Wireless & Telecom (4G/5G) test (Intermediate)

Sample questions

5 sample questions from the Wireless & Telecom (4G/5G) test, with the answers. Samples are taken out of the live test, so you will not meet these when you sit it.

1. Which of the following statements is correct regarding the MME in LTE architecture?

   1. The MME is involved in user-plane data forwarding during handovers.
   2. The MME is control plane only.
   3. The MME is responsible for user-plane data forwarding.
   4. The MME participates in both control-plane and user-plane functions.

   Answer: B. The MME is control plane only.

   In LTE, the MME (Mobility Management Entity) is solely a control-plane node responsible for handling signaling, mobility management, and NAS (Non-Access Stratum) procedures. It does not participate in user-plane data forwarding, which is managed by the S-GW and P-GW. This distinction is crucial for understanding the separation of control and user planes in LTE.

2. Which of the following statements about IMS architecture is correct?

   1. IMS is used for VoLTE and other IP-based services, not for traditional circuit-switched voice.
   2. IMS is primarily responsible for managing circuit-switched voice calls in LTE networks.
   3. IMS is used exclusively for data services and does not support voice or video.
   4. IMS is the same as the traditional circuit-switched core network and supports both IP and circuit-switched services.

   Answer: A. IMS is used for VoLTE and other IP-based services, not for traditional circuit-switched voice.

   IMS (IP Multimedia Subsystem) is a key component of VoLTE (Voice over LTE) and supports IP-based multimedia services. It is not used for traditional circuit-switched voice, which is handled by the legacy CS (Circuit Switched) domain. IMS provides a framework for delivering voice, video, and other multimedia services over IP networks, but it is not directly responsible for circuit-switched voice, which is a common misconception.

3. Which statement correctly compares SON in LTE networks with manual configuration and identifies when each is typically used?

   1. SON in LTE networks is used for automatic optimization of network performance, whereas manual configuration is typically used in dynamic environments.
   2. SON in LTE networks is used for manual configuration, whereas automatic optimization is used in dynamic environments.
   3. SON in LTE networks is used for automatic optimization of network performance, whereas manual configuration is typically used in static environments where changes are infrequent.
   4. SON in LTE networks is used exclusively for manual configuration in all network environments.

   Answer: C. SON in LTE networks is used for automatic optimization of network performance, whereas manual configuration is typically used in static environments where changes are infrequent.

   SON (Self-Organizing Networks) in LTE networks is designed to automatically optimize network performance, such as through self-configuration, self-optimization, and self-healing. This is particularly useful in dynamic environments where network conditions change frequently. Manual configuration, on the other hand, is typically used in static environments where changes are infrequent, and network parameters do not require frequent adjustments.

4. Which statement accurately describes how core network slicing behaves in the 5G core network?

   1. It defines logical end-to-end networks with specific QoS and service requirements.
   2. It physically separates network resources for each slice.
   3. It assigns unique IP addresses to each network slice for isolation.
   4. It is only applicable in the radio access network (RAN).

   Answer: A. It defines logical end-to-end networks with specific QoS and service requirements.

   Network slicing in the 5G core allows the creation of logical, end-to-end networks tailored to specific use cases and services, such as eMBB, URLLC, or mMTC, with defined QoS and service requirements. This is achieved through the use of S-NSSAI (SST + SD) and is managed by network functions like the SMF and UPF. Other options are incorrect because they do not accurately describe the purpose or behavior of network slicing in the 5G core.

5. In a project involving the deployment of a 5G core network, which of the following best represents the application of core network virtualization?

   1. Using dedicated hardware for all network functions to ensure maximum performance.
   2. Focusing solely on physical infrastructure without any software-defined components.
   3. Deploying network functions as virtual machines on a shared cloud infrastructure.
   4. Implementing a centralized control plane with no distributed processing.

   Answer: C. Deploying network functions as virtual machines on a shared cloud infrastructure.

   Core network virtualization involves using cloud-based virtual machines to implement network functions, allowing for greater flexibility, scalability, and cost efficiency. This approach replaces traditional hardware-based network nodes with software-based equivalents, enabling dynamic resource allocation and faster service deployment. Other options are either incorrect or unrelated to the concept of core network virtualization.