How Municipal WiFi Functions

Imagine being a reporter covering a tense hostage situation with a looming deadline. There's no time to return to the office, and leaving the scene would mean missing crucial developments. Luckily, you have wireless internet access, allowing you to write and submit your story without stepping away from the action.

Your article details how law enforcement officers monitor live security camera feeds. From their squad cars, they observe the situation and have access to building blueprints, showing key details like entrances, exits, and hiding spots. This vital information aids in their decision-making. Additionally, a secure connection links them to a hostage negotiator for support.

Once the crisis is resolved, it’s clear that the municipal wireless network and the data it transmitted played a significant role in achieving a peaceful outcome.

This article explores the incredible potential of municipal networks, going beyond just offering affordable or even free internet access. You'll also discover the technology powering these networks and why the term 'Municipal WiFi' might not always be accurate.

Wireless Fundamentals

In the early days of home internet, users had to connect a modem to a computer to dial into a network and maintain a connection. This process was slow and inconvenient. As modems improved in speed, people quickly realized how slow the earlier 300 baud connections had been. Eventually, those who could afford the higher price tags upgraded to broadband via digital subscriber lines (DSL), cable

and satellite connections.

Broadband offers faster speeds than dial-up, but until recently, you still had to connect your computer to a wall outlet or equipment. Wireless networking, or WiFi, has revolutionized this. Using 802.11 networking standards, WiFi networks enable devices to communicate. In a WiFi setup, data travels through radio waves. Although a wireless router must still be connected to a modem, you can now move your computer freely between locations.

The 802.11 networking standard utilizes the unlicensed radio spectrum to transmit data. Other parts of the radio spectrum, like those carrying radio and TV signals, require a license to access. However, the unlicensed spectrum is available to anyone with the proper equipment. For wireless networking, that means a router and compatible wireless technology in the device you're using.

Since 2002, home wireless networks have become common, with businesses following suit to offer employees greater mobility. Public spaces like coffee shops, parks, and libraries have created WiFi hotspots, aiming to attract more businesses. The number of these hotspots has increased rapidly, with experts predicting 200,000 hotspots by 2008 [ref].

Cities have begun launching municipal wireless networks. By January 2006, 186 cities in the United States had either established or planned networks, a significant rise from 122 in July of the previous year [ref]. Some cities offer free or low-cost high-speed Internet, while others restrict access to city employees, such as police and fire departments, enabling them to carry out tasks remotely.

Cities proposing new networks aim to enhance worker productivity, make their areas more appealing to businesses, stimulate the local economy, and bridge the digital divide — sometimes achieving all of these goals with a single network. The U.S. ranks 16th in global broadband penetration, which some believe signals the country's decline in this sector [ref]. A wireless network could help make broadband access more widespread and affordable for more people.

Often referred to as "municipal WiFi," these networks go beyond just using 802.11 standards. The wireless access points in municipal networks differ from typical WiFi hotspots. Next, we'll explore the "mesh" structure that underpins a wireless network.

Technology and Networks

Mesh

Most WiFi hotspots found in coffee shops and similar venues use a hub and spoke system. A central radio (the hub) sends and receives data for multiple users (the spokes). The wireless router is physically connected to the internet via a wire, which it uses to transmit data to and from several users simultaneously.

Adding a wireless router to an existing wired setup is a simple and efficient way to enable wireless access on a small scale. Wireless routers are affordable and typically offer various sign-on and encryption options, ensuring a basic level of security.

However, if a wireless router fails, there may not be another nearby to take over its role. Additionally, on a large scale—like a city-wide network—connecting every router to the internet via physical wires becomes prohibitively expensive.

This is why most municipal wireless networks opt for a mesh configuration instead of a hub and spoke model. A mesh consists of multiple radio transmitters, each of which can communicate with at least two others, forming a network of radio signals spread throughout the city. The signals pass from one router to another through this interconnected cloud.

In some networks, signals transfer from one receiver to another until they reach a node with a wired internet connection. Other networks make use of backhaul nodes, which perform the task suggested by their name — collecting data from several transmitters and sending it back to the internet by routing it through a wired connection. These backhaul nodes are typically point-to-point or point-to-multipoint connections, either linking one point to another or connecting a single point to multiple others.

When you connect your laptop to the internet through a mesh network, here's the process that occurs:

If you're in a city with public access, you can likely connect without additional equipment. However, if you're attempting to access the network from home, you may require a more powerful radio or possibly a directional antenna. While signals from the city network can reach your home, your computer's signal may not be strong enough to reach the network. Most service providers address this by supplying the necessary equipment for a small fee or for free, similar to what they offer with DSL or cable modems.

This system has several benefits over the traditional hub-and-spoke hot spots. First, it's more cost-effective because there are fewer wires. If some nodes fail, others within the mesh can take over. Besides being much cheaper than running high-speed cables throughout an entire city, it's also much quicker to set up.

When a city decides to build a wireless network, it typically issues a request for proposal (RFP). An RFP is simply a formal request for information from companies interested in constructing the network. Although a city could build the network itself, most prefer to outsource this task to a company with expertise in Internet and networking technology.

Businesses that are interested in the project respond to the RFP with a proposal outlining their plan for building and maintaining the network. This proposal details everything, from the number and type of radios to the overall cost. The design of the network must account for the city's size, layout, tree cover, landscape, and other factors. The proposal also specifies whether the city or the company will own, operate, and maintain the network.

In the early days of proposed municipal networks, some cities owned and controlled their networks. However, companies such as ISPs and telecommunications firms opposed these plans, arguing that competition between municipalities and the private sector was unfair or even illegal.

Today, most current and proposed networks follow one of the four main models:

The city evaluates all the submitted RFPs and selects the proposal that best meets its needs. For instance, EarthLink has been chosen to build networks in Anaheim, California, and Philadelphia, Pennsylvania, and is a finalist in several other cities. Additionally, EarthLink is partnering with Google to develop a wireless network in San Francisco.

The final form of the network depends on a few key factors, starting with the city's specific goals for the network. A city-wide network intended for general public access can look very different from a network focused on public safety, which would be accessible only to emergency responders. (See "Wireless Applications" and "Public Safety" for more on the potential uses of these networks.)

Proposals from different businesses can vary greatly based on the hardware and protocols they plan to use. For example, EarthLink’s projects combine mesh and point-to-multipoint networks. In most of its proposals, radio transmitters are mounted on light poles around the city to create the wireless signal cloud. Tall buildings or towers with radio antennas communicate with smaller antennas placed throughout the cloud, while point-to-multipoint antennas provide the backhaul, transmitting data from the wireless cloud to the wired Internet.

Typically, after a city selects the company responsible for building, operating, and maintaining the network, the next step is to implement a pilot program. A pilot program serves as a test or preview of a smaller version of the network. It’s usually much smaller than the final network, allowing the city to evaluate its suitability.

Now, let's explore the different ways a city can utilize a wireless network once it is fully operational.

Wireless Network Applications and Public Safety

A municipal network can offer affordable, high-speed internet access to the general public. Several cities have used this as a justification for the cost of building the network. The idea is that people no longer paying for a high-speed connection could instead reinvest that money into the local economy.

Wireless networks have been established in developing nations to offer Internet access in places where traditional infrastructure is unfeasible. In some U.S. cities, the goal is to use these networks to bridge the digital divide. For example, Philadelphia, Pennsylvania plans to complement its network with affordable computers for low-income families. The initiative also includes training teenagers to offer tech support within their own neighborhoods. You can learn more about these efforts through Wireless Philadelphia, the nonprofit organization managing the network.

While free or affordable internet access is a key benefit, it’s just one of the many things a municipal network can provide. In rural areas, wireless networks can enable farmers to access security cameras and manage irrigation and other essential systems in real time. They also make Voice over IP (VoIP) phone calls more affordable, saving money for individuals, businesses, and local governments. Networks can simplify tasks for city employees, too, such as automating meter readings. Inspectors in fields like building, fire safety, and restaurants can file reports on the go, cutting down on travel time. This helps cities get a return on their investment by reducing expenses related to travel, equipment, and fees for existing communication networks.

Wireless networks can also give first responders, like police and firefighters, access to crucial resources such as security cameras, blueprints, criminal records, and other vital information remotely. They can even show witnesses mug shots or conduct virtual line-ups at the crime scene. U.S. cities can apply for funding for such public safety applications through the Department of Homeland Security.

Public Safety Most people use the 2.4 GHz band to connect to a wireless network, and public safety workers do the same, but with the added benefit of secure, encrypted connections. They also have access to another band, the 4.9 GHz spectrum, which is licensed and restricted to public safety use only. This ensures that public safety traffic doesn’t experience delays during peak usage times. To operate on this frequency, wireless transmitters must be equipped with separate 4.9 GHz radios.

Public safety networks also benefit from specialized radio technology. Motorola’s Mesh Enabled Architecture (MEA®) systems, which originated from military applications, provide enhanced capabilities for police officers, firefighters, and other emergency responders, offering features beyond the capabilities of standard networks.

MEA radios facilitate the establishment of an ad-hoc network, where Multi-Hopping® technology allows signals to travel between users directly, bypassing central nodes. The radios are able to detect one another autonomously, creating a self-forming network. They operate as routers or repeaters, transmitting signals across the network. This capability allows officers with MEA-enabled radios to enter remote locations without direct access to other networks and still maintain communication. Enhanced security is ensured by media access control (MAC) filtering and encryption protocols.

Consider a scenario where a tornado devastates a town, knocking down light poles and disabling power and communication lines. Such destruction would typically cripple communication systems. However, with MEA radios, officers equipped with vehicle-mounted modems can enter the affected area and establish a network amongst themselves. Devices such as rugged laptops and PDAs, equipped with MEA-enabled wireless cards, can also connect to the ad-hoc network. If any of these radios can link both the ad-hoc and mesh networks, it can bridge the gap, enabling broader communication.

MEA-enabled equipment offers distinctive features, one of which is the ability to track the precise location of users within the network—something most wireless networks are unable to do. This becomes particularly valuable in emergency situations, where accurate location data is crucial. Unlike traditional WiFi networks, which make it difficult to pinpoint a user’s location, MEA technology, which originated from military applications, can track individuals even when they are out of sight of GPS satellites.

MEA radios are capable of measuring the duration it takes for an officer's signal to reach three designated nodes, known as 'time of flight.' The system then uses this data to pinpoint the officer's location. This technology can significantly shorten the time it takes for rescue teams to locate firefighters trapped in burning structures or to quickly find injured police officers. It can also be applied to vehicles.

Most modern wireless radios are capable of maintaining a signal even while traveling at speeds of 30 to 40 miles per hour (48-64 kilometers per hour). Many public safety radios can transmit signals at speeds reaching up to 250 miles per hour (402 kilometers per hour). Similar technologies are used in motorsport to send vehicle telemetry data to the pit crew.