The question of free urban Wi-Fi most often comes up in the context of travel — as tourists we want to be able to connect easily and for free from wherever we are. But with well over half the world owning a smartphone, every urban dweller wants to know they’ll be able to get the content and functionality they want from their smartphone wherever they are. These days, we aren’t just accessing data more often, we’re accessing more of it, more of the time, and the “always on” lifestyle requires a constant shroud of Wi-Fi coverage to follow us wherever we go.

Moreover, with the rise of the Internet of Everything and M2M, municipal wireless networks are becoming as much about a connected trash can as they are about the end user streaming YouTube on their smartphone. Beyond offering free Wi-Fi to citizens and tourists, the wireless networks of our cities will have to be robust enough to handle huge amounts of data on the one hand or many small bursts of bits-and-bytes of data on the other. Furthermore, some of the services and applications — like traffic control and power grid communications — will be considered “mission critical,” while others, like smart meter readings, are less time-sensitive. It’s critical, therefore, that the city’s wireless network be both flexible and scaled enough with respect to the different services and their respective needs.

Cities across the world are struggling to come up with a solution to providing reliable public Wi-Fi to meet these new consumer and urban demands, and many — like Taiwan, Paris, Tel Aviv and Perth to name just a few — have developed and implemented free Wi-Fi networks shrouding downtown areas, designed to make the urban experience more enjoyable for both tourists and residents. But these networks often aren’t geographically comprehensive, and they are barely equipped to deal with the kind of traffic they are getting now, let alone the traffic we can expect to see in the coming years.

Instead of trying to build entirely new networks, cities, supported by internet service providers and mobile carriers, would be better served by leveraging already existing networks, like all the private residential Wi-Fi networks that are already spread throughout the city.

Imagine turning every home currently connected to the internet into a mini Wi-Fi hotspot serving the public, so that anytime a subscriber walked past a participating home network their phones would automatically connect to that Wi-Fi network, thereby lessening their own data charges and significantly reducing the strain on mobile carrier networks. All this is made possible by home subscribers giving up a small, likely unused, percentage of their Wi-Fi to make it available for public use.

Major global internet service providers like Comcast, Fon and Liberty Global have already started to implement this kind of home network partitioning, splitting off some of the unused private Wi-Fi to create a public network of community hotspots, and then often offering home subscribers access to other Wi-Fi hotspots in the same “community” in return. In many ways, this trade-off model represents an ideal solution to the problem of providing public Wi-Fi. It takes advantage of an already existing Wi-Fi network, and appears as a win-win situation — even residential subscribers stand to benefit from public Wi-Fi when they are out and about.

Nevertheless, such network partitioning brings with it a range of issues which will need to be resolved in order for community Wi-Fi to be a truly viable option. Internet service providers will need to be able to control the amount of bandwidth that public subscribers can use so that they don’t “steal” too much bandwidth from the home network and degrade the experience of the home user. Like a problem child, hogging their parents’ attention, smartphones with simpler Wi-Fi technology embedded will exert a much heavier strain on bandwidth than most other in-home devices. Basic Wi-Fi behavior could enable a passing public user, who is connecting to the Wi-Fi router from the street, to drain most of the bandwidth so that the private user’s experience is compromised.

Assuring quality of service for the private home network will therefore be a critical issue if community Wi-Fi is to succeed. ISPs must avoid a situation where this new service causes an upswing in service calls and increased churn as unhappy private home subscribers resist sharing their Wi-Fi, while also ensuring they don’t put too many constrains or limitations on the public Wi-Fi service, making it inaccessible or unattractive. In order for public Wi-Fi hotspots to work effectively, ISPs must find a way to control their Wi-Fi networks so that a manageable portion of the Wi-Fi resource is allocated for public use, and certain kinds of data or users have priority.

Community Wi-Fi holds a lot of potential for enabling a functional connected future, where the barriers between private and public Wi-Fi blur to the extent that both humans and machines are able to be constantly and reliably connected. The key to ensuring that the connected city, and indeed the connected world works, is to make sure that just as the traffic on our streets is regulated, so too is the data traffic in our air.

Lior Weiss is VP of Marketing at Celeno Communications.