Not too many people are plugging their laptop into an ethernet cable anymore. In fact, just about everyone in our office relies on wireless for their connectivity. In the past, wireless was too slow and somewhat unreliable, but it has come a long way and the convenience of not having to plug in far outweighs the performance impact if any.
Coverage is obviously one of the key elements for a good wireless deployment. It needs to work in your office, in the boardroom, in the lunch room and maybe even at the picnic table just outside your building. Ideally it should work anywhere your phone, tablet or laptop goes.
What gets missed quite often is planning for capacity. Coverage ensures there is a signal, but each access point can only service so many clients before it becomes slow, unresponsive and ultimately useless. It is also important to understand the applications that will be used over the wireless to get an idea of how many users per AP is ideal.
Some vendors make a recommendation of 20-25 users per AP. This is probably a good number if they are web browsing and checking email, anything more and I would suggest you will run into problems. In some cases, where large files are being saved to servers on a regular basis it is advisable to stick with ethernet. Overall however, I would suggest that you don’t want anymore than between 10-16 users per AP.
Interfering APs may also have an impact on your deployment. In some cases I have seen an AP detect up to 59 neighboring APs. This can cause havoc with your deployment. Site surveys prior to your deployment can certainly help mitigate this, but remember that a site survey is done at a point in time. If there is a new office building going up next door, you can expect more interference in the near future. Site surveys are good for determining the most effective placement of your APs and some tools will help you plan based on capacity as well.
When APs were standalone the deployments were much more complex than they are today with Controller based APs. The controller centralizes the configurations and pushes them out the the APs. Since the controller has a holistic view of the entire network, it can instruct the APs to make channel adjustments without affecting its neighboring APs. One of my favorite features in a Controller based deployment is the ability to detect rogue on-wire APs and even block any clients from joining them. A rogue on-wire access point is a AP that has been installed on the LAN via ethernet, but is not part of the controller based system. When configured, the controller will sent out disconnect messages to any clients that attempt to join the rogue AP.
My only complaint with a controller based deployment is that the cost is much higher than a standalone deployment. The Controller based AP is the same cost as a Standalone AP, but the controller hardware and licensing is extra.
The list of environmental challenges that can affect your wireless deployment is endless. Elevators, Microwaves, Cordless Phones, Water, Steel, Concrete, Small Rocks, you name it. They can all have an effect.
And of course security. One of the most important aspects of a good wireless deployment is ensuring only you and your staff can use it. A good deployment will have LDAP or RADIUS integration. If security is top priority then you should consider coupling the LDAP or RADIUS with a second factor, using key fobs or software that provides OTP (one time passwords).
The same AP’s that access your corporate network can also provide guest access. When providing guest access you can make it difficult so that only people you authorize can use it, or you can make it simple and provide a splash page where guest users are asked to provide an email address or simply agree to the terms of usage.