Using visual tags to bypass Bluetooth device discovery
Dave Scott, Richard Sharp, Anil Madhavapeddy and Eben Upton.
Journal paper in SIGMOBILE Mob. Comput. Commun. Rev. (vol 9 issue 1).
One factor that has limited the use of Bluetooth as a networking technology for publicly accessible mobile services is the way in which it handles Device Discovery. Establishing a Bluetooth connection between two devices that have not seen each other before is slow and, from a usability perspective, often awkward. In this paper we present the implementation of an end-to-end Bluetooth-based mobile service framework designed specifically to address this issue. Rather than using the standard Bluetooth Device Discovery model to detect nearby mobile services, our system relies on machine-readable visual tags for out-of-band device and service selection. Our work is motivated by the recent proliferation of cameraphones and PDAs with built-in cameras. We have implemented the described framework completely for Nokia Series 60 cameraphones and demonstrated that our tag-based connection-establishment technique (i) offers order of magnitude time improvements over the standard Bluetooth Device Discovery model; and (ii) is significantly easier to use in a variety of realistic scenarios. Our implementation is available for free download.
papersRelated News
Using visual tags to bypass Bluetooth device discovery / Jan 2005
While designing Spotcodes, we realised that visual tags are a much better mechanism to advertise security keys to users instead of the error prone and much more difficult to use Bluetooth device discovery protocol. We duly implemented the direct system, and conducted a user study with Eleanor Toye Scott who was down the corridor working with the HCI group in the Computer Lab. The resulting journal paper on our SpotCode visual tag login system is a fun blend of systems and human factors.
We do not believe that printed tags are competing with RFID and NFC for the prize of "universally accepted connection establishment technology". Instead we observe that each offers complementary tradeoffs in terms of cost, data capacity, interaction distance, client-device compatibility and visibility. We predict that all three of these technologies will ultimately be integrated into mobile applications to provide consumers with the flexibility and functionality they require.
(Update: and indeed, two decades on in 2025, this has played out pretty accurately. It is common now to use QRCodes to access services, and wireless scanning is a relatively rare thing to do but still available.)
Dave Scott, Richard Sharp, Anil Madhavapeddy and Eben Upton.
Journal paper in SIGMOBILE Mob. Comput. Commun. Rev. (vol 9 issue 1).