Re: More context on ATSSS use case

[Olivier Bonaventure <[e-mail]>]

David,

> 
>     1)Increased capacity, 2) increased coverage and 3) increased
>     reliability.
> 
>     Let’s assume for simplicity an user which would be charged for the
>     amount of data he/she would use over a cellular network using
>     licensed spectrum while for all the data exchanged over the WiFi.
>     While the user is under a good WiFi coverage all his traffic is
>     going to be routed over the WiFi, no data traffic is going over the
>     cellular. However, when the user is in an area of limited coverage
>     or the level of interference reaches a certain threshold the quality
>     of the communication over the WiFi access degrades. As a result the
>     achievable throughput over the WiFi may get below a certain
>     threshold. At this moment the WiFi access may not be able to sustain
>     the throughput the user may require. The user may either switch over
>     to the cellular (paying a higher penalty) or use both accesses, WiFi
>     and cellular. When both accesses are used,  all the traffic below a
>     maximum threshold will go over the WiFi access, while all the
>     leftover traffic will go over the cellular access.
> 
> 
> Thank you - this is exactly the kind of user benefit I was asking for. 
> In other words: the user can save on monetary costs when watching a high 
> quality video in this very precise scenario of functional but slow Wi-Fi 
> while in range of high speed but expensive cellular. We can debate how 
> common this scenario is and how impactful the solution would be, but I 
> agree that this is an actual end-user benefit.

Today, most of the WiFi networks that the user can access are:
- home Wi-Fi where he/she has manually added a WPA/WEP key
- enterprise/school WiFi that rely on 802.1x or similar technologies

In addition to these two isolated WiFi networks, there ongoing 
deployments of roaming solutions that will allow the users to 
automatically access millions of WiFi access points.

Those who are part of the academic community know eduroam (see RFC7593) 
that basically enables any student to use with his/her credentials the 
WiFi network of any university network throughout the world.

Several network operators have deployed authentication techniques that 
enable their customers to be authenticated in any of the WiFi access 
points that they have deployed in homes and in various locations like 
shopping malls, train stations, ...

In parallel, there are efforts to enable users to roam from one of these 
managed WiFi network to another. The openroaming initiative ( 
https://wballiance.com/openroaming/ ) is one example of these solutions.

With WiFi roaming, each user will be able to potentially access millions 
of WiFi access points. These WiFi access points will provide very 
different an unpredictable performance compared to a fully managed 
cellular network. With ATSSS, users will be able to use the roaming WiFi 
networks when they work well and automatically offload/switch to 
cellular when their performance is not sufficient.

We've all experienced the situation of been connected to a WiFi network 
in a pub and then need to manually disable WiFi to force the utilisation 
of the cellular network between the pub's DSL link is currently 
overloaded. ATSSS would make this seamless for the enduser for all 
applications and will also allow to use the WiFi network for part of the 
traffic which will be beneficial for the user's bill.

I expect that this scenario will be very common

Olivier