The cellular phone system was initially made possible by [choose one]: A. shortening the distance between phones and base stations.  B. high power portable transmitters that fit into phones.  C. revolutionary battery technology.  D. revolutionary antenna technology.  E. digital radio technology. Cell phones: [select all that apply] A. receive and transmit signals in separate channels.  B. communicate through satellites.  C. sometimes share channels with other phones in the same cell.  D. use the same radio band as wi-fi.  E. must be able to transmit in any of hundreds of channels. You manage an analog cell phone system that needs to expand its number of users. You now have a fixed amount of radio bandwidth. Which of the following strategies would be effective? [Select all that apply] A. Use improved digital signal technology to share existing channels.  B. Make each channel in your band twice as wide.  C. Build more base stations and make the cells smaller.  D. Buy more bandwidth when it becomes available.  E. Keep the number of base stations the same, but increase their power. Digital, Analog, or Both types of cell network?A. NeitherB. DigitalC. AnalogD. Both  select A B C D 1. Each phone is issued its own channel.  select A B C D 2. Channels are reused in different cells.  select A B C D 3. Channels are shared within a cell.TDMA and CDMA are…[select all that apply]: A. are still used in cell phone networks.  B. are essentially the same.  C. different ways for cell networks to share channels among users.  D. allow phones to use wide channels.