Introduction to Indoor Wireless
A very large part of the usage of mobile devices – and mobile and other wireless networks – is indoors. Estimates vary but perhaps 70-80% of all wireless data is used while fixed or “nomadic”, inside a building. However, the availability and quality of indoor wireless connections (of all types) varies hugely. This impacts users, network operators, businesses and, ultimately, governments and society.
Whether the use-case is watching a YouTube video on a tablet from a sofa, booking an Uber from a phone in a company’s reception, or controlling a moving robot in a factory, the telecoms industry needs to give much more thought to the user-requirements, technologies and obstacles involved. This is becoming ever more critical as sensitive IoT applications emerge, which are dependent on good connectivity – and which don’t have the flexibility of humans. A sensor or piece of machinery cannot move and stand by a window for a better signal – and may well be in parts of a building that are inaccessible to both humans and many radio transmissions.
While mobile operators and other wireless service providers have important roles to play here, they cannot do everything, everywhere. They do not have the resources, and may lack site access. Planning, deploying and maintaining indoor coverage can be costly.
Indeed, the growing importance and complexity is such that a lot of indoor wireless infrastructure is owned by the building or user themselves – which then brings in further considerations for policymakers about spectrum, competition and more. There is a huge upsurge of interest in both improved Wi-Fi, and deployments of private cellular networks indoors, as some organisations recognise connectivity as so strategically-important they wish to control it directly, rather than relying on service providers. Various new classes of SP are emerging too, focused on particular verticals or use-cases.
In the home, wireless networks are also becoming a battleground for “ecosystem leverage”. Fixed and cable networks want to improve their existing Wi-Fi footprint to give “whole home” coverage worthy of gigabit fibre or cable connections. Cellular providers are hoping to swing some residential customers to mobile-only subscriptions. And technology firms like Google see home Wi-Fi as a pivotal element to anchor other smart-home services.
Large enterprise and “campus” sites like hospitals, chemical plants, airports, hotels and shopping malls each have complex on-site wireless characteristics and requirements. No two are alike – but all are increasingly dependent on wireless connections for employees, visitors and machines. Again, traditional “outdoors” cellular service-providers are not always best-placed to deliver this – but often, neither is anyone else. New skills and deployment models are needed, ideally backed with more cost—effective (and future-proofed) technology and tools.
In essence, there is a conflict between “public network service” and “private property” when it comes to wireless connectivity. For the fixed network, there is a well-defined “demarcation point” where a cable enters the building, and ownership and responsibilities switch from telco to building owner or end-user. For wireless, that demarcation is much harder to institutionalise, as signals propagate through walls and windows, often in unpredictable and variable fashion. Some large buildings even have their own local cellular base stations, and dedicated systems to “pipe the signal through the building” (distributed antenna systems, DAS).
Where is indoor coverage required?
There are numerous sub-divisions of “indoors”, each of which brings its own challenges, opportunities and market dynamics:
• Residential properties: houses & apartment blocks
• Enterprise “carpeted offices”, either owned/occupied, or multi-tenant
• Public buildings, where visitors are more numerous than staff (e.g. shopping malls, sports stadia, schools), and which may also have companies as tenants or concessions.
• Inside vehicles (trains, buses, boats, etc.) and across transport networks like metro systems or inside tunnels
• Industrial sites such as factories or oil refineries, which may blend “indoors” with “onsite”
In addition to these broad categories are assorted other niches, plus overlaps between the sectors. There are also other dimensions around scale of building, single-occupant vs. shared tenancy, whether the majority of “users” are humans or IoT devices, and so on.
In a nutshell: indoor wireless is complex, heterogeneous, multi-stakeholder and often expensive to deal with. It is no wonder that most mobile operators – and most regulators – focus on outdoor, wide-area networks both for investment, and for license rules on coverage. It is unreasonable to force a telco to provide coverage that reaches a subterranean, concrete-and-steel bank vault, when their engineers wouldn’t even be allowed access to it.
How much of a problem is indoor coverage?
Anecdotally, many locations have problems with indoor coverage – cellular networks are patchy, Wi- Fi can be cumbersome to access and slow, and GPS satellite location signals don’t work without line- of-sight to several satellites. We have all complained about poor connectivity in our homes or offices, or about needing to stand next to a window. With growing dependency on mobile devices, plus the advent of IoT devices everywhere, for increasingly important applications, good wireless connectivity is becoming more essential.
Yet hard data about indoor wireless coverage is also very patchy. UK regulator Ofcom is one of the few that reports on availability / usability of cellular signals, and few regulators (Japan’s is another) enforce it as part of spectrum licenses. Fairly clearly, it is hard to measure, as operators cannot do systematic “drive tests” indoors, while on-device measurements usually cannot determine if they are inside or outside without being invasive of the user’s privacy. Most operators and regulators estimate coverage, based on some samples plus knowledge of outdoor signal strength and typical building construction practices. The accuracy (and up-to-date assumptions) is highly questionable.
- Executive Summary
- Likely outcomes
- What telcos need to do
- Introduction to Indoor Wireless
- Where is indoor coverage required?
- How much of a problem is indoor coverage?
- The key science lesson of indoor coverage
- The economics of indoor wireless
- Not just cellular coverage indoors
- Yet more complications are on the horizon…
- The role of regulators and policymakers
- Systems and stakeholders for indoor wireless
- Technical approaches to indoor wireless
- Stakeholders for indoor wireless
- Home networking: is Mesh Wi-Fi the answer?
- Is outside-in cellular good enough for the home on its own?
- Home Wi-Fi has complexities and challenges
- Wi-Fi innovations will perpetuate its dominance
- Enterprise/public buildings and the rise of private cellular and neutral host models
- Who pays?
- Single-operator vs. multi-operator: enabling “neutral hosts”
- Industrial sites and IoT
- Can technology solve MNO’s “indoor problem”?
- Indoor coverage data is hard to find
- Insulation impacts indoor penetration significantly
- 3.5GHz 5G might give acceptable indoor coverage
- Indoor wireless costs and revenues
- In-Building Wireless face a dynamic backdrop
- Key indoor wireless architectures
- Different building types, different stakeholders
- Whole-home meshes allow Wi-Fi to reach all corners of the building
- Commercial premises now find good wireless essential
- Neutral Hosts can offer multi-network coverage to smaller sites than DAS
- Every industrial sector has unique requirements for wireless