Accelerating Telemedicine: Portable Video Communications via Cellular Networks
The fundamental goal of telemedicine is to minimize the time and distance needed to top medical care. Rather than bring the patient to the doctor, it attempts to bring the doctor to the patient by providing real-time communications and data about a patient's vitals while en route to the hospital. One of the key challenges for telemedicine, however, has been how to include real-time video for these assessments. Without video, doctors cannot visually assess a patient's condition or symptoms, which limit their ability to provide timely and effective medical guidance to emergency responders on the scene.
Therein lays telemedicine's challenge. Historically, the biggest impediment to streaming video has been its demand for network bandwidth because live streaming requires more bandwidth than what conventional mobile communications infrastructures--such as cellular networks--can provide.
There are two approaches to this problem: Leverage wireless networks with more bandwidth, or use video encoder technology sophisticated enough to use the bandwidth available.
Most emergency response agencies lack the resources to access or maintain their own dedicated network. Some communities, such as San Diego County, have pooled resources from several public safety agencies to address this. The county's Regional Command and Control Communications (3Cs) system, for example, uses directional microwave antennas to transmit video from police helicopters to ground-based receivers via microwave, and then stream the feed to command and control via conventional ground-based networks. The county's approach has been instrumental in fighting wildfires.
Microwave-based networks provide more than enough bandwidth for streaming high-quality video, but come at the high cost and complexity of deployment. They are further limited by the need for a clear line of sight. Dedicated satellite networks are able to combine voice with high-quality video high data rates. Plus, they provide wide-ranging (even global) accessibility. But, like microwave, satellite is an expensive approach for sending video, and it doesn't escape microwave's deployment complexity. Hence both networks have limited application in telemedicine.
The Benefits of Cellular Networks
One alternative is cellular networks, which are both ubiquitous and comparatively low cost to access. Plus, the rapid expansion of cellular technology continues to enable more efficient use of bandwidth, and has made streaming video an increasingly viable medium for entertainment and information purposes.
More important, cellular networks are not reserved exclusively for emergency communications. Hence, when the U.S. Federal Communications Commission (FCC) recently proposed that emergency communications traffic could be given higher priority on consumer cellular networks in the event of a catastrophe, it sparked a sharp response from the Public Safety Alliance (PSA), a coalition of groups representing police, fire and emergency medical services. The PSA's rebuttal stated a preference for dedicated frequencies on the communications spectrum, far from those used for consumer traffic. It further cited the perceived unreliability of cellular networks--not only during a 9-1-1 scenario, but even when millions of American Idol fans simultaneously text in their votes.
But remember, network issues--cellular or otherwise--only pose the first challenge to streaming video from a mobile platform. Conventional encoders that are ill-equipped to transmit video over different network environments, pose the second.
Fortunately, emergency medical response teams can cost-effectively leverage the same sophisticated video encoder technology that's used by the U.S. military to stream live video over dedicated satellite and secure point-to-point networks. More to the point, this technology is easily adapted to work reliably on cellular and other data networks.
Underlying this reliability are certain features of today's advanced video encoders, such as the ability to adjust frame rate and resolution to compensate for lower bandwidth networks. Also, rather than simply digitizing video for transmission, some video encoders enable packet labeling. This, in essence, allows video streams from public safety teams to be tagged with a higher priority than other traffic streaming over dedicated or commercial networks.
Select video encoders have evolved to allow IT administrators to use Simple Network Management Protocol (SNMP) applications like HP Openview to gather detailed statistics and information about how well their encoder is operating over the network, and to optimize its performance accordingly. In short, these sophisticated video appliances incorporate multiple protocols for streaming video, enabling intelligent, automatic adaptation to virtually any network environment--including cellular.
To be clear, even the most advanced video appliance is only as reliable as the network over which it streams. Today's sophisticated encoder technology is being utilized to develop a hand portable device able to send the most robust video stream possible over cellular frequencies.
The technology clearly isn't designed to address every telemedicine application. Cellular coverage is weakest, for example, in extremely remote areas where telemedicine's reach and immediacy is more frequently needed.
It's important to remember, however, that minimizing the time and distance to medical care is just as critical in city gridlock as it is in cellular network blind spots. Moreover, the device could easily be configured with different cards to operate on any network-- including IP, microwave, satellite or networks customized for public safety. These advances-- and the many likely to come in the years ahead--are bound to revolutionize the way public safety teams react to incidents and make communication in an emergency easier than ever before.
Erik Herz is the Video Services Director at VBrick Systems.