The Bring Your Own Device (BYOD) trend means the number of smartphones and tablets are making their way onto corporate networks will only rise. An increasing number of these devices, including the Amazon Kindle Fire and Google Nexus 7 tablets, are Wi-Fi only; this inevitably puts a strain on existing Wi-Fi networks. For businesses that are either (very) late to the Wi-Fi bandwagon or looking to overhaul an anarchic wireless infrastructure, here are several important points to consider.
Get Business-Grade Access Points
There's a big disparity between the cost of consumer access points (AP) with business-centric models from leading brands such as Aruba, Cisco and Ruckus Wireless. Confused by what may appear to be similar specifications, small businesses may opt for cheaper consumer-grade Wi-Fi APs that are, in fact, inadequate for the task at hand.
To be fair, some of these differences are difficult to quantify. This includes less-than-rock-solid reliability under round-the-clock use and a tendency to perform poorly when faced with external interference from neighboring Wi-Fi networks. Indeed, even top-tier AP models targeted at consumers can overload with just a few dozen simultaneous connections. Finally, nonbusiness APs typically lack advanced capabilities in crucial areas such as security, manageability, load management and remote deployment and upgradability.
Business APs, on the other hand, are designed for rock-solid performance in the face of 24/7 operation and the crushing workload generated from dozens of simultaneously active Wi-Fi devices. This is a stark contrast from the handful of intermittently accessed Wi-Fi devices typical of a home environment. Moreover, you can expect a business-centric AP to incorporate as standard features crucial security, manageability, load management and remote deployment and upgradability capabilities (which will be discussed below).
Weigh 2.4GHz, 5GHz Frequency Bands Carefully
At the moment, there are two main frequencies bands designed for 802.11 Wi-Fi networks: 2.4GHz and 5GHz. The larger amount of bandwidth available in the 5GHz band makes it the preferred option in business environments, though Wi-Fi clients operating at the 2.4GHz frequency block do have a better range. Most business-grade APs can operate in both frequency bands, while higher-end models can serve Wi-Fi clients in both bands simultaneously. The shorter range of 5GHz does allow APs to be deployed in closer proximity without signals overlapping and interfering with one another. This, in turn, allows for a higher number of AP to be deployed.
It should be noted that most Wi-Fi clients still do not work on the 5GHz band. While the iPad 2 and new iPad will work on a 5GHz network, lower-end tablets such as the Amazon Fire and Google Nexus 7 will connect on only the 2.4GHz band. Similarly, most smartphones are 2.4GHz only.
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In recognition of the uneven support for 5GHz Wi-Fi, some APs can be configured to backhaul data over the 5GHz frequency band, serving wireless clients on the 2.4GHz band. This is particularly useful for bolstering weak wireless reception at locations that wired cabling cannot easily reach. Moreover, it is possible to set up a hybrid environment where both 2.4GHz and 5GHz radios are simultaneously in use. Devices that support 5GHz can be directed to connect on this frequency band to reduce congestion on the more crowded 2.4GHz band.
Pay Attention to Density of Access Points
As outlined in the previous section, upping the number of APs could increase the amount of interference being generated, reducing overall responsiveness and throughput. Indeed, a large number of APs deployed in a haphazard manner can actually reduce the number of devices a wireless network can supported. Yet with each worker carrying as many as three Wi-Fi capable devices (e.g., a laptop, a tablet and a smartphone) IT departments should expect the number of such devices to increase, if not skyrocket.
Careful positioning and configuration is thus required to deploy a high density of APs to properly support a large number of wireless clients. Brands such as Xirrus offers a high density of APs by ditching omnidirectional antennas in favor of directional ones, and by packing up to 16 of them in one enclosure with each antenna facing out.
Implement Strong Management, Security Mechanisms
Management and security of Wi-Fi networks is another aspect that businesses need to consider. Attempting to configure multiple APs individually in a business environment is not only highly inefficient; it's also prone to errors.
As you can imagine, a well-designed management system plays an important role when dealing with more than a handful of APs. In addition, the evolving security landscape has increased the importance of built-in security features. Wi-Fi vendors now incorporate security features that, among other things, identify unauthorized networks, defend against spoofing attempts or stymie brute-force attacks. Moreover, the capability to log important system or security events to a syslog server or console is invaluable, making it possible to identify both wireless bottlenecks and security threats.
Another capability that is important for businesses is the support for multiple Service Set Identifiers (SSIDs). An SSID is the network name that users see when connecting to a wireless network. While having multiple SSIDs does not increase the actual capacity of an AP, this feature does offer a number of important advantages on the security and management front.
For example, it is possible to configure varying levels of security for each SSID. A network for guest users may be designated as an open network, while wireless network cameras could be connected to a network protected by a long Wi-Fi Protected Access 2 (WPA2) static key, while yet another network can be setup to authenticate via RADIUS and used to serve employee laptops. Depending on SSID, wireless clients can be channeled through different virtual LANs to segregate the traffic, tagged with a different quality of service level or even routed through a security appliance.
Explore Access Point Power Options
A less obvious problem when setting up multiple wireless APs is the possibility of having to deploy them at inconvenient locations for maximum coverage. Powering these APs using Power over Ethernet (PoE) simplifies the problem while also sparing businesses the cost of laying separate electrical cable runs to each AP. PoE provides power over the same Ethernet cables that feed data to the APs while offering speeds of up to 1 Gbps, which is more than adequate throughput for the fastest commercially available APs today.
Businesses that do not already have a PoE infrastructure in place can easily deploy midspan PoE injectors at the server room or closet. Alternatively, PoE-capable network switches are relatively affordable now and is a good choice when keeping the server closet equipment count down is a priority. Powering APs via PoE also helps on the maintenance front; IT departments can more easily replace standard PoE injectors or switches that fail compared to having to scramble for a specific AC adapter. In the same vein, it is far easier to troubleshoot a single cable than to separately verify that the data link and power adapters of individual APs are working.
Finally, PoE allows for the use of standard UPS equipment to power PoE switches or injectors to protect APs from power outages. Obviously, a PoE strategy necessitates the use of APs with inherent PoE support, a feature usually found only in business-centric APs.
Understand Controller Architecture Options
The need to manage and coordinate multiple APs mandates that you use a central controller for anything other than the smallest deployments. As vendors have already built their Wi-Fi solutions around one or two different architectures, the controller architecture is less of an influence on purchasing than factors such as manageability and interoperability. This should not stop businesses from properly understanding the strengths and limitations of each option, however.
The most common design entails the use of a central appliance for configuring and managing multiple APs on the network. There are also vendors that incorporate controller logic inside existing network appliances, such as the WAN load-balancers from Peplink that can be used to manage the APs sold by the company. Meanwhile, Wi-Fi specialist Xirrus uses a "thin" access point strategy in which each array independently manages all on-board APs. A variant of that would be the virtual controller; here, an embedded controller within an AP manages smaller deployments of four to eight other APs.
Finally, there are cloud-based controllers managed entirely over the Internet, such as those made by Meraki. In a bid to reap the benefits of a centralized console without having to invest in a controller-based solution, startup Tanaza has built a cloud-based management solution in which standard non-cloud APs are configured online and changes are pushed out automatically.
Looking Ahead: 802.11ac Not Worth the Wait
With the 802.11ac wireless standard around the corner, the capability to upgrade to what is widely termed as "Gigabit Wi-Fi" would obviously be an appealing feature to many businesses.
It is important to remember, though, that is still under development at this point and is not expected to be completed until next year. Indeed, APs currently shipping with 802.11ac are essentially noncertified, and client devices that implement 802.11ac will likely only arrive a few months after the 5GHz standard gets rectification.
For these reasons, businesses looking to implement Wi-Fi today should just go ahead with their current plans rather than hold back and wait for technology that's at least a year away.
Paul Mah is a freelance writer and blogger who lives in Singapore. Paul has worked a number of years in various capacities within the IT industry. You can reach Paul at firstname.lastname@example.org and follow him on Twitter at @paulmah.