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.
- 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.
- 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.
- GSM is dominant in Europe and Asia. CDMA is dominant in the US. CDMA can use the same channel in adjacent cells, providing more channel reuse and so more customers.
4 True/False questions
Compare voice and data traffic; How are circuit switching and packet switching used with voice and data traffic? Why? → Voice traffice is fairly constant. Data traffice is short bursts with long silences. Circuit switching is not efficient with data.
Describe the general structure of the PSTN - local loop, transport core, trunk line → 1-pair Voice Grade UTP, 2-pair data-grade UTP, and optical fiber
What media are used for the local loop? → DAC is Digital to Analog Conversion where as ADV is Analog to Digital conversion.
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.