The radiofrequency spectrum is a scarce resource. In Canada, ISED regulates its use to prevent interference between different users. With respect to interference, there are two types of users:

1. Primary users are given priority of a frequency and are protected from interference.
2. Secondary users cannot interfere with primary users, and are not protected from interference.

For voice communications in Canada, CB radios and FRS radios are the two main license-exempt options. However, from ISED FAQ #6:

It is illegal for consumers to import radio devices into Canada that do not bear a label with an Industry Canada certification/registration number.

For voice, FRS radios are the most practical option.

Channels

There are 22 channels in the 462 and 467 MHz band:

To help quiet (squelch) unwanted signals, FRS radios have the option of transmitting a CTCSS tone or DCS code (AKA: “PL tones”, or “sub-audible tones”). These are low “bass notes” or digital information that the radio transmits on top of the voice, but which can't really be heard. If the receiver is configured to expect a specific tone/code, it will keep the speaker squelched unless that tone/code is detected. This is useful to ignore chatter from others on a busy channel, but if two radios with different tones transmit at the same time on the same channel, they will interfere with one another.

K0TFU has a really good article explaining all of this for FRS radios: FRS/GMRS Privacy Codes Demystified, and our own site goes a little deeper in the context of ham radios.

• The antenna of FRS devices shall be an integral part of the unit.
• FRS/GMRS devices shall not:
  • be designed to interconnect to public switched telephone networks
  • be designed to transmit data in store-and-forward packet operation mode
  • incorporate one or more scrambling features (e.g. encryption, voice inversion, obscuring)
• All frequency determining circuitry, including crystals and programming controls, shall be internal to the transmitter and made inaccessible to the user from the exterior of the device.

First Use Setup

Refer to the user manual for specific instructions, but in general, you should try and:

• Disable the CTCSS/DCS on all 22 channels. On the Revetis RB48, the CTCSS/DCS is represented by a number between 1 and 121 (on the right). The number 0 means that CTCSS or DCS is disabled.
• A Roger Beep is a short chirp that's transmitted when you let go of the PTT button to indicate that you're done talking. It can be pretty annoying for others and you should turn it off.
• VOX is an option to transmit without pressing the PTT. You should turn that off unless you have a good reason for using it since you could transmit without meaning to.

From Wikipedia:

MeshCore is an open-source mesh networking protocol and software platform designed for off-grid, low-power text communication using LoRa (Long Range) radio technology. The system enables decentralized, multi-hop wireless messaging without reliance on cellular networks or internet infrastructure.

Use cases include emergency and disaster communications, outdoor and remote activities, [...] and experimental and educational deployments of low-power mesh networking.

[It] is designed to [...] operate in unlicensed ISM frequency bands such as 868 MHz and 915 MHz, depending on regional regulations.

The basic idea is that you get a small companion device that you pair to your cell phone via bluetooth, and via that device, you can text others or post public messages using the 915 MHz band, all without a special license.