Voce communication in tactical multihop networks

The development of tactical communications is moving towards mobile networks with high kapacity. In several of these concepts, voice communication is a service with high priority. Mobile ad hoc networks are wireless multi hop networks that are independent of fixed infrastructure, with the ability to dynamically adapt to changing conditions. In a software-defined radio, much functionality is implemented in software. The part of the software that defines the radio system is usually called a waveform. One or more different waveforms can be used in the same hardware platform. The main issue of this report is to determine if voice and data communication should be implemented in a single waveform or in two separate waveforms. It is not possible to give a simple answer to that question, but we consider the pros and cons of the two options. We evaluate two concepts for voice in tactical multihop networks. One concept is that voice communication is handled in a separate narrowband waveform while data communication is handled in a broadband waveform. The second concept means that all communication, including voice, is handled in the wideband waveform. The focus is on voice group calls, as it makes special demands on the design of the communication system. We conclude that it is possible to realize voice communication over several hops with both wideband and narrowband waveforms. With range calculation examples, we show that narrowband waveforms have a longer range over each hop. The wideband waveform requires a larger number of hops over intermediate nodes to provide a good range.