The country code for calling Ethiopia is 251. The city code for Addis Ababa, as of Sep 2005, is 011 (or 11 from outside Ethiopia).
Ethiopia uses GSM network which is operated by Ethiopian Telecommunications Corporation. Currently there is decent coverage around the big cities such as Addis Ababa, Dire Dawa,Bahir Dar, Debre Markos, Dese, Gonder,Harar, Mekele, and Nekemete. It is expanding into most small cities.
Roaming charges are very steep. For a short visit, your best option for mobile access is to rent a SIM card with a phone. Only a few stores rent SIM cards: You can rent SIM card and phone inside Addis Ababa Sheraton hotel but it is expensive. Another option is to rent a SIM card and mobile phone from local stores.
A third option is to buy a sim card that will cost you about 30 birr (March 2014). Ask a cell phone retailer (there are many of them, especially in the piazza). If the retailer does not sell them, he or she will point you in the right direction. Be prepared: you will need to provide a passport sized picture and a photocopy of your passport that the seller will keep. The quickest way to buy a SIM card is probably in the Hilton Hotel. Assuming that you have the necessary documents (photocopy of your passport and two passport sized pictures), it should take less than 5 minutes to get your SIM card.
In Addis Ababa, especially in Bole Subcity, you can find quite a number of internet cafes. Some cafes still use Dial-Up connections, but broadband is becoming more popular and accessible. Most of the high-end hotels have internet connections (either Ethernet or WiFi), which are reasonably fast and often free for hotel guests.
A general problem with the Internet in Ethiopia is the unstable international high-speed connection. If it is not working, even broadband cafes can only deliver Dial-Up speeds and less. The local definition of high speed broadband is 128kbps. Another general problem is the shortage of electricity, forcing daytime blackouts of whole areas one to two days a week, so it is good to plan ahead where you are going for internet access.
Skype and VoIP service are legal in Ethiopia.
3G Internet services (known as WCDMA or UMTS) are available in many parts of Addis Ababa. A special SIM card and capable phone is required. CDMA is available as well, which also requires capable devices at prices. EVDO requires a USB device and is faster than CDMA. CDMA and EVDO are also available in all regional and most zonal capitals in Ethiopia.
WiFi will be available at the venue of the conference. Technical support for presentations must be arranged in advance onsite with the Events Team