"The terms 'mobile identification' and 'Mobile ID devices' can conjure up several different interpretations. In the strictest sense, it may consist of an untethered device used to capture one or more biometric samples from a subject. The captured data sample(s) may then be compared to other samples contained in a database resident on that device. The data may also be transmitted to and compared to samples in a central repository or an onboard computer repository located in a nearby vehicle. Such vehicles may include jurisdictional police cars, border patrol vehicles, military combat vehicles such as Humvees1, etc. This scenario allows for comparison to larger databases than otherwise available on a handheld device or in a nearby vehicle. Additionally, a device physically attached to a computer located in a vehicle that acquires biometric samples may also be considered as a Mobile ID device. For purposes of this report, the exact definition or categorization of the Mobile ID device is not a factor. The Mobile ID device should be viewed in the context of a portable biometric acquisition station -- one that is not intended to be stationary and hardwired to a much larger system used for comparing or matching biometric samples. This is in contrast to traditional booking stations and other biometric enrollment stations incorporating physically secured full‐sized live‐scan fingerprint readers, other biometric modality capture devices, or photo capture stations with setups adhering to distance, lighting, and other photo capture standards."
National Institute of Standards and Technology: http://csrc.nist.gov/