Computer Repair · October 25, 2026 · ComputerKing Team

You Upgraded to Mesh — So Why Are There Still Wi-Fi Dead Zones?

Upgrading to Mesh does not automatically remove dead zones. The causes are usually placement, backhaul, roaming, interference, or old settings — this guide covers the seven post-upgrade causes and an eight-step acceptance checklist.

Key Summary: Upgrading hardware does not automatically remove dead zones. The problem usually lies in node placement, backhaul, roaming, interference, or old settings — not in the router being too cheap. This article breaks down the seven main causes of dead zones after an upgrade and shows you how to test a new system room by room, so you stop buying hardware on guesswork.

Introduction: The New System Is Installed, but the Dead Zone Is Still There

The previous article in this series explained how to measure dead zones with data and tell coverage, interference, backhaul, and device problems apart. This one deals with a more frustrating situation: you have already upgraded to Mesh and a new router, the money is spent, and yet the corner of the bedroom or study still buffers and video calls still freeze.

The following is a hypothetical scenario, not a real case: suppose you place a brand-new Mesh node directly inside a room that previously had no signal. Your phone shows full bars, but streaming still buffers. Or suppose you walk from the living room into the study, and your phone, standing right next to the new node, stubbornly stays connected to the distant living-room node. Neither situation means the new hardware is broken. It means the upgrade replaced hardware without replacing the deployment.

The core idea is simple: Mesh and new routers only carry the existing signal to more places. They do not change the walls, they do not change spectrum congestion, they do not make your broadband plan faster, and they do not automatically clean up old settings. When dead zones survive an upgrade, the first step is not to buy another node, but to find out which layer is failing and fix that layer.

1. Cause One: Wrong Node Placement — Putting the Node Directly Inside the Dead Zone

This is the most common and most wasteful cause of post-upgrade dead zones. A repeater or Mesh node can only forward the signal it receives; it cannot create bandwidth out of nothing. If you place a node directly inside a room that already has no signal, the node itself receives an attenuated signal, and whatever it rebroadcasts will be the same attenuated, low-quality connection. The result is a phone showing full bars while actual speeds stay slow — because full bars only mean the local link between the phone and the node is strong, not that the data pipe between the node and the main router is healthy.

The correct placement is halfway between the main router and the dead zone, in a transitional spot where the signal is still good — for example a corridor, a stair landing, or an open area between the living room and the bedroom — so the node first receives a clean, fast signal and then covers the final stretch. Manufacturer guidance offers concrete references: nodes should sit at least about one to one and a half feet off the floor, in an open position, away from walls and metal objects, and away from 2.4 GHz interference sources such as microwave ovens, Bluetooth devices, and USB 3.0 devices. Before installation, check the satellite node's signal in the app and aim for at least two bars. On a wireless connection, units should not be more than about fifty feet apart, and the path should ideally cross no more than one or two interior walls. Nodes should not be stuffed inside cabinets.

After moving a node, always re-test: use the same device in the same dead-zone spot and check whether real usage has actually improved, rather than just counting bars.

2. Cause Two: The Backhaul Becomes the Bottleneck

A device going online travels two legs: from the device to the node, and then from the node to the main router. The second leg is the backhaul. On a dual-band Mesh system, if the same band carries both backhaul and fronthaul traffic, the two compete for bandwidth, and every additional wireless hop reduces throughput further. In other words, it does not matter how strong the node looks if the backhaul between the node and the main router is already weak — everything downstream slows down with it.

Wi-Fi 7's MLO multi-link operation carries a common misunderstanding worth spelling out: MLO mainly improves the fronthaul link between devices and the router, while the backhaul between Mesh nodes does not automatically gain the same improvement. Some products do implement MLO for backhaul; check the backhaul design for the exact model before buying, and do not judge by the MLO label alone. If you shop by headline speeds and ignore backhaul design, a Wi-Fi 7 upgrade can still stall at the backhaul bottleneck. Separately, 6 GHz is relatively clean with wider available channels and suits high-throughput devices in the same room, but its wall penetration is weaker than 5 GHz and 2.4 GHz, and the signal drops noticeably after a single load-bearing wall. Using 6 GHz for cross-room backhaul therefore needs care; nodes should ideally keep line of sight or only light obstruction between them.

The most stable solution is wired backhaul: connecting nodes with Ethernet cable gives stable bandwidth, unaffected by wireless interference, and lets nodes sit further apart. The trade-off must be stated plainly: wired backhaul needs existing cabling or a willingness to run cables. In a rented flat where cables cannot be run, the acceptance standard itself should be lower — do not promise wired-backhaul performance from a wireless backhaul. Cabling and drilling work is quoted individually.

Backhaul Options Compared

Option	How it works	Advantages	Drawbacks and costs
Wired backhaul	Nodes connect to the main router by Ethernet cable	Best speed, latency, and stability; unaffected by walls and interference	Needs cabling or existing network ports; a finished flat may need surface trunking, and tenants may need the landlord's permission first
Tri-band dedicated wireless backhaul	A dedicated band carries node-to-node traffic	Better than shared dual-band, since device traffic does not give up half its bandwidth to backhaul	Backhaul itself is still affected by walls, distance, and interference
Dual-band shared wireless backhaul	Nodes and devices share the same band	No cabling needed, plug and play	Backhaul competes with devices for bandwidth, and speeds drop further with each hop

For a comparison of backhaul options, see the complete guide to home Wi-Fi dead zones.

3. Cause Three: Sticky Clients — Standing Next to the New Node but Still Connected to the Old One

Whether a device switches nodes is ultimately decided by the device itself, not the router. Many devices, to avoid frequent switching, cling to their original node even when its signal has weakened and a stronger node is nearby, causing speeds to collapse or connections to stutter. This is called a sticky client, and it is especially common when moving across floors or between distant rooms.

The three roaming standards 802.11k, v, and r each do a different job, and they should not be lumped together as simply "turning roaming on":

802.11k (neighbour reports): The access point gives the device a list of nearby access points in advance, so the device does not have to scan every channel blindly, saving scan time.
802.11v (BSS transition management): The network can proactively suggest that a sticky device move to a nearer, less congested access point. This is the most direct mechanism against sticky clients. But remember: a suggestion is only a suggestion — the device may accept it or ignore it.
802.11r (fast BSS transition): Encryption keys are pre-cached on neighbouring access points, cutting re-authentication during a switch from hundreds of milliseconds to under fifty milliseconds, reducing pauses in video and voice calls.

Practical steps include: checking in the Mesh app which node and band the device is actually connected to; toggling the device's Wi-Fi off and on to force a reconnection, which usually picks the nearest node; checking whether the Mesh system has fast roaming enabled; keeping the same SSID and security settings across all nodes so the device treats the Mesh as one network; and enabling automatic firmware updates, since vendors keep fine-tuning roaming and sticky-client behaviour. One boundary must be stated: all three standards only work when both the device and the network support them. Older devices may not benefit, so never write that switching roaming on guarantees a switch.

4. Cause Four: 2.4 GHz Congestion and IoT Devices Slowing the Whole Network

The 2.4 GHz band in practice has only three non-overlapping channels. In Hong Kong's high-density housing, with many flats per floor and more than ten neighbouring networks overlapping, congestion is routine — and that is before counting microwave ovens, Bluetooth devices, cordless phones, and baby monitors sharing the same spectrum. Even with full bars, devices must take turns transmitting, so speeds fall. Many smart-home devices support only 2.4 GHz, run at low speeds, and send small amounts of background data constantly, adding further congestion.

Acceptance testing after an upgrade should therefore look at 2.4 GHz and 5 GHz separately: devices near the router and high-speed devices should use 5 GHz or 6 GHz, while distant rooms and smart-home devices stay on 2.4 GHz. Moving capable devices to 5 GHz is itself a way to relieve 2.4 GHz congestion, and it costs nothing.

5. Cause Five: DFS Channels and 160 MHz Bandwidth Causing Intermittent Dropouts

If your home suffers intermittent, whole-home, short dropouts rather than constant slowness, suspect DFS and bandwidth settings. Some 5 GHz channels are shared with radar, and regulations require Wi-Fi to vacate a channel immediately when radar is detected, so devices briefly disconnect and switch channels. A 160 MHz channel bonds eight 20 MHz channels together; the more channels bonded, the greater the chance of hitting a DFS channel, and once radar is detected the channel stays out of use for at least thirty minutes, while the network may fall back to 80 MHz.

The practical implication is: when dropouts occur intermittently, first check the router log for radar-detection records. If they match, consider disabling 160 MHz or avoiding DFS channels as a test. But channel numbers vary by local regulation, so Hong Kong users should go by local rules and the channels their own devices actually offer, not by copying an overseas channel table.

6. Cause Six: Double NAT — When the New and Old Systems Fight, the Symptoms Are Not Simply "Slow"

When an ISP modem-router combination and the new Mesh main node both perform NAT (network address translation) at the same time, the result is double NAT: two layers of private IP translation stacked on top of each other. Double NAT rarely shows up directly as slow speeds. More often it produces strange connection problems that are easily mistaken for a Mesh fault — for example stricter NAT types and connection failures in online games and real-time applications, port-forwarding difficulties, work VPNs that will not connect, printers that cannot be found, and remote CCTV that works intermittently.

The check is straightforward: check whether the Mesh main node's WAN IP is a private-range IP (192.168.x.x / 10.x.x.x / 172.16–31.x.x); if it is, and the ISP gateway's WAN IP is a public IP, that is double NAT. If the ISP itself uses CGNAT, check with the ISP to confirm — do not conclude double NAT just because the two IPs differ. The clean fix is to leave only one device routing: set the ISP combination device to bridge mode so it acts only as a modem and the Mesh system takes over routing, or switch the Mesh system itself to access-point mode and let the ISP gateway keep routing, at the cost of losing some Mesh-specific router features. Before doing this, ask the provider whether the device also carries IPTV or a home telephone line, because bridge mode may switch those services off too. Also, old routers and old Wi-Fi names left running can cause devices to connect to the wrong network, so after an upgrade the old system should be disabled or properly dealt with — never run two overlapping networks side by side.

7. Cause Seven: The ISP Line and Old Equipment Are Themselves the Bottleneck

Mesh cannot increase the speed your broadband connection itself provides. Before acceptance testing, you must establish which segment is slow: if a wired connection is slow too, the problem lies with the line, the ISP, or the gateway, and adding nodes will not fix it. Good Wi-Fi near the router but poor Wi-Fi far away points to coverage; good wired speeds but poor Wi-Fi even close to the router points to radio or congestion problems.

The same logic applies to old devices. A Wi-Fi 6 router can connect Wi-Fi 5 and Wi-Fi 4 devices, and those old devices will work normally, but they will not gain every Wi-Fi 6 feature. In a mixed old-and-new node setup, functionality is limited to what all units share. A 2.4 GHz-only device cannot even see a 5 GHz network, so no matter how powerful the Mesh, it will keep running on congested 2.4 GHz. Acceptance testing must therefore include the devices the user actually uses — never judge a system by a single new laptop, because a device with better antennas, newer drivers, and cleaner roaming behaviour can make a weak design look healthy.

8. Hong Kong Home Structures: Why a More Expensive Router Still Cannot Get Through That Wall

Hong Kong homes themselves are often the cause of dead zones, and a more expensive single router cannot change the physical reality that a signal must cross two or three load-bearing walls. Concrete is dense and holds moisture, which heavily attenuates signals, and the steel reinforcement inside reflects and interferes further. Metal cabinets, metal doors, security gates, and foil-backed insulation effectively block radio signals. Mirrors usually have a thin metal coating on the back that absorbs, reflects, and refracts radio waves. Fish tanks and other bodies of water absorb radio waves, so a tank sitting between the router and the device forms a wall of water. Related causes and solution options are covered in the complete guide to home Wi-Fi dead zones.

The higher the frequency, the weaker the wall penetration, and this trade-off must be stated clearly: 2.4 GHz penetrates best and covers furthest but has the most crowded channels; 5 GHz is faster and more interference-resistant but penetrates walls less well; 6 GHz wall performance should not be overestimated at all. Within the same room, 5 GHz is preferable; across rooms and long distances, 2.4 GHz is more likely to hold a connection. Never write that Wi-Fi 7 or 6 GHz penetrates walls better — that claim is simply wrong.

Hong Kong's 6 GHz situation carries a separate trap that must be explained on its own. According to the Communications Authority (OFCA), the 6 GHz range for Wi-Fi in Hong Kong is 5.925 to 6.425 GHz, and 6.425 to 7.125 GHz does not apply to Hong Kong Wi-Fi. Within that, 5.925 to 5.945 GHz is a guard band, so usable channels start at 5.945 GHz. The 2024 auction of 6/7 GHz spectrum was for mobile services, not home Wi-Fi, and the two must never be confused. The same guidance gives an example: two Wi-Fi 7 products can have completely different band lists — one with only 2.4 GHz plus 5 GHz, the other with 2.4, 5, and 6 GHz. Before buying, check the full band list for the exact model, and check whether the phone or laptop itself supports 6 GHz. OFCA also warns against bringing back access points operating in the 6.425 to 7.125 GHz band from overseas; under the Telecommunications Ordinance, possessing or using unauthorised radiocommunications apparatus carries a maximum penalty of HK$50,000 and two years' imprisonment. That is the penalty ceiling stated in public information, not legal advice in this article.

9. Tenants, Village Houses, and Duplex Flats: Different Homes Need Different Acceptance Standards

Different home types deserve different post-upgrade acceptance standards. Applying one yardstick to all of them is itself a mistake.

Tenants: Tenancy agreements generally prohibit tenants from making structural alterations without the landlord's prior written consent, so before drilling walls, running trunking into walls, or altering fixed wiring, tenants must ask the landlord and the building management, and the individual tenancy agreement governs. Tenant upgrades should prioritise no-drilling options such as wireless Mesh, existing cable routes, or short cables to fixed devices. Acceptance testing should also state plainly that a rented flat's coverage ceiling may be lower than that of an owner-occupied flat where wired backhaul can be installed.

Village houses: With tall floors, thick floor slabs, and large layouts, a single main router plus wireless Mesh nodes across floors must push backhaul through floor slabs, and performance will be far worse than on a single floor. Acceptance testing must therefore measure floor by floor, not just the living room. Separately, when the fibre box is too far away or separated by roads, rivers, or other people's land, extra works may be needed; 5G home broadband is a common alternative, but this article only says readers may ask ISPs whether it applies to them, and all prices are quoted individually — never cite a price-comparison site's monthly fee as an official price.

Duplex flats: Concrete floor slabs plus steel reinforcement attenuate signals just like walls do, and stairwell corners force signals to reflect many times before arriving, so the more winding the path, the worse the coverage. Nodes should not be placed only "symbolically" at the stairwell; every floor needs at least one node with good signal, and the backhaul quality between nodes is a hard acceptance metric.

10. Accepting a New System: An Eight-Step Checklist to Tick Off Before You Call It Done

The acceptance goal should not be "every corner of the home runs at full plan speed" but "the places actually used are fast enough, stable, and do not disconnect." Speeds far from the router will always be lower than speeds beside it — that is a physical limit, not an acceptance failure. Signal bars are not an acceptance standard either; speed tests, video-call stability, and whether streaming buffers are.

1. Start with a wired baseline: Connect a computer by cable directly to the main router while other devices are not heavily using the network, and measure once, so you know how fast the incoming line itself is. Every later Wi-Fi test should be compared against this baseline to tell whether the bottleneck is wireless or upstream.

2. Confirm all nodes are online: The Mesh app should show every node connected, with a stable backhaul link. Check each node's backhaul signal quality in the app, using your app's own labels; if your app uses Good / Excellent / Fair / Poor grades, Good or Excellent passes; Fair or Poor means the placement or backhaul has a problem and the node must be moved or switched to wired backhaul.

3. Test every frequently used spot individually: Do not test only beside the router. Bedrooms, work areas, and the TV position each need a real-use test — browsing, a video call, or streaming — not just a glance at signal bars.

4. Compare near, medium, and far distances: Test close range, a longer non-line-of-sight distance through walls, and the distance after the extension node is enabled. Restart the device and reconnect before testing, then check in the Mesh app which node the device is actually connected to before starting the test.

5. Do a walking roaming test: Keep streaming or a video call running while walking from one node's coverage area into another's, and watch for obvious pauses, disconnections, or frozen frames. A well-designed Mesh should keep streaming running without obvious pauses and real-time calls connected.

6. Test multiple devices under load: Run streaming, video calls, browsing, and downloads at the same time, and watch whether nodes crash, restart, lose backhaul stability, or lose throughput over time.

7. Check each band and device type: Phones, laptops, old devices, and IoT devices do not perform alike, so acceptance testing should include the devices actually used, and should look at 2.4 GHz and 5 GHz performance separately.

8. Observe overnight and clean up old networks: A good speed test right after installation does not prove long-term stability, so watch for intermittent dropouts on the first night and during the first week. At the same time, confirm only one device routes between the ISP gateway and the Mesh main node, and that old routers and old Wi-Fi names have been disabled, so devices cannot connect to the wrong network.

11. Common Misconceptions, Taken Apart One by One

Misconception	The truth
Full signal bars mean fast	Signal bars only reflect the strength of the signal the device receives from the router. They do not measure download speed, latency, packet loss, or the quality of the connection between the router and the ISP
Putting a node inside the dead zone fixes the dead zone	A node only forwards the signal it receives. Placed inside a dead zone, it rebroadcasts an already attenuated signal, so speeds stay slow under the illusion of full bars. The correct position is a halfway transition point
More nodes are always better	Nodes placed too densely waste channel resources and cause co-channel interference. A small flat may not need a three-pack; test the problem area and start with the fewest nodes
Upgrading to Wi-Fi 7 or a new router fixes everything	If the bottleneck is the upstream ISP plan, backhaul bandwidth, device standards, or double NAT, a new router will not fix it automatically. Wi-Fi 7's MLO mainly improves fronthaul, not necessarily backhaul; some products do implement MLO for backhaul, so check the exact model
More bars on 2.4 GHz mean it is faster than 5 GHz	2.4 GHz penetrates better and usually shows more bars, but the band is more congested and slower. A laptop on 5 GHz with two bars may outperform a device on 2.4 GHz with four bars
Uplink and downlink signals are symmetrical	Router transmit power is usually higher than that of a phone or laptop, so a device may clearly receive the router's signal while the router struggles to hear the device's reply. The result looks like full bars but with slow uploads and stuttering video calls
Switching ISPs or upgrading the plan fixes dead zones	The ISP decides the incoming speed; dead zones are an in-home coverage problem. A plan upgrade only makes speeds beside the router faster, while dead zones stay dead
Buying Mesh guarantees seamless roaming	Roaming is ultimately decided by the device. It requires 802.11k, v, and r to be enabled and supported by the device, and older devices may not benefit. A network suggestion is not a guarantee the device will listen

12. Closing: When You Can Fix It Yourself, and When to Ask for an On-Site Check

If you follow the process above and find the cause is placement, channels, double NAT, or sticky clients — and the fix needs no drilling and no changes to shared building facilities — adjusting it yourself is usually enough: move the node to a halfway point, change channels, narrow the bandwidth, clean up old networks, or toggle the device's Wi-Fi to force a reconnection. Change one thing at a time, and re-test in the same spot with the same device after each change.

If you follow the full troubleshooting process, change settings, and move nodes without solving it — especially with dead zones across the whole home — or if the home is large, a duplex, or a village house, or the job is pre-renovation planning, or interference is suspected to be severe with strong signals but slow speeds, or the work needs cabling, drilling, outdoor installation, or distribution-box changes, or coordination with building management or the ISP is required, it is worth considering a professional on-site survey (Wi-Fi repair service). A professional survey may include point-by-point measurement, and access-point location and channel recommendations, and afterwards you should verify against the survey rather than simply accepting a single diagram. Charges are quoted individually.

Need help? Contact ComputerKing at +852 2115 9219. We can help diagnose Wi-Fi dead zones in your home. Charges are quoted individually.

FAQ

1. Why is my internet still slow after upgrading to Mesh, even though my phone shows full bars?

Full bars only mean the local link between the phone and the node is strong; they say nothing about the backhaul between the node and the main router. If the node was placed directly inside the dead zone, it is already receiving an attenuated signal and can only rebroadcast that same poor connection. Move the node to a halfway transition point between the main router and the dead zone, and verify with a real-use test, not just by counting bars.

2. Where should a Mesh node go, and how far from the main router is right?

Place it halfway between the main router and the dead zone, in a spot where the signal is still good — for example a corridor, stair landing, or open area between rooms. Keep it about one to one and a half feet off the floor, in the open, away from walls and metal objects, and away from 2.4 GHz interference sources such as microwave ovens. On a wireless connection, units should not be more than about fifty feet apart, and the path should ideally cross no more than one or two interior walls. After placing it, check the node's backhaul signal quality in the app, using your app's own labels; if your app uses Good / Excellent / Fair / Poor grades, Good or Excellent passes.

3. How big is the difference between wired and wireless backhaul? What if a rented flat cannot run cables?

Wired backhaul gives the best speed, latency, and stability, unaffected by walls and interference. Wireless backhaul shares spectrum with devices, and each additional hop reduces speed further; tri-band dedicated backhaul is better than dual-band shared backhaul, but still suffers from walls, distance, and interference. If cables cannot be run, consider tri-band wireless Mesh or short cables to fixed devices to reduce wireless load. Before drilling walls or running trunking into walls, tenants must ask the landlord and building management, and the individual tenancy agreement governs. Acceptance standards should also be lowered accordingly.

4. Why does my device stay connected to the distant node even when I stand next to the new one?

This is a sticky client: the device, not the router, ultimately decides whether to switch, and many devices wait until the signal drops to a certain level before looking for a new node. Check in the Mesh app which node the device is actually connected to, toggle the device's Wi-Fi off and on to force a reconnection, and check whether 802.11k, v, and r roaming settings are enabled. But remember: a network suggestion is not a guarantee the device will listen, and older devices may not support these standards.

5. What do 802.11k, v, and r each do?

802.11k provides neighbour reports — a list of nearby access points so the device does not have to scan every channel blindly. 802.11v provides BSS transition management, letting the network proactively suggest a move to a nearer, less congested access point. 802.11r provides fast BSS transition, pre-caching encryption keys so re-authentication during a switch drops from hundreds of milliseconds to under fifty milliseconds. All three only work when both the device and the network support them; enabling them does not guarantee a switch.

6. Why does my whole home briefly disconnect from time to time, then recover on its own?

One possible cause is DFS channels: some 5 GHz channels are shared with radar, and when radar is detected, Wi-Fi must vacate the channel immediately, so devices briefly disconnect and switch channels. A 160 MHz channel bonds eight channels, increasing the chance of hitting a DFS channel, and the affected channel stays out of use for at least thirty minutes. Check the router log for radar-detection records, then consider disabling 160 MHz or avoiding DFS channels as a test. Channel numbers vary by local regulation, so follow local rules and the channels your own devices actually offer rather than copying an overseas channel table.

7. What is double NAT, and how do I know if my home has it?

Double NAT happens when an ISP modem-router combination and the new Mesh main node both perform NAT, stacking two layers of private IP translation. The symptoms are usually not "slow" but strange connection problems — for example VPNs that will not connect, printers that cannot be found, remote CCTV that works intermittently, or port-forwarding difficulties. Check whether the Mesh main node's WAN IP is a private-range IP (192.168.x.x / 10.x.x.x / 172.16–31.x.x); if it is, and the ISP gateway's WAN IP is a public IP, that is double NAT. If the ISP itself uses CGNAT, check with the ISP to confirm — do not conclude double NAT just because the two IPs differ. The clean fix is to leave only one device routing, using bridge mode or access-point mode. Before doing this, ask the provider whether it will affect IPTV or a home telephone line.

8. How does Hong Kong's 6 GHz Wi-Fi differ from overseas, and what should I check before buying a Wi-Fi 7 device?

The 6 GHz range for Wi-Fi in Hong Kong is 5.925 to 6.425 GHz, and 6.425 to 7.125 GHz does not apply to Hong Kong Wi-Fi. Within that, 5.925 to 5.945 GHz is a guard band, so usable channels start at 5.945 GHz. Before buying, check the full band list for the exact model, because one Wi-Fi 7 product may offer only 2.4 GHz plus 5 GHz while another offers 6 GHz as well, and check whether the phone or laptop itself supports 6 GHz. Do not bring back access points operating in the 6.425 to 7.125 GHz band from overseas if they do not meet Hong Kong's technical specifications.

9. How do I properly accept a new Wi-Fi system?

Start with a wired baseline, then test every frequently used spot with real usage, compare near, medium, and far distances, run a walking roaming test, test multiple devices under load, check each band and device type separately, observe overnight, and clean up old networks while confirming there is no double NAT. The acceptance goal is places actually used being fast enough, stable, and free of disconnections — not every corner matching full plan speed. Signal bars are not an acceptance standard.

10. When should I ask for a professional on-site survey instead of trying again myself?

When the full troubleshooting process, setting changes, and node moves have not solved it, especially with dead zones across the whole home; for large flats, duplexes, village houses, or pre-renovation planning; when interference is suspected to be severe with strong signals but slow speeds; or when the work needs cabling, drilling, outdoor installation, or distribution-box changes, or coordination with building management or the ISP. A professional survey may include point-by-point measurement, and access-point location and channel recommendations, verified afterwards against the survey. Charges are quoted individually.