Interaction with customers offline via mobile app

Maria S, Lead Mobile Developer
Maria S, Lead Mobile Developer
Mar 18, 2024
10 minutes
Do you still think that when a McDonald's waiter finds you in the most hidden corner of the restaurant and brings your order, it's magic? I don't want to upset you, but this is technology. Moreover, they are not that difficult, but very interesting. The whole secret is in special beacons and BLE technology. Let's figure out how to set everything up and what cases can be used for using them for catering and retail.

For what?

Navigation in large retail spaces

The trick is that we can determine in three-dimensional space, with an accuracy of up to a centimeter, where a person is.
We can tell the courier where the goods are located in the warehouse. Build a path in the shopping center to the desired establishment. After all, unlike GPS, this technology sees you not just in a building, but on a specific floor.
We can send push notifications at the desired stand and show something specific in the application. For example, I went to the shelves with rum or tequila, watched a video in the application, what cocktails can be prepared, what ingredients are needed. I built a route to the shelves with the necessary goods.
In general, build analytics of customer movements: where they went, where they stayed longer. And then, based on this, make a layout and sell the best places to suppliers.

Personalized approach

A guest approaches a restaurant, his phone tracks a beacon installed in the establishment and “wakes up” the application, it sends a request to a backend, and the backend can do anything. For example, we can show hostesses the names and preferences of those who enter the restaurant, if this is in our database. Or, on the contrary, we can show the guest that there is a promotion in the cafe he is passing by today. And if this is a store, remind them that there is an unpaid item in the cart.
Sounds interesting? Let's dive a little into the technology, and then talk about business opportunities.

What is BLE?

No matter what anyone says, Bluetooth Low Energy (BLE) technology, also known as Bluetooth 4.0 and higher, still has no equal. It has become especially popular for developing Internet of Things (IoT) applications.
BLE is a version of Bluetooth optimized for minimal power consumption. It’s not difficult to guess that they love it precisely for this and use it to its fullest in devices that operate on batteries without recharging for a long time.
Unlike traditional Bluetooth, which is designed for exchanging large amounts of data (such as audio files), BLE is optimized for transferring small data packets with maximum energy efficiency. This allows devices such as fitness bracelets, smart watches, medical sensors and beacons to operate on a single battery for months, and sometimes years. Everyone’s favorite airtag immediately comes to mind, which is thrown into suitcases and backpacks, hung on keys, etc., to keep track of their property.
So, sometimes behind some devices that amaze us with their genius are such simple technologies. BLE is constantly being used to develop new types of devices and applications due to its energy efficiency, wide compatibility, low cost and ease of use.


Beacons are small wireless devices that transmit signals over short distances using Bluetooth Low Energy (BLE) technology. They are designed to convey a unique identifier that can be recognized by smartphones and other devices nearby.
This mechanism allows:
• determine location indoors
• provide contextual information
• use yourself as a trigger for certain actions of applications on a smartphone when a specific beacon is detected

Distance tracking using BLE and RSSI

RSSI (Received Signal Strength Indicator) is based on measuring the signal strength between two devices: the closer the devices are to each other, the stronger the signal.
In other words, when you bring your smartphone closer to a BLE beacon, the smartphone notices that the signal from the beacon is getting stronger, and based on the change in signal strength, it can estimate the distance to the beacon.
However, the accuracy of this measurement method can vary greatly due to various factors. First, physical obstacles such as walls or furniture weaken the signal, making the beacon appear further away than it actually is. Secondly, interference from other signal sources, such as other BLE devices or Wi-Fi networks, can also distort measurements. In addition, different device models have different receiver sensitivity, which also affects the accuracy of distance determination.
To improve the accuracy of RSSI-based distance tracking, various filtering and correction algorithms are often used to take into account and minimize these influencing factors. For example, methods are used to average RSSI values over a period of time or algorithms that analyze changes in signal strength to refine distance estimates.

Why should this be used in business?

We will, of course, as always, use the example of food technology. Beacons are used here to improve customer service, optimize processes and increase business efficiency. For example:

Improving customer experience

• Place beacons inside a restaurant or cafe to automatically detect a customer's stay and provide personalized offers through a mobile application.
• Implement a self-service system where customers can place orders and pay through a mobile application, and beacons will help determine their location for accurate delivery of the order.

Optimizing processes in a restaurant

• Use beacons to track staff movements to optimize task distribution and improve overall work efficiency.
• Automate warehouse inventory processes and warn about the need for restocking when beacons detect inventory levels below a certain threshold.

Increasing customer loyalty

• Use beacons to provide bonuses, discounts or special offers to customers who visit your establishment regularly.
• Create loyalty programs where beacons track customer purchases, providing bonuses or discounts when a certain consumption level is reached.

Analytics and data collection

• Collect data on the movement of customers within the establishment to optimize table placement, improve room design and manage customer flow.
• Analyze data about customer preferences based on their location to improve menus and offer more relevant dishes.

Delivery and to-go service

• Use beacons to track orders and locate couriers, which can help optimize the delivery process.
• Notify customers about order status and provide delivery information in real time through mobile apps.
The development and improvement of the tracking system using BLE and RSSI opens up new prospects for creating effective and convenient solutions in a variety of areas, from retail to food tech, providing a new level of user experience. But that's a completely different story...