IN THIS CHAPTER, YOU WILL LEARN ABOUT THE FOLLOWING:

• WLAN site survey interview
  • Customer briefing
  • Business requirements
  • Capacity and coverage requirements
  • Existing wireless network
  • Infrastructure connectivity
  • Security expectations
  • Guest access
• Documentation and reports
  • Forms and customer documentation
  • Deliverables
  • Additional reports
• Vertical market considerations
  • Outdoor surveys
  • Aesthetics
  • Government
  • Education
  • Healthcare
  • Hotspots
  • Retail
  • Warehouses
  • Manufacturing
  • Multitenant buildings

Chapter 16, “Site Survey Systems and Devices,” discusses wireless site surveys from a technical perspective. You will learn about all the procedures and tools required for proper coverage, spectrum, and capacity planning. In this chapter, however, we discuss the wireless site survey from an administrative perspective. Much preparation must take place before the WLAN site survey is conducted. The needs of the WLAN must be predetermined and the proper questions must be asked.

In this chapter, we cover all the necessary preparations for the site survey and the documentation that must be assembled prior to it. We also discuss all the final reports that are delivered upon completion of the WLAN site survey. Finally, we outline unique wireless site survey considerations that should be given to different vertical markets.

WLAN Site Survey Interview

Is a site survey even needed? The answer to that question is almost always a resounding yes. If an owner of a small retail flower shop desires a wireless network, the site survey that is conducted may be as simple as placing a small office, home office (SOHO) Wi-Fi router in the middle of the shop, turning the transmit power to a lower setting, and making sure you have connectivity. Performing a site survey in a medium or large business entails much more physical work and time. Before the actual survey is conducted, a proper site survey interview should occur to both educate the customer and properly determine their needs.

Asking the correct questions during a site survey interview not only ensures that the proper tools are used during the survey, it also makes the survey more productive. Most important, the end result of a thorough interview and thorough survey will be a WLAN that meets all the intended mobility, coverage, and capacity needs. The following sections cover the questions that should be thoughtfully considered during the site survey interview.

Customer Briefing

Even though 802.11 technologies have been around since 1997, much misunderstanding and misinformation about wireless networking still exists. Because many businesses and individuals are familiar with Ethernet networks, a “just plug it in and turn it on” mentality is prevalent. If a wireless network is being planned for your company or for a prospective client, it is highly recommended that you sit management down, give them an overview of 802.11 wireless networking, and talk with them about how and why site surveys are conducted. You do not need to explain the inner workings of orthogonal frequency division multiplexing or the Distributed Coordination Function; however, a conversation about the advantages of Wi-Fi, as well as the limitations of a WLAN, is a good idea.

There is a good chance that the company already has a WLAN and the customer briefing is about an upgrade to the existing WLAN. However, a brief explanation about the advantages of mobility would be an excellent start for a customer that is looking to deploy Wi-Fi for the very first time. Chances are that a wireless network is already being considered because the company's end users have requested wireless access to the company network using their own personal devices such as smartphones and tablets.

Just as important is a discussion about the bandwidth and throughput capabilities of 802.11a/b/g/n/ac technology. Enterprise users are accustomed to 100 Mbps full-duplex or better speeds on the wired network. Because of vendor hype, people often believe that a Wi-Fi network will automatically provide them with similar bandwidth and throughput. Management will need to be educated that because of overhead, the aggregate throughput of a WLAN is 50 percent to 70 percent of the advertised data rate.

It should also be explained that the medium is a half-duplex shared medium and not full-duplex. The average customer usually has many misconceptions in regard to WLAN bandwidth versus actual throughput. The advent of 802.11n and now 802.11ac WLAN equipment has addressed greater throughput needs, thus making the bandwidth/throughput conversation less painful.

Another appropriate discussion is why a site survey is needed. A very brief explanation on how RF signals propagate and attenuate will provide management with a better understanding of why an RF site survey is needed to ensure the proper coverage and enhance performance. A discussion and comparison of a 2.4 GHz vs. a 5 GHz WLAN might also be necessary. If management is properly briefed on the basics of Wi-Fi as well as the importance of a site survey, the forthcoming technical questions will be answered in a more suitable fashion.

Business Requirements

The first question that should be posed is, What is the purpose of the WLAN? If you have a complete understanding of the intended use of a wireless network, the result will be a better-designed WLAN. For example, a VoWiFi network has very different requirements than a heavily used data network. If the purpose of the WLAN is only to provide users a gateway to the Internet, security and integration recommendations will be different. A warehouse environment with 200 handheld scanners is very different from an office environment. A hospital's wireless network will have different business requirements than an airport's wireless network. Here are some of the business requirement questions that should be asked:

What applications will be used over the WLAN? This question could have both capacity and quality of service (QoS) implications. A wireless network for graphic designers moving huge graphics files across the WLAN would obviously need more bandwidth than a wireless network for nothing but wireless bar code scanners. If time-sensitive applications such as voice or video are required, legacy proprietary QoS needs might have to be addressed, and standardized 802.11e/WMM solutions will need to be deployed to meet these QoS needs.

Who will be using the WLAN? Different types of users have different capacity and performance needs. Users may also need to be separated for organizational purposes. Groups of users might be segmented into separate SSIDs and VLANs or even segmented by different frequencies. This is also an important consideration for security roles.

What types of devices will be connecting to the WLAN? Will employees be allowed to connect their personal devices to the network? Does the company have a bring your own device (BYOD) strategy and is a mobile device management (MDM) solution needed? Handheld wireless barcode scanners may also be segmented into separate VLANs or by frequency. VoWiFi phones are always put in a separate VLAN than data users with laptops. Many handheld devices use older 802.11b or 802.11g radios and can transmit in only the 2.4 GHz ISM band. The capabilities of the devices may also force decisions in security, frequency, technology, and data rates.

We discuss the varying business requirements of different vertical markets later in this chapter. Defining the purpose of the WLAN in advance will lead to a more productive site survey and is imperative to the eventual design of the WLAN.

Capacity and Coverage Requirements

After the purpose of the WLAN has been clearly defined, the next step is to begin asking all the necessary questions for planning the site survey and designing the wireless network. Although the final design of a WLAN is completed after the site survey is conducted, some preliminary design based on the capacity and coverage needs of the customer is recommended. You will need to sit down with a copy of the building's floor plan and ask the customer where they want RF coverage. The answer will almost always be everywhere. If a VoWiFi deployment is planned, that answer is probably legitimate because VoWiFi phones will need mobility and connectivity throughout the building. Furthermore, because of the proliferation of mobile devices such as smartphones and tablets, broad coverage is usually a necessity.

However, the need for blanket coverage might not be necessary. Do laptop data users need access in a storage area? Do they need connectivity in the outdoor courtyard? Do handheld bar code scanners used in a warehouse area need access in the front office? The answer to these questions will often vary depending on the earlier questions that were asked regarding the purpose of the WLAN. However, if you can determine that certain areas of the facility do not require coverage, you will save the customer money and yourself time when conducting the physical survey.

Depending on the layout and the materials used inside the building, some preplanning might need to be done as to what type of antennas to use in certain areas of the facility. A high-density area may require semidirectional patch antennas for sectorized coverage as opposed to using omnidirectional antennas. When the survey is performed, this will be confirmed or adjusted accordingly.

The most often neglected aspect prior to the site survey is determining capacity needs of the WLAN. As mentioned in Chapter 11, “WLAN Deployment and Vertical Markets,” you must not just consider coverage; you must also plan for capacity. Cell sizing for a high-density WLAN design might be necessary to properly address your capacity requirements. In order for the wireless end user to experience acceptable performance, a ratio of average number of users per access point must be established. The answer to the capacity question depends on a host of variables, including answers to earlier questions about the purpose of the WLAN. Capacity will not be as big of a concern in a warehouse environment using mostly handheld data scanners. However, if the WLAN has average to heavy data requirements, capacity will absolutely be a concern. The following are among the many factors that need to be considered when planning for capacity:

Data Applications The applications that are used will have a direct impact on the number of Wi-Fi devices that should be communicating on average through an access point. So the next question is, what is a good average number of connected devices per access point? Once again, it depends entirely on the purpose of the WLAN and the applications being used. However, in an 802.11a/b/g/n network, 35–50 data WLAN devices per radio is an often-quoted figure for typical WLAN applications such as web browsing and email. Many WLAN vendors' marketing material states that 100 or 200 devices can connect to an 802.11n access point at the same time. Although more than a hundred devices might be able to connect to an AP radio, these numbers are not realistic for active devices due to the nature of the half-duplex shared medium. 35 to 50 active Wi-Fi devices per radio on a dual-frequency 802.11n access point is realistic with average application use, such as web browsing. 802.11ac access points can provide for a greater number of active connections and might be a viable solution in areas with a high density of users and devices.

User and Device Density Three important questions need to be asked with regard to users. First, how many users currently need wireless access and how many Wi-Fi devices will they be using? Second, how many users and devices may need wireless access in the future? These first two questions will help you to begin adequately planning for a good ratio of devices per access point while allowing for future growth. The third question of great significance is, Where are the users? Sit down with network management and indicate on the floor plan of the building any areas of high user density. For example, one company might have offices with only 1 or 2 people per room, whereas another company might have 30 or more people in a common area separated by cubicle walls. Other examples of areas with high user density are call centers, classrooms, and lecture halls. Plan to conduct the physical survey when the users are present and not during off-hours. A high concentration of human bodies can attenuate the RF signal because of absorption.

Peak On/Off Use Be sure to ask what the peak times are—that is, when access to the WLAN is heaviest. For example, a conference room might be used only once a day or once a month. Certain applications might be heavily accessed through the WLAN at specified times. Another peak period could be when one shift leaves and another arrives.

Existing Transmitters This does not refer just to previously installed 802.11 networks. Rather, it refers to interfering devices such as microwaves, cordless headsets, cordless phones, wireless machinery, and so on. Often, this is severely overlooked. If a large open area will house the help desk after the wireless is installed, you may be thinking of capacity. However, if you don't know that the employees are using 2.4 GHz cordless headsets or Bluetooth keyboards and mice, you may be designing a network destined for failure.

Portability vs. Mobility There are two types of mobility. The first is related to being portable and the other is true mobility. To help explain this, think of a marketing manager working on a presentation and saving it on a network share. He later wants to give that presentation in the boardroom. If he picks up his laptop, closes the lid, and walks to the conference room, where he opens the laptop, connects to the wireless network, and gives his presentation, that is being portable. He may have disconnected in between access points, and that is okay.

However, having true mobility means that a user remains connected 100 percent of the time while traveling through the facility. This would be indicative of VoWiFi or warehouse scanning applications. As mentioned earlier, most users now carry some sort of personal mobile device, such as a smartphone; therefore, true mobility is almost always an understood requirement.

Determining which type of connectivity is necessary can be key for not only troubleshooting an existing network but also for designing a new one.

Backward Compatibility for Legacy Devices It should be understood in advance that if there is any requirement for backward compatibility with legacy clients, the 802.11 protection mechanisms will always adversely affect throughput. The impact of protection mechanisms is not as severe on an 802.11n network, but it can be significant on a legacy 802.11b/g network. Enterprise deployments will almost always require some level of backward compatibility to provide access for older 802.11a/b/g radios found in handhelds, VoWiFi phones, or older laptops. Many handheld mobile devices, such as older barcode scanners, still do not have 802.11n radios and backward compatibility will be required.

Carefully planning coverage and capacity needs prior to the site survey will help you determine some of the design scenarios you might need, including AP power settings, types of antennas, and cell sizes. The physical site survey will still have to be conducted to validate and further determine coverage and capacity requirements.

Existing Wireless Network

Quite often the reason you are conducting a WLAN site survey is that you have been called in as a consultant to fix an existing deployment. Professional site survey companies have reported that as much as 40 percent of their business is troubleshooting existing WLANs, which often requires conducting a second site survey or discovering that one was never conducted to begin with.

As more corporations and individuals become educated in 802.11 technologies, the percentage will obviously drop. Sadly, many untrained integrators or customers just install the access points wherever they can mount them and leave the default power and channel settings on every AP. Usually, site surveys must be conducted either because of performance problems or difficulty roaming. Performance problems are often caused by RF interference, low SNR, adjacent cell interference, or cochannel cooperation. Roaming problems may also be interference related or caused by a lack of adequate coverage and/or by a lack of proper duplicate cell coverage for roaming. Here are some of the questions that should be asked prior to the reparative site survey:

What are the current problems with the existing WLAN? Ask the customer to clarify the problems. Are they throughput related? Are there frequent disconnects? Is there any difficulty roaming? In what part of the building do the problems occur most often? Is the problem happening with one WLAN device or multiple devices? How often do the problems occur, and have any steps been taken to duplicate the troubles?

Are there any known sources of RF interference? More than likely the customer will have no idea, but it does not hurt to ask. Are there any microwave ovens? Do people use cordless phones or headsets? Does anyone use Bluetooth for keyboards or mice? After asking these interference questions, you should always perform a spectrum analysis, which is the only way to determine whether there is any RF interference in the area that may inhibit future transmissions.

Are there any known coverage dead zones? This is related to the roaming questions, and areas probably exist where proper coverage is not being provided. Remember, this could be too little or too much coverage. Both create roaming and connectivity problems.

Does prior site survey data exist? Chances are that an original site survey was not even conducted. However, if old site survey documentation exists, it may be helpful when troubleshooting existing problems. It is important to note that unless quantifiable data was collected that shows dBm strengths, the survey report should be viewed with extreme caution.

What equipment is currently installed? Ask what type of equipment is being used, such as 802.11a (5 GHz) or 802.11b/g (2.4 GHz), and which vendor has been used. Is the customer looking to upgrade to an 802.11n or 802.11ac network? Once again, the customer might have no idea, and it will be your job to determine what has been installed and why it is not working properly. Also check the configurations of the devices, including service set identifiers (SSIDs), WEP or WPA keys, channels, power levels, and firmware versions. Often issues can be as simple as all the access points are transmitting on the same channel or there is a buffer issue that can be resolved with the latest firmware update.

Depending on the level of troubleshooting that is required on the existing wireless network, a second site survey consisting of coverage and spectrum analysis will often be necessary. After the new site survey has been conducted, adjustments to the existing WLAN equipment typically are adequate. However, the worst-case scenario would involve a complete redesign of the WLAN. Keep in mind that whenever a second site survey is necessary, all the same questions that are asked as part of a survey for a new installation (Greenfield survey) should also be asked prior to the second site survey. If wireless usage requirements have changed, a redesign might be the best course of action.

Infrastructure Connectivity

You have already learned that the usual purposes of a WLAN are to provide client mobility and to provide access via an AP into a preexisting wired network infrastructure. Part of the interview process includes asking the correct questions so that the WLAN will integrate properly into the existing wired architecture. Asking for a copy of the wired network topology map is highly recommended.

For security reasons, the customer may not want to disclose the wired topology, and you may need to sign a nondisclosure agreement. It is a good idea to request that an agreement be signed to protect you legally as the integrator. Be sure that someone in your organization with the authority to sign finalizes the agreement.

Understanding the existing topology will also be of help when planning WLAN segmentation and security proposals and recommendations. With or without a topology map, the following topics are important to ensure the desired infrastructure connectivity:

Roaming Is roaming required? In most cases, the answer will be yes, because mobility is a key advantage of wireless networking. Any devices that run connection-oriented applications will need seamless roaming. Seamless roaming is mandatory if handheld devices and/or VoWiFi phones are deployed. With the advent of smartphones and tablets, most end users expect mobility. Providing for secure seamless roaming is pretty much an afterthought.

It should also be understood that there might be certain areas where the WLAN was designed so that roaming is a very low priority, such as areas with a high density of users. For example, a gymnasium filled with 800 people might have APs on the ceiling with MIMO patch antennas to provide for unidirectional sectorized coverage. This is a WLAN design with high density as the priority, as opposed to mobility and roaming.

Another important roaming consideration is whether users will need to roam across layer 3 boundaries. A Mobile IP solution or a proprietary layer 3 roaming solution will be needed if client stations need to roam across subnets. Special consideration has to be given to roaming with VoWiFi devices because of the issues that can arise from network latency. With regard to the existing network, it is imperative that you determine whether the wired network infrastructure will support all the new wireless features. For instance, if you want to roll out three SSIDs with different VLANs but haven't checked to see if the customer's network switches can be configured with VLANs, you may have a serious problem.

Wiring Closets Where are the wiring closets located? Will the locations that are being considered for AP installation be within a 100-meter (328-foot) cable drop from the wiring closets?

Antenna Structure If an outdoor network or point-to-point bridging application is requested, some additional structure might have to be built to mount the antennas. Asking for building diagrams of the roof to locate structural beams and existing roof penetrations is a good idea. Depending on the weight of the installation, you may also need to consult a structural engineer.

Switches Will the access points be connected by category 5 (CAT5) cabling to unmanaged switches or managed switches? CAT5e or higher grade cabling is usually needed to maximize 802.3af PoE. An unmanaged switch will only support a single VLAN. A managed switch will be needed if multiple VLANs are required. Are there enough switch ports? What is the power budget of the switch? Who will be responsible for configuring the VLANs?

PoE How will the access points be powered? Because APs are often mounted in the ceiling, Power over Ethernet (PoE) will likely be required to remotely power the access points. Very often the customer will not yet have a PoE solution in place, and further investment will be needed. If the customer already does have a PoE solution installed, it must be determined whether the PoE solution is compliant with 802.3af or 802.3at (PoE Plus). Also, is the solution an endpoint or midspan solution? If the customer is migrating toward a future 802.11ac deployment of access points, more power will be needed and 802.3at power sourcing equipment will be necessary.

Regardless of what the customer has, it is important to make sure that it is compatible with the system you are proposing to install. If PoE injectors need to be installed, you will need to make sure there are sufficient power outlets. If not you, who will be responsible for installing those? If you are installing 802.11ac access points, they may require an 802.3at PoE Plus solution to properly power all MIMO radios.

Segmentation How will the WLAN and/or users of the WLAN be segmented from the wired network? Will the entire wireless network be on a separate IP subnet tied to unique VLANs? Will VLANs be used, and is a guest VLAN necessary? Will firewalls or VPNs be used for segmentation? Or will the wireless network be a natural extension to the wired network and follow the same wiring, VLAN numbering, and design schemes as the wired infrastructure? All these questions are also directly related to security expectations.

Naming Convention Does the customer already have a naming convention for cabling and network infrastructure equipment, and will one need to be created for the WLAN?

User Management Considerations regarding RBAC, bandwidth throttling, and load balancing should be discussed. Do they have an existing RADIUS server or does one need to be installed? What type of LDAP user database is being used? Where will usernames and passwords be stored? Will usernames and passwords be used for authentication, or will they be using client certificates? Will guest user access be provided?

Device Management Will employees be allowed to access the WLAN with their own personal devices? How will personal and company-issued mobile devices be managed? Do they want to provide different levels of access based upon device type, such as, for example, smartphone, tablet, personal laptop, or corporate laptop? A BYOD strategy may be needed, as well as an MDM solution.

Infrastructure Management How will the WLAN remote access points be managed? Is a central management solution a requirement? Will devices be managed using SSH2, SNMP, or HTTP/HTTPS? Do they have standard credentials that they would like to use to access these management interfaces?

A comprehensive site interview that provides detailed feedback about infrastructure connectivity requirements will result in a more thorough site survey and a well-designed wireless network. Seventy-five percent of the work for a good wireless network is in the pre-engineering. It creates the road map for all the other pieces.

Security Expectations

Network management personnel should absolutely be interviewed about security expectations. All data privacy and encryption needs should be discussed. All AAA requirements must be documented. It should be determined whether the customer plans to implement a wireless intrusion detection or prevention system (WIDS or WIPS) for protection against rogue APs and the many other types of wireless attacks. Older devices may not support fast secure roaming mechanisms, and 802.1X/EAP might not be an option for those devices.

A comprehensive interview regarding security expectations will provide the necessary information to make competent security recommendations after the site survey has been conducted and prior to deployment. Industry-specific regulations such as the Health Insurance Portability and Accountability Act (HIPAA), Gramm-Leach-Bliley, and Payment Card Industry (PCI) may have to be taken into account when making security recommendations. U.S. government installations may have to abide by the strict Federal Information Processing Standards (FIPS) 140-2 regulations, and all security solutions may need to be FIPS compliant.

All of these answers should also assist in determining whether the necessary hardware and software exists to perform these functions. If not, it will be your job to consider the requirements and recommendations that may be necessary.

Guest Access

Because of the widespread acceptance of Wi-Fi in business environments, most companies offer some sort of wireless guest access to the Internet. Guest users access the WLAN via the same access points. However, they usually connect via a guest SSID that redirects the guest users to a captive portal. The guest captive portal serves two purposes:

• The login screen forces guest users to accept the corporate legal disclaimer.
• After logging in, the guest users are provided with a gateway to the Internet.

It should be noted that all users who connect with the guest SSID should be allowed to go only to the Internet gateway and should be properly segmented from all other network resources in a separate guest VLAN. Firewall restrictions and bandwidth throttling are also common when deploying guest WLANs. Another topic of conversation is who will manage the guest network. Guest user management is discussed in great detail in Chapter 20.

Documents and Reports

During the site survey interview (and prior to the site survey), proper documentation about the facility and network must be obtained. Additionally, site survey checklists should be created and adhered to during the physical survey. After the physical survey is performed, you will deliver to the customer a professional and comprehensive final report. Additional reports and customer recommendations may also be included with the final report. This report should provide detailed instructions on how to install and configure the proposed network so that anyone could read the report and understand your intent.

Forms and Customer Documentation

Before the site survey interview, you must obtain some critical documentation from the customer:

Blueprints You need a floor plan layout in order to discuss coverage and capacity needs with network administration personnel. As discussed earlier in this chapter, while reviewing floor plan layouts, keep in mind that capacity and coverage requirements will be preplanned. Photocopies of the floor plan will also need to be created and used to record the RF measurements that are taken during the physical site survey, as well as to record the locations of hardware placement. Some software survey tools allow you to import floor plans, and the software will record the survey results on the floor plan for you. Figure 15.1 is an example of a typical floor plan. These are highly recommended and make the final report much easier to compile.

What if the customer does not have a set of blueprints? Blueprints can be located via a variety of sources. The original architect of the building will probably still have a copy of the blueprints. Many public and private buildings' floor plans might also be located at a public government resource such as city hall or the fire department. Businesses are usually required to post a fire escape plan. Many site surveys have been conducted using a simple fire escape plan that has been drawn to scale if blueprints cannot be located. In a worst-case scenario, you may have to use some graph paper and map out the floor plan manually. In Chapter 16, “Site Survey Systems and Devices,” we discuss RF modeling software that can be used to create predictive capacity and coverage simulations. Predictive analysis tools require detailed information about building materials that may be found in blueprints. Blueprints may already be in a vector graphic format (with the filename extensions .dwg and .dwf) for importing into a predictive analysis application, or they may have to be scanned.

FIGURE 15.1 Typical Floor Plan

Topographic Map If an outdoor site survey is planned, a topographic map, also called a contour map, will be needed. Contour maps display terrain information, such as elevations, forest cover, and the locations of streams and other bodies of water. Figure 15.2 depicts a typical topographic map. A topographic map will be a necessity when performing bridging calculations, such as Fresnel zone clearance.

Network Topology Map Understanding the layout of the customer's current wired network infrastructure will speed up the site survey process and allow for better planning of the WLAN during the design phase. A computer network topology map will provide necessary information such as the location of the wiring closets and layer 3 boundaries. The WLAN topology will be integrated as seamlessly as possible into the wired infrastructure. VLANs will normally be used for segmentation for both the wired and wireless networks.

Acquiring a network topology map from the customer is a highly recommended practice that will result in a well-designed and properly integrated WLAN. Some organizations may not wish to reveal their wired network topology for security reasons. It may be necessary to obtain security clearance and/or sign nondisclosure agreements to gain access to these documents.

Security Credentials You might need proper security authorization to access facilities when conducting the site survey. Hospitals, government facilities, and many businesses require badges, passes, and maybe even an escort for entrance into certain areas. A meeting with security personnel and/or the facilities manager in advance of the survey will be necessary in order to meet all physical security requirements. You do not want to show up at the customer site and be asked to return at another time because somebody forgot to schedule a security escort. Regardless of the security requirements, it is always a good idea to have the network administrator alert everyone that you will be in the area.

As a site survey professional, you will have created your own documentation or necessary checklists that will be used during the site survey interview as well as during the actual physical survey. There are several types of survey checklists:

Interview Checklist A detailed checklist containing all the questions to be asked during the site survey interview should be created in advance. The many detailed interview questions discussed earlier in this chapter will all be outlined in the interview checklist.

FIGURE 15.2 Topographic map

Installation Checklist Many site survey professionals prefer to record all installation details on the floor plan documents. An installation checklist detailing hardware placement and mounting for each individual access point is also an option. Information about AP location, antenna type, antenna orientation, mounting devices, and power sources may be logged.

Equipment Checklist For organizational purposes, a checklist of all the hardware and software tools used during the survey might also be a good idea. All the necessary tools needed for both indoor and outdoor site surveys are covered in Chapter 16.

Deliverables

After the interview process has been completed and the survey has been conducted, a final report must be delivered to the customer. Information gathered during the site survey will be organized and formatted into a professional technical report for the customer's review. Compiled information contained in the deliverables will include the following:

Purpose Statement The final report should begin with a WLAN purpose statement that stipulates the customer requirements and business justification for the WLAN.

Spectrum Analysis Be sure to identify potential sources of interference.

RF Coverage Analysis Define RF cell boundaries.

Hardware Placement and Configuration Recommend AP placement, antenna orientation, channel reuse pattern, power settings, and any other AP-specific information such as installation techniques and cable routing.

Capacity and Performance Analysis Include results from application throughput testing, which is sometimes an optional analysis report included with the final survey report.

Chapter 16 covers in detail the methods and tools used to compile all the necessary analytical information that belongs in the final report. A detailed site survey report may be hundreds of pages, depending on the size of the facility. Site survey reports often include pictures that were taken with a digital camera during the survey. Pictures can be used to record AP placement, as well as to identify problems such as interfering RF devices or potential installation problems such as a solid ceiling or concrete walls. Professional site survey software applications exist that also generate professional-quality reports using preformatted forms.

Additional Reports

Along with the site survey report, other recommendations will be made to the customer so that appropriate equipment and security are deployed. Usually, the individuals and/or company that performed the site survey are also hired for the installation of the wireless network. The customer, however, might use the information from the site survey report to conduct their own deployment. Regardless of who handles the installation work, other recommendations and reports will be provided along with the site survey report:

Vendor Recommendations Many enterprise wireless vendors exist in the marketplace. It is a highly recommended practice to conduct the site survey using equipment from the same vendor who will supply the equipment that will later be deployed on site. Although the IEEE has set standards in place to ensure interoperability, every Wi-Fi vendor's equipment operates in some sort of proprietary fashion. You have already learned that many aspects of roaming are proprietary. The mere fact that every vendor's radios use proprietary RSSI thresholds is reason enough to stick with the same vendor during surveying and installation. Many site survey professionals have different vendor kits for the survey work. It is not unheard of for a survey company to conduct two surveys with equipment from two different vendors and present the customer with two separate options. However, the interview process will usually determine in advance the vendor recommendations that will be made to the customer.

Implementation Diagrams Based on information collected during the site survey, a final design diagram will be presented to the customer. The implementation diagram is basically a wireless topology map that illustrates where the access points will be installed and how the wireless network will be integrated into the existing wired infrastructure. AP placement, VLANs, and layer 3 boundaries will all be clearly defined.

Bill of Materials Along with the implementation diagrams will be a detailed bill of materials (BOM) that itemizes every hardware and software component necessary for the final installation of the wireless network. The model number and quantity of each piece of equipment will be necessary. This includes access points, bridges, wireless switches, antennas, cabling, connectors, and lightning arrestors.

Project Schedule and Costs A detailed deployment schedule should be drafted that outlines all timelines, equipment costs, and labor costs. Particular attention should be paid to the schedule dependencies, such as delivery times and licensing, if applicable.

Security Solution Recommendations As mentioned earlier in this chapter, security expectations should be discussed during the site survey interview. Based on these discussions, the surveying company will make comprehensive wireless security recommendations. All aspects of authentication, authorization, accounting, encryption, and segmentation should be included in the security recommendations documentation.

Wireless Policy Recommendations An addendum to the security recommendations might be corporate wireless policy recommendations. You might need to assist the customer in drafting a wireless network security policy if they do not already have one.

Training Recommendations One of the most overlooked areas when deploying new solutions is proper training. It is highly recommended that wireless administration and security training sessions be scheduled with the customer's network personnel. Additionally, condensed training sessions should be scheduled with all end users.

Vertical Market Considerations

No two site surveys will ever be exactly alike. Every business has its own needs, issues, and considerations when conducting a survey. Some businesses may require an outdoor site survey instead of an indoor survey. A vertical market is a particular industry or group of businesses in which similar products or services are developed and marketed. The following sections outline the distinctive subjects that must be examined when a WLAN is being considered in specialized vertical markets.

Outdoor Surveys

Some of the focus of this book and the CWNA exam is on outdoor site surveys for establishing bridge links. Calculations necessary for outdoor bridging surveys are numerous, including the Fresnel zone, earth bulge, free space path loss, link budget, and fade margin. However, outdoor site surveys for the purpose of providing general outdoor wireless access for users are becoming more commonplace. As the popularity of wireless mesh networking continues to grow, outdoor wireless access has become more commonplace. Outdoor site survey kits using outdoor mesh APs will be needed.

Weather conditions, such as lightning, snow and ice, heat, and wind, must also be contemplated. Most important is the apparatus that the antennas will be mounted to. Unless the hardware is designed for outdoor use, the outdoor equipment must ultimately be protected from the weather elements by using NEMA-rated enclosure units (NEMA stands for National Electrical Manufacturers Association) like the one pictured in Figure 15.3. NEMA weatherproof enclosures are available with a wide range of options, including heating, cooling, and PoE interfaces.

Safety is also a big concern for outdoor deployments. Consideration should be given to hiring professional installers. Certified tower climbing courses and tower safety and rescue training courses are available.

All RF power regulations, as defined by the regulatory body of your country, will need to be considered. If towers are to be used, you may have to contact several government agencies. Local and state municipalities may have construction regulations, and a permit is almost always required. In the United States, if any tower exceeds a height of 200 feet above ground level (AGL) or is within a certain proximity to an airport, both the FCC and Federal Aviation Administration (FAA) must be contacted. If a roof mount is to be installed that is greater than 20 feet above the highest roof level, the FCC and FAA may have to be consulted as well. Other countries have similar types of height restrictions, and you must contact the proper RF regulatory authority and aviation authority to find out the details.

FIGURE 15.3 NEMA enclosure

Photo courtesy of Netrepid, Inc.

Aesthetics

An important aspect of the installation of wireless equipment is the “pretty factor.” Many businesses prefer that all wireless hardware remain completely out of sight. Aesthetics is extremely important in retail environments and in the hospitality industry (restaurants and hotels). Any business that deals with the public will require that the Wi-Fi hardware be hidden or at least secured. WLAN vendors continue to design more aesthetic-looking access points and antennas. Some vendors have even camouflaged access points to resemble smoke detectors. Indoor enclosures, like the one pictured in Figure 15.4, can also be used to conceal access points from sight. Most enclosure units can be locked to help prevent theft of expensive Wi-Fi hardware.

Government

The key concern during government wireless site surveys is security. When security expectations are addressed during the interview process, careful consideration should be given to all aspects of planned security. Many U.S. government agencies, including the military, require that all wireless solutions be FIPS 140-2 compliant. Other government agencies may require that the wireless network be completely shielded or shut off during certain times of the day. Be sure to check export restrictions before traveling to other countries with certain equipment. The United States forbids the export of AES encryption technology to some countries. Other countries have their own regulations and customs requirements.

FIGURE 15.4 Indoor enclosure

Photo courtesy of Netrepid, Inc.

Obtaining the proper security credentials will most likely be a requirement before conducting the government survey. An identification badge or pass often is required. In some government facilities, an escort is needed in certain sensitive areas.

Education

As with government facilities, obtaining the proper security credentials in an education environment usually is necessary. Properly securing access points in lockable enclosure units is also necessary to prevent theft or tampering. Because of the high concentration of students, user density should be accounted for during capacity and coverage planning. K–12 schools across the United States are implementing 1:1 iPad deployments, where every student in every classroom has access to an iPad tablet. Because of these 1:1 programs, it is not uncommon to deploy an access point in every classroom to meet the device density needs. More information about Apple and the education vertical market can be found at www.apple.com/education.

In campus environments, wireless access is required in most buildings, and very often bridging solutions are needed between buildings across the campus. Some older educational facilities were constructed in such a manner as to serve as disaster shelters. That means that propagation in these areas is limited. Most school buildings use dense wall materials such as cinderblock or brick to attenuate the sound between classrooms. These materials also heavily attenuate RF signals.

Healthcare

One of the biggest concerns in a healthcare environment is sources of interference from the biomedical equipment that exists on site. Many biomedical devices operate in the ISM bands. For example, cauterizing devices in operating rooms have been known to cause problems with wireless networks. There is also a concern with 802.11 radios possibly interfering with biomedical equipment.

A meeting will be necessary with the biomedical department that maintains and services all biomedical equipment. Some hospitals have a person responsible for tracking and monitoring all RF devices in the facility.

A thorough spectrum analysis survey using a spectrum analyzer is extremely important. We recommend that you conduct several sweeps of these areas and compare them to ensure the greatest probability of capturing all the possible interferers. Because of the many potential sources of interference in the 2.4 GHz ISM band, it is likely that 5 GHz hardware will be deployed in many areas. Often, the dense environments require 5 GHz simply because you will need more channel options to prevent co-channel interference. Hospitals are usually large in scale, and a site survey may take many weeks; a predictive site survey can save a lot of time. Long hallways, multiple floors, fire safety doors, reflective materials, concrete construction, lead-lined X-ray rooms, and wire mesh safety glass are some of the physical conditions that you will encounter during the survey.

The applications used in the medical environment should all be considered during the interview and the survey. Numerous healthcare applications now exist for handheld iOS and Android devices. Tablets and smartphones are being used by doctors and nurses to access these mobile applications. Mobile devices are also used to transfer large files, such as X-ray graphics. Medical carts use radios to transfer patient data back to the nursing stations. VoWiFi phone deployments are commonplace in hospitals because of the communication mobility that they provide to nurses. Wi-Fi real-time location systems (RTLSs) using active 802.11 RFID tags are commonplace in hospitals for asset management tracking. Because of the presence of medical patients, proper security credentials and/or an escort will often be necessary. Many applications are connection oriented, and drops in connectivity can be detrimental to the operation of these applications.

Hotspots

Hotspots continue to grow in popularity, and many businesses are looking to provide wireless Internet access for their customers. Many hotspots are small, and care should be taken to limit the RF coverage area by using a single access point at a lower power setting. However, some large facilities, such as airports and convention centers, have begun offering wireless access, and obviously multiple access points and wider coverage will be needed. Security solutions at hotspots are usually limited to a captive portal solution for user authentication against a customer database.

Retail

A retail environment often has many potential sources of 2.4 GHz interference. Store demonstration models of cordless phones, baby monitors, and other ISM band devices can cause problems. The inventory storage racks and bins and the inventory itself are all potential sources of multipath problems. Heavy user density should also be considered, and a retail site survey should be done in the height of the shopping season as opposed to late January when the malls are empty.

Wireless applications that are used in retail stores include handheld scanners used for data collection and inventory control. Retail stores may also be looking for a retail analytics solution to monitor customer behavior and trends over the WLAN. Point-of-sale devices, such as cash registers, may also have Wi-Fi radios. You may still run into older frequency hopping equipment that may cause all-band interference with an 802.11b/g/n (2.4 GHz) network. Steps may be necessary to upgrade the older equipment. Coverage is usually a greater concern than capacity because wireless data-collection devices require very little bandwidth, and the number used in a particular area is typically limited.

Warehouses

Some of the earliest deployments of 802.11 technology were in warehouses for the purpose of inventory control and data collection. A 2.4 GHz WLAN will likely be deployed because most handheld devices currently use 2.4 GHz radios. Coverage, not capacity, is usually the main objective when designing a wireless network in a warehouse. Warehouses are filled with metal racks and all sorts of inventory that can cause reflections and multipath. The use of directional antennas in a warehouse environment may be a requirement if legacy 802.11a/b/g access points are still being used. High ceilings often cause mounting problems as well as coverage issues. Indoor chain-link fences that are often used to secure certain areas will scatter and block a 2.4 GHz RF signal. Seamless roaming is also mandatory because the handheld devices will be mobile. Forklifts that can move swiftly through the warehouse often have computing devices with Wi-Fi radios. Legacy deployments of 802.11 FHSS hardware and/or legacy 900 MHz radios still exist in some warehouse environments. Handheld WLAN barcode scanners are now often being replaced with smart phones that use barcode scanning applications.

Manufacturing

A manufacturing environment is often similar to a warehouse environment in terms of multipath interference and coverage design. However, a manufacturing plant presents many unique site survey challenges, including safety and the presence of employee unions. Heavy machinery and robotics may present safety concerns to the surveyor, and special care should be taken so as not to mount access points where they might be damaged by other machines. Many manufacturing plants also work with hazardous chemicals and materials. Proper protection gear may need to be worn, and ruggedized access points or enclosures may have to be installed. Technology manufacturing plants often have clean rooms, and the surveyor will have to wear a clean suit and follow clean room procedures if they are even allowed in the room.

Many manufacturing plants are union shops with union employees. A meeting with the plant's union representative may be necessary to make sure that no union policies will be violated by the site surveyor team.

Multitenant Buildings

By far the biggest issue when conducting a survey in a multitenant building is the presence of other WLAN equipment used by nearby businesses. Office building environments are extremely cluttered with 802.11b/g/n wireless networks that operate at 2.4 GHz. Almost assuredly all of the other tenants' WLANs will be powered to full strength, and some equipment will be on nonstandard channels such as 2 and 8, which will likely interfere with your WLAN equipment. If at all possible, strong consideration should be given to deploying a WLAN using the 5 GHz U-NII bands.

Summary

In this chapter, you have learned about all the preparations and questions that must be asked prior to conducting a wireless site survey. The site survey interview is an important process necessary to both educate the customer and determine the customer's wireless needs. Defining the business purpose of the wireless network leads to a more productive survey. Capacity and coverage planning, as well as planning for infrastructure connectivity, is all part of the site survey interview. Before the site survey interview, you should obtain critical documentation such as blueprints or topographical maps from the customer. Interview and installation checklists are used during the site survey interview and during the actual physical survey. Different survey considerations are required for different vertical markets. After the site survey is completed, you will deliver to the customer a final site survey report, as well as additional reports and recommendations.

Exam Essentials

Define the site survey interview. Be able to explain the importance of the interview process prior to the wireless site survey. Understand that the interview is for educating the customer and clearly defining all their wireless needs.

Identify the questions necessary to determine capacity and coverage needs. Understand the importance of proper capacity and coverage planning. Define all the numerous considerations when planning for RF cell coverage, bandwidth, and throughput.

Explain existing wireless network troubleshooting concerns. Be able to explain the questions necessary to troubleshoot an existing WLAN installation prior to conducting a secondary site survey.

Define infrastructure connectivity issues. Understand all the necessary questions that must be asked in order to guarantee proper integration of the WLAN into the existing wired infrastructure.

Identify site survey documentation and forms. Correctly identify all the documentation that must be assembled and created prior to the site survey. Be familiar with all the information and documentation that is needed in the final deliverables.

Explain vertical market considerations. Understand the business requirements of different vertical markets and how these requirements will alter the site survey and final deployment.

Review Questions

1. You have been hired by the XYZ Company for a wireless site survey. Which statements best describe site survey best practices when choosing vendor equipment to be used during the survey? (Choose two answers.)
   1. When conducting a wireless site survey with a WLAN switch, you should use both standalone and contoller-based access points.
   2. When conducting a wireless site survey with standalone access points, you should use different vendors' APs together.
   3. When conducting a wireless site survey with a WLAN controller, you should use the controller-based access points from the same vendor.
   4. When conducting a wireless site survey with standalone access points, you should use standalone access points from the same vendor.
   5. When a wireless site survey is conducted, proprietary security solutions are often implemented.
2. Name a unique consideration when deploying a wireless network in a hotel or other hospitality business. (Choose the best answer.)
   1. Equipment theft
   2. Aesthetics
   3. Segmentation
   4. Roaming
   5. User management
3. Which of the following statements best describe security considerations during a wireless site survey? (Choose all that apply.)
   1. Questions will be asked to define the customer's security expectations.
   2. Wireless security recommendations will be made after the survey.
   3. Recommendations about wireless security policies may also be made.
   4. During the survey, both mutual authentication and encryption should be implemented.
4. The ACME Corporation has hired you to design a wireless network that will have data clients, VoWiFi phones, and access for guest users. The company wants the strongest security solution possible for the data clients and phones. Which design best fits the customer's requirements?
   1. Create one wireless VLAN. Segment the data clients, VoWiFi phones, and guest users from the wired network. Use an 802.1X/EAP authentication and CCMP/AES encryption for a wireless security solution.
   2. Create three separate VLANs. Segment the data clients, VoWiFi phones, and guest users into three distinct VLANs. Use an 802.1X/EAP authentication and TKIP encryption for security in the data VLAN. Use WPA2-Personal in the voice VLAN. The guest VLAN will have no security other than possibly a captive portal.
   3. Create three separate VLANs. Segment the data clients, VoWiFi phones, and guest users into three distinct VLANs. Use an 802.1X/EAP authentication with CCMP/AES encryption for security in the data VLAN. Use WPA2-Personal in the voice VLAN. The guest VLAN traffic will require a captive web portal and guest firewall policy for security.
   4. Create two separate VLANs. The data and voice clients will share one VLAN while the guest users will reside in another. Use an 802.1X/EAP authentication and CCMP/AES encryption for security in the data/voice VLAN. The guest VLAN will have no security other than possibly a captive portal.
5. What are some additional recommendations that can be made along with the final site survey report? (Choose all that apply.)
   1. Training recommendations
   2. Security recommendations
   3. Coverage recommendations
   4. Capacity recommendations
   5. Roaming recommendations
6. What documents might be needed prior to performing an indoor site survey for a new wireless LAN? (Choose all that apply.)
   1. Blueprints
   2. Network topography map
   3. Network topology map
   4. Coverage map
   5. Frequency map
7. What roaming issues should be discussed during an interview for a future VoWiFi network? (Choose all that apply.)
   1. Layer 2 boundaries
   2. Layer 3 boundaries
   3. Layer 4 boundaries
   4. Latency
   5. Throughput
8. You have been hired by the Barry Corporation to conduct an indoor site survey. What information will be in the final site survey report that is delivered? (Choose all that apply.)
   1. AP placement
   2. Firewall settings
   3. Router access control lists
   4. Access point transmit power settings
   5. Antenna orientation
9. The Kellum Corporation has hired you to troubleshoot an existing WLAN. The end users are reporting having difficulties when roaming. What are some of the possible causes? (Choose all that apply.)
   1. Clients stations can only hear a −70 dBm signal from one access point.
   2. Clients stations hear a −70 dBm signal from 30 access points.
   3. The RF coverage cells are co-located.
   4. There is interference from the cellular network.
   5. There is interference from 2.4 GHz portable phones.
10. After conducting a simple site survey in the office building where your company is located on the fifth floor, you have discovered that other businesses are also operating access points on nearby floors on channels 2 and 8. What is the best recommendation you will make to management about deploying a new WLAN for your company?
    1. Install a 2.4 GHz access point on channel 6 and use the highest available transmit power setting to overpower the WLANs of the other businesses.
    2. Speak with the other businesses. Suggest that they use channels 1 and 6 at lower power settings. Install a 2.4 GHz access point using channel 9.
    3. Speak with the other businesses. Suggest that they use channels 1 and 11 at lower power settings. Install a 2.4 GHz access point using channel 6.
    4. Recommend installing a 5 GHz access point.
    5. Install a wireless intrusion prevention system (WIPS). Classify the other businesses' access points as interfering and implement deauthentication countermeasures.
11. The Harkins Corporation has hired you to make recommendations about a future wireless deployment that will require more than 300 access points to meet all coverage requirements. What is the most cost-efficient and practical recommendation in regard to providing electrical power to the access points?
    1. Recommend that the customer replace older edge switches with new switches that have inline PoE.
    2. Recommend that the customer replace the core switch with a new core switch that has inline PoE.
    3. Recommend that the customer use single-port power injectors.
    4. Recommend that the customer hire an electrician to install new electrical outlets.
12. The Chang Company has hired you to troubleshoot an existing legacy 802.11a/b/g WLAN. The end users are reporting having difficulties with throughput performance. What are some of the possible causes of the difficulties? (Choose all that apply.)
    1. Multipath interference
    2. Co-channel interference
    3. Co-location interference
    4. Inadequate capacity planning
    5. Low client device transmit power
13. What factors need to be considered when planning for capacity and coverage in a 5 GHz WLAN? (Choose all that apply.)
    1. Data applications
    2. User density
    3. Peak usage level
    4. DFS channels
14. During the interview process, which topics will be discussed so that the WLAN will integrate properly into the existing wired architecture?
    1. PoE
    2. Segmentation
    3. User management
    4. Infrastructure management
    5. All of the above
15. The Jackson County Regional Hospital has hired you for a wireless site survey. Prior to the site survey, employees from which departments at the hospital should be consulted? (Choose all that apply.)
    1. Network management
    2. Biomedical department
    3. Hospital security
    4. Custodial department
    5. Marketing department
16. Typically what are the biggest concerns when planning for a WLAN in a warehouse environment? (Choose all that apply.)
    1. Capacity
    2. Coverage
    3. Security
    4. Roaming
17. What type of hardware may be necessary when installing APs to be used for outdoor wireless coverage? (Choose all that apply.)
    1. NEMA enclosure
    2. Parabolic dish antennas
    3. Patch antennas
    4. Outdoor ruggedized core switch
18. What is a telecommunications unit of measurement of traffic equal to 1 hour of telephone traffic in 1 hour of time?
    1. Ohm
    2. dBm
    3. Erlang
    4. Call hour
    5. Voltage Standing Wave Ratio
19. What additional documentation is usually provided along with the final site survey deliverable? (Choose all that apply.)
    1. Bill of materials
    2. Implementation diagrams
    3. Network topology map
    4. Project schedule and costs
    5. Access point user manuals
20. The WonderPuppy Coffee Company has hired you to make recommendations about deploying wireless hotspots inside 500 coffee shops across the country. What solutions might you recommend? (Choose all that apply.)
    1. WPA2-Personal security solution
    2. 802.11 a/b/g/n access points at 100 mW transmit power
    3. 802.11a/b/g/n access points at 1 to 5 mW transmit power
    4. NEMA enclosures
    5. Captive portal authentication
    6. 802.1X/EAP security solution