Industry standards can’t stand still, especially when they cover mobile devices. This year, for example, there have been two major changes to the IEEE 802 wireless suite of standards: an update and simplification of the IEEE 802.11 networking standard, known as Wi-Fi, and a new standard, IEEE 802.15.6, which covers wireless networks used in medical devices in and around a person’s body.
Despite the rapid expansion of wireless networking and a blizzard of mobile devices, the IEEE 802.11 Wi-Fi standard has kept pace with advances—undergoing several revisions and amendments since it was released in 1997. But anyone who wanted to implement Wi-Fi had to plow through the standard’s 3000 pages and its 10 amendments. That changed this year with the issuance of IEEE 802.11-2012, which simplifies and clarifies the standard while incorporating important new advances.
To make the standard easier to use, the 2012 revision rolls up the prior revisions and amendments into a single document and cleans up the standard’s language, even reordering many clauses. It also has been expanded to support faster and more secure devices and networks while offering improved quality of service and cellular-network hand-offs.
Among the enhancements unveiled in the 2012 revision are support for the 3.65- and 3.7-gigahertz bands to avoid interference with the many services and devices now operating at 2.4 and 5 GHz. The standard has been modified and extended to yield higher throughputs, up to 600 megabits per second without the complications of MIMO (multiple input, multiple output) antenna technology.
It also enhances support for direct-link setup, mesh networking, in-car networks, faster cellular hand-offs, roaming, security, broadcast/multicast and unicast data delivery, interworking with external networks and network management, and more. The result, according to the IEEE Standards Association, represents the state of the art in Wi-Fi and will help ensure a high degree of interoperability between the many millions of current and future Wi-Fi devices.
Five years in the making, the latest IEEE 802.11 revision drew on the expertise and efforts of hundreds of volunteers from a sweeping cross-section of industry around the world. Since 802.11’s initial release in 1997, “Continuous enhancement of the standard has helped drive technical innovation and global market growth,” says Bruce Kraemer, chair of the IEEE 802.11 Working Group. “Work on the next generation of IEEE 802.11 already has begun, with a variety of project goals including extensions that will increase the data rate by a factor of 10, improve audio/video delivery, increase range, and decrease power consumption.”
A relatively new wrinkle in the networking world is the body-area network (BAN). This extremely short-range network is used for wireless communication between ultra-low-power devices operating in or around a human or animal body. In health care and medical research, typical uses involve real-time monitoring of vital signs including temperature, blood pressure, respiration and heart rates, blood oxygenation, and glucose levels.
Body types vary, as a day at the beach clearly shows, and the new IEEE 802.15.6 standard addresses and compensates for the effects of bodily variations on network performance. For example, performance of the antennas placed in male, female, tall, short, thin, and heavy bodies can all vary, and radiation pattern shaping is needed to minimize a body’s specific absorption rate of RF energy. In addition, signal propagation characteristics change when the wearer moves around.
Officially known as the IEEE Standard for Local and Metropolitan Area Networks—Part 15.6: Wireless Body Area Networks, the standard relies on existing industrial, scientific, and medical radio bands as well as frequency bands approved by national medical or regulatory authorities. In May, when the standard was adopted, the U.S. Federal Communications Commission set aside the band from 2350 to 2400 megahertz for medical BANs. That adds no traffic to hospital Wi-Fi networks, which already are clogged by laptops, tablets, and other mobile devices. It also reduces the risk to the BAN of interference.
IEEE 802.15.6 covers encryption and data-integrity checking, both crucial in medical applications. It also enables direct machine-to-machine data collection, which ensures against data “fudging” by patients entering their own data manually, and includes support for quality-of-service and data rates up to 10 megabytes per second. A big plus for implantable devices is that because the distance between devices is short, transmission power can be low, reducing battery requirements.
Practical effects of IEEE 802.15.6 could be far-reaching. Convenient remote monitoring that does not impair patient mobility should prove important in a health care system with an aging population plagued by common conditions while hospitals are squeezed to send patients home as soon as they can.
By helping medical devices communicate with one another, the standard could lead to such advances as drug-delivery systems that administer dosages calculated from real-time sensor data. Other medical applications might include neural stimulators for conditions such as Parkinson’s disease, retinal implants for the blind, and control of prosthetic devices. Networked sensors that do not impede mobility could aid in sports training.
IEEE 802.15.6 could lead to other applications, too, including a variety of novel consumer uses including wearable computers, gaming, and the exchange of business profile data through a handshake (or of more personal information communicated by a kiss).
“The existence of a body area network standard provides myriad opportunities to create a wide variety of new products and capabilities aimed at enhancing people’s comfort and well-being in ways we can only begin to imagine,” says Art Astrin, chair of the IEEE 802.15.6 Task Group.
Both standards are available for purchase: US $5 for a PDF or $99 for a print version.