Researchers in India have developed an application (app) for Android smart phones that allows two users to make voice calls to each other even if they have neither data nor internet connectivity provided that they can both access a local Wi-Fi network. The app is thus limited to the range of the wireless network, but effectively allows the phones to be used like “walkie-talkies” or an “intercom” system without having to connect to a cell-mast or even have be connected to the wider internet.
The app could be useful in remote areas in the developing world or in a military zone where internet access may be limited or entirely off-limits, but a local wireless network can be sustained from a single server at a central location or military base, for instance.
Writing the in the International Journal of Information Technology and Management, computer scientist Shalini Goel of Mahavir Swami Institute of Technology, in Delhi-NCR, India, and colleagues Vipul Garg, Deepak Garg, and Manshiv Kathait of the Maharaja Agrasen Institute of Technology, also in Delhi, describe details of WiFi_Intercom. The app uses communications classes that allow a user to connect with other users through the Wi-Fi wireless standard protocol using a point to point system on the wireless local area network (WLAN). Voice communication can then be made between any Android-based wireless devices that have a microphone and speaker and can connect to the WLAN. The system offers full duplex conversation just as anyone has with a conventional phone call, as opposed to the walkie-talkie where only one person can speak at a time.
The next step will be to extend the app to encompass encryption and so take security up to the requisite level for most users, but particularly for those with sensitive conversations to make in such an environment, particularly for military use. The team will also develop ways to lower energy consumption and improve call clarity.
Goel, S., Garg, V., Garg, D. and Kathait, M. (2019) ‘Voice transmission through WiFi‘, Int. J. Information Technology and Management, Vol. 18, Nos. 2/3, pp.268-283.