How LEVER's unique, patent-pending LoRaWAN survey capabilities define the new industry standard for LoRaWAN networks

Why Carry Out a LoRaWAN Survey?

LoRaWAN can provide exceptional range and building penetration, but this can sometimes create a false sense of security.

A LoRaWAN packet successfully reaching a gateway does not necessarily mean that a production network has sufficient:

• RF link margin
• gateway diversity
• resilience
• uplink reliability
• downlink reliability
• coverage in difficult locations

Buildings, terrain, machinery and other physical obstructions can have a major impact on RF propagation.

Basements, plant rooms, service tunnels, reinforced concrete structures, steel-framed buildings and metal equipment can be particularly challenging — and these are often precisely the locations where IoT sensors need to operate.

A professional LoRaWAN coverage survey replaces assumptions with measured data.

What Does a LoRaWAN Survey Measure?

A LEVER LoRaWAN survey can evaluate:

• Received Signal Strength Indicator — RSSI
• Signal-to-Noise Ratio — SNR
• RF path loss
• LoRaWAN link margin
• spreading factor requirements
• uplink coverage
• downlink coverage
• gateway coverage
• gateway overlap
• gateway diversity
• weak and marginal coverage areas
• RF interference
• suitability of proposed gateway locations

We can compare multiple potential gateway locations to determine which combination provides the optimum balance of coverage, resilience and cost.

The objective is not merely to demonstrate that a packet can be received. We want to establish whether the LoRaWAN network will continue to work reliably when deployed as a real operational system.

LoRaWAN Gateway Placement

Gateway placement is one of the most important decisions in a LoRaWAN network design.

Placing gateways wherever installation happens to be easiest can result in poor coverage, excessive dependence upon individual gateways or unnecessary infrastructure.

LEVER can temporarily position survey equipment at proposed gateway locations and measure performance from representative sensor locations throughout the site.

This allows us to determine:

• which gateway positions provide the strongest overall coverage
• which provide the best penetration into difficult areas
• where gateway overlap occurs
• which areas depend upon a single gateway
• whether additional gateways provide meaningful benefit
• whether gateways can be removed without compromising the design

This can reduce both technical risk and unnecessary installation cost.

Survey Before You Install

Many LoRaWAN deployments follow a simple approach:

1. Install gateways.
2. Install sensors.
3. Discover where the network does not work.
4. Add or relocate gateways.

A properly engineered network reverses that process.

Where practical, LEVER can survey candidate gateway locations before the final network is installed.

This is conceptually similar to the AP-on-a-Stick survey methodology widely used in professional Wi-Fi design, but adapted specifically for the very different characteristics of LoRaWAN.

Temporary survey equipment is positioned at potential gateway locations while measurements are taken throughout the intended coverage area.

The resulting data allows final gateway locations to be selected using engineering evidence rather than guesswork.

More Than a Simple Signal Test

One of the weaknesses of simplistic LoRaWAN testing is the assumption that successful reception equals adequate coverage.

It does not.

If a sensor transmission reaches a gateway, we know that the link worked at that moment. It does not necessarily tell us how close the radio link was to failure.

This is why link margin is so important.

A location with apparently good coverage but almost no additional RF margin may become unreliable when conditions change due to people, vehicles, moving stock, machinery, doors, vegetation or building modifications.

LEVER therefore evaluates the quality and margin of the link rather than simply recording whether communication occurred.

RSSI, SNR and Link Margin

Two important measurements in LoRaWAN surveying are RSSI and SNR.

RSSI — Received Signal Strength Indicator — provides an indication of the received radio signal level.

SNR — Signal-to-Noise Ratio — indicates how strongly the LoRa signal can be distinguished from the surrounding RF noise.

LoRa modulation can successfully decode signals at extremely low signal levels and at negative signal-to-noise ratios. This makes LoRaWAN exceptionally effective for long-range and difficult indoor applications.

It also means that interpreting LoRaWAN coverage requires more than applying a simple minimum RSSI threshold.

RSSI, SNR, spreading factor, receiver sensitivity and link margin need to be considered together.

Uplink and Downlink Coverage

LoRaWAN communication is not necessarily symmetrical.

For an uplink:

Sensor → Gateway

several gateways may receive the same transmission.

For a downlink:

Gateway → Sensor

a selected gateway transmits towards the device.

Differences in transmit power, antenna systems, receiver sensitivity, RF conditions and device installation mean that good uplink coverage does not automatically guarantee equivalent downlink performance.

Applications that require acknowledgements, remote control or device configuration can therefore require particular attention to downlink coverage.

LoRaWAN Coverage Maps

Survey measurements become considerably more useful when they are related to physical locations.

LEVER can use survey data to create LoRaWAN coverage maps and heatmaps illustrating:

• RSSI
• SNR
• link margin
• gateway coverage
• gateway overlap
• gateway diversity
• weak coverage areas

Results may be presented for individual gateways or as a combined network view.

This can reveal where relatively small changes to gateway placement could produce disproportionately large improvements in network performance.

RF Spectrum Analysis

LoRaWAN normally operates in licence-exempt radio spectrum.

Where appropriate, a LEVER LoRaWAN survey can include RF spectrum analysis to identify potential interference or unusually high RF utilisation.

Spectrum analysis may reveal:

• persistent transmitters
• intermittent interference
• elevated noise levels
• unexpected radio systems
• heavily occupied frequencies

LoRaWAN Validation Survey

Surveying is not only useful before installation.

After a LoRaWAN network has been deployed, LEVER can perform a post-installation LoRaWAN validation survey to confirm that the finished network satisfies its coverage and resilience requirements.

Validation can include:

• coverage testing
• RSSI and SNR measurements
• identification of marginal locations
• gateway diversity assessment
• uplink and downlink testing
• interference investigation
• confirmation of gateway locations

LoRaWAN Troubleshooting Surveys

Poor LoRaWAN communications may be caused by RF coverage, but this is far from the only possibility.

LEVER can investigate issues including:

• poor sensor antenna placement
• metal enclosures
• inappropriate gateway locations
• antenna or feeder problems
• interference
• incorrect radio configuration
• spreading-factor issues
• Adaptive Data Rate behaviour
• gateway problems
• Network Server configuration
• excessive downlink traffic
• application or integration problems

Our expertise extends beyond RF surveying into the complete LoRaWAN architecture, allowing us to distinguish genuine coverage problems from network, server or application issues.

Typical LoRaWAN Survey Environments

• commercial buildings
• industrial sites
• manufacturing facilities
• warehouses and distribution centres
• hospitals
• universities
• business campuses
• historic and heritage buildings
• utilities
• smart buildings
• agricultural sites
• outdoor infrastructure

LoRaWAN Survey Deliverables

Depending upon the project, survey deliverables can include:

• survey findings and analysis
• coverage maps and heatmaps
• gateway coverage comparisons
• RSSI and SNR measurements
• path-loss data
• assessment of link margins
• gateway diversity analysis
• recommended gateway locations
• identification of weak areas
• RF spectrum findings
• engineering recommendations
• design changes
• post-installation validation results

The LEVER Difference

LEVER is not tied to a particular gateway manufacturer, Network Server or IoT platform.

Our wider expertise encompasses RF engineering, Wi-Fi, LoRaWAN, IoT networking, spectrum analysis, packet analysis, network architecture and wireless security.

Professional Wi-Fi surveying has benefited from sophisticated specialist survey tools and methodologies for many years. LoRaWAN surveying has traditionally been much less developed.

LEVER is working to change that.

Our proprietary, patent-pending LoRaWAN survey technology and methodologies have been developed from decades of practical wireless network engineering experience.

They allow us to evaluate LoRaWAN coverage and gateway placement in ways that conventional single-device survey techniques cannot readily achieve.

Better information produces better wireless networks.