I think the parent here is suggesting though that you should be able to dynamically choose which tower/provider your phone is using, and would just be charged for the time on the system that you use. It’s a bold idea, and would destroy the existing carriers business model (which is largely dependent on contracts)
Of course the last thing that any ISP (wired or wireless) wants to do is commoditize their service as a a dumb data pipe - they all want the margins of those over-the-top services.
The SIM card contains information that allows it to negotiate with available cells regarding which cells and with what parameters it can connect.
The cell relay network (NodeB/RNC/etc) the connection to their owner service which sets up authentication with the SIM card - either by consulting service's "phone number database" based on the IMSI number of the SIM card, or by forwarding it to roaming peer's database (HLR). Then it keeps tunnels between phone and appropriate gateway.
SIM provides the identity of the "account/connection".
IMEI provides the identity of the actual terminal (arguably a bit like MAC address) - called "User Equipment" in UMTS/LTE/5G
BTS/NodeB/RNC/etc. - the radio segment - BTS/NodeB/ENodeB being the "base stations" and RNC is the radio controller (also called Mobile Management Entity in newer standards) which handles setting up connectivity from UE over NodeB to appropriate gateways (connecting to IP network or circuit switched phone networks)
HLR/HSS - Home Location Register / Home Subscriber Server - the part of the system that authenticates the subscriber identified by SIM. It's what maps the connection to right entity in network (to route phone numbers, match billing, etc.) - when you use roaming, the RNC/MME is set up in a way where it can find your original HLR/HSS (tackling extra fees as necessary)
gateways - different depending on version of network as well as whether you use IMS-only network (aka VoLTE/VoNR, in actuality part of 3G known better to people here as VoIP/SIP), or whether circuit switched fallback is used (operates purely on 2G and 3G, with latter being added in later revision).
Unless the consequences of violating the rules is sufficiently expensive to harm earnings and growth, any rule you set forth is just cost of business.
i.e Local Roaming. The problem is there is no way to ensure QoS over the network. You will need additional functions to ensure the network is best every time you switch.
>What do people here think of that? Would it help?
I am assuming you are talking about US MNOs or Carriers. And I am often lost and dont understand how anything in US works. It seems there are decent options, like Mint [1] which offer very decent 5G price plan, especially considering the wages across US. $30 for Unlimited or $25 for 20GB is very respectable.
So I am not exactly what the proposal would help, or trying to fix or improve.
Edit: I will add more context. If it is about better coverage and more site being built. Then this is actually a property ( surprise surprise ), regulation and market issues. No Technology is going to save you if the market, regulation or the people / culture does not allow you to install a 5G radio because they are scared.
European here and not an expert on this, maybe it's different in the US or I'm gravely misunderstanding something.
You can't select any network, your home carrier has to have an agreement with the network you select.
They're talking about switching operators, not roaming - roaming means your traffic is still routed to your own provider. The concept, if I understand it correctly, is that you'd pay the best offered rate per byte around you at the moment, and your phone would be dynamically switching networks based on the offers.
The problem with this is that unlimited plans would go out of the Windows and we'd be back to paying per byte. Not great imho.
We could mandate that providers must accept cell phones which can dynamically switch between networks at will. The wireless protocol can communicate the cost of access at any given moment and the device can decide which network to use.
Under such a system, lock-in is eliminated and providers finally see the full power of competition. Right now with high entrance and exit fees, competition is reduced significantly. This would aim to fix that.
What do people here think of that? Would it help?