IMAGINE you’re a reporter writing about a tense hostage situation, and you’re on a tight deadline.
You don’t have time to drive back to your office, and if you leave you’ll miss out on the developing story.
Fortunately, you have wireless access to the Internet - you can write and file your story without leaving the scene.
Part of your article describes how police have access to real-time feeds from security cameras.
From their patrol cars, officers monitor the situation and access blueprints of the building, including its entrances, exits and hiding places.
They use this information to plan what to do.
They also have a secure network connecting them to a hostage negotiator.
When the situation is over, everyone believes this municipal wireless network and the information it carried helped lead to a peaceful resolution.
The early days of home Internet access required using a modem connected to a computer to dial a number and maintain a connection.
It was cumbersome and slow.
The faster modems became, the more people realised how painfully sluggish data transmission had been in the days of 300 baud.
Eventually, home users who could afford a jump in price could get broadband access via digital subscriber lines (DSL), cable and satellite.
Broadband access is faster than dial-up, but until recently you still to plug your computer into a wall jack or a piece of equipment.
Wireless networking, or WiFi has changed all that.
Wireless networks use 802.11 networking standards to allow devices to communicate.
In a WiFi network, data travels from place to place via radio waves.
You still have to physically connect a wireless router to a modem, but you can move your computer from place to place.
802.11 networking uses the unlicensed radio spectrum to send and receive data.
Many other parts of the spectrum, such as the bands that carry radio and TV signals, require a license to use.
The unlicensed spectrum is accessible to anyone who has the right equipment.
In the case of wireless computer networking, that’s a wireless router and wireless technology in the device you’re using.
Since 2002, many people have set up wireless networks in their homes.
Businesses have done the same, giving their employees additional mobility. Public gathering places, like coffee shops, parks and libraries, have created WiFi hot spots, hoping to draw in additional businesses.
The number of public hot spots has grown rapidly - analysts estimate that there will be 200,000 of them by 2008.
Now, cities have begun setting up municipal wireless networks.
As of January 2006, 186 United States cities had their networks up and running or had definite plans to build one.
That’s up from 122 cities in the previous July.
Some of these networks provide high-speed Internet access for free, or for substantially less than the price of other broadband services.
Others are for city use only - they allow police and fire departments and other city employees to do certain aspects of their jobs remotely.
Cities currently proposing networks have several goals.
They want to improve worker productivity, make the city more attractive to businesses, bolster the economy, bridge the digital divide or do all these things with one network.
The United States is also 16th in the world in broadband penetration, which some leaders believe is a sign that the nation is falling behind.
A wireless network might make broadband access more available and affordable for more people.
Often called “municipal WiFi,” these networks use more than just 802.11 networking.
A wireless access point in a municipal network is also different from a typical WiFi hot spot.
Most WiFi hot spots in coffee shops and other locations have a hub and spoke configuration.
One radio (the hub) sends and receives data for several users (the spokes).
The wireless router has a physical connection to the Internet - a wire - and it transmits data from multiple users through that wire.
Adding a wireless router to an existing wired connection is an easy, convenient way to provide wireless access on a small scale.
Wireless routers are relatively inexpensive. Most allow people to choose from various sign-on and encryption options, providing a layer of security.
But if a wireless router goes down, there’s not always another router nearby to pick up the slack.
And on a large scale, like a whole city, using a physical wire to connect every wireless router to the Internet is expensive.
That’s why most municipal wireless networks use a mesh rather than a hub and spoke.
A mesh is a series of radio transmitters.
Each transmitter is able to communicate with at least two others.
They create a cloud of radio signals through the city.
Signals travel from router to router through this cloud.
In some networks, signals hop from one receiver to another until they reach a node that has a wired connection to the Internet.
Other networks use backhaul nodes.
These nodes do exactly what their name implies - they gather up all the data from many transmitters and haul it back to the Internet by sending it to a router with a wired connection.
Backhaul nodes are usually point-to-point or point-to-multipoint nodes.
They can either connect one point to exactly one other, or they can connect one point to several points.

* Information supplied by HowStuffWorks

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