Unplanned wireless network – safety in numbers? I don’t think so.

To plan or not to plan, that is the question!

Planning your wireless network does cost, but not as much as not planning it!
Sometime back, I read a very interesting article noting that many heads of IT of larger organisations claimed their company’s wireless network was not planned. Resulting in inefficient and overloaded networks. Clearly, there is no safety in running with the pack.

I am not surprised by this at all and in my experience the lack of planning doesn’t lie with IT Directors alone as I have experienced many installations that have been installed by ‘professional’ installers that also showed no evidence of planning or design.

One of the problems in my opinion is the dumbing down of network design and installation. Planning for any network – fixed or wireless – is essential as the network is there to support critical business applications. Anyone with any experience of planning telephone traffic and busy hour planning will have some idea of the detail required. Early Ethernet coaxial and hub networks required careful planning, a critical requirement for the success of the network deployment. These old coaxial and hub networks only allowed one device to transmit at any time as the cable and hubs were shared media. Wireless networks operate in a similar way – any device using the same channel in the same air space contend for transmission time. This fact alone makes careful planning a necessity.

Another problem in my experience is some IT Directors engage the services of professional installers to take care of the wireless network. There are some good companies out there with highly qualified and experienced technicians and engineers but there are also many who have set up shop or added wireless to their portfolio to capitalise on the rapid growth in wireless business. Unfortunately, the problems rarely arise before the project is closed and the bills are paid. Only then do the unsuspecting IT Directors realise they have a big problem on their hands. In some instances, the problem may have started with the wireless manufacturer responsible for training the installer. I have been told by more than one wireless equipment manufacturer that wireless surveys are not required with their systems. This has been very costly advice for many organisations. There are some circumstances where a wireless survey is not necessary but that is a decision that can only be made when all the facts are taken into consideration.

“I would argue that it is no more a pain [planning a wireless network installation] than any other engineering challenge. Isn’t that why we have trained and qualified engineers?”

I would argue that it is no more a pain than any other engineering challenge. Isn’t that why we have trained and qualified engineers? Structured cabling systems require planning, Ethernet switched networks require planning, wide area networks require planning so why should wireless networks be any different? There are a number of useful radio frequency (RF) planning tools, ranging from free to very expensive but in most situations, they give a fairly rough guide to estimate the number of access points required. Unless some on site data can be input into the tools it is common for the output of these planning tools to be not far short of useless. However, it is a starting point and it is better than nothing.

“…noise is any signal other than the signal you want to receive”

RF planning is only one aspect – albeit a very important aspect – of wireless network planning. It is critical because noise is any signal other than the signal you want to receive. In a multi access point installation, any access point within range of the access point your device is trying to communicate with is a source of noise. As noise increases the performance of the wireless network decreases. Some walls within buildings allow almost unimpeded flow of certain bands of RF from one side to the other while others virtually block the RF. So, what is best? A wall that allows our RF through or a wall that blocks our RF? I don’t know… and neither does anyone else without a plan. Without a plan, we fall at the first hurdle.

To add some detail to this… if your wireless network is to support a small number of guest users to provide them with access to the Internet for browsing and email then a small number of access points may be all that is required. In this instance having walls that allow RF through would be useful to reduce the number of access points required. But what if the wireless network was required to support Voice over IP and critical business applications? High density installations require more access points to support a number of concurrent users in any given area of the building. This is essential to maintain a good level of experience for voice and business application users. If we install a high density of access points within a building, walls that allow our RF to pass freely are no longer our friend. As every access point, our device, and every other access point can ‘hear’ noise from all the other devices and access points. To maintain a good quality wireless network, it is essential to maintain a big gap between noise and the signal we want to receive. If our building is constructed of walls that block our RF we can now use this to our advantage by containing the RF from each access point. We are fortunate in some installations as the building materials work for us. But many work against us and without a survey we may not know until the installation has been completed and the users are experiencing problems.

“…the RF engineer embarks on an exercise similar to a game of 3D chess”

From the above example, you can see the RF planning will depend on the operational requirements of the wireless network. Once armed with the application, user, device and traffic requirements, the RF engineer embarks on an exercise similar to a game of 3D chess. The planner needs to determine the number of access points required to support a given number of users, based on their traffic type and quantity requirements. Further controls may be required such as multiple SSIDs, Quality of Service (QoS), different levels of security and this all may seem daunting at the outset. However, if this vitally important stage of the wireless network deployment is missed the costs are likely to escalate over a period of time.

On the subject of security, many security breaches are also due to a lack of planning. It is essential for any organisation to understand their airspace. I have witnessed many examples of staff members connecting wireless access points to their employers’ network. Regardless of whether you have a wireless network or not, this is a serious and very real security issue that could bypass your corporate firewalls. It is like buying the best locks and burglar alarm money can buy to secure your home and then leaving the windows and doors open and the alarm switched off when going on holiday. In my opinion, this is more of a network security and access control issue than a wireless network issue.

So, what can be done to recover from a poorly installed wireless network that lacked planning from the outset?

In all of the installations I have been engaged to investigate after the event, I have rarely had to advise ripping out and starting again. This will depend on a number of factors not least the equipment deployed. The first phase in any remedial work is to go back to the planning stage. Once we understand the expectations of the wireless network we can determine what needs to happen to get from where the installation is now to get to a position where it supports the business requirements. In some installations, a small amount of remedial work combined with a tighter definition of the levels of access allowed on the wireless network may be enable a realignment of the wireless network to the organisation’s expectations.

Getting the wireless access points under some form of management and monitoring is also very useful and may be achievable even in mixed vendor installations. Having some visibility of the wireless network components will accelerate the remedial process. The actual work involved may require relocation of access points, antenna repositioning, access point power adjustment, changes to SSID, VLAN or user role prioritisation. This will all depend on the capabilities of the installed equipment and the building structure.

“An experienced wireless network supplier will be able to help you to plan and design your wireless network installation to support your organisational needs…”

Wireless networks by their nature can be complex to plan, design, deploy and support. Outsourcing this work may also be challenging so my advice here is to make sure you check the credentials and experience of any potential supplier. An experienced wireless network supplier will be able to help you to plan and design your wireless network installation to support your organisational needs. If a wireless network is planned and designed effectively it may even be more secure than the average wired network. Network management and monitoring will remove much of the burden of managing a wireless network from IT staff, freeing them up to support your organisation.

In addition to this, automating the on-boarding process for BYOD users will prevent having to install a queuing system resembling border control outside your IT department, again freeing up IT resource to support business needs. Automating Network Access Protection will prevent virus and malware infiltration from BYOD and corporate devices significantly reducing the risk of downtime and potentially demands on IT resource to resolve security issues. Network Access Control can ensure wired, wireless and VPN users are granted access to areas of the network relevant to their user credentials, their device, their location and the time of day. All of these features come at a cost but with potential significant resource savings and reduction in risk to your organisation.