more noob cell phone questions

[Yes]

From what I've read, it looks like I have three main options or various
combinations of them for phone service at my home

1. landline - traditional method and what I have now
2. cellular service
3. VoIP - voice over interent

I currently have a landline but am willing to ditch it if I can
significantly cut my current monthly costs. I have AT&T's basic high
speed internet service that includes their router; I think they call it
Gateway but am not sure. It has several ethernet ports and a wireless
component. I use the ethernet connection (wired) to connect it to my
pc.

Cellular service. Never used one before because I'm on the phone a lot
and the cost of cell phone service seemed like it would run me $100+
per month. That's not in my budget. But it seems like cell phone
companies have cut their prices quite a bit and offer more plans since
I last cared to look at them.

VoIP. Never used it before because it was immature tech. Reviews of
it now are much, much better. It seems to offer a very cost
competitive alternative to cellular phone service as long as I'm at
where I've got it set up.

Here's what I want to accomplish -
1. be able to make and receive phone calls at various spots within my
home.

2. Be able to make emergency calls to 911 and perhaps to taxi service
if I'm not at home.

3. have a handset similar to traditional phones but that I can change
the volume as needed.

4. SMS - I haven't made up my mind. The local bus line offers SMS to
check current bus schedule, which is nice. That's all that I've used
SMS for so far. So it's nice but not necessary.

5. get the best bang for the buck :-) I guess that these days I'm on
the phone at least 5 hours per week. When I research stuff, I can be
on the phone about twenty hours a week for several weeks running.


Web surfing, and video/music streaming services for a phone are not
desired. I can use my desktop for that. So a basic cell phone seems
most suitable for what I expect to do.

I've been Googling for info, but it's GIGO if you don't know the
"right" search terms to use.

First question. are there any cell phone companies that offer unlimited
talk time not bundled with anything else? If I use a phone for talking
only, data service is superfluous, and I already have internet service
at home. Nor do I have wireless devices at home, so the capability to
view stuff on a TV is also redundant.

I initially thought I had gotten terminology and what can be used with
what straight. but read a comment that threw me off. It seemed like
the comment was saying that a cell phone provider can block a cell
phone from using wi-fi service provided by a competitor. Even though
wi-fi and cellular phone service are both "wireless", I thought that
they were independent services, that cellular phone service was
described as WAN whereas wi-fi service was called LAN with a working
radius of 50-100 feet or so.

Do all cell phones have the capability to send and receive wireless
(LAN) signals?

Does the cell phone have to be registered and activated with either a
cell phone carrier or what is called an MVNO in order to use the Wi-Fi
(LAN) capability?

In other words, could I buy a basic - not Smartphone - cell phone off
the shelf at a local store and immediately use it on a LAN? Does it
have to have a SIM card in order to work with a Wi-Fi (LAN)?

Power supply. Are the basic cell phones designed to be left turned on
24/7? I'm thinking of the scenario in which the cell phone replaces my
landline. Battery life is clearly an issue. Are they designed so that
you can remove the battery and plug the phone into a power source such
as an AC/DC power converter, saving the battery to use only when you're
in the field? Alternatively, are cell phones designed so that you can
leave the power source plugged in all the time without damaging the
battery?

It seems like VoIP may be a more cost effective alternative to either a
traditional landline or to a cell phone, but it has its own equipment
requirements and can only be used at a location where the equipment has
been set up. I can live with that particular constraint. Most of what
I've read has been using VoIP with traditional phone equipment, both
wrt wiring and to handsets or to expensive equivalents.

Is there a way to use a basic cell phone, like in the example I posed
wrt to wi-fi (LAN), but with VoIP instead? Or would it require a
SmartPhone to use VoIP at my home? I want to be able to walk around to
various spots in my house to carry on a conversation, but the stuff
I've read for VoIP talks about using the existing landline wiring in
the house to plug in handsets, and from discussions I've had in another
forum re-purposing the existing phone wires in my home is not practical
unless I wanted to spend a lot of money.

Thanks,

John