5 Written Questions
4 Multiple Choice Questions
- Converts digital computer signals to analog and sent over telephone lines. 3G is for sending data faster with a speed 2-3 Mbps. WiMAX is to replace DSL, Cable and cellular service with 1-4 Mbps. Satellite is very expensive because of long transmission distance. Two way data transmission is expensive. Some carriers are pushing fiber directly to the home with 100 Mbps or more.
- Voice traffice is fairly constant. Data traffice is short bursts with long silences. Circuit switching is not efficient with data.
- Analog is electrical signals made from pressure waves.Digital is either on or off.
- ADSL uses 1 VG UTP lines. Cable uses optical fiber to the neighborhood with thick coaxal cables. Thin coaxial drop cables go to the residences.
4 True/False Questions
Compare GSM and CDMA. Where are they dominant? What advantage does CDMA have in terms of channel usage? → Analog is electrical signals made from pressure waves.Digital is either on or off.
What is VoIP? What purpose does the VoIP gateway serve? What is required to be able to use VoIP? What layer-four protocol is used for VoIP? → Pulse code modulation is the signal being sampled 8,000 times per second. Each sample is 1/8000 of a second. Each sample period, the amplitude of the signal is sampled. Each filter can distinguish 256 loudness levels.Produces 8 bits per sample.
What is DAC? ADC? → ADSL uses 1 VG UTP lines. Cable uses optical fiber to the neighborhood with thick coaxal cables. Thin coaxial drop cables go to the residences.
What is a cellular telephone cell? What functions does the mobile telephone switching office serve? → A cell is an area covered by a cellsite with antenna and equipment to serve mobile phones in the cell. The MTSO coordinates activity among the cellsites. It connects wired customers via a POP.