A number of factors make it difficult to maintain a business Wi-Fi network in urban areas. By learning about the factors that influence wireless connectivity, small business owners can solve their own Wi-Fi issues.
Seamless Wi-Fi helps businesses avoid the extreme cost of downtime: potentially tens of thousands of dollars per hour.
As a certified Ubiquiti Enterprise Wireless Administrator (UEWA), I have deployed hundreds of wireless access points throughout the world for JS Technology Group and have learned different locations and environments present unique challenges for a strong Wi-Fi connection, especially crowded urban areas.
For successful Wi-Fi deployment in urban areas, businesses need to consider four factors:
• Internet service provider
• Device positioning
Optimizing these factors will allow a stable Wi-Fi connection in urban environments. However, professional assistance may be necessary for stronger results.
Scale Your Network Properly
Wi-Fi is a contentious medium. Only one device can send signals at a time and devices trying to connect to the same router or access point have to share airtime with other devices.
For example, you have a wireless channel that can operate at a speed of 100 megabits per second. If two devices are on the channel, each device can communicate at a theoretical average speed of 50 megabits per second.
Now, imagine an urban office with 40 employees and a minimum of 80 devices.
Those 80 devices are now competing for the same 100 megabits. If one user is using significant bandwidth, all others will suffer from slower connections because there are only 100 megabits to go around.
Consider this graph of airtime for a test network where the blue and light grey segments represent airtime used by devices and noise.
This graph shows the limited amount of bandwidth available to wireless devices in a sample office environment.
If one blue segment grows significantly, representing a slow device or a device that is transferring a large amount of data, then less free airtime is available for other devices on the channel.
The graph also illustrates diminishing average speeds with more devices. To estimate the average airtime available to each device, imagine dividing the entire pie by the number of devices that you have.
Each device has a smaller average share, and the user experience deteriorates with each new device.
So how many devices are too many?
It depends on your router or access point, but Actiontec recommends 50 devices or less.
If your team is using more than 50 devices you can add additional wireless access points.
Additional access points must be wired back to your router or switch and configured to operate on different channels. This way, there are multiple separate lines of communication, and everyone has more bandwidth.
You can add an unlimited number of access points as long as you are careful not to overlap channels which can create interference and may require devices to retransmit data multiple times, slowing access for all clients. Expert help may be necessary for environments with multiple wireless access points.
Your Internet Service Provider (ISP) Affects Your Wi-Fi
Many people confuse Wi-Fi with the underlying internet connection. Your Wi-Fi network links your devices to your provider’s internet connection.
What should you look for in an internet connection?
A dedicated link is most important. Many inexpensive connection options, such as cable or Fios, share bandwidth between businesses in the same area. At high traffic times, your connection may be limited because you and your neighbors are using the same network.
On a cable connection, for example, hundreds of businesses can share the same pipeline.
To combat this source of slowness, consider a dedicated internet connection from an enterprise ISP.
How do you know that your connection is dedicated?
Dedicated connections come with a guarantee called a Service Level Agreement (SLA).
An SLA contractually limits the downtime of an internet connection, and it requires that the service provider monitor and notify you of an outage.
SLAs typically guarantee 99.999% uptime, which means less than 5.26 minutes of downtime per year. The internet provider credits your bill for additional outages!
Consider the sample SLA below.
North America <45 msec
North America to Europe <110 msec
North America to Asia/Pacific <150 msec
|Network Availability||99.99% core to core|
T1 = 30 days (1.544 Mbps)
DS3 = 40 days (44Mbps)
OC3 = 65 days (155 Mbps)
The SLA provides 99.99% uptime (see Port Availability above) and specifies bandwidth for different levels of service. For example, DS3 service delivers 44 megabits per second (Mbps), while the T1 service delivers only 1.544 Mbps, according to the provisioning section.
Any SLA similar to this one contractually guarantees a better experience than shared internet. Always look for an SLA when making purchasing decisions around internet service.
Position Your Wireless Devices for Optimal Signal Strength
A single device with poor signal strength can slow every device on a network.
Only one device can “talk” at a time. If that device is far away, it will talk more slowly so that the wireless access point can understand it. No other device can talk until that entire conversation is finished.
The more quickly and accurately that each device can send its message, the faster all wireless devices operate.
How do you ensure fast and accurate conversations?
It’s important to position access points properly. Devices perform best when they are within physical sight of the router or wireless access point.
If there are walls between the access point and the device, they can interfere with the signal.
Sheetrock walls slightly block a wireless signal. Brick, plaster, glass, and metal walls can have a major impact on signal strength, and in some cases, can block a Wi-Fi signal completely.
Consider this Wi-Fi heatmap of a sample office. The green areas indicate a strong signal. Warmer colors indicate a weaker signal, with red marking the areas with the poorest signal. Wi-Fi access points are indicated with a wireless icon.
In this office, those in Office B will enjoy the strongest Wi-Fi connection, while those in the conference room or middle cubicles might experience outages.
Remember that the wireless signal decreases the farther it is from an access point and when it passes through walls and doors. Areas with a direct line of sight to an access point have the strongest signal.
You can add additional access points so that each device is within sight of at least one access point.
Be Mindful of 2.4 GHz and 5 GHz Bands
Wi-Fi devices operate on two distinct bands that offer certain benefits.
The 2.4 GHz band was part of the original wireless standard. As the lower frequency band, it generally travels farther than 5 GHz wireless. It’s also less affected by materials that stand in its way.
However, the 2.4 GHz band is often so crowded in an urban environment that it’s basically unusable. Devices will experience slow connection speed, frequent loading or buffering, and disconnects.
A signal scan of the 2.4 GHz (left) and 5 GHz (right) bands in a sample office is below. The fill of each channel block indicates usage. Channels in red are at capacity and not recommended for use.
Significantly more channels are available on the 5 GHz band, making each channel less crowded.
According to the scan, there are no usable 2.4 GHz channels in the scanned environment, which is often the case in a large city.
While you may need to keep the 2.4 GHz band enabled to support older devices, you should consider assigning it a separate network name, or SSID. This way, you can choose exactly which devices connect to the older 2.4 GHz network and which connect to the modern 5 GHz network.
The 5 GHz network is your best bet for fast wireless. In cities, the 5 GHz band is less crowded than the 2.4 GHz band and supports a wider channel width. This allows devices to communicate faster, and use less airtime. The result is a faster connection for all devices.
Older routers and access points do not support 5 GHz wireless. Consider upgrading equipment if your device falls into this category.
Consider Your Situation When Optimizing Your Office’s Wi-Fi
Although optimizing scale, selecting a solid internet service provider, properly positioning devices, and using the 5 GHz band can do wonders for your urban wireless network, there could be additional factors that cause intermittent issues and decreased productivity.
If you still experience inconsistent performance after optimizing across these areas, it may be time to call a specialist.
IT consultants and Wi-Fi specialists have access to the right surveying tools to understand the current pitfalls of your wireless network and optimize your office’s Wi-Fi.
Look for a specialist that offers a performance guarantee and consider buying Wi-Fi as a service instead of paying for one-time installation.
By paying for your office Wi-Fi monthly, you guarantee the quality of service with the continued involvement of a Wi-Fi specialist.
As the wireless environment changes, you’ll maintain that relationship and have consistently excellent Wi-Fi.