CMT Network Technologies & Connectivity 3 — Questions and Answers
Question 1: What technology allows a mobile device to communicate with a payment terminal by tapping within a few centimeters?
- Bluetooth LE
- NFC (Correct answer)
- UWB
- Zigbee
Correct answer: NFC
Near Field Communication (NFC) operates at 13.56 MHz over distances of up to ~4 cm, making it ideal for contactless payments.
Question 2: Which cellular generation first introduced true broadband mobile internet with theoretical peak speeds exceeding 100 Mbps?
- 2G EDGE
- 3G HSPA
- 4G LTE (Correct answer)
- 5G NR
Correct answer: 4G LTE
4G LTE was the first cellular standard to deliver true broadband speeds, with theoretical peaks over 100 Mbps for mobile users.
Question 3: What is the function of carrier aggregation in LTE-Advanced and 5G networks?
- Combines signals from multiple towers to increase reliability
- Bonds multiple frequency bands together to increase total bandwidth (Correct answer)
- Reduces latency by bypassing the core network
- Switches between carriers automatically for best price
Correct answer: Bonds multiple frequency bands together to increase total bandwidth
Carrier aggregation combines two or more LTE/5G frequency bands simultaneously, effectively multiplying available bandwidth for higher speeds.
Question 4: A customer reports their phone drops calls whenever they walk to a specific area of their home. Which component is LEAST likely to be the cause?
- Weak in-building cellular signal
- Damaged cellular antenna
- Loose antenna connector on the logic board
- Failing GPS module (Correct answer)
Correct answer: Failing GPS module
GPS is a receive-only positioning system and has no effect on cellular voice calls or signal strength.
Question 5: What does the term 'roaming' mean in mobile networking?
- Using Wi-Fi instead of cellular data
- Connecting to a partner carrier's network outside your home coverage area (Correct answer)
- Switching between 4G and 5G automatically
- Enabling hotspot mode on a device
Correct answer: Connecting to a partner carrier's network outside your home coverage area
Roaming occurs when a device connects to a partner carrier's infrastructure because the home carrier has no coverage in that area.
Question 6: Which Wi-Fi security protocol is considered most vulnerable and should never be used on modern networks?
- WPA3
- WPA2-AES
- WEP (Correct answer)
- WPA2-CCMP
Correct answer: WEP
WEP (Wired Equivalent Privacy) uses a weak RC4 cipher and can be cracked in minutes; it has been deprecated and should never be used.
Question 7: A technician is configuring mobile hotspot on a repaired device. The customer wants to share their LTE connection with a laptop. Which setting must be enabled on the phone?
- VPN passthrough
- Personal Hotspot / Tethering (Correct answer)
- Wi-Fi Direct
- USB Debugging
Correct answer: Personal Hotspot / Tethering
Personal Hotspot (tethering) must be enabled, and the carrier plan must support it, for the phone to share its cellular data connection.
CMT Network Technologies & Connectivity 3
What technology allows a mobile device to communicate with a payment terminal by tapping within a few centimeters?