IMAGE TRANSMISSION ON-DEMAND OVER ReFLEX PAGING CHANNELS
Original Publication Date: 1997-Dec-01
Included in the Prior Art Database: 2002-Jun-13
Liangchi Hsu: AUTHOR [+2]
In the past decades, the paging technology has been applied to provide various communication services including tone, beep, simple message, data, and voice. Besides these existing services, new emerging wireless narrowband personal communi- cation services (NBPCS) using paging technologies are expected to further expand the presence of paging in the wireless industry. One of these new services is the interactive, i.e., on-demand, wireless image transmission.
MOTOROLA Technical Developments
IMAGE TRANSMISSION ON-DEMAND OVER ReFLEXTM PAGING CHANNELS
by Liangchi Hsu, Kyung Tae Mun and K. R. Rae
In the past decades, the paging technology has been applied to provide various communication services including tone, beep, simple message, data, and voice. Besides these existing services, new emerging wireless narrowband personal communi- cation services (NBPCS) using paging technologies
are expected to further expand the presence of paging in the wireless industry. One of these new services is the interactive, i.e., on-demand, wireless image transmission.
The new service would bring about many services/applications. The potential applications include:
* image data retrieval on-demand via wireless channel,
* visual information telebrowsing in picture archival and communication systems (PACS),
* wireless interactive videotext,
* electronic mail order shopping via two-way messaging channels, and
* remote and wireless medical diagnostics such as computer tomography (CT) and magnetic resonance imaging (MRI).
Clearly, the ramification of this type of service is enormous. Opportunities created by the new service has a great business potential.
However, this advanced service is not practically feasible due to following limitations in today's pag- ing technologies. First, it is obviously impossible to provide any interactive communication in the tradi- tional one-way paging. Moreover, the bandwidth
(i.e. bit rate) of paging channel allocated for each paging subscriber is limited. It is not economically effective to transmit large image data via paging
channel. The size of image data can be very large, not only because it is not well compressed, but also it is not well structured.
With a proliferation of Motorola's FLEXrM fam- ily of protocols (i.e., FLEXrM, ReFLEXTM, and InFLEXionr") and an advent of two-way paging, combined with the Joint Photographic Experts
Group (./PEG) image compression standard, a widely accepted and developed international image com- pression standard, and Progressive Image Transmission (PIT) scheme, the advanced service of the interactive wireless image transmission can be accomplished in an economically feasible and technologically sound way. The two-way FLEXTM family of protocols, such as ReFLEXTM with a minor modification to support binary data, makes progressive or interactive image transmissioniappli- cations possible, and the JPEG standard, specifically its progressive mode, provides an efficient method to allow a compression of large image data into a progressive structure.
To make visual communications efficient, image or any visual information is compressed in a progressive format using the JPEG standard and stored in an image server (i.e., provider). Through the ReFLEXTM reverse channel, a ReFLEXTM receiver requests the image "progressively" based on the level of image quality needed and/or the quality of service (QoS) allowed, and consequently, through the ReFLEXT...