A Guide to Wi-Fi Requirements.

Do you know what you want, what you really, really want?

Sometimes we need to flesh out real requirements for a Wi-Fi service.  A common request from customers is simply, “Install Wi-Fi at xyz location”.  Actual requirements start with understanding the desired outcome or performance expectations and working backwards from there.

There are relevant questions.  Such as what type of user experience is required and what density of users will be simultaneously using the Wi-Fi service. Or what existing systems does the service need to integrate with?

Business questions first.  If we don’t understand the business reasons for wireless in the first place, we won’t be able to design a solution that meets expectations.  Why is the business investing in a wireless service, what are the required business outcomes and timelines and how will the business measure the success of the installation?  What applications will they run and what type of activities do the business expect users to perform over the wireless medium?

Technical questions that address wireless functionality naturally follow. The customer may have standards that must be followed to integrate a wireless service:  user authentication, encryption, device management, reporting, logging, wireless intrusion detection (and desired responses), application performance, density of users, or different user groups.

From answers to these business and technical questions, we are able to begin noting the Wi-Fi requirements.  The discovery phase will assist here:  identifying supporting infrastructure, is there adequate bandwidth for the solution, is Quality of Service (QoS) required for application performance and which 802.11 standards need to be supported.

During the process of discovery, in some situations we may find that a Wi-Fi solution will not actually be fit for purpose!

The physical environment where wireless service will be installed prompts its own questions.  If site access for an inspection is difficult: a picture tells a thousand words.  A few well-chosen photos of the wireless environment will tell us a lot about what needs further analysis.  The environment will mandate if internal or external (weatherproof) Wi-Fi equipment is necessary, if internal or external antennas will be required, where there may be coverage challenges and so forth.  Physical security of equipment inside the environment should also be taken into consideration.

Site surveys are crucial.  We will want to know if the proposed environment is subject to wireless interference or,  if it has to contend with 50 foreign Wi-Fi networks fighting for the same channel space.  Site surveys can discover useful information that then become technical requirements that feed into the design.  For example, if a site survey uncovers heavy amounts of interference on a commonly used channel by Wi-Fi, then the design can avoid using this channel.

Most importantly: with Wi-Fi it is all about the client.  If the technology the client is using to connect to the wireless infrastructure is poor, then the experience will be poor.  No matter how good the wireless system.  If you have a mixed bag of client devices, old and new, fast and slow; all of this will affect the design.

So tell us what you want.  What you really, really want.

 

 

Coverage, Capacity, Density.

Last year at a seminar, wireless coverage inside the convention centre was excellent.  The numbers of people (density) jumping on the service however, affected the capacity of the centre’s network. While accessibility was excellent, the use of the application on the service was really slow.

Enterprise wireless coverage is more than just reach. It usually has to support x numbers of users seamlessly roaming between business areas without dropping connectivity and support a connection quality to complete business activities in an expedient manner.

Wi-Fi should invisibly and reliably, work in the background.  A slow network or a blackspot area quickly becomes noticed – internal social media is often the place where problems are ‘discussed’. Plugging these gaps usually has a cost involved but the value gained from increased productivity and job satisfaction, often outweighs this.

In the wired world, coverage means both ends of the link are connected.  With wireless, the strongest device has the better coverage. The power and ability of antennas (and therefore the reach and signal quality) on a tablet or smartphone will not match that of a laptop or the wireless infrastructure.  Both ends of a Wi-Fi link should therefore be aligned in order that the quality of coverage expectations are consistent.

So what are the factors that determine our Wi-Fi service experience? Fundamentally, it is a combination of coverage, capacity, type of business activity (e.g multimedia), numbers of users and the types of devices being used. Client device selection has a measurable impact in a wireless environment; since Wi-Fi is a shared resource, too many ‘slow’ devices will lower performance for everyone.

To sum up, coverage and capacity define the infrastructure needed to deliver a certain level of service, to an expected density of user devices.  Get it right and you won’t notice the network at all.

The importance of site surveys

Before and after any wireless network installation, one or more wireless site surveys will prove valuable.

Site surveys provide certainty and reduce risk before any Wi-Fi implementation.  They usually uncover the gotchas before its too late and contribute important information towards planning and deployment.

In return, the business gets accuracy and assurance.  Professional site surveys audit a location’s Radio Frequency (RF) environment in order to determine the wireless resources necessary for the required level of Wi-Fi service and performance.  Namely, how much and what types of equipment and where best to deploy it to meet the service objectives within your unique wireless environment.

If this isn’t done, you may be left with too little or too much hardware or kit that is not fit for purpose. Which mean re-engagement of professional soft services, extra procurement of kit and probably an adjustment of timelines (aka lost productivity).

The financial benefit gained from site surveys is the certainty that project costs do not escalate beyond budget.  The correct amount of resource to achieve the desired outcome will be allocated from the beginning. In fact, site surveys often reduce cost to an organisation as they save on having to come back later to fix anything missed the first time.

Usually, two to three site surveys are needed per location. Best practice is to run a virtual site survey first and follow that up with actual on-site surveys before and after implementation to ensure the design objectives are met.

Unless the office or environment is small and contained and wireless users do not require service out of that contained area, I would recommend surveys as an important part of any wireless network upgrade or installation.