Recently, WiFi has moved from large corporate environments to implementation of home networks for home and small business offices, domestic internet connections and other IP based applications such as home security and CCTV.

Network designers need to keep some practical issues in mind when designing WiFi implementations. There are no real shortcuts to a good design. Here are some practical hints that hopefully will help.

• Choose the Network Architecture and AP locations

  

  Access points need both IP and power connections.

  IP

  The choice here is between UTP and mesh connectivity.  In the business environment, a mesh infrastructure is likely to be better since only the first access point needs a UTP connection to the nearest network switch.   However, that may not necessarily be the case if an exiting cabling system is already in use, or the building layout or materials make connectivity between access points an issue.

  A mesh infrastructure can sharply reduce the switch requirement and therefore cost.  It also provides flexibility if the area being covered changes in use.  Access points can be moved, added and removed easily without the need for new cables.

  Decide on mesh or UTP before designing the network.  Read further for other design considerations.

  In the small office or domestic environment, there is not much choice unless you want to cable your home. It’s WiFi.

  IP Bandwidth

  You need to seriously consider bandwidth in any network deployment. It can have a major effect on cost.

  Simply put, each user connected to an access point gets a portion of the bandwidth of the access point.  The access point’s bandwidth is limited by itself and the speed of the switch it’s attached to.

  In the business environment, you will need at least Gig connectivity from an access point to switch to provide broadband speeds to your WiFi users.   If you currently have 100Mb switches at the access layer (edge of the network) these will need to be replaced with Gig switches.  If you have a distribution layer architecture, you may even need to consider 10Gb switches for backhaul to the core.

  This will not be a consideration in most home networks, but some small office deployments moving large files around, for example, publishers and media houses may need broadband speed.

  Power

  Access Points need power.  This can be provided by using mains power and a power brick or Power over Ethernet through the data cable.  However, that requires an adjacent powerpoint or Power over Ethernet (“PoE”) capable switches.  New switches or power injectors will be needed if the existing switches are not PoE capable.  

  Battery-powered and solar access points are available.   Using them means an operational requirement to regularly check and change the batteries.  Solar-powered access points only work during the day unless they have battery backup.

• Coverage – Practical Design Considerations

  

  It is often assumed that the number and position of WiFi Access points is calculated around the area to be covered.  To be sure, area coverage is a serious consideration but the density of coverage required is also a key determinant in the number and positioning of WiFi access points.

  For example, areas with large numbers of users using WiFi such as a cafeteria will have significantly greater numbers of access points than open-plan offices.   The type of access point will also be different.

  The software used to generate the heat maps will need to reflect this in the configuration of the area.

  This tends not to so much of an issue in domestic environments because of the small number of users.

• Assessment of the Effect of Building Materials on Coverage

  

  WiFi Coverage is affected by building materials.  For example, reinforced concrete walls with rebar effectively block WiFi signals.  This will affect the number and positioning of access points. It may also affect network cable routing decisions.

  It can be a significant issue in homes.  The entry point of the fibre providing the internet connection usually defines the positioning of the WiFi router.  If the house is a brick or concrete structure, you will probably need WiFi extenders to deliver coverage to upper floors or distant rooms.

It’s an unfortunate thing that all too often designers concentrate on the architecture of a WiFi network and forget the practical implications of their design. That can be an expensive mistake.