A wireless network uses radio waves, just like cell phones, televisions and radios do. In
fact, communication across a wireless network is a lot like two-way radio communication.
A computer's wireless adapter translates data into a radio signal and transmits it using an
wireless router receives the signal and decodes it. The router sends the information to the Internet using a physical, wired
process also works in reverse, with the router receiving information from the Internet, translating it into a radio signal
and sending it to the computer's wireless adapter.
The radios used for WiFi communication are very similar to the radios used for walkie-talkies,
cell phones and other devices.
They can transmit and receive radio waves, and they
can convert 1s and 0s into radio waves and convert the radio waves back into 1s and 0s. But WiFi radios have a few notable
differences from other radios:
transmit at frequencies of 2.4 GHz or 5 GHz. This frequency is considerably higher than the frequencies used for cell phones,
walkie-talkies and televisions. The higher frequency allows the signal to carry more data.
They use 802.11 networking standards, which come in
several flavors: 802.11a transmits at 5 GHz and can move up to 54 megabits of data per second.
It also uses orthogonal frequency-division multiplexing (OFDM), a more efficient coding technique that splits
that radio signal into several sub-signals before they reach a receiver. This greatly reduces interference. 802.11b is the
slowest and least expensive standard.
For a while, its cost made it popular,
but now it's becoming less common as faster standards become less expensive. 802.11b transmits in the 2.4 GHz frequency band
of the radio spectrum. It can handle up to 11 megabits of data per second, and it uses complementary code keying (CCK) modulation
to improve speeds. 802.11g transmits at 2.4 GHz like 802.11b, but it's a lot faster -- it can handle up to 54 megabits of
data per second.
802.11g is faster because it uses the same OFDM coding
as 802.11a. 802.11n is the newest standard that is widely available. This standard significantly improves speed and range.
For instance, although 802.11g theoretically moves 54 megabits of data per second, it only achieves real-world
speeds of about 24 megabits of data per second because of network congestion. 802.11n, however, reportedly can achieve speeds
as high as 140 megabits per second.
The standard is currently in draft
form -- the Institute of Electrical and Electronics Engineers (IEEE) plans to formally ratify 802.11n by the end of 2009.
802.11 standards focus on specific applications of wireless networks, like wide area networks (WANs) inside vehicles or technology
that lets you move from one wireless network to another seamlessly.
WiFi radios can transmit on any of three frequency bands. Or, they can "frequency
hop" rapidly between the different bands.
Frequency hopping helps reduce
interference and lets multiple devices use the same wireless connection simultaneously.
As long as they all have wireless adapters, several
devices can use one router to connect to the Internet.
This connection is convenient,
virtually invisible and fairly reliable; however, if the router fails or if too many people try to use high-bandwidth applications
at the same time, users can experience interference or lose their connections.
If you want to take advantage of public WiFi hotspots or start a wireless
network in your home, the first thing you'll need to do is make sure your computer has the right gear. Most new laptops and
many new desktop computers come with built-in wireless transmitters.
If your laptop doesn't,
you can buy a wireless adapter that plugs into the PC card slot or USB port. Desktop computers can use USB adapters, or you
can buy an adapter that plugs into the PCI slot inside the computer's case. Many of these adapters can use more than one 802.11
Once you've installed your wireless adapter
and the drivers that allow it to operate, your computer should be able to automatically discover existing networks. This means
that when you turn your computer on in a WiFi hotspot, the computer will inform you that the network exists and ask whether
you want to connect to it.
If you have an older computer, you may need to use a software
program to detect and connect to a wireless network.
able to connect to the Internet in public hotspots is extremely convenient. Wireless home networks are convenient as well.
They allow you to easily connect multiple computers and to move them from place to place
without disconnecting and reconnecting wires.
Monthly connections to Panera's wireless network at its 1,565 locations have grown to 2.7 million sessions
in April from 2.2 million a year ago.
The downside is slow Internet service. The company's
network sometimes gets clogged because so many people are online at once.
locations will restrict Internet use to 30 minutes during the busy lunch hour. But Hurst is looking for solutions.
He's experimenting with rewarding frequent Panera customers with loyalty
program benefits: unrestricted Wi-Fi. "Is there a way you get
guaranteed access because you're a frequent Panera
shopper?" Hurst says.
"How do we make it better for our guests?"
Nicole Miller Regan, an analyst at Piper Jaffray, says Panera would
be smart to tie premium Wi-Fi with its MyPanera loyalty program,
which she says has "extremely high" participation.
Panera says some 45% of all transactions are by loyalty members, who get free "surprises" (cookies, cupcakes,
coffee) periodically in exchange
for signing in with the card.
"The loyalty program is even more important
than the Wi-Fi," she adds. "The technology of the program tells Panera who you are,
what you like, what your patterns are and how to incentivize you."
Clear Cloud met with Hurst at a Panera that sports the name
"St. Louis Bread Co.," which it acquired.
and iPads were
as customers typed away on devices over coffee, bagels and sandwiches.
Restaurant giant Panera Bread made a big business bet eight years
ago to offer free Wi-Fi to its customers as a way to boost sales, long before Starbucks.
The fresh breads eatery aimed to court customers in between meals. The experiment worked,
raising sales early on about 15%.
But now, it's become a challenge to meet the Wi-Fi demand , says Panera's vice president
of technology, Blaine Hurst. "Withmobile carriers cracking down on data plans, more and more people say,
'I'll go to Panera for free Wi-Fi.' How do we make sure we have capacity?"
Wi-Fi available at national chains such as Starbucks and McDonald's, and becoming more accessible without charge at hotels
or airports, Panera is grappling with how to keep its Wi-Fi customers happy amid heated rivalry.
Panera has got a gold-plated problem: Customers' use of its Wi-Fi is way up. efinition:
A hotspot is any location
where Wi-Fi network access (usually Internet access) is made publicly available.
You can often find hotspots in
airports, hotels, coffee shops, and other places where business people tend to congregate. Hotspots are considered a valuable
productivity tool for business travelers and other frequent users of network services.
Technically speaking, hotspots consist of one or several wireless access points installed
inside buildngs and/or adjoining outdoor areas.
These APs are typically networked to printers and/or a shared
high-speed Internet connection. Some hotspots require special application software be installed on the Wi-Fi client, primarily
for billing and security purposes, but others require no configuration other than knowledge of the network name (SSID).
service providers like T-Mobile generally own and maintain hotspots. Hobbyists sometimes setup hotspots as well, often for
non-profit purposes. The majority of hotspots require payment of hourly, daily, monthly, or other subscription fees.
providers strive to make connecting Wi-Fi clients as simple and secure as possible.
However, being public, hotspots
generally provide less secure Internet connections than do other wireless business networks.
If you want to take advantage of
public WiFi hotspots or start a wireless network in your home, the first thing you'll need to do is make sure your computer
has the right gear. Most new laptops and many new desktop computers come with built-in wireless transmitters.
If your laptop doesn't, you can
buy a wireless adapter that plugs into the PC card slot or USB port.
Desktop computers can use USB adapters, or you can buy an adapter that plugs into the PCI
slot inside the computer's case. Many of these adapters can use more than one 802.11 standard.
you've installed your wireless adapter and the drivers that allow it to operate, your computer should be able to automatically
discover existing networks. This means that when you turn your computer on in a WiFi hotspot, the computer will inform you
that the network exists and ask whether you want to connect to it.
If you have an older computer, you may need to use a software program to detect and connect
to a wireless network.
Being able to connect to the Internet in public hotspots is extremely convenient. Wireless
home networks are convenient as well.
They allow you to easily connect multiple computers and to move them from
place to place without disconnecting and reconnecting wires.
Back in December, our regular clear-cloud
crowd offered their thoughts. As can be expected,
the trends shaping the broader IT picture this year—cloud computing, XaaS, the influx of mobile devices and explosion
of the app market—will largely determine the direction WiFi takes this year, as well. The following are three of the
key developments expected from wireless technology in 2012 that will likely impact how IT organizations manage the network.
Finalization of the 802.11ac standard is expected by the
end of this year, with final Working Group approval in 2013. But just as with 802.11n we can expect to see draft standard
products well in advance of final approval, which should hit around the fall of this year.
This is a real game changer: For the first time, wireless
speeds will rival those of the desktop. Gigabit wireless means that more and more companies will choose not to run cables
to the desk top in new construction. Of course, the corollary to this is that we’ll have more and faster wireless endpoints
contending for bandwidth.
Fires, Nooks, iPods, Galaxys, smart phones, video cameras—they’re everywhere and soon they will all be fighting
to consume the same bandwidth. And this is likely to have a profound effect on the way we design wireless networks. For example:
Cell size will become less important
than device density.
will have to make sure that they have a sufficient network backbone to handle the increased traffic and throughput capabilities
of the individual devices.
the Access Points are providing gigabit traffic to the switch port, 10 gigabit backhaul from the edge switch may prove insufficient.
In addition, 802.11ac operates in the
5 GHz band, which may signal the abandonment of the 2.4 GHz band. However, its death has been predicted many times before—usually
just before someone comes up with a new, creative use for the frequency band.
Of course, there are many client devices that operate only at 2.4 GHz, so expect
to see multi-band access points (APs) that run 802.11n at 2.4 and 802.11ac at 5 GHz. In the higher band, you can expect to
see wider channel bandwidths—up to 160 MHz versus the 40 MHz of 8021.11n and double the number of MIMO streams. There
will also be multiuser MIMOs.
sounds a little like mumbo jumbo but what it means to you is the ability to use wireless in more sophisticated ways like streaming
HD video to multiple devices.
an example of an organization taking advantage of 802.11ac, consider Broadcom. This maker of chipsets for network devices plans
to incorporate 802.11ac into its automotive products to reduce weight and improve functionality. Backup cameras, for example
will be made lighter without wire and will network endpoints so that they can serve multiple purposes.
Not too many years ago the WiFi industry existed to support easy transport of bar
code information. The wireless device read the bar code tag and sent the information back to a computer that stored inventory
information. It was a simple task, but for companies like Walmart that mastered its capabilities for logistics and control
it provided industry dominance.
Today WiFi networks do far more: They open and lock doors, allow physicians to examine patients half a world away,
permit students to virtually experience real-time conditions on Mt. Everest, and much, much more. With these dramatically
increased capabilities have come increased design and management complexities.
WiFi networks have become living ecosystems where a lot of things can go wrong.
RF problems, network problems, structural changes, client issues—any of these can have a negative impact on the wireless
Manufacturers are doing their best
to minimize the impact of these factors. Cisco, for instance, has introduced clearair architecture to their AP lineup. With CleanAir, APs we can now detect RF
interference in the air, and dynamically change the access points channels and power settings to mitigate the congestion.
That helps, but because of the increased
complexities, many customers—particularly those managing remote locations—have started to outsource the management
of their wireless networks. In these cloud-managed WiFi solutions, distributed wireless networks are centrally managed through
either a public or private cloud model. The advantages include:
Lower staffing requirements
Faster and easier deployments
Quicker problem resolution
Pooled equipment spares.
In a cloud-managed model, WiFi expertise resides at a central location that monitors and
administers the remote sites.
an example of an organization that benefits from this model, look no further than your local fast-food chain. Most McDonald’s
restaurants now provide WiFi, though the company can’t afford to have a wireless engineer in every location. So, they
put one to two APs in every restaurant that are centrally managed through the cloud. This same solution works extremely well
for several of our district-12 and healthcare customers who must support a campus environment.
WiFi as a Service
If you go to McDonald’s and the
WiFi doesn’t work, it’s an inconvenience. In a hospital, non-working WiFi could cost a life. On a manufacturing
floor, loss of the wireless network may disrupt an entire production facility.
To ensure continuity, some organizations that have adopted the cloud-managed
model are going beyond it, and treating wireless as a utility. This scenario typically calls for the provider to
supply the wireless network, including equipment and connectivity. The user organization then subscribes to the network much
like they would to any utility.
Payment models can vary from area covered to number of APs to concurrent users allowed. In any case, it usually
moves the WiFi network from the Capital to the Operating budget. User organizations can negotiate Service Level Agreements
based on uptime, throughput or other critical factors.
WiFi as a utility is a model similar to cable TV. Customers for cable don’t want to put up
their own satellites or dishes.; they just want the content. What goes on in the background to get the services to them isn’t
The same looks
likely to become common for wireless: Customers will outsource the WiFi network and leave worries about bandwidth, reliability
and client onboarding to their provider. Security, however, typically remains the province of the customer
and will conform to their network security policies. Reports to the customer include AP usage, Internet Latency (from provider
to customer) and channel utilization.
What are you doing to keep your organization’s wireless access user-friendly, secure and well managed? What
questions do you have about the advancements outlined above? Please share your thoughts and questions in the comments below.