unications carriers may not be as obvious as a driving force for WDM. Thus, let's take a brief look at the effect of graphics on transmission. Until relatively recently the average email was approximately 2000 bytes in length. With the introduction of signature blocks and the placement of other graphics into an email, the size of this commonly used business communications tool considerably increased. For example, consider a Chapter Six small signature block rectangular in shape consisting of 180 X 64 pixels. When inserted into an email, the signature block by itself adds 180 X 64/8 bits per byte, or 1440 characters to the length of the email. In both business and consumer environments, people are commonly using digital cameras for a variety of functions. When this author was involved in a fender-bender and took his car to the local insurance adjuster, the adjuster used a digital camera to photograph the modifica- tion made by a Land Rover bumping the rear of the author's sports car. The adjuster explained that damage reports for the insurance compa- ny's home office are now prepared using a word processing template with digital camera photographs attached and are then emailed to the company's home office. With the camera having a resolution of 1074 X 768 pixels, the resulting effect of adding just one picture has a pro- nounced effect on the transmission of an accident repair estimate report. For example, normally the insurance company's accident repair estimate report, prior to the use of a digital camera, was limited to hardcopy text and was approximately 4000 characters in length. Adding the equivalent of a 3 X 5-in photograph resulted in 1074 X 768 X 15 in, or 1.546 Mbytes if the photograph was in black and white. Of course, digital cameras take color photographs, SO we would be remiss if we did not consider the effect of color. Because most digital cameras use "true color," which provides over 16 million colors using 24 bits associated with each pixel, to represent a distinct color, we need to multiply 1.546