10 Wireless Communication Interview Questions With Answers

Updated 6 September 2022

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Wireless communications are an increasingly crucial part of business communication and operations. Many businesses require network administrators and related-IT professionals to be proficient in wireless communication technologies and equipment. If you are preparing for a position that involves wireless network administration or setup, it might be helpful to prepare questions on wireless technologies before an upcoming interview. In this article, we share a few wireless communication interview questions, explain why the hiring panel might ask them and share sample answers that you can use as inspiration to develop your own.

Wireless Communication Interview Questions With Sample Answers

Here are a few wireless communication interview questions that you can expect in an upcoming interview:

1. Explain the differences between WLAN and WiMax.

The interview panel might begin the session with a few basic questions to make the interviewee feel at ease before moving on to the more challenging ones. Structure your response by discussing the definitions of these technologies while highlighting their fundamental differences.

Example: 'WLAN stands for wireless local area network and offers wireless connectivity between devices that are WLAN compliant. The Institute of Electrical and Electronics Engineers (IEEE) sets the standards for WLAN such as 11a, 11ac, 11ad, 11b, 11g and 11n. WiMAX is a wide area network that offers interconnectivity between compatible wireless devices across a bigger geographical boundary. It follows the IEEE 16d and 16e standards.'

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2. Which is better: UDP or TCP?

This is a common question in wireless communication interviews, especially for entry-level roles. Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) are the two popular protocols for internet data transmission. You can begin your response with a brief definition of these two protocols and then highlight the advantages of TCP over UDP.

Example: 'TCP is a connection-oriented protocol, where connected nodes transmit data bi-directionally. In UDP, the sender node continuously transmits data to the recipient, whether or not the receiver receives it. TCP has built-in systems that check for errors and guarantee data reception, making it the ideal protocol for sending images, web pages and other data files. UDP is unreliable as there are chances for the data getting lost during transmission.'

3. What is Piconet?

You can expect questions on specific terminologies like Piconet if they are relevant to the role for which you are applying. Ensure that you review the job description carefully to identify the required skills, tools and responsibilities so that you can revise these concepts thoroughly before the interview.

Example: 'Piconet is an ad-hoc network that links a group of users using Bluetooth technology. It allows one controller device to connect with seven active dependent devices. The range of the Piconet network depends on the connected Bluetooth class and the data transfer rate varies from 200 to 2100 kilobytes per second.'

4. What is the difference between correlation and auto-correlation?

The interviewer might ask questions like these to check if you have a strong understanding of wireless communication techniques and related terminologies. At the outset, both these terms might sound similar. But they have crucial differences. Revising confusing terminologies while preparing for an upcoming interview can help you answer similar questions confidently.

Example: 'Correlation is a tool that checks the similarities between two different signals, while auto-correlation checks the similarity between an original signal and its time-lapsed version.'

5. If you were to design WLAN equipment, what would be your design priorities?

A wireless local area network (or WLAN) is a group of connected devices using radio transmissions. Setting up, installing, maintaining and upgrading WLANs is a common job responsibility for network technicians and other wireless communication professionals. Interviewers might ask this question to evaluate your proficiency in everyday wireless tasks, which might be part of the role.

Example: 'My design priorities would be ease of operation, low power, safety and security and global operations. Since users of all ages and technical expertise use WLAN devices, ease of operation is critical. I would ensure that the device is easy to set up and use, preferably working on a plug-and-play basis, instead of requiring complex installation procedures. Since most devices that use WLAN rely on battery power, I would also focus on special power saving modes and additional power management functions to conserve power.'

6. What is 5G and how does it work?

5G is the latest digital system for transferring data units over the air. It utilises much higher radio frequencies to share more data over the air. The interviewer might ask this question to test your knowledge of the latest trends and technologies in wireless communications. You can structure your response by including key data facts about 5G and explaining its advantages over 4G.

Example: '5G uses millimetre wave spectrum, that allows more devices within the same geographic area. For example, 4G technologies can currently support around 4000 mobile devices per square kilometre. With 5G, the number of supported devices within a square kilometre rises exponentially up to one million. 5G uses the massive multiple input, multiple output (MIMO) technology that uses multiple targeted beams to follow users around a cell site. This results in improved coverage and users can enjoy much faster data speeds, lower latency and reduced congestion.'

7. What is a VPN and why is it essential for businesses?

Virtual private networks (VPNs) are an increasingly common part of business networks, especially when the organisation has hybrid or remote employees. Asking this question helps interviewers evaluate your understanding of essential wireless technologies like VPNs. Also, if they use VPNs in their company, this question helps them measure your readiness to work with VPNs in your new role.

Example: 'A remote access VPN provides remote employees with secure access to their organisation's network from anywhere in the world. The VPN encrypts all traffic that remote employees receive and send from the business network, protecting and securing business data. In my previous role as a network administrator, I suggested implementing a business VPN, which allowed the organisation to transition to a remote-first model, reducing overhead costs while increasing data security.'

8. Can you explain the steps to perform a wireless site survey?

Installing wireless equipment is one of the everyday tasks of network administrators. The interviewer might ask this question to evaluate your grasp of the site survey process and to determine if you would be able to complete standard tasks as part of the new role. A step-by-step explanation of the survey process can help demonstrate your practical work experience to the interviewer.

Example: 'The first thing I do before a wireless site survey is to inspect the facility diagram to identify any potential radio frequency (RF) obstacles. Next, I do a thorough visual inspection of the facility to identify potential barriers. Then, I identify ideal user areas to determine preliminary access points (AP) locations. The next step involves doing the actual survey to verify the AP location. I recommend using the same AP model for both survey and production. Depending on the survey results, I relocate APs and repeat the testing process. Finally, I record the findings and signal logs.'

9. My WLAN system has radio frequency interference from another device. Can you suggest a few ways to overcome this issue?

Since wireless communication is a practical field with numerous real-life applications, you can expect the interviewer to ask a few application-based questions like these. Structure your answer to demonstrate your problem-solving skills.

Example: 'The first step to reducing interference is to relocate the WLAN equipment as far as possible from potential sources of electromagnetic interference (EMI) or radio frequency interference (RFI). Alternatively, you can try reorienting the point-to-point antennas away from the emitter to reduce interference. I highly recommend conducting a site survey before installing a WLAN. This helps you detect all existing interference sources and plan WLAN installation based on key parameters like noise, signal strength and data.'

10. What is the Fresnel zone and how do you calculate it?

Unlike the line of sight, which is an unobstructed straight line, the Fresnel zone defines the line of sight of radio frequency waves. It is an ellipse-shaped zone between two radio antennas. The interviewer might include this question to gauge your knowledge of core wireless concepts. You can structure your answer by explaining the Fresnel zone and then providing the formulae to calculate it.

Example: 'The Fresnel zone is the area around the visual line of sight around which radio waves spread on leaving the antenna. A clear line of sight is ideal for maintaining sight strength, specifically for 2.4 GHz wireless equipment. Obstructions like trees and water bodies reduce the signal strength as they increase the signal-to-noise ratio. The formula to calculate the radius of the widest point of the Fresnel zone is 17.32 x square root of (d/4f), where d is the distance between the two antennas in kilometres and f is the transmission frequency in GHz.'