About Us — The Team Behind Sole Akbil
Last updated: 08.08.2026 · Technical content: SoleAkbil Engineering Team
Sole Akbil is a Türkiye-made automated fare collection (AFC) system developed by the software R&D department of Gray Teknoloji Sistemleri Danışmanlık San. ve Dış Tic. Ltd. Şti. and offered under the Sole System brand. We build validator hardware and cloud-based management software for district municipalities, minibus and shared-taxi cooperatives, private bus operators and shuttle transport companies.
Who We Are
Gray Teknoloji Sistemleri is an Istanbul-based technology company working in access control and automatic identification systems. Sole System is our product brand, and Sole Akbil is that brand's public transport fare collection solution.
Both the in-vehicle terminal software and the cloud-based management panel of Sole Akbil are developed in our own R&D department, by our own team. We do not repackage an externally licensed platform; we built the architecture and we own the source code. In practice that means a need arising in the field can be addressed within the same week.
Why We Focus on This Segment
The automated fare collection market in Türkiye was shaped for a long time around metropolitan tenders. As a result, district municipalities, cooperatives and private bus operators were either pushed towards enterprise solutions too heavy and expensive for their scale, or settled for simple systems lacking critical security layers.
We saw that gap and took a deliberate position: to deliver the technical depth expected at metropolitan scale at the budget and setup speed of a small or medium operator. That is why in Sole Akbil an offline-first architecture, an immutable transaction ledger, clone card detection and 22 ready-made reports are standard — not add-on modules.
Our Product Approach
| Put field reality at the centre | Tunnels, rural routes and weak signal are not exceptions but daily reality. That is why offline operation is not a fallback plan but the foundation of the architecture. |
|---|---|
| Don't assume revenue security — prove it | The fare is always calculated on the server and every movement is written to an immutable ledger. Behind every figure in a report there are traceable transactions. |
| Collect as little data as possible | National ID numbers are not collected, birth years are not stored, card UIDs are masked. The safest data is data never collected. |
| Free the operator from spreadsheets | 22 ready reports produce output ready for council, audit and accounting separately. |
| One device, many methods | Mifare card, NFC phone, QR ticket and EMV credit card on the same validator — choice for the passenger, one infrastructure for the operator. |
Our Deployments
Sole Akbil is currently running in the field on municipal public transport routes. For the municipalities where we have deployed and our field notes, see our projects page:
- Varto Municipality (Muş) — AFC system, student and free card implementation
- Solhan Municipality (Bingöl) — AFC system, discounted card implementation
- Gerede Municipality (Bolu) — AFC system and minibus camera system
- Çayırbağ Municipality (Afyonkarahisar) — minibus AFC deployment
Our Other Areas of Expertise
Gray Teknoloji Sistemleri does not work in public transport alone. Our other products and brands in access control and automatic identification:
- solesystem.com.tr — Sole System corporate site (barriers, access control, parking systems)
- grayteknoloji.com — Gray Teknoloji Sistemleri corporate site
- plaka-tanima-sistemleri.com — licence plate recognition and access control systems
- hgsotoparksistemleri.com — parking systems with HGS/OGS integration
- yemekhanesistemleri.com — card-based canteen and staff tracking systems
That experience feeds directly into Sole Akbil: card technologies, relay and hardware integration, field installation and the practice of operating long-lived systems all come from the same team.
Company Details and Contact
| Legal name | Gray Teknoloji Sistemleri Danışmanlık San. ve Dış Tic. Ltd. Şti. |
|---|---|
| Brand | Sole System · Sole Akbil |
| Address | Perpa Ticaret Merkezi B Blok Kat:5 No:582, Şişli / Istanbul, Türkiye |
| Phone | +90 212 221 11 09 |
| bilgi@solesystem.com.tr | |
| +90 555 827 18 50 | |
| Field of activity | Automated fare collection systems, city cards, validator hardware and cloud-based transit software |
This page contains only verifiable corporate information. Our reference deployments are listed with field notes on the projects page.
Frequently Asked Questions
Who develops Sole Akbil?
Sole Akbil is developed by our own team in the software R&D department of Gray Teknoloji Sistemleri Danışmanlık San. ve Dış Tic. Ltd. Şti. and offered under the Sole System brand. Both the in-vehicle terminal software and the cloud panel are ours.
What is the relationship between Sole System and Gray Teknoloji?
Gray Teknoloji Sistemleri is the company's legal name and Sole System is the product brand. Sole Akbil is the Sole System brand's public transport fare collection solution.
Is the system made in Türkiye?
Yes. Sole Akbil's software is developed in Türkiye, in our own R&D department. No externally licensed platform has been repackaged; the architecture and source code are ours.
Which municipalities is it deployed in?
We have deployments at Varto (Muş), Solhan (Bingöl), Gerede (Bolu) and Çayırbağ (Afyonkarahisar) municipalities. They are listed with field notes on our projects page.
Why focus on district municipalities and cooperatives rather than metropolitan cities?
This segment was long either pushed towards enterprise solutions too heavy and expensive for its scale, or left with simple systems lacking critical security layers. We chose to deliver the technical depth expected at metropolitan scale at the budget and setup speed of a small or medium operator.
Let's Talk About Your Project
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