Türk Telekom

Turkey met with GSM technology in 1994, when the system was first put into service for subscribers in Ankara, Istanbul, and İzmir. On 24 April 1995, the telecommunication and postal services of PTT were separated, leading to the foundation of Türk Telekomünikasyon A.Ş.

In April 1998, the GSM network was licensed for 25 years to the firms Turkcell and Vodafone Turkey. In June 1999, ADSL service was introduced to provide high-speed voice and image communication. Cable Internet applications began in 2000 on the existing cable TV infrastructure.

In January 2001, Aycell Haberleşme ve Pazarlama Hizmetleri A.Ş. was founded, followed by the start of operations by Iş-TIM Telekomünikasyon Services Inc. under the commercial name Aria in March 2001.

In February 2004, TT&TIM Communication Services Inc. was established through the merger of Türk Telekom's GSM operator Aycell and İŞ-TİM. Its commercial name was changed to Avea İletişim Hizmetleri A.Ş. in October 2004. In July 2004, Türksat A.Ş. was formed as a separate entity.

On 14 November 2005, Türk Telekom's privatization was completed, with 55% of its shares sold to Saudi Oger. On 15 September 2006, Türk Telekom acquired İŞ-TİM's 40.56% stake in Avea for US$500 million, increasing its ownership to 81.12%.

On 15 May 2008, an initial public offering of 15% of Türk Telekom shares was completed, and the shares began trading on the Istanbul Stock Exchange. In July 2009, Avea launched 3G services.

On 22 December 2018, Oger Telekom's creditors took control of Türk Telekom following billions of dollars in unpaid debt. In 2022, the Turkey Wealth Fund purchased 55% of the company, regaining the shares previously held by Oger Telekom.

TTNET

TTNET is a Turkish Internet service provider. The 2013 annual report stated that TTNET had 6.3 million subscribers, 620,000 fiber subscribers, and 1.8 million TV subscribers.

It provides ADSL, dial-up, Wi-Fi, G.SHDSL, ATM, Frame Relay, and Metro Ethernet Internet access services to corporate and personal customers in 81 cities in Turkey. TTNET became the first Turkish company to be accepted into the United Nations' "Business Call to Action (BCtA)" program, which seeks to encourage companies to "develop inclusive business models that offer the potential for both commercial success and development impact", for its "Internet 4All initiative".

Innova IT Solutions

Innova Bilişim Çözümleri A.Ş. provides services to the institutions in areas, such distribution, finance, and telecommunications. It includes the consultancy-design-application development-integration-maintenance value chain.

AssisTT

AssisTT is a customer service and call center company that also provides sales and marketing data. Türk Telekom holds a 100% interest in AssisTT, which was established in November 2007. As of the end of 2013, there were 115 million incoming calls (an 11% annual increase), which generated 360 million minutes of service time (a 13% annual increase).

Controversies

Spyware injection

Citizen Lab has found out that a series of middleboxes on Türk Telekom’s network were being used to redirect hundreds of users attempting to download certain legitimate programs to versions of those programs bundled with spyware. The spyware Citizen Lab found bundled by operators was similar to that used in the StrongPity APT attacks. Before switching to the StrongPity spyware, the operators of the Turkey injection used the FinFisher “lawful intercept” spyware, which FinFisher asserts is sold only to government entities.