“Never touch a running system,” is a widespread sentiment among network administrators and stems from the experiences gained from operating-system updates. The general opinion is: Once a system is set up and configured, think twice about changing it. These days this is a rather negligent approach, as the acceleration in technological development has resulted in constantly shifting needs and requirements.
Studies show that the Wi-Fi landscape will undergo severe changes within the next couple of years. The enormous increase in the number of mobile clients has led to unprecedented growth in the data volumes transferred via wireless networks. According to Gartner, mobile data usage will quadruple in 2016 compared to 2013. The total number of mobile devices will increase to 26 billion (laptops, smart phones, tablets, M2M and IoT devices all taken into account) by 2020 according to a study by Ericsson. Wireless technologies and networks have to be adjusted in order to face this new reality.
But how can system administrators prepare their wireless networks for these developments without repeatedly having to change the core infrastructure? There is a smart way: Optimize your wireless network, and get the best out of what you already have. But let us take a look at what pushes networks to their limits, and how this can be avoided.
6 ways to make your wireless network smarter:
One of the most common problems is that Wi-Fi areas are becoming denser and more crowded. This means that not only is the number of clients per network on the increase, the same is true of the number of wireless networks themselves (e.g. BLE or ZigBee in the 2.4GHz frequency band) all transmitting in the same radio field. The problems magnify when all of them use the same Wi-Fi channels, because then they also share the available bandwidth. The effects on performance can be severe.
Radio Frequency (RF) Optimization can help here. The access points permanently scan the radio field for interfering signals. If a certain threshold is exceeded on the current Wi-Fi channel, the network device can adaptively or manually change to a channel that is qualitatively better. This function enables the network to dynamically adapt to an ever-changing radio field in order to maximize the shared bandwidth.
But often the cause of a poor wireless experience is not the infrastructure alone. When faced with the already high load on each Wi-Fi channel, clients using the 2.4GHz frequency band suffer the most. Along with the dynamic selection of the best available Wi-Fi channel, a wireless network at its limits is also helped out by Band Steering. This capability with dual-radio access points controls the switching of clients from the 2.4 to the 5GHz network. If a client sends probe requests on both frequencies, the access point checks its internal data and only answers on the 5GHz frequency band. The wireless module advises the client to use the (comparatively under-used) 5GHz network, which frees up bandwidth in the 2.4GHz frequency band. This again improves the overall performance and stability.
An additional capability that helps to improve the distribution of the available bandwidth is Airtime Fairness. Here you have several options to distribute the transmission time (“airtime”) among the clients. For example, giving equal amounts of Wi-Fi transmission time to all of the active clients on the network, which allows the faster ones to achieve greater data throughputs in the same amount of time. This can significantly increase the overall capacity of the network.
As mentioned earlier, competing wireless networks also lead to interference. This is particularly evident in dense areas such as college campuses, sport stadiums, train stations, within large cities, or in office buildings. Here the number of different Wi-Fi networks is often so high that the situation becomes a stress test for the network. Within these areas with so much noise and potential sources of interference, Adaptive Noise Immunity helps access points to ignore clients that are too far away from the access point.
These clients often have a low received signal strength indicator (RSSI), and access points with Adaptive Noise Immunity can focus exclusively on wireless clients with sufficient signal strength. The wireless module constantly measures and delivers information about interference in the radio field. If a predefined threshold is exceeded, the receiving sensitivity of the Wi-Fi module is reduced in order to ignore the clients and signals that are too distant or too weak.
Another challenge network administrators often have to face is wireless clients competing for the same access point. Frequently, a client will associate with the first access point it finds and maintains this connection even when the network is overloaded and when the client moves around the building or area. Compounding the issue are slower legacy devices that slow down the faster clients. The result: “Queues” within access points, which throttle the performance. One solution of wireless controllers is Client Steering, which is ideal for optimized client balancing. Connected devices are steered to the ideal access point depending on predefined scenarios or individually set parameters. All of this takes places adaptively, without the need to change any client configurations.
Not to be underestimated is the interference from non-Wi-Fi sources. These can be, for example, wireless cameras, microwaves, cordless phones or any type of Bluetooth devices that use the same frequency band. The sheer variety of these sources of interference can be overwhelming and, in extreme cases, they can cause the complete failure of a wireless network. An analytic tool like the Spectral Scan helps to find these interference sources.
This professional utility monitors the momentary load on individual channels and offers visualizations and a chronological history. An administrator can detect whether specific channels are under heavy load at any particular time. The conclusion might be that a source of interference was operating at a certain moment in time, for instance a microwave at lunch time, or a gaming console at night. Based on this information the IT administrator can remove the source of interference or change the channel accordingly. This active intervention has the advantage that there is no need for any undesirable configuration changes.
It has to be noted that the network optimization capabilities mentioned here are not available with every wireless network on the market, and that they are limited to enterprise products only. A professionally configured wireless network reacts adaptively to changes and stays flexible under varying conditions. The continuous improvements to the firmware provide the fine-tuning that keeps your network future-proof. Ongoing optimizations continually enhance the performance, get the best out of your existing wireless network, and make more effective use of the available bandwidth. By staying up to date, administrators are helping themselves to easier network configuration and management. True to the motto, “Never touch a running system.”