The project was revealed to Computer Weekly in an exclusive interview with Cisco chief development officer Mario Mazzola.
Mazzola said, "Using a hybrid 802.11/cell phone handset the user will be able to switch from GSM outside the building to higher bandwidth and richer services on the wireless Lan inside using the same telephone number."
The combination of wireless and mobile devices may simplify management, with the end-user having one phone inside and outside the building.
There could also be benefits for companies with mobile workers with large data requirements that could be satisfied by moving from a mobile cell to a wireless hotspot; or for staff who need to operate where a mobile cell is unobtainable or forbidden, such as in hospitals.
The news has been welcomed by business users. Pete Smith, head of IT at satellite communications firm Inmarsat, said, "This is a winning combination, provided the handset is priced like a typical GSM phone and switches between the two systems without user intervention.
"Sharing existing 802.11 infrastructure makes sense and saves money on GSM costs. Deployment on a large scale will need careful planning due to bandwidth limits and security requirements," he said.