An e-commerce company with 60 people in Haizhu District, 500 square meters of office (With an 80-square-meter warehouse and two conference rooms), the network status quo is "bought three home routers for wireless use": one at the front desk, one in the middle of the office area, and one in the warehouse. They dial up or bridge each other, but the SSID is different.(company, company-2, warehouse). The pain points are very specific: when you go to the conference room to open a video conference, you must drop the connection, the warehouse scanning gun often cannot be connected, and the employees walk from the station to the pantry without stopping the Internet but have to manually switch the Wi-Fi.
The first thing the boss asked was,"Do you want to buy a more expensive router?"It's not that the router isn't expensive enough, it's that the solution is wrong.
Diagnosis: Three major causes
We did a 40-minute site survey with a Wi-Fi analyzer (NetSpot + a laptop with channel scanning):
| pathogenesis | field measurement | consequence |
|---|---|---|
| same frequency interference | 3 routers are all crowded in 2.4G channel 6; there are 11 co-channel APs in the surrounding office buildings | 2.4G actual throughput dropped to 8Mbps, scanning gun (only supports 2.4G) frequent packet loss |
| No roaming capability | 3 independent SSIDs, switching depends on the client itself, the signal will not change until-85dBm | Walk around "sticky" on remote AP, video conference directly disconnected |
| Point and wall | Warehouse AP is behind the shelves, 2 load-bearing walls + metal shelves in the middle, measured-87dBm; conference room location without AP, close to the office AP penetration,-78dBm | The warehouse and conference room are basically unavailable in two high frequency areas |
Add a background: The penetration rate of Wi-Fi 6 terminals in office buildings is not low (employees 'mobile phones are basically Wi-Fi 6/6E), but the home router is opened on 2.4G congested channels, and even the best terminals cannot run out of speed. This is a typical "the equipment is fine, the planning is poor".
Scheme design: AC + AP, one SSID full field roaming
Core idea:One AC (wireless controller) is used to manage all APs in a unified way, and there is only one SSID in the whole field. Roaming handover is completed cooperatively among APs.Wherever the client goes, it is served by the nearest AP, and the user has no feeling at all.
Point planning (determined by survey results, not by "uniform placement"):
- 5 AP in office area: arranged in cellular staggered manner, covering the station area, each AP radius 12-15 meters, adjacent AP signal overlap area control in 15-20%(too little overlap roaming will be broken, too much will interfere with the same frequency).
- Meeting Room 1 AP: Independent coverage, avoid video conference wall attenuation, and at the same time there are many people in the conference room (10-15 devices concurrent), a single AP guarantees the capacity.
- Warehouse 2 AP: The metal shelf has great attenuation to 2.4G/5G, the warehouse is arranged directionally, and the scanning gun station is given priority.
Channel Planning: This is the most overlooked but critical step
2.4G has only three non-overlapping channels, 1, 6 and 11, while 5G has many more available channels (36-165). Our allocation principle:
| frequency band | use | channel allocation |
|---|---|---|
| 2.4G | Only code scanners, older printers, IoT devices (compatibility first) | Adjacent APs are staggered 1/6/11, reducing power to 50%(reducing cross-zone interference) |
| 5G | All cell phones, laptops, video conferencing | Use DFS outer channels such as 36/44/149/157, with at least 2 channels between adjacent APs; open 80MHz bandwidth but use 40MHz in dense areas |
| Band Steering | Let dual-band terminals connect 5G first | AC is globally enabled, 2.4G only retains low-rate access |
Two other things:Turn off low rate(Disable 1/2/5.5/11Mbps to prevent an old device from slowing down the air interface time of the entire AP);Limit single AP load(Set 30, more than automatic guidance to adjacent AP).
Equipment list and quote (500 ping/ 8 AP actual transaction price)
| equipment | model | quantity | unit price | subtotal |
|---|---|---|---|---|
| Wireless Controller AC | H3C WX2540H (including License, Management 32AP) | 1 | 3800 | 3800 |
| Ceiling AP (Wi-Fi6) | H3C WA6320 (AX3000, dual frequency) | 8 | 680 | 5440 |
| PoE switch | H3C S5130S-28P-PWR (24-port Gigabit PoE+, total power 370W) | 1 | 3200 | 3200 |
| egress gateway | Keep the original enterprise-class routing (performance is sufficient, do not change) | - | 0 | 0 |
| Network cable and auxiliary materials | Super Class VI non-shielded 305m/box ×2, PVC trunking, crystal head, panel | - | - | 2100 |
| construction and commissioning | Cabling 4 persons ×2 days, AP installation, AC configuration, channel tuning, acceptance report | - | - | 4800 |
| total | —— | —— | —— | $19,340 |
The easiest part of this price to cut is the construction cost, but it is also the part that determines the effect:Cabling, AP installation height and angle, channel tuning, acceptance testing, accounting for 60% of the overall project quality. The same equipment, installed well and installed poorly, the field signal energy difference of 20dB.
Acceptance data (pre-retrofit vs post-retrofit)
| location | Signal before modification | signal aft modification | Measured throughput (5G) |
|---|---|---|---|
| Center of work station area | -58dBm (Channel 6 congestion) | -45dBm | 620 Mbps |
| Meeting Room (10 people meeting) | -78dBm, video interruption | -48dBm | 540 Mbps, 1 hour video conference without stagnation |
| Warehouse scanning station | -87 dBm, frequent drops | -56dBm | 180 Mbps (scan gun delay 10ms) |
| Pantry/corridor roaming | Wi-Fi must be switched manually | No inductive switching, measured switching time 50 ms< | —— |
Judgment criteria Remember two numbers:-60dBm is excellent,-70dBm is the available bottom line. Below-75dBm, there will be obvious speed drop and disconnection. Acceptance must be carried out with a mobile phone or analyzer to each actual use position, not only under the AP.
Key points of construction (for enterprises preparing for transformation)
- AP Ceiling not Wall: Ceiling installation signal radiation downward, the highest coverage efficiency; wall will be blocked by furniture and human body. Installation height 2.8-3.5 meters best.
- Stay away from metals and mains powersAP is at least 1 meter away from metal ceiling, air conditioning duct and power cable tray. Metal will reflect signals and cause multipath fading.
- PoE budget should be enoughWi-Fi 6 AP single peak power consumption 20-25W (802.3at), 8 is 200W, the total power of the switch to leave 30% margin, do not buy 150W total power "24 port PoE switch".
- Survey before quote: The proposal quoted without looking at the site is either insufficient (poor effect) or redundant (excessive cost). Our on-site survey + out-of-site map + quote within Guangzhou, survey fee RMB 500, contract deduction.
- Wired priority: Fixed workstation, conference room screen host, checkout counter all go wired, Wi-Fi only service mobile devices. Take the wired devices off the Wi-Fi, air pressure immediately reduced by half.
ACCPC undertakes Guangzhou enterprise Wi-Fi network engineering: site survey, point design, Structured Cabling, AC+AP installation and debugging, channel optimization, acceptance report (including signal and throughput measured data of each point), follow-up to provide annual warranty inspection. At the same time, it does Guangzhou computer wholesale and accessories wholesale, enterprise networking procurement can be packaged and negotiated.020-39029800.