Some Developments in Wireless Communication Systems
Image courtesy of American Innovations Much has been said about creating wired technical communities. Following the wired phase, the modern trend is to become unwired again through the use of wireless communication systems. Some developments in the wireless domain are highlighted below: |
| Cellular networks are available for transferring
corrosion monitoring data from the field over long distances. Much of North America is
covered by analog cellular networks. The North (and South) American analog systems are
said to conform to the AMPS (Advanced Mobile Phone Service) standards. Other
specifications may be used in other parts of the World. The analog systems are considered
to be the first generation (G1) of cellular technologies. Digital cellular communication systems are a more recent development, with increasing emphasis on high-speed (broadband) transmission capabilities |
| An important development in wireless web access is WAP (Wireless Application Protocol) technology. It facilitates web access via personal digital assistants (PDAs), cell phones and pagers through the use of WML (Wireless Markup Language). It is the WML code, a scaled-down version of HTML, that is is utilized by these mobile devices. Essentially, HTML code used by a conventional server is transformed into WML via a WAP Gateway (and vice versa). This facilitates communication between the above mobile devices and conventional web servers. |
| Packet-switched data involves the transmission of data through a cellular network in "bursts" or "packets". With this methodology, the network communication channel is only tied up for the duration of the data transmission. It represents efficient use of the communication network. |
| It is also useful to transmit corrosion monitoring data
over short distances, within an office environment. Bluetooth is
a wireless communication standard, supported by numerous manufacturers, that facilitates
wireless data transfer over distances up to about 10 meters. This standard is designed to
facilitate data transfer between various devices such as cell phones, PC's, cameras, etc. Bluetooth
technology has recently been evaluated for wireless sensors in the domain of aging
aircraft health monitoring - see www.agingaircraft2001.com
(paper by Michael Gandy). In principle, a cell phone can also act as a long-distance communication vehicle to the outside world and then transmit data to a nearby PC, thereby indirectly giving the PC wireless long-distance access. |
References/Literature: W.W. Manges and G.O. Allgood: "Wireless Sensors - Buyer Beware",
Sensors Magazine, April 2001. Links:
|
