Wireless Site Survey Guidelines
41 min
this document provides all the information required to conduct a successful wireless site survey in accordance with nile's guidelines it is organized into two parts best practices to follow during the site survey ap placement, radio power, ap height, capacity planning, secondary coverage, 6 ghz/afc behavior, etc a checklist to validate before you upload the ekahau or hamina file to the site survey job note all power values in this guide are expressed as eirp (effective isotropic radiated power), not conducted/transmit power assumptions and prerequisites this guide assumes that the person performing the survey already understands standard wireless site survey fundamentals, including survey preparation, floor plan validation, scaling, wall attenuation, ap on a stick methodology, rf behavior, coverage validation, and report generation these general survey concepts are not covered in detail here the purpose of this document is to capture nile specific survey expectations, design targets, eirp guidance, 6 ghz considerations, secondary coverage validation, and pre upload requirements design principles design for the business use case start the design by identifying the customer’s business use case and the least capable, most important client device in the environment examples include barcode scanners in warehouses, paging devices in healthcare facilities, and laptops in enterprise office environments also account for the applications that will use the wireless network, such as video, voip, cloud backups, dorm room gaming devices, or other high throughput and latency sensitive applications design for redundancy and resiliency nile slas depend on a redundant and resilient wireless design a key design target is to aim for 67 dbm secondary signal strength on the 5 ghz spectrum design for capacity before coverage in dense offices in typical enterprise office spaces, capacity often needs closer attention than coverage a typical ap can cover a radius of up to 50 ft in open space when mounted at 10–12 ft, but modern open office layouts often create high density environments where each desk may have multiple connected devices for these environments, reducing transmit power does not necessarily mean over deploying aps the ap count is usually justified by the capacity requirement rather than coverage alone rf power planning and eirp guidelines recommended eirp planning matrix the values in the following table are intended to serve as practical starting points and are expected to be suitable for most deployments however, every environment is unique, and these recommendations should be adjusted as needed final design decisions should consider factors such as client density, application requirements, mounting height, building characteristics, and redundancy requirements surveyors are encouraged to use predictive surveys, ap on a stick testing, and field validation to fine tune the design in lower density environments where secondary coverage is not required, transmit power may be increased cautiously after verifying coverage, roaming behavior, and interference levels deployment scenario 2 4 ghz eirp 5 ghz eirp 6 ghz lpi eirp 6 ghz sp eirp typical enterprise, ceiling up to 12 ft 8 dbm 11 dbm for wi fi 6e / wi fi 7 14 dbm for wi fi 6 14 dbm 17 dbm with afc high density enterprise office 5 dbm 11 dbm 14 dbm 17 dbm with afc regular enterprise, ceiling below 20 ft, secondary coverage required 8 dbm 14 dbm 12–13 dbm 17 dbm with afc warehouse or auditorium, ceiling 20–28 ft, no secondary coverage 11 dbm 17 dbm turn off wait for standard power with afc 19 dbm with afc larger venue, ceiling 29–35 ft 13 dbm 19 dbm turn off wait for standard power with afc 20 dbm with afc mounting height 35–40 ft active survey required active survey required turn off wait for standard power with afc active survey is required standard power with afc required above 40 ft not supported not supported not supported not supported why is 14 dbm eirp recommended on 5ghz (wifi6) ? a 14 dbm eirp target helps maintain transmit power symmetry between aps and client devices this is important for roaming and performance because excessive ap transmit power can cause sticky clients that remain connected to distant aps even when a better ap is available many client radios operate around 12–14 dbm, so operating close to that range can provide a better client experience starting around 14 dbm also provides headroom for nile’s coverage hole mitigation algorithm to increase power where needed, especially in wireless zones where maximum radio power may be capped for wi fi 6e/7 aps, the recommended 5 ghz baseline is 11 dbm because the 6 ghz radio contributes to the overall cell budget eirp vs conducted power while we are on the topic of radio power, let's also understand the difference between eirp and conducted power effective isotropic radiated power (eirp) is the total amount of power that appears to be emitted by the antenna it takes into account the conducted power and also the antenna gain eirp = conducted power + antenna gain conducted power is the rf energy delivered from the transmitter into the antenna feed this is the value most survey tools accept as input configuring eirp in ekahau and hamina ekahau in the tool, when we configure a radio tx power to be 9dbm, the tool automatically adds the antenna gain, and there is a small text annotation that displays the eirp hamina unlike ekahau, hamina does not automatically add antenna gain to the configured tx power — the value you enter is treated as conducted power, not eirp you must therefore convert your target eirp to conducted power yourself using the per ap antenna gain reference below before entering it into the project example for an nwa1100 (wi fi 6e) on 5 ghz, the internal antenna gain is 2 dbi to achieve the recommended baseline of 11 dbm eirp on 5 ghz, enter a tx power of 9 dbm in hamina (11 − 2 = 9) conversely, if you leave the tx power at 9 dbm without converting, the actual radiated eirp will be 11 dbm, which is correct for this ap, but on an nwa1000 (wi fi 6, 5 dbi on 5 ghz), the same 9 dbm setting would produce 14 dbm eirp, which may exceed the design intent always validate the math per the ap model before generating the report nile ap antenna gain reference ap wi fi gen indoor / outdoor antenna type 2 4 ghz 5 ghz 6 ghz nwa1000 wi fi 6 indoor omni (internal) 4 6 dbi 5 dbi — nwa1050 wi fi 6 outdoor omni (internal, downtilt) 7 dbi 7 dbi — nwa1100 wi fi 6e indoor omni (internal) 2 dbi 2 dbi 2 dbi nwa1200 (alexandria) wi fi 7 indoor omni (internal) 5 dbi 6 dbi 6 dbi nwa1250 (rosetta) wi fi 7 outdoor directional (internal) 6–8 dbi 8–9 dbi 8–9 dbi 6 ghz design considerations 6 ghz introduces design decisions that do not exist for 2 4 ghz and 5 ghz, especially the choice between low power indoor and standard power with afc lpi vs standard power — what's the difference mode where it operates max eirp afc required? typical use low power indoor ( lpi ) indoor only, full 6 ghz band (u nii 5, 6, 7, 8) 23 dbm (or 5 dbm/mhz psd) no dense / high capacity indoor deployments where the higher ap count is already justified by capacity standard power ( sp w/afc ) u nii 5 and u nii 7, indoor or outdoor 36 dbm (or 23 dbm/mhz psd) required coverage driven deployments (warehouses, larger venues), where the higher eirp reduces ap count when to use lpi use lpi for dense indoor environments such as stadiums and conference halls lpi allows more aps to be deployed while reducing power to avoid interference when to use standard power with afc use standard power 6 ghz carefully because it requires afc and higher eirp values plan based on the afc availability and the coverage requirement aligning 5 ghz and 6 ghz cell sizes for the best client experience on 6 ghz, the 6 ghz and 5 ghz cell sizes should be similar cell size decreases as frequency increases if 2 4 ghz, 5 ghz, and 6 ghz operate at the same power level, the expected cell size order is 2 4 ghz > 5 ghz > 6 ghz for high density enterprise offices, use the high density row in the recommended eirp planning matrix as the starting point, then adjust based on the environment being designed coverage, resiliency, and interference validation secondary signal strength as you know, nile has an incredible automation built into the channel planner let's look at how this affects planning using the site survey tools when using ekahau/hamina, the secondary signal strength is purely the second highest rssi observed at any given x, y, when all the aps are operating at the same power level when an ap goes offline, the channel planner automatically reclassifies its immediate neighbours as border aps and raises their tx power by 3 dbm to backfill the lost coverage factor this +3 dbm uplift to the baseline into your secondary coverage validation rather than designing for the static rssi values that ekahau or hamina report co channel interference and neighboring aps if increasing the tx power, be sure to increase the distance between aps to reduce interference for aps placed at higher elevations (e g , above 28 feet), ensure they are spaced far enough apart (consider 25–50 feet depending on tx power) if you must exceed 14 dbm for tx power, ensure that aps are sufficiently separated to avoid interference that degrades performance survey execution guidelines surveying multi storied buildings in addition to characterizing the walls on the floor, we also need to understand how the rf penetration is happening through the floor as well so, while performing the active ap on a stick survey, please navigate to the floor below and collect the data as well brownfield locations understand the current ap placement from the customer and generate a predictive survey to see if it matches nile standards if it doesn’t match the nile standards, then follow the steps outlined above to generate the ap locations sensor locations placement of nile physical sensors is a very important step that we need to identify during the wireless survey some general rule of thumb for the sensor placement should be around the perimeter of the building identify important areas in the floor, like executive rooms, big conference rooms, and all hands meeting areas make sure there are working power outlets after a sensor location is determined checklist please make sure that the following items are present in the esx file and the report before closing the site survey job mobile app inputs set the scaling factor using a real time measurement and a large object at the site, i e , the length of a room, the length of a hallway, etc , as that will give us accurate data draw the coverage area where wireless is needed and add any exclusion areas if applicable draw all the walls on the floor ap properties please make sure that all the simulated aps in the ekahau/hamina file have the following properties mounting type wall mounting (vertical or horizontal mounting), ceiling mounting height access point height from the ground ceiling types these are nile specific and can be derived from the template esx file provided a note to be placed on the floor plan indicating “sensor location” generating report (ekahau) the final report must be generated after characterizing the signal attenuation from the different wall types that were found during the active survey in ekahau, navigate to reporting >> one click reporting bands 5 ghz floors select all the relevant floors paper a4 document format pdf sections coverage and performance signal strength secondary signal strength number of aps requirements coverage and performance network issues requirements capacity capacity clients per ap access points my network access points notes map notes upload the esx file with the final location of the aps with the above mentioned properties, tags, and notes to the site survey job generating report (hamina) in hamina, navigate to "create a new report " bands 5 ghz bill of materials notes and zones ap placement coverage secondary coverage ap list switch & cabling locations finally, click on the export icon → export floor plans dialog opened format file (openintent) selected (not cisco catalyst / dna center) openintent file saved locally with a clear, customer identifiable filename upload the openintent file with the final location of the aps with the above mentioned properties, tags, and notes to the site survey job
