WiFi audit

WiFi audit is a comprehensive assessment of a wireless network aimed at determining network coverage, speed, sources of interference, and connection quality in different areas of the premises. A properly conducted audit allows for the optimization of network infrastructure, ensuring effective device operation.

During the audit, the "TamoGraph Site Survey" software is used, allowing for active and passive network analysis based on the floor plans provided by the client. The technician moves through the premises with the equipment, collecting data on signal strength, speed, interference, and access point coverage. The collected information is presented as visual maps and indicator lists that help make informed decisions regarding network expansion or optimization.

Additionally, the spectrum analyzer "WiPry Clarity" is used, which allows for the precise identification of radio frequency (RF) interference in both the 2.4 GHz and 5 GHz bands. This is particularly useful when the performance of the WiFi network is affected by non-WiFi sources such as microwaves, wireless cameras, or Bluetooth devices. With "WiPry Clarity," it is possible to identify channel congestion, external noise, and select the optimal channels for network performance.

During the audit, various wireless network (WiFi) parameters are evaluated to determine the network's speed, reliability, and quality in specific indoor locations. They are obtained through three tests: Passive, which shows the signal strength; Active, which shows the data transmission and reception speed of the network and their loss; and Spectrum, which shows the activity of possible non-WiFi related interference. Each indicator helps to thoroughly understand the performance of the existing network infrastructure and its possible shortcomings.

• Signal strength (in English: Signal Level): indicates the intensity of the radio signal, expressed in dBm. The closer the value is to zero (e.g., -30 dBm), the stronger the signal. The lower the value (e.g., -90 dBm), the weaker the signal, and the connection may be unstable or may not work at all. It shows the intensity of the radio signal, expressed in dBm. The smaller the value (closer to -100 dBm), the weaker the signal. A strong signal is required for a good connection (e.g., above -67 dBm).

• Signal-to-Noise Ratio (SNR): indicates how much stronger the signal is than the background noise. The value is expressed in decibels (dB) – the higher the value, the better the quality of the connection.

• Signal-to-Interference Ratio (SIR): indicates how much stronger the signal is than the interference that can be caused by other nearby operating access points. A low SIR significantly reduces throughput.
• Access point coverage areas visually represent the signal coverage of each access point and help identify uncovered zones or excessive overlap.
• Number of APs: indicates how many different access points cover a certain area. The presence of multiple access points in one location helps ensure continuity of connection and load balancing among clients.
• Expected physical speed (Eng. Expected PHY Rate): the predicted theoretical physical layer speed (Mbps) that depends on the connection conditions at a specific location.
• Physical data transmission speed (eng. Actual PHY Rate): the actual physical layer data transmission speed between the client and the AP, recorded during measurements.
• TCP data speed (TCP Upstream & Downstream Rates): the speed of useful (application layer) data transmission using the TCP protocol, separately for sending and receiving directions.

• UDP data rate (English: UDP Upstream & Downstream Rates): the speed of sending or receiving data using the UDP protocol. This protocol is often used in real-time services (e.g., VoIP).

• UDP packet loss (engl. UDP Upstream & Downstream Loss): the percentage of lost UDP packets. High loss often indicates network congestion or instability.

• Response time (in English, Round-Trip Time, RTT): measures the time it takes for a packet to travel to the server and back. This metric is important for networks used for interactive services.
• Associated AP (English: Associated AP): shows which access point the device was connected to at a specific measurement moment. It is used to analyze roaming behavior.
• Frame Format: specifies what type of 802.11 frames are used – older (Non-HT), mixed (HT-mixed), or only new (HT-Greenfield).
• Used channel bandwidth: whether 20 MHz or 40 MHz channels are used. A wider bandwidth allows for higher speeds but can increase interference.
• Channel maps (English: Channel Map 2.4 / 5 / 6 GHz): visually show which channels are used in different frequency bands, allowing the identification of channel overlap.
• Compliance with requirements (Eng. Requirements): assesses whether the predetermined technical requirements (e.g., signal strength or speed) are met at a specific location.

• Spectrum analysis (eng. Spectrum Analysis): provides a graph of radio frequency spectrum activity at a specific moment in time. Useful for identifying sources of interference.

In certain cases, when there is no wireless network yet or it is planned to be changed, a predictive WiFi audit can be performed. It allows modeling of network coverage, signal strength, and expected speed without physical measurements. Using the TamoGraph Site Survey application, a network model is created based on:

• With room layouts (PDF or DWG),
• By the type of used building materials (walls, windows, floors),
• Location of planned access points (AP), model, antenna type.

The results include preliminary coverage maps, expected data transfer rates, and analysis of potential disruptions. This method is particularly suitable for planning or optimizing new projects even before installation.

• Evaluate the WiFi signal coverage, strength, and quality in different areas of the building.
• Determine the wireless network speed using TCP and UDP protocols, in both upload (upstream) and download (downstream) directions.
• Evaluate the reliability of the connection, considering the signal-to-noise ratio (SNR) and the signal-to-interference ratio (SIR).
• Analyze the physical data transmission speed (Actual PHY rate) under real conditions.
• Identify locations with high UDP packet loss, which may indicate network congestion or disruptions.
• Determine the locations of existing access points (AP), SSIDs, MAC addresses, and their coverage areas.
• Evaluate the channel allocation in the 2.4 GHz, 5 GHz, and, if applicable, 6 GHz frequency bands.
• Identify unnecessary AP coverage overlapping and potential channel interference.
• Perform a spectrum analysis to identify non-WiFi interference sources (e.g., microwave ovens, wireless devices).
• Provide conclusions and recommendations regarding network layout, channel planning, and performance improvement.

In order to conduct a comprehensive WiFi network audit, technicians must have the following preliminary resources:

• Room plans in PDF or DWG format (scale accuracy is important).
• Free physical access to all audited areas (including closed premises, if the network is accessible there).
• Information about the existing WiFi infrastructure – access point (AP) models, MAC addresses, SSID, channel configuration.
• Functional WiFi network during measurement (if active analysis is performed).
• The possibility to connect the testing computer to the local network if it is necessary to measure the actual TCP/UDP speed to the server.

• "TamoGraph Site Survey (Professional Edition)" is professional software designed for both active and passive WiFi network analysis, providing visual results and diagnostic indicators.
• A laptop with an external WiFi adapter – used for data collection throughout the entire indoor area. The external adapter provides more accurate measurements than the integrated equipment.
• "Oscium WiPry Clarity" – a spectrum analyzer that helps identify radio frequency interference and channel congestion in both 2.4 GHz and 5 GHz frequency bands.

By performing active and passive analysis, the following key results are generated:

• Signal strength heatmap – visually shows how strongly the WiFi signal spreads in different areas of the premises.
• Signal and noise ratio (SNR) and interference (SIR) maps – allow assessing the quality of the connection considering the noise level and the impact of other access points.
• The coverage contours of access points indicate which areas are covered by each specific access point and where potential uncovered locations are.
• Network speed maps based on TCP and UDP protocols – they present data stream speeds in both sending (upstream) and receiving (downstream) directions.
• UDP packet loss maps - identify areas where part of the data is lost, which can affect real-time services.
• Round-trip time (RTT) indicators reflect the network response time from the device to the server and back.
• Association information – shows with which AP the device was connected at a specific measurement time, useful for roaming.
• Channel distribution maps (2.4 GHz, 5 GHz, 6 GHz) – allow assessing channel load and overlaps that can cause interference.
• Analysis of frame formats indicates whether old (Non-HT), mixed (HT-mixed), or modern (VHT, HE, EHT) formats are used.
• Spectral analysis graphs – if 'WiPry Clarity' was used, data on RF activity and non-WiFi interference sources is provided.
• The SSID and MAC address list provides information about all detected access points, their identifiers, and signal levels.
• Compliance analysis – areas are marked with color maps where the pre-defined criteria (e.g., minimum signal strength, minimum speed) are not met.
• Recommendations - suggested optimization opportunities, such as the locations of new access points, reconfiguration of channels, or removal of noise sources.

• The accuracy of measurements depends on the environmental conditions during the audit, such as human traffic, furniture arrangement, open/closed doors, or the influence of electrical appliances.
• The presented results are valid only for the current situation and may change if the situation changes (for example, after a reorganization, changing the configuration of access points, or equipment).
• The final conclusions are based on the drawings and information about the existing network provided by the client. Incorrect or incomplete data may affect accuracy.
• Non-functioning, hidden, or unauthorized access points (AP) may go undetected during analysis.
• Predictive analysis (if performed) is based on theoretical modeling and does not reveal actual sources of disturbances or noise.

• TCP (Transmission Control Protocol) is a protocol that ensures reliable data transmission between the sender and the receiver. It uses a handshake mechanism and acknowledgments to ensure that all data reaches the receiver correctly. Therefore, TCP is suitable for email, web browsing, and file transfers.
• UDP (User Datagram Protocol) is a lighter, faster protocol that does not use acknowledgments and error checking. As a result, it puts less strain on the network but does not guarantee that all data will be delivered. UDP is often used for real-time services such as video calls, streaming video, or online gaming.
• Non-HT (Non-High Throughput) – these are frames of the 802.11a/b/g standards that do not use 802.11n and newer transmission optimizations, such as MIMO or channel bonding. These frames are transmitted slower and lack high-performance features.
• HT-Mixed is the 802.11n mode that allows operation for both new devices (with HT features) and older ones (802.11a/b/g), ensuring compatibility. However, due to additional headers, performance may be slightly reduced for compatibility.
• HT-Greenfield – 802.11n mode, optimized only for next-generation devices, without using additional frames for compatibility with older standards. It allows for maximum performance but is not compatible with 802.11a/b/g devices.
• VHT (Very High Throughput) – the 802.11ac standard, allowing the use of wider channels (up to 160 MHz), more spatial streams, QAM256 modulation, and MU-MIMO, thus ensuring significantly higher performance.
• HE (High Efficiency) – 802.11ax (WiFi 6) frames designed to operate efficiently in dense network environments. Advanced methods are used, such as OFDMA, MU-MIMO in both directions, TWT (Target Wake Time) – all of which increase efficiency, reduce latency, and energy consumption.
• EHT (Extremely High Throughput) – 802.11be (WiFi 7) frames aimed at very high speed, ultra-low latency, and extensive channel bandwidth utilization (up to 320 MHz), additionally supporting Multi-Link Operation (MLO), 4096-QAM, and other performance optimizations.

Interested in a WiFi audit? Contact us at Email: info@topologija.lt or Phone: 8 698 34555