In the electronics world everybody is using electromagnetism in some way. All signals are electromagnetic, so in the electrical engineering environment electromagnetism is a leading topic of concern. One of our out of class assignments was to interview a practicing engineer. I was assigned to interview Mr. Gary J Trennison. Mr. Trennison is head engineer for Bell South. His work is related to DSL technology (Digital Scribers Line Technology). During the interview I asked Mr. Trennison about the relationship of electromagnetic theory in the engineering work environment, also about contemporary issues that the engineers face in their work environment that has a global and societal impact. I also ask Mr. Trennison about environment issues related to professionalism and ethics.
Electromagnetism is used for various purposes in our daily lives; one of the uses related to Mr. Trennison's work is DSL. DSL is a new way to utilize our existing copper telephone lines to deliver very high-speed internet connections.
English: Electromagnetic waves can be imagined as ...
English: Electromagnetic waves can be imagined as ...
English: Electromagnetic waves can be imagined as ...It works like ours existing, slow dial-up modem but without the slow dial-up part. DSL subscribers are always connected directly to the Internet with their own secure, dedicated line. DSL modems are digital unlike dialup modems which are analog. DSL is accomplished by multiplexing different electromagnetic waves line into three separate bandwidths and frequencies. Currently our voice is carried over the lower frequencies (30 Hz to 4 kHz) leaving the higher frequencies and bandwidth unused. The multiplexed electromagnetic signals are sent through the copper telephone lines to the modem, then them modem demodulates the electromagnetism signal. As a result DSL technology has enabled us to utilize the unused higher frequencies for two-way high speed data transmission. This way an ISP can use the 300 kHz to 700 kHz electromagnetic band for upstream transmission and the 1000 kHz and above very high speed...