A remotely accessible USB hub : software design and testing

Remote use of USB peripherals has been identified as useful for Aava Mobile customers. Therefore, the commercial feasibility of an accessory that allows accessing USB devices remotely was studied at Aava, and a prototype device was built. The software in this accessory was required to transfer data securely, be automatically detectable on a local network, and operate autonomously. It is explored in this thesis how remote USB sharing and the requirements could be implemented using open-source software components.

New USB remote use programs that support the required capabilities were created as part of this thesis. These applications run on Linux-based operating systems and make use of the existing open-source USB/IP tool protocol. The new client program uses the existing Linux USB/IP virtual host controller driver, and the server is implemented in user space.

After the software work was concluded, measurements were performed for evaluation purposes. Optimal encryption ciphers for the prototype hardware were also selected. It was verified by testing that network delay causes major performance degradation. Other significant performance concerns were network adapter speed, the use of encryption, USB port speed, and the user space server implementation. However, while these aspects reduced the performance of the prototype, they were not determined to be critical. The accessory was not intended for high-performance use cases, and therefore the use of cost-effective components can be justified.