Wi-Fi Direct has been gaining popularity in recent years as a mean for device-to-device communications. Adopting such technology allows portable devices, such as smart phones, to form groups for data sharing without the need for any infrastructure support. Interconnecting multiple groups allows broader coverage and enables the use of Wi-Fi direct in applications such as disaster recovery. However, the current implementation of Wi-Fi direct in popular software environments, such as Android, lacks proper support for multi-group communications. One of the limitations in Android is that all created groups share the same IP subnet. Thus, even if multiple Wi-Fi Direct groups could be interconnected, still bidirectional communications between some devices would not be possible. In this paper, we propose an IP Subnet Negotiation Protocol for Seamless Multi-Group Communications (ISNP) to address such limitation. ISNP is composed of two modules, one at the application level and the other at the OS level that allow Wi-Fi Direct groups to have distinct IP subnets. ISNP can be integrated with other Wi-Fi Direct multi-grouping protocols to allow bidirectional links between groups. In addition, ISNP is flexible, as it allows devices with no modification to its OS to still participate in the protocol, and lightweight, as it does not force the devices to form any type of connection before running ISNP. ISNP is validated through implementation on Android devices. The validation results have confirmed ISNP's efficiency and its ability of avoiding conflicts between IP subnets.
['Ahmed A. Shahin', 'Mohamed F. Younis']
IP subnet negotiation in Wi-Fi direct for seamless multi-group communications