A network is a connection of devices and its purpose is to facilitate communications between these connected devices or nodes as the industry calls them. A wireless network serves the same purpose; the major difference being the absence of wires and the use of Radio Frequencies (RF) to facilitate said connectivity. WiFi technology continues to grow in popularity to the point where the technology is used in almost every business to deliver or support critical services. This can be seen in Hotels, Coffee Shops, Banks, Airports, Universities, Hospitals and many more…
The technology is used by a varying skillset but the common expectation is that it should just work and consistently and connect all required devices. Our experience and understanding of WiFi technology has shown us that the alignment of this expectation relies heavily on the proper design and implementation of the WiFi network. There are many factors that contribute to the deployment of a proper functioning WiFi network; one that will sustain all required business connections with the same reliability as a Wired network. Our experience has shown that these are often ignored:
- Proper Wireless Site Survey – it’s by no accident that I used the word “Proper”, just not to confuse this task with a mere walk around while looking at the overall building structure and knocking walls to determine construction material. A proper wireless survey is by far more extensive than a walkthrough. While it may include at least an initial walkthrough of the location to determine the scope of coverage required. The survey should include at least the following activities:
- Throughput Testing
- Understanding of the intended use of the WiFi Solution
- Spectrum Analysis
- Physically Diagramming the intended location
- Understanding Intended Purpose and Application Usage – Any architect, in the delivery of the plans for a building must take in to consideration the intended use of the building as well as any other details that may determine special considerations. This concept also applies to the design of a Wireless Network. A network whether wired or wireless is charged with the responsibility for carrying varying data types i.e. Voice, Video etc. The applications that actually use these data types can also be different for example, Voice and / or Video for Skype, Video for Surveillance, and the list can go on and on. These varying types (payload) all react differently to available network bandwidth. Voice is latency sensitive and cannot sustain much delays in transmission while network browsing is more tolerant to such issues. The point is that each application or scenario warrants different consideration that will directly affect the design of the wireless network. It really pays to do it right the first time.
- Understanding the Number of Clients – Why is this even important, especially when I purchased a wireless device that has great range? There are a number of answers to that question; the first thing that comes to mind is that . “All wireless devices are NOT created Equal”. We will go with this answer for now – Theoretically wireless, unlike Ethernet Switching is shared bandwidth, though there have been advancements in the way that the access points resources are shares for example MU-MIMO, it still pays to fully understand the client environment. The number of clients on wireless network directly effects performance; it pays to consider this at the design stage.
- 2.4 GHz / 5.0 GHz – What should I use – WiFi is delivered over two (2) frequencies; 2.4 GHz and 5.0 GHz. Some of the differences of the two frequencies are :
- Range – the 2.4 GHz is farther reaching than the 5.0 GHz and is less susceptible to signal degradation form objects like walls etc.
- Cost – the device support for the 2.4GHz frequency is normally cheaper than that for the 5.0 GHz
- Higher Interference – the 2.4 GHz frequency has less channels and also shares channel space with household devices like Microwaves, Cordless Phones and others.
- More Channel Capacity – The 5.0 GHz frequency has more channels to work with than the 2.4 GHZ; this makes it better in terms of reduced interference
- Advanced Technology – the latest Wi-Fi standard 802.11AC is only deployed on the 5.0 GHz frequency
- Faster Speeds – the 5.0GHz frequency has technology that can support higher speeds than the 2.4 GHz
There are pros and cons of both frequency options, both options will work but only one may deliver on the business requirements. Many access points are equipped with dual radios to support both frequencies. Taking the time to consider frequency options influences the overall design and cost of the solution.
- What is a Channel and how does this play into the overall wireless solution – On a wireless network, communication is done on a particular frequency. Data is actually transmitted on the frequency using channels. Each frequency is made up of a number of channels. The size of a channel (channel width) as well as the actual channel chosen directly affects the data transfer capability as well as the overall performance of the wireless network. Have you done any channel planning lately, this can be affecting your existing wireless network? Just so you know, the 5Ghz frequency using 802.11AC supports wider channel widths than the 2.4 Ghz frequency.
- Channel usage and Co-Channel Interference – Is this really important ? – Interference if not managed, can cripple a wireless network. Co-Channel Interference is basically caused when there are too many devices (wireless and client) communicating on the same channel. The more devices that are on the same channel, the longer a client has to wait to communicate.
Some sources of Co- Channel Interference are
- Neighbouring Access Points
- Wi-Fi Clients
- In a business network, Co-Channel interference can lead to service degradation, high response times, and in some cases non -functionality of business critical applications. Here are some of the ways that you can manage Co-Channel interference
- Proper Channel Plan – properly plan channel assignments at the design stage of the project, especially in high density deployments
- Perform a Proper Site Survey – you often pick up the state of the present RF environment at this stage and it informs the steps needed to mitigate interference very early
- Manage Access Point Power Levels – too much coverage is not always the best approach. Just enough coverage is a strategy to reduce interference
- Solid Roaming Plan – take the time to design a proper roaming plan
- Polarization Diversity – what is it and why should I care? – Polarity simply broken down is the orientation of the signal. This signal can either be horizontally or vertically polarized i.e. waves that move up and down (vertically polarized) or moving like a snake from left to right (horizontally polarized). A misalignment in polarity between access point and end device like a cell phone or PC can result in the loss of more than half of the power from the access point antenna; this can equate to bad signal reception and Wi-Fi performance. It pays to really understand the clients that are to be supported on your wireless network as well as whether the intended platform can support such technologies like Polarization Diversity among others. Wireless networks are being flooded with mobile clients like tablets and cell phones; all of which are used in varying orientations. Polarization Diversity will really help minimise the data loss and retransmissions associated with polarization misalignment.
Are you considering a Wi-Fi deployment or are you having issues presently. Give us a call on (868) 223-1576 to discuss