Establishing a stable connection between remote sites often becomes a complex engineering task, requiring the installation of expensive fiber optic cables. However, modern technologies make it possible to create high-performance wireless channels without excavation work and permits for cable laying. Construction WiFi bridge (Wireless Bridge) is the most cost-effective way to connect two local networks or transmit Internet over a distance of several kilometers.
In this article, we'll take a detailed look at the physical and logical architecture of such connections. You'll learn how to select the right equipment, configure radio module operating modes, and avoid common antenna alignment errors. A well-designed system point-to-point The system will provide speed comparable to a wired connection at minimal cost.
The basic operating principle is that one device acts as a signal source and the other as a receiver, transparently transmitting data packets between them. It's important to understand the difference between a simple repeater, which throttles speed, and a fully-fledged bridge operating at the MAC address level. line of sight between antennas is a critical success factor, without which it is almost impossible to build a stable link.
Selection of equipment and network architecture
The first step is to determine the type of equipment that will be used to build the channel. The market offers a variety of solutions, from universal home routers with WDS support to specialized outdoor access points from Ubiquiti, MikroTik, or TP-Link. For short distances (up to 300-500 meters), two routers with external antennas are sometimes sufficient, but for longer distances, a separate router is required. highly specialized equipment.
The key selection parameter is the frequency range. The 2.4 GHz band has better penetration and range, but it is heavily polluted by household appliances and neighboring networks. For backbone channels, it is preferable to use 5 GHz or even 60 GHz, where the air is cleaner and the channel width allows for gigabit data transfer speeds.
⚠️ Attention: When choosing the 5 GHz frequency, keep in mind that the signal has poorer penetration through obstacles, but is less susceptible to interference. In dense urban areas, using 2.4 GHz for a bridge can lead to constant connection drops due to airwave congestion.
You also need to decide on the antenna polarization and connector type. Professional devices often use N-type connectors for a secure connection to the feeder, while consumer models may have built-in antennas. Don't forget about lightning protection, which is mandatory for outdoor equipment.
- 📡 Range: For distances up to 1 km, omnidirectional or sector antennas are suitable; for distances over 3 km, only highly directional parabolic or panel antennas with a high gain are suitable.
- ⚡ Nutrition: Make sure the access points you choose support the PoE (Power over Ethernet) standard to transmit power and data over a single cable, simplifying installation.
- 🌦️ Protection: The device's enclosure must be IP65 certified or higher for protection against moisture, dust, and UV radiation.
Installation Preparation and Visibility Requirements
Before configuring the software, it's important to conduct a thorough reconnaissance of the area. Ideally, there should be a clear line of sight (LOS), meaning there are no physical obstacles between the transmitting and receiving antennas. Even if objects are visible, it's important to consider Fresnel zone - an ellipsoid around the line of sight, which must be free of trees and buildings.
To assess the terrain, use specialized applications on your smartphone or web tools such as Ubiquiti Link Planner or MikroTik Link CalculatorThese tools allow you to create a path profile, calculate signal attenuation, and determine the required mast height. Ignoring the Fresnel zone is the most common cause of network instability, even with visual contact.
Installation work requires adherence to safety precautions. Climbing onto the roof or mast must be done only with a safety harness, and all electrical work must be performed with the power off. The Ethernet cable running to the antenna must be shielded (Cat5e or Cat6) and have properly terminated connectors.
☑️ Checking the installation location
If line-of-sight is impossible, installing a repeater at an intermediate height can sometimes help, but this complicates the network architecture and reduces overall throughput. In such cases, it's better to consider alternative technologies, such as LTE modems with external antennas.
Setting up WDS and Client Bridge mode
The logical configuration of the bridge depends on the capabilities of the equipment used. The most common mode for creating a transparent bridge on consumer routers is WDS (Wireless Distribution System). This protocol allows for the unification of multiple wireless network segments into a single infrastructure. However, WDS requires that both devices be from the same manufacturer or support common implementation standards.
A more universal and modern approach is to use the mode Client Bridge or simply "Bridge." In this setup, one device (the AP) broadcasts the signal, and the second (the Client) connects to it as a regular client, but then broadcasts the internet to its LAN port. This allows you to connect any device to the receiver: computers, cameras, smart TVs.
When setting up, it's important to disable the DHCP server on the receiving (client) side so that only the main router distributes addresses. IP addresses should be in the same subnet, but not conflict with each other. The subnet mask is usually left at the default value. 255.255.255.0.
| Parameter | Main router (AP) | Receiver (Client/Bridge) |
|---|---|---|
| Opening hours | Access point (AP) | Client / Bridge |
| IP address | 192.168.1.1 | 192.168.1.2 (static) |
| DHCP Server | On | Turned off |
| SSID (Network Name) | MyNetwork_Bridge | MyNetwork_Bridge (matches) |
| Channel | Fixed (eg 36) | Fixed (matches) |
⚠️ Attention: Never leave the DHCP server enabled on the receiving side of a bridge unless it's isolated to a separate subnet. This will cause address conflicts and network downtime for all connected users.
What if the devices are of different brands?
If your main router is an ASUS and your receiver is a TP-Link, WDS mode may not work due to proprietary extensions. In this case, configure the main router to AP mode and the receiver to "Wireless Client" or "Media Bridge" mode. This will ensure compatibility at the 802.11 standard.
Setting up specialized equipment (MikroTik, Ubiquiti)
Professional equipment requires more advanced setup, but offers significantly more features and stability. In the ecosystem MikroTik protocol is used NV2 or standard Wireless mode. To create a bridge, you need to create a bridge interface in the menu Bridge, add a wireless interface and a LAN port to it, and then configure a security profile with the same encryption key.
In devices Ubiquiti AirMax Configuration is done through the simplified AirOS interface. It's important to select the correct mode: "Access Point" for the transmitting side and "Station" for the receiving side. The system will automatically scan the air and prompt you to select the best channel. For maximum speed, it's recommended to use the widest channel possible. 40 MHz or 80 MHz, if noise levels allow.
Pay special attention to security. An open bridge is a hole in your network. Be sure to use encryption. WPA2-AES or WPA3In professional settings, it is also recommended to disable unnecessary services (Telnet, HTTP) and leave only SSH, changing the default ports and passwords.
# Example command for setting a static IP on MikroTik (via terminal)
/ip address add address=192.168.88.2/24 interface=bridge1
/ip route add gateway=192.168.88.1
After the basic setup, you need to check the signal strength (RSSI) and connection quality (CCQ). The optimal signal strength is considered to be between -50 and -65 dBm. If the signal is weaker than -75 dBm, the link will be unstable, especially in poor weather.