CMNS 253W Chapter Notes - Chapter 4: Electromagnetic Spectrum, Microblogging, Tangled

• School: Simon Fraser University
• Department: Communication
• Course: CMNS 253W
• Professor: Frederik Lesage

Document Summary

Mobile - user and device could move while device was being used (ex. Portable - device could be moved but not while in use (ex. Electromagnetic spectrum - contains frequencies on which different o. Excessive use can create too many waves which can cancel one technologies operate another out o. Solution to problem - cellular radio system design - distributes sending/receiving responsibilities into small hexagonal shapes responsible for certain areas. Cell system deliberately low powered so that radio frequencies could be used over and over again. Texting started as an idea for service providers to alert users of, say, new. Telephone had to listen to one tower and ignore the others voicemails. Idea to allow user-to-user texting was almost an afterthought o. Sms (short message service) was at first popular because it was cheap (or at least cheaper than voice calls)