Irancell (MTN), MCI, Iran Taliya and Rightel offer relatively cheap (60,000 rials) pre-paid SIM cards for international travellers. It is possible to buy recharge cards from all newsstands and supermarkets for 20,000-10,000 rials. These networks specially MCI and Irancell, works quite well in all cities and rural areas. GPRS and MMS is also available at very low prices, specially at night, for surfing the web or checking your email. WiFi with your mobile phone or tablet is a good option in Iran.
MCI and Irancell are another popular operators that cover most Iranian territory. Even in villages or borders, MCI and Irancell have GPRS and MMS as well. The recharge cards are 50,000 rials or 10,000 rials in value. The Taliya operator network is a bit weak. Kishcell and Isfahancell are operating in some region/locally only.
Now Rightel has got broadband network [3G] and have very cheap voice video conference calls rates.
You can readily access WiFi internet services (depending upon network availability) in many areas, and in all provinces.