Asterisk to Cellular - recommendations?

Investigating a potential solution for the company I work for. Very small company, just a handful of people and perfectly willing to share one traditional-style outside line (one person using it at a time).

Because the offices are moving, and our current provider can’t be arsed to provide us with the same features at the new location, I am looking into Asterisk. Got into it briefly about five years ago, worked like a charm. Looking to repeat my success here.

My question involves more hardware and any configuration difficulties. I would like to move the company’s phone number over to a cell provider, and have only minutes on that cell SIM. I want to then connect that SIM card via an adapter up to Asterisk such that the cell SIM becomes the PBX gateway. Asterisk will also be connected to the network, and it is through the network that calls can be routed to RJ-45 VoIP phones and across the Internet to the appropriate mobile apps on our personal cell phones.

I already have surplussed hardware that I can use for the Asterisk installation. What would I need (for a desktop-style computer) to have a cell SIM as the gateway? would it be an internal card to plug into a PCI/PCI-e slot, or would it be an external USB dongle? What would be the recommended models to search for?

Only one SIM will be attached to Asterisk. It will accept incoming calls (from customers, to the PBX) and be able to make outgoing calls (to customers, via on-phone apps or through the VoIP RJ-45 phones in-house). The machine currently being earmarked for Asterisk will be accessible from the Internet and will have its own subdomain attached to it.

Suggestions? Recommendations? Opinions? Looking for guidance so I can be shoved in the right direction; anything beyond that is just a bonus.

You can get GSM gateways, but their use may be illegal in some countries, because they waste air interface resources that are really intended for truly mobile devices.

Where they are allowed, it is mainly for fixed to mobile calls, and there is usually a ban on third party traffic.

This sounds like exactly what we are looking for. Two way communication across the Cell network to an internal VoIP system that also includes apps on our personal phones. That way, people can phone a single number and get any of us through a standard Asterisk menu tree.

Are there models you would recommend for ease-of-use and appropriateness for Canada?

I’m using a 3G-Dongle connected to a USB port. I tried a Huawei E173 and a Huawei E180. Both working fine.

frank71 - could you please give some details how you set up usb dongle on your Asterisk ?