations as it can be.

So yes, we are talking about HetNets again but this time around the narrative needs to be a good deal more granular. A continual regime of minor changes and improvements will be necessary to incrementally move the user towards the holy grail of a truly converged network experience. It will be a long road, but by using existing and emerging convergence protocols and analysing user and device behaviour, networks can be evolved and connectivity improved to deliver the experience expected by the user.