As our earlier article on Wi-Fi Standards and Testing introduced the different generations of Wi-Fi and pre-compliance testing of Wi-Fi interfaces, this article will cover the functional testing in detail. Functional testing of Wi-Fi for a product is a critical aspect of ensuring products reliability, performance, and user satisfaction. Wi-Fi technology plays a pivotal role in enabling seamless connectivity and communication across a wide range of devices, from smartphones and laptops to IoT sensors and industrial equipment. Functional testing focuses on evaluating the Wi-Fi features of a product, including its ability to establish connections, maintain stability, and handle various network scenarios effectively. This process involves testing the functionality of Wi-Fi stations, access points, and peer-to-peer communication to ensure that the product meets the demands of diverse use cases and environments. By conducting thorough functional testing, manufacturers can identify and address any issues related to Wi-Fi connectivity, thereby enhancing the overall quality and performance of their products. Let’s look into few test cases for functional testing.

Station/Access Point Configuration Testing

In case of target edge product acting as access point, tester need to configuring access point. That involves Creating SSID name, Password, Selecting security type etc. Tester will be doing basic configuration tests below.

Test Case Description	Expected Outcome
Verify creation of SSID name	Ensure that the SSID name can be created successfully without any special characters or escape sequences
Verify creation of Password	Ensure that the password can be created successfully without any special characters or escape sequences
Verify selection of security type	Ensure that the selected security type (e.g., WPA, WPA2, WEP) can be configured successfully
Verify handling of special characters in SSID name	Verify that the system correctly handles special characters (such as !, @, #, $, %, etc.) in the SSID name, ensuring that they are either rejected or appropriately processed as per product expected behaviour
Verify handling of escape sequences in SSID name and password	Test with various escape sequences (e.g., \a, , , \ooo, \d) in both SSID name and password to ensure that they are correctly interpreted and do not result in unexpected behavior or errors
Verify backend implementation of user input handling	Validate that the backend system handles user input (SSID name, password, etc.) consistently across different products, ensuring that it conforms to expected standards and does not introduce any vulnerabilities or unexpected behavior
Verify impact of escape sequences in SSID name and password on backend implementation and outcome	Test the impact of escape sequences on the backend system, ensuring that they do not cause any issues such as system crashes, data corruption, or incorrect functionality due to misinterpretation or mishandling
Verify handling of disallowed characters in SSID name and password	Test with a list of characters known to be disallowed in SSID names and passwords to ensure that the system correctly rejects them and provides appropriate error messages or prompts for valid input
Verify creation of SSID name and password with valid characters but maximum length	Test with the maximum allowable length for SSID names and passwords, ensuring that the system accepts them without any issues and does not truncate or mishandle the input
Verify creation of SSID name and password with valid characters but minimum length	Test with the minimum allowable length for SSID names and passwords, ensuring that the system accepts them without any issues and does not reject them erroneously
Verify creation of SSID name and password with valid characters and random lengths between minimum and maximum	Test with random lengths between the minimum and maximum allowable lengths for SSID names and passwords, ensuring that the system accepts them correctly and handles them without any unexpected behavior

Wi-Fi Stability Testing

In case the product is positioned with poor signal quality, there is a possibility of an increase in occurrence of disconnections and re-connections. This will impact the higher level protocols such as TCP/IP running on top of the Wi-Fi interface. Those actions need to be simulated by tester and resulting performance of the higher level layers has to be validated.

Test Case Description	Expected Outcome
Verify disassociation and association behavior during DHCP address release and renewal (graceful restart)	ValidateTest the behavior of the device when disassociating and associating while the DHCP address is released and renewed (graceful restart). Ensure that the device maintains connectivity and functionality without any disruptions
Verify disassociation and association behavior when DHCP is restarted on the station without releasing the address	Test the behavior of the device when disassociating and associating while DHCP is restarted on the station without releasing the address. Ensure that the device maintains connectivity and functionality without any disruptions
Verify disassociation and association behavior when the address is not released, but DHCP is restarted on the station	Test the behavior of the device when disassociating and associating without releasing the DHCP address, but DHCP is restarted on the station. Ensure that the device maintains connectivity and functionality without any disruptions
Verify disassociation and association behavior when the address is not released, nor renewed	Test the behavior of the device when disassociating and associating without releasing or renewing the DHCP address. Ensure that the device maintains connectivity and functionality without any disruptions
Verify the impact on the DUT's state based on different sequences of disassociation and association	Test the device under various scenarios to determine if disassociation and association in different sequences result in the DUT arriving in a bad state. Ensure that the device remains stable and functional regardless of the order of operations

There are multiple ways testers can test the above test cases. One way is testers can simulate association and disassociation of access point or station by changing the credentials either manually or using some automation tool.

Wi-Fi Channel Configuration tests

In case the product is expected to be used in multiple countries across the world, then the tester needs to make sure that the product is working as geography regulation guidelines/frequency bands. Not meeting as per geographic regulation will cause interference, network instability, market rejection and legal liability.

Some of the band’s w.r.t geography are listed below.

Region	Freq	Regulatory Body	Frequency Range
North America	2.4 GHz, 5 GHz	FCC (United States)	2.400 GHz - 2.4835 GHz (2.4 GHz) 5.150 GHz - 5.850 GHz (5 GHz)
Europe	2.4 GHz, 5 GHz	CEPT (European Union)	2.400 GHz - 2.4835 GHz (2.4 GHz) 5.150 GHz - 5.725 GHz (5 GHz)
Japan	2.4 GHz, 5 GHz	MIC	2.400 GHz - 2.4835 GHz (2.4 GHz) 5.150 GHz - 5.875 GHz (5 GHz)
China	2.4 GHz, 5 GHz	MIIT	2.400 GHz - 2.4835 GHz (2.4 GHz) 5.725 GHz - 5.850 GHz (5 GHz)
Australia	2.4 GHz, 5 GHz	ACMA	2.400 GHz - 2.4835 GHz (2.4 GHz) 5.150 GHz - 5.850 GHz (5 GHz)

So, testers need to verify that only geo specific frequency channels are allowed in configuration. Few testcases are listed below.

Test Case Description	Expected Outcome
Configure 2.4GHZ in North America and configure for channel number 12,13 & 14	If the Geography configured as North America, 13,14 and 15 should not be shown as options for channel selection
Configure 2.4GHZ in Europe and configure for channel number 14	If the Geography configured as Europe, 14 should not be shown as an option for channel selection

Seamless Handover Testing

Assess the seamless handover of devices between different access points in a mesh or multi-AP environment. e.g., moving between floors or buildings

Test Case Description	Expected Outcome
Static Roaming Test	Manually move a device from one access point's coverage area to another access point's coverage area within the same network (e.g., moving between floors or buildings). Ensure that the device seamlessly transitions to the new access point without any noticeable interruption in connectivity.
Dynamic Roaming Test	Continuously move a device between different access points within the network while actively using network services (e.g., streaming video, browsing websites). Ensure that the device maintains a stable connection and smoothly switches between access points without any disruption or degradation in network performance
Application Performance Testing While Moving Between 2 Access Points	Perform tasks such as streaming video, VoIP calls, or downloading files on a device while moving between two access points. Evaluate the performance of these applications in terms of latency, jitter, packet loss, and overall user experience during the handover process
Coverage and Signal Strength Evaluation	Conduct signal strength measurements and coverage assessments throughout the testing area, including areas with potential handover points (e.g., areas between floors or buildings). Ensure that there are no significant gaps in coverage and that signal strength remains consistent during device movement
Interference and Co-channel Interference Testing	Introduce interference sources or simulate co-channel interference in the testing environment to assess the impact on roaming performance. Evaluate how well the devices and access points handle interference scenarios and maintain seamless connectivity during handovers
Scalability Testing	Increase the number of devices simultaneously moving between access points to assess the scalability of the network and its ability to handle handovers efficiently under high device density scenarios. Ensure that the network maintains stable performance and seamless handover for all devices
Security Handover Testing	Test handover scenarios while utilizing different security protocols (e.g., WPA2, WPA3) and encryption methods. Verify that devices seamlessly transition between access points while maintaining secure connections and adhering to security protocols without compromising network security
Handover Recovery Testing	Intentionally disrupt the handover process by introducing temporary network outages or access point failures during device movement. Evaluate the network's ability to recover from such disruptions and seamlessly re-establish connections with alternative access points without user intervention

While the provided test cases cover critical aspects of Wi-Fi functionality, it's important to note that there are numerous additional use cases and scenarios to be tested to ensure comprehensive validation of Wi-Fi performance and functionality.

Conclusion

By harnessing the combined strengths of both manual and automation tools, testers can achieve comprehensive Wi-Fi testing coverage. This approach enables thorough validation of functionality, performance, and security aspects, ultimately leading to the delivery of high-quality Wi-Fi solutions that not only meet user expectations but also comply with regulatory requirements. Through automation, testers can enhance test coverage, accelerate regression testing, scale testing efforts, and streamline the testing process within CI/CD pipelines. By incorporating automation into Wi-Fi testing practices, organizations can ensure the reliability, scalability, and security of their Wi-Fi solutions, ultimately enhancing the overall user experience.