Conventional 3D TIs are the van der Waals bound, binary compounds such as Bi 2 Te 3 , [10] Bi 2 Se 3 , [11,12] Sb 2 Te 3 , [13] as well as alloys of these elements. [14,15] For a quasi 1D nanowire, due to the inclusion of the Berryphase of a particle traversing the perimeter of the nanowire, the surface band structure is determined to be gapped. [16-18] By applying a magnetic flux parallel to the nanowire axis Φ = ±Φ 0 /2, where Φ 0 = h/e, this gap will be closed. The non-degenerate, topologically protected linear surface bands will re-emerge periodically with a period of a full flux quantum Φ = (n + 1/2) Φ 0 threading the wire. The observation of such periodic Aharonov-Bohm (AB) oscillations has previously been reported. [19-24] Making use of a selective area growth approach, nanowires of aforementioned materials can as well be deposited by molecular beam epitaxy (MBE). [25-28] These nanowires have a rather rectangular cross-section and are therefore referred to as nano ribbons. As a scalable bottom-up approach, these selectively grown nanoribbons are beneficial for desired Majorana surface architectures. [29] However, MBE grown 3D TI compounds usually Quasi-1D nanowires of topological insulators are candidate structures in superconductor hybrid architectures for Majorana fermion based quantum computation schemes. Here, selectively grown Bi 2 Te 3 topological insulator nanoribbons at cryogenic temperatures are investigated. The nanoribbons are defined in deep-etched Si 3 N 4 /SiO 2 nano-trenches on a silicon (111) substrate followed by a selective area growth process via molecular beam epitaxy. The selective area growth is beneficial to the device quality, as no subsequent fabrication needs to be performed to shape the nanoribbons. In the diffusive transport regime of these unintentionally n-doped Bi 2 Te 3 topological insulator nanoribbons, electron trajectories are identified by analyzing angle dependent universal conductance fluctuation spectra. When the sample is tilted from a perpendicular to a parallel magnetic field orientation, these high frequent conductance modulations merge with low frequent Aharonov-Bohm type oscillations originating from the topologically protected surface states along the nanoribbon perimeter. For 500 nm wide Hall bars low frequent Shubnikov-de Haas oscillations are identified in a perpendicular magnetic field orientation. These reveal a topological, high-mobility, 2D transport channel, partially decoupled from the bulk of the material.