Wireless LAN Deployment - Nueva Vizcaya State PDF

Republic of the Philippines NUEVA VIZCAYA STATE UNIVERSITY Bayombong, Nueva Vizcaya INSTRUCTIONAL MODULE...

Republic of the Philippines NUEVA VIZCAYA STATE UNIVERSITY Bayombong, Nueva Vizcaya INSTRUCTIONAL MODULE IM No.: IM-ITT2_3-2NDSEM-2023-2024 College: Arts and Sciences Campus: Bayombong DEGREE PROGRAM: Information Technology COURSE NO.: ITT2_5 SPECIALIZATION: NDM COURSE TITLE: Wireless and WAN Technologies WK YEAR LEVEL: 3rd Year TIME FRAME: 15 Hours 1-3 IM NO.: 2 NO.: I. UNIT TITLE/CHAPTER TITLE Chapter 3 II. LESSON TITLE Deployment III. LESSON OVERVIEW This lesson aims to provide a foundational understanding of Wireless Local Area Networks (WLANs) play a pivotal role in modern connectivity, providing flexible and efficient communication for a variety of devices. Successful WLAN planning is essential to ensure optimal performance, reliability, and scalability. This overview delves into the key components and considerations involved in planning a WLAN. IV. DESIRED LEARNING OUTCOMES At the end of the chapter, the students are expected to: Conduct a comprehensive evaluation of current network client needs, considering device types, data requirements, and usage patterns. Evaluate spatial density within coverage areas to prevent congestion and ensure consistent performance. Design effective signal coverage areas, considering building layouts, obstacles, and sources of interference. Develop deployment strategies, including access point placement, cabling, and power considerations. V. LESSON CONTENT Site surveys, that is, detailed inspections of the deployment site, are pivotal in deploying the wireless network. The results of a site survey help determine some of the most important decisions in deployment, Page 1 of 7 NVSU-FR-ICD-05-00 (081220)  Republic of the Philippines NUEVA VIZCAYA STATE UNIVERSITY Bayombong, Nueva Vizcaya INSTRUCTIONAL MODULE IM No.: IM-ITT2_3-2NDSEM-2023-2024 such as frequency selection, mounting location and channel assignments. During and after equipment installation, administrators should make software and hardware adjustments based on the results of benchmarks and real- world tests until the desired WLAN performance is achieved. The physical construction of the WLAN environment greatly affects deployment since what is ‘possible’ in one location may not be in a different setting. In general, wireless admins should consider the following details when deploying access points: Pre-install site surveys (blueprints/maps? mounting locations? construction materials?) Spectrum analysis (noise sources? dead zones? co-channel interference?) Attenuation (desks/people/trees/signs/doors/walls/windows? path loss?) Channel assignments (2.4/5 GHz? 1/6/11? 36/44? 36/40/44? 20/40/80 MHz?) Mounting UAPs (ceiling/wall/post/seats? obstacles/open?) Wiring (switches/PoE injectors? CAT5e/CAT6? UTP/STP? ferrite beads?) Post-install site surveys (SNR? overlap? co-channel interference?) Benchmarking (range/latency/jitter/speeds? roaming? applications work?) Site Surveys Before, during and after deployment, wireless admins should perform site surveys of the WLAN area. Surveying an area requires one visit to the premises to identify possible mounting locations for UAPs as well as barriers in building design or construction materials that could attenuate signals. Obtain copies of building floor plans to make note of objects not appearing on the blueprints (e.g., humans, computers) and consult them when designing the WLAN architecture. Later, upload these maps into the UniFi Controller to measure UAP coverage areas. Power-over-Ethernet (POE) & Wiring Page 2 of 7 NVSU-FR-ICD-05-00 (081220)  Republic of the Philippines NUEVA VIZCAYA STATE UNIVERSITY Bayombong, Nueva Vizcaya INSTRUCTIONAL MODULE IM No.: IM-ITT2_3-2NDSEM-2023-2024 Despite its name, “wireless” networks still rely on cables and wires to connect access points to switches and routers. It’s imperative that Ethernet connections function properly in full duplex and at advertised data rates (100/1000 Mbps), otherwise bottlenecks will occur. These problems can occur when line and EMI interference is present. Whenever possible, use outdoor- rated, shielded-twisted pair (STP) Ethernet cables like TOUGHCable to protect against harsh weather and RF environments. Ethernet cables are also responsible for supplying power to the wireless access points through Power over Ethernet (PoE). UAPs, IP cameras and other PoE-ready equipment are called powered devices (PDs) since they receive power from power sourcing equipment (PSEs) like EdgeSwitch. All UAPs come with a voltage specific PoE (Power over Ethernet) adapter, however admins can consolidate power outlets by using a single UniFi Switch to power as many as 24 separate UAPs. Make sure that proper voltage is specified on each port since a misconfiguration could damage hardware. 802.3af and 802.3at define two of today’s PoE standards. Some UAP models including PRO and AC are compliant with these standards since they require more power (48V) to support advanced features like dual radios and 3x3 MIMO. Other UAPs use passive PoE due to their lower power consumption (24V) but can be paired with adapters to use CAT5e or later Ethernet cables; operators can run cable up to 100m+ distance to provide PoE at the end of the UAP. However, this distance is subject to decrease in situations where more power is needed (e.g., 48V, Gigabit Ethernet). Select UAP models feature a secondary Ethernet port for bridging network connections without the use of a switch. This is particularly useful when an extra wired connection is needed to connect another network node. While the secondary Ethernet port itself does not provide PoE passthrough, it does act as a simple bridge port and can extend the reach of the wired LAN in a wireless uplink scenario. Device Forecasting Besides estimating the minimum number of access points based on total number of clients and their bandwidth requirements, forecasting the number of required network devices can take on several pieces of evidence. For example, the sum of the used Wattage for each POE device in the proposed network can help estimate the minimum number of UniFi Switches needed to supply POE throughout the LAN. As a network consultant, you are often required to submit equipment costs and estimates to governments and other organizations to win project bids. The Ubiquiti UniFi Network Planner tool gathers admin information about the planned site to generate a Bill of Materials, which you can use to secure project bids. Page 3 of 7 NVSU-FR-ICD-05-00 (081220)  Republic of the Philippines NUEVA VIZCAYA STATE UNIVERSITY Bayombong, Nueva Vizcaya INSTRUCTIONAL MODULE IM No.: IM-ITT2_3-2NDSEM-2023-2024 Spectrum Analysis Site planning also requires wireless administrators visit the site to measure the noise and receive signal levels. Wireless devices transmit signals that are invisible to the human eye, so spectrum analyzers are used to read energy levels across the spectrum. If any noise sources exist in the WLAN environment, installers must know prior to deployment. Spectrum analysis data helps administrators choose wireless channels for deployment, as well as anticipate the client signals, SNR, and data rates throughout the WLAN. Commonly, urban and densely populated areas face wireless saturation, that is, overcrowded channels. This is especially true in the 2.4 GHz band. In such cases, smaller channel widths (20 MHz especially) are important as they ensure the best possible SNR. After deploying UAPs, perform signal and speed tests throughout the WLAN using real- world client devices. Second Generation UAP-AC devices allow administrators to scan the RF environment using a built-in spectrum analyzer tool. During the RF Scan, UniFi 2G/5G radios stop transmitting (i.e., stop broadcasting WLANs) to "listen" to the RF environment. All wireless clients using the UAP are disconnected, until after approximately five minutes, when the Controller presents the reported data from the UAP under scan. Client WLAN Scanning On client devices, use software like inSSIDer to measure the receive signal levels and noise floor based on nearby networks. At the very least, client spectrum analysis software should identify RSSI, channel, SSID and MAC addresses, to differentiate between neighbor APs and competing wireless networks. Where client signals are weaker than expected, consider introducing a new UAP on an adjacent or non- adjacent channel to decrease the probability of co-channel interference. This will help keep SNR at high levels across the WLAN and ensure smooth performance as the WLAN scales larger. Recall also that Page 4 of 7 NVSU-FR-ICD-05-00 (081220)  Republic of the Philippines NUEVA VIZCAYA STATE UNIVERSITY Bayombong, Nueva Vizcaya INSTRUCTIONAL MODULE IM No.: IM-ITT2_3-2NDSEM-2023-2024 smaller channel bandwidths can achieve better signals and greater wireless range due to greater power density. Make sure that UAP cells overlap enough for the application by always testing client applications and tweaking cell areas. If cells overlap too much, then co-located networks which compete for access to the same channel, may hear each other at similar levels to the clients. This would likely result in greater abundance of interference for both networks. If on the other hand, cells don’t overlap enough, clients may experience poor performance or AP-assisted roaming could fail altogether. In the case of roaming, cells must overlap but since they use the same channel assignment, the potential for collisions and co-channel interference is increased. Estimating overlap can be tricky and will ultimately depend on the application needs of the WLAN. It’s generally a good idea to identify a minimum SNR or receive signal desired among clients across the entire wireless network (e.g., 24 dB, -70 dBm). Then adjust neighboring AP cells that use the same channels so that their signals do not arrive at each other’s cell edges beyond what is necessary. Although signals will propagate beyond this point, the signal arriving from a neighbor cell on the same channel shouldn’t exceed this threshold. For example, if UAP A can be ‘heard’ at -85 dBm by UAP B’s clients, who hear UAP B at -70 dBm, then the SNR is only 15 dB every time UAP A talks. In this way, administrators can plan for coverage across the entire network while making sure that unwanted signals from overlap never exceed those desired signals. Minimum RSSI Minimum RSSI (Received signal strength indicator) is an important part of managing an enterprise network. Its main purpose is to help client devices during roaming, ensuring that clients remain connected to the appropriate UAP. Often a single low-signal client can drag down the performance of the entire wireless network through wasted airtime, slow data rates and unstable activity. Currently, UniFi allows users to set minimum RSSI on individual UAPs by radio bands (2G and 5G). Minimum RSSI relies on de-authentication packet requests sent to the station (like the reconnect button found in the Controller UI). As a soft-kick technique, the final decision of whether to de-authenticate and look for another UAP is ultimately the decision of the Client device. From the perspective of the Client device, if only a single clear UAP is within ‘good’ range, it is possible that the station will connect, then Page 5 of 7 NVSU-FR-ICD-05-00 (081220)  Republic of the Philippines NUEVA VIZCAYA STATE UNIVERSITY Bayombong, Nueva Vizcaya INSTRUCTIONAL MODULE IM No.: IM-ITT2_3-2NDSEM-2023-2024 reconnect over and over, causing frustration to the end-user. Therefore, configure Minimum RSSI with caution, and only in a properly-design WLAN. Mounting UAPs Mounting and orienting UAPs is a simple yet often overlooked part of managing wireless coverage areas. To create the most effective coverage area possible, wireless admins should always consult the antenna radiation diagrams of the access points being deployed. These diagrams provide detailed knowledge of antenna gain levels to maximize receive signal levels arriving at wireless stations. UniFi APs come with mounting kits to be easily mounted on walls, ceilings, or poles. Although mounting UAPs in visible locations is aesthetically pleasing, it also can serve to help users identify the UAP cell so they can move closer to improve their signal. In some scenarios, it may be necessary to place the UAP in a concealed location (e.g., underneath seats, on poles), like in large open space (e.g., concert hall) where walls/ceiling are distant from the center of the room. Page 6 of 7 NVSU-FR-ICD-05-00 (081220)  Republic of the Philippines NUEVA VIZCAYA STATE UNIVERSITY Bayombong, Nueva Vizcaya INSTRUCTIONAL MODULE IM No.: IM-ITT2_3-2NDSEM-2023-2024 Regardless of how and where the UAP is mounted, wireless administrators must be conscious of how signals propagate and undergo loss. As seen with distance and free space path loss, higher frequency signals attenuate more when passing through obstacles. Compared to less dense materials like glass or wood, materials like metal attenuate signals greater. A great deal of data has been published those details specific attenuation levels for different materials of varying thickness. Be careful when placing UAPs in environments with many obstacles, especially metal surfaces, since reflections can create a degree of unpredictability for WLANs. In large-scale deployments, several hundreds, or thousands of UAPs may be adopted in a short period. It therefore becomes necessary to identify UAPs not only in the real-world (with markers or label makers) but in the Controller as well. The UniFi Controller features a handy locate tool for identifying each individual UAP as well as an Alias tag for specific, name-based identification within the Controller. The UniFi Discovery Tool is a standalone software program that also allows admins to locate UniFi APs on the local network, without any need to log into a Controller at the site. Although the Discovery Tool will be studied in greater detail in Chapter 7, this software is useful in identifying the model/firmware and resetting the UAP to factory defaults (when the Device Username and Password are known). Wireless Uplink is a proprietary technique for extending the range of the WLAN without the use of cables. Comparable to mesh and WDS repeater topologies, Wireless Uplink requires one UAP establish downlinks (up to four) to nearby UAPs. Although downlinked UAPs cannot themselves participate as uplink UAPs to another UAP, all UAPs (uplink and downlink alike) act as servicing access points to client stations. Wireless Uplink will be discussed later in the student manual. Page 7 of 7 NVSU-FR-ICD-05-00 (081220)