On the Feasibility of Digital VHF Communications in Crisis Scenarios

Communication is key, especially during a crisis. In case of larger incidents, existing infrastructure often faces outages, making it difficult - if not impossible - to communicate. While first responders have communication solutions for these cases, civilians remain disconnected. To avoid such stressful situations, we study Rattlegram, a novel communication solution that uses acoustic coupling of smartphones with VHF/UHF handheld radios to transmit digital information. We compare it to existing protocols for the VHF/UHF band and evaluate its performance in simulations and field tests. We demonstrate its applicability, showing that even a cheap handheld radio can be used to establish communication up to a distance of over 18km in rural and close to 1 km in urban environments. The results highlight that Rattlegram is a viable technology that can be the base for affordable, infrastructure-less emergency communication for the masses.