Since its intial rollout in 1985 with three carriers using an analogue-based system, the cell phone industry has evolved and grown into a product and service that have become almost essential to out everyday lives. Now, 25+ years later we have multiple carriers offering various services marketed towards key consumer segments. There are only three carriers (Telus, Bell, Rogers) that build and maintain physical networks (and now a new fourth, Wind), although there are many brand names reselling services on those networks (Koodo, Solo, Fido, Virgin, PC Choice, 7-11, etc). Below is a chart outlining the technology breakdown of the three main carriers and their five main physical networks.

CARRIER	NETWORK	VOICE Frequency Band	DATA Frequency Band
	CDMA	1900 MHz	1900 MHz
	HSPA*	1900 MHz	800 MHz
	Mike (iden)	800 MHz**	800 MHz**
	CDMA	1900 MHz	1900 MHz
	HSPA*	1900 MHz	800 MHz
	GSM	1900 MHz	1900 MHz

* this is a joint-venture network shared between Telus & Bell
** this 800 MHz band is not the same as the cellular 800 MHz band and requires different amplifier equipment

Voice Band includes: voice calls, standard text messaging, and voicemail notification
Data Band includes: multimedia text messaging, email, and web browsing

Each hardware device is specific to a carrier and is also specific to a network for that carrier. 
The frequency assignments (aka channels) in a given frequency band are unique to each carrier.

There are a number of carrier towers throughout the city, province, and country. For example, Telus has over 450 CDMA towers in Alberta and about 125 in Calgary alone.

Some towers are exclusive to a specific carrier and others are shared by multiple carriers.

Tower height is very important in that a shorter tower will more likely be affected by terrain and obstructions.
Cellular signals will not penetrate or go over hills or metal structures.

Antenna placement on a given tower is generally one of two configuration types. The most common type is three antennas placed 120 degrees apart with the first pointing roughly north. The second type is two antennas 180 degrees apart pointing along a road and/or through a valley.