In war medics tend to be thrown into situations where wounded soldiers require urgent and immediate attention where a trained surgeon would be most helpful, and said surgeon would be able to better do his job once he has gotten the background information on the injury and the subsequent medical details in order to dispense with the proper care.
With that said the US Army wants to develop a system which is capable of managing patient data from injury site to recovery, where it will include delivering live audio/video communication for medics in the field. This will help the medics in the field also determine who needs to ride the medevac first depending on the wounded soldiers condition and need for medical attention.
This is where the Army says the system will definitely need to fall back on a range of devices as well as 4G cellular networking in order to send vitals to communicate with the doctor, with everything being said recorded for further review. There are no further details on the 4G communication system the Army will be using.