All Canadian mobile providers offer some type of prepaid cellular phone plan, which are not backed by a contract, require no monthly minimum and offer students, casual users and people will bad or no credit history the opportunity to activate a plan.

Prepaid services, commonly referred to as pay as you go (a Rogers brand) are usually more expensive to maintain than monthly or contract plans and tend to offer users less options than what you would normally expect -- Internet access being one of them.

GSM Services

GSM services are a standard collection of applications and features available to mobile phone subscribers all over the world. The GSM standards are defined by the 3GPP collaboration and implemented in hardware and software by equipment manufacturers and mobile phone operators. The common standard makes it possible to use the same phones with different companies' services, or even roam into different countries. GSM is the world's most dominant mobile phone standard.

The design of the service is moderately complex because it must be able to locate a moving phone anywhere in the world, and accommodate the relatively short battery life, limited input/output capabilities, and weak radio transmitters on mobile devices.

Canada currently has two prepaid sim providers. Fido and Rogers Wireless. The former was purchased somewhat recently by the latter, but they continue to maintain separate monthly and prepaid services. Fido's prepaid coverage, however, is not currently expanded to the extent of the Rogers GSM network.

CDMA Services

CDMA services are operated by both Telus Mobility and Bell Mobility along with the rest of the Mobility Canada network, such as Sasktel. The services are not operated by a simcard, but usually a dial-in number to activate phonecards purchased in places like malls and convenient stores. Bell's service is called "Solo" and Telus "Pay and Talk". Both services are comparable in price, but the cheapest is probably Fido.

More information about Prepaid:

Bell Mobility Solo:
http://www.solomobile.ca/

Fido Prepaid Service:
http://www.fido.ca/

Rogers Pay-as-you-go:
http://www.shoprogers.com/

Telus Mobility Pay & Talk:
http://www.telusmobility.com/