The idea of providing wireless internet access to entire neighborhoods or even a metropolis sounds incredibly appealing. Imagine a world where you walk out of your home and instantly connect to the global network without having to search for passwords or pay mobile phone bills. The Dream of Universal Wi-Fi has been in the air for two decades, ever since this technology became widespread.
However, the technical implementation of such a project faces strict laws of physics and radio frequency regulation. Standard routersThe wireless devices you have in your home aren't designed to operate in open spaces with long range. Their antennas have a circular pattern, which causes the signal to fade quickly.
Moreover, even if the equipment were powerful enough, the problem of airwaves congestion would arise. Thousands of devices attempting to connect to a single access point would simply choke the communication channel. Therefore, the answer to the question of how to provide citywide Wi-Fi lies not in a single powerful transmitter, but in a complex infrastructure.
In this article, we'll explore why home-based methods don't work over long distances, what equipment providers use, and what viable alternatives exist for creating Smart City-scale networks.
It's worth noting right away that creating a city network is a task for telecom operators and municipalities, not for enthusiasts with a soldering iron. Legislative restrictions The use of the frequency spectrum does not allow private individuals to install powerful emitters.
Why a home router won't cover the city
Many users mistakenly believe that replacing the router's antenna with a more powerful one or an external one will improve signal coverage from several kilometers away. This misconception stems from a misunderstanding of the principle. two-way communicationEven if a powerful transmitter can reach your smartphone from a distance of 3 km, the weak transmitter in your phone simply won't be able to reach the router.
Besides, IEEE 802.11 standardThe Wi-Fi protocol, which underlies Wi-Fi, was originally designed for local area networks. The data exchange protocol requires constant packet acknowledgment, which, with significant delays and signal loss, makes connection impossible. The signal simply fades as it passes through walls, trees, and precipitation.
⚠️ Warning: Increasing transmitter power above permitted limits (usually 100 mW or 20 dBi EIRP in the 2.4 GHz band) is a violation of the law and may result in fines from Roskomnadzor, as well as interference for aviation and intelligence agencies.
There's another critical factor: interference. In urban environments, the airwaves are oversaturated with signals from hundreds of neighboring networks. If you try to create a "super-hotspot" on a public frequency, it will become just one of many, and speed will drop to zero due to packet collisions.
WISP Technologies: How Providers Do It
The real way to provide internet to a large area or city is through the use of technology WISP (Wireless Internet Service Provider)Unlike home Wi-Fi, it uses completely different equipment and network architecture. Providers build a network of base stations that are connected via dedicated channels (backhaul), often using radio relay lines.
To distribute the signal to clients, access points with sector antennas are installed. These cover a specific sector, for example, 90 or 120 degrees, and can transmit the signal over a distance of up to 5-10 kilometers with a direct line of sight. Ubiquiti equipment And MikroTik is the de facto standard in this industry due to its reliability.
A crucial element of such a network is frequency planning. To avoid interference, providers use not only the standard 2.4 and 5 GHz bands, but also licensed bands and TDMA (Time Division Multiple Access) technologies. This allows for coordinated data transmission between hundreds of subscribers, preventing them from interfering with each other.
What is the difference between TDMA and regular Wi-Fi?
In conventional Wi-Fi, devices speak in turns when a channel becomes available (CSMA/CA), which creates latency under heavy load. TDMA strictly allocates time slots to each client, ensuring stable ping even at 100% sector load, which is critical for IP telephony and gaming.
Urban network architecture is typically built using the "star" or "mesh" principle. A base station is installed on the roof of a tall building and distributes the signal to subscriber receivers. Directional dish antennas, which ensure high data transfer rates, are used to connect base stations.
Necessary equipment for large-scale networks
If you're planning to deploy a coverage network for a private community or campus, you'll need specialized equipment. Standard consumer routers won't work due to their lack of support for management protocols and low receiver sensitivity.
First of all, it is necessary base stationsThese are devices with high output power and are connected to professional antennas. They manage the connection of all clients in the sector. An example is the series LiteAP or PowerBeam.
Customer Premises Equipment (CPE) devices are installed for clients. These are external receivers mounted on the building's facade or roof and pointed directly at the base station. Inside, a cable runs from them to a standard router or computer.
| Equipment type | Purpose | Range (line of sight) | Example of a model |
|---|---|---|---|
| Base Station (Sector) | Signal distribution to the sector | up to 5-7 km | MikroTik SXTsq 5 ac |
| Access Point (Omni) | Circular covering (parks) | up to 2-3 km | Ubiquiti UniFi AC Mesh |
| Radio bridge (P2P) | Connecting buildings | up to 20+ km | Ubiquiti airFiber |
| Client device | Subscriber receiving a signal | up to 5 km | MikroTik LHG 5 ac |
Don't forget about switching equipment either. All base stations should be connected to each other using gigabit switches that support PoE (Power over Ethernet). This simplifies installation, as there's no need to run a separate power cable to the roof.
☑️ Preparing to launch a WISP network
Interference problems and frequency planning
The biggest technical challenge in deploying a city network is radio frequency interferenceIn the 2.4 GHz band, which has the longest range, it's often impossible to find a clear channel. Neighboring networks, Bluetooth devices, microwave ovens, and even wireless cameras create a signal "mess."
To solve this problem, engineers are switching to the 5 GHz band and higher. It's less noisy and allows for wider data transmission channels. However, it has a physical drawback: the 5 GHz signal is less able to bypass obstacles and fades faster in rain.
⚠️ Important: When designing a network, be sure to use spectrum analyzers. Visually assessing the environment will not help – you won't see invisible sources of interference, such as active radars or illegal amplifiers.
There's also the concept of "hidden terminal." This occurs when two clients are far apart and can't "hear" each other's transmissions, but both are within earshot of the base station. If they begin transmitting data simultaneously, a collision will occur at the base station, and packets will be lost. WISP protocols are designed to combat this, but effectiveness depends on proper timing settings.
Frequency planning requires careful consideration. Simply placing two base stations next to each other on the same frequency is not enough. Channels must be alternated, antenna polarization (vertical and horizontal) must be used, and sectors must be properly oriented to minimize coverage overlap.
Legal aspects and limitations
Before installing equipment, it's important to review your country's telecommunications laws. In Russia and many other countries, the use of certain frequencies requires a license. For example, the 5 GHz band (UNII-2) is often restricted to indoor use only or requires registration with the Radio Frequency Center (RFC).
Installing antennas on the roofs of apartment buildings also involves bureaucratic hurdles. You'll need the consent of the property owners or the management company. Unauthorized installation may be regarded as a violation of the rules for the operation of the housing stock.
Furthermore, a communications service provider must have a license to provide telecommunications services. Selling internet access without a license is illegal. For private use (for example, connecting your home to a sauna), licenses are generally not required if the equipment's capacity does not exceed established standards.
Alternatives: Mesh networks and LoRaWAN
If the goal is not to provide high-speed internet, but to create a network for smart city sensors or to transmit small amounts of data, it is worth considering the technology LoRaWANIt allows data transmission over distances of up to 10-15 km in the city with very low power consumption.
For organizing coverage within one large building or campus area, they are ideal Mesh systemsUnlike the classic router-client design, each device here retransmits the signal to others. This allows for complex architectures to be covered without the need for cables, although overall network throughput is reduced.
There are also community networking projects such as Freifunk or NinuxEnthusiasts connect their routers into a single decentralized network. This is a complex but interesting way to create a local internet community, although access to the global network still requires a connection to a provider.
Outdoor access points with omnidirectional antennas, paired with a controller, are often used to cover park areas or squares. The controller automatically switches the client between access points, ensuring seamless roaming. As the user walks through the park, their device automatically selects the closest access point.
Is it possible to use satellite internet to distribute internet throughout the city?
Technically feasible, it's not economically feasible for the masses. Very high-speed satellite terminals (VSAT) have high latency and limited bandwidth. Distributing such internet to hundreds of people via Wi-Fi would result in extremely low speeds per user. This solution is only suitable for remote locations where other connectivity options are unavailable.
Why does free Wi-Fi in the city often require SMS authorization?
This is a legal requirement for user identification. The access point owner is required to maintain logs and know who exactly was using the network at a specific time. Phone number authentication allows an anonymous IP address to be linked to a specific person.
Does weather affect city Wi-Fi?
Yes, especially for 5 GHz bands and above. Heavy rain, snow, or even dense fog can significantly attenuate the signal. When designing microwave links, a fade margin is always included to cover deteriorating weather conditions.
In conclusion, creating a city-scale network is a high-level engineering challenge that requires significant financial investment and coordination with government agencies. However, understanding the operating principles of such networks helps better configure home Wi-Fi or provide coverage for a small town using proven WISP technologies.