MTN Pulse · Architecture · Draft 8 Oct 2026
Pulse Site Kit
One kit per state. The kit keeps one network link. The phones connect to it by USB and use their own SIMs for test traffic.
Proposal. MTN has not agreed to the phone gateway in the office rack yet.Two ways to build the kit
Both builds use the same phone gateway, a Raspberry Pi, and the same USB hub in MTN's existing server rack. They differ in how they hold the phones. Variant A uses only parts that we buy. Variant B adds one custom 3D-printed rack module.
The models use real sizes in millimetres. "approx." marks a size that is not confirmed.
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- 1MTN rack. MTN's existing 19-inch rack, drawn as a 6U section. Hole spacing 465 mm, inner width 450 mm, 1U = 44.45 mm. Its depth is not confirmed (drawn at 600 mm).
- 2Phones. 3 × Galaxy A6, 150 × 71 × 8 mm, stand upright. 7 faded phones show later phones at the 170 × 78 × 9 mm maximum.
- 3Phone stand. A plain metal stand with 10 slots, 336 × 100 × 85 mm, with no electronics (seller photo). The 15 mm slot is tight for a 12 mm phone. The cable gap under the phones is not confirmed.
- 4Phone cables. Right-angle micro-USB, 27 cm, from the bottom of each phone to the hub. Later phones use 0.25 m right-angle USB-C cables.
- 5USB hub. RSHTECH RSH-A10, 10 ports, approx. 240 × 60 × 25 mm, behind the stand.
- 6Raspberry Pi. Raspberry Pi 5, 4 GB, in a small case, approx. 94 × 63 × 30 mm. It is the phone gateway: adb server (open to the VM only), USB port resets and a watchdog.
- 7The one link. One Ethernet cable from the Pi to MTN's network. adb runs over it, for the VM only.
- 8Tray. 1 tray for 600 × 450 cabinets, 1U. The listing gives no depth. The model uses 300 mm (estimate).
- 9Power strip. APC SurgeArrest, 5 outlets, at the back of the tray. It plugs into MTN's rack power strip (PDU). Two parts plug into it: the Pi power supply and the hub's own power adapter. The other 3 outlets stay empty.
The model also shows the USB cable from the hub to the Pi, the 2 power cables and the power strip's own lead. They have no number.
- Variant A uses only parts that we buy.
- A plain metal stand with 10 slots holds the phones upright. It has no electronics.
- A short right-angle cable runs from the bottom of each phone to the RSHTECH hub behind the stand.
- Everything sits on 1 tray: the stand, the hub, the Raspberry Pi and the power strip.
- We do not use the Dinggong box. Its built-in hub does not support Samsung phones and cannot switch port power from software.
The 3D view did not load.
The view needs three.js from cdn.jsdelivr.net and a browser with WebGL. Connect to the internet and reload the page. The part list below and the rest of the page work without it.
- 1MTN rack. MTN's existing 19-inch rack, drawn as an 8U section. Its depth is not confirmed.
- 2Phones. The 3 phones of today are solid. 7 later phones are faded and drawn at the 170 × 78 × 9 mm maximum.
- 3Printed module. 3U (133 mm) × 19-inch, 482.6 mm wide with the rack ears, about 250 mm deep. PETG or ASA. It prints in 2 halves. Design target, not built.
- 4Phone slots. 10 upright slots, 12 mm wide, about 80 mm deep. You insert each phone from the top. The slot spacing in the model is not confirmed.
- 5Label strip. A strip at the front names each slot.
- 6Rear bay. It holds the Raspberry Pi and the USB hub. The lid has vent slots. The Ethernet cable and the 2 power cables leave through an opening in the back wall.
- 7Rack ears. 2 separate printed parts.
- 8The one link. One Ethernet cable from the Pi to MTN's network. adb runs over it, for the VM only.
- 9Cable channels. One channel runs from under each slot to the hub. The exploded view shows them.
- 10Tray. 1 tray for the power strip. The model uses a 300 mm depth (estimate).
- 11Power strip. APC SurgeArrest, 5 outlets, on the tray. It plugs into MTN's rack power strip (PDU). Two parts plug into it: the Pi power supply and the hub's own power adapter. The other 3 outlets stay empty.
The exploded view moves the 2 halves, the ears, the lids, the phones and the hub apart. The Pi stays in place. It makes the module see-through and shows the hidden cables.
- Variant B replaces the bought holder with one printed 3U rack module. It is a design target, not a built part.
- Ten upright slots at the front hold the phones. You insert each phone from the top.
- A channel under each slot takes the cable to the hub. The Raspberry Pi and the hub sit in the rear bay, so no cable shows.
- A label strip at the front names each slot. The lid over the rear bay has vent slots.
- It prints in PETG or ASA as 2 halves plus 2 rack ears, because most printer beds are 220 to 256 mm.
A against B
| A · Bought parts | B · 3D-printed | |
|---|---|---|
| Phone holder | A plain metal stand with 10 slots, 336 × 100 × 85 mm. It has no electronics. | One printed 3U rack module in PETG or ASA. It holds the phones, and its rear bay holds the Raspberry Pi and the hub. Design target, not built. |
| Fit of the slots | 15 mm slots (seller photo). The slot is tight for a 12 mm phone. The cable gap under the phones is not confirmed. | Exact slot size: 12 mm wide, about 80 mm deep. The slots take phones up to 170 × 78 × 9 mm. |
| Cable routing | A short right-angle cable runs from the bottom of each phone, out of the back of the stand, to the hub behind it. The cables stay in view. | A channel runs from under each slot to the hub in the rear bay. No cable shows. |
| Look | Separate parts on 1 tray. | One module and 1 tray. A label strip at the front names each slot. |
| Lead time | Not confirmed. The stand ships from AliExpress with free shipping. | Not confirmed. B needs a CAD design and a print quote before the first print. |
| Cost of the holder | ₦79,587, free shipping. | Not confirmed. It needs a print quote. |
| Risk | The 15 mm slot is tight for a 12 mm phone. The cable gap is not confirmed. No off-the-shelf holder met all 8 of our requirements. | Design iterations, print quality, and finding a print service. |
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The rack setup
In an MTN server room the kit needs no cabinet. It sits on 1 tray in MTN's existing rack. MTN plugs the kit into the rack power strip (PDU), which runs on the room's UPS and generator. The table shows only the parts and the height to lift the phones out.
| Rack units | A · Bought parts (6U) | B · 3D-printed (8U) |
|---|---|---|
| U7 to U8 | Not part of A (A ends at U6) | Height to lift the phones out |
| U6 | Height to lift the phones out | Height to lift the phones out |
| U5 | Height to lift the phones out | Top of the phones |
| U2 to U4 | Phones in the stand | Printed module: phones, Raspberry Pi, USB hub |
| U1 | Tray: phone stand, USB hub, Raspberry Pi, power strip | Tray: power strip |
- Variant A needs 6U with today's phones. Phones up to 170 mm tall need 7U, because they rise higher when you lift them out.
- Variant B needs 8U: 1U for the tray, 3U for the module, and the rest to lift the phones out.
- A kit that stands on its own needs a cabinet: the Millennals 6U wall cabinet, 600 × 450 (Jiji, Ikeja, ₦65,000). Its front door is not confirmed.
- Variant A now fits the 6U cabinet with today's phones, including the height to lift them out. Variant B does not fit, because it needs 8U.
- The tray fits 600 × 450 cabinets. Its fit in MTN's rack is not confirmed. Check the rack depth before you buy it.
- Check the socket type of MTN's rack PDU before you buy the power strip. The strip in the listing photo has a UK plug.
- In a steel cabinet, test the phones' cellular signal with the door closed.
Today: the interim setup
Today the phones are in our apartment. MTN testers use the console in a browser. An MTN VM serves the console through a small reverse proxy (Caddy).
Scroll the diagram sideways to see all of it.
The VM never talks to a phone. Every tap and screen read stays on the PC over USB. Only the console, clicks and live video cross the internet.
We prefer Tailscale for the one link. The other option is an SSH tunnel that the PC opens to the VM.
The MTN router gives the phones Wi-Fi for app traffic only. A UPS for the router and the hub comes later.
Across the country
MTN's RHEL 9 VM runs the whole backend: the scheduler, the AI model calls, the run store and the console. Each kit is a small phone gateway: a Raspberry Pi that holds the phones over USB. The VM drives the phones through the gateway, over MTN's network. The centre gives MTN one console and one report for every state.
Scroll the diagram sideways to see all of it.
A run makes hundreds of round trips to its phone, one after another. Each trip now crosses MTN's network from the VM to the gateway, so a direct network path matters. On our own fleet on 9 Sep 2026, a direct LAN gave 68–95 ms per round trip. A Tailscale relay through Paris gave 0.3–1.1 s. If the link to the centre drops, the tests in that state pause.
One link per state, not one per phone
In a cable-free setup, each phone keeps its own network path to the server. In the kit, a cable connects each phone to the Pi gateway. So each state has one network link to keep alive.
Scroll the diagram sideways to see all of it.
Inside one kit
The Raspberry Pi holds the phones over USB and powers them through the hub. It runs only three things: the adb server (open to the VM only), uhubctl for USB port resets, and a small watchdog. The watchdog keeps the phones charged and awake. The VM drives the phones through it. Control needs no root. Every time a phone connects, the Pi reapplies the phone settings over USB: stay awake, doze off and system updates blocked. Only 1 or 2 capture phones are rooted, and they also run the keeper module. MTN's rack power strip (PDU) powers the Pi and the hub. It runs on the room's UPS and generator. Each phone reaches the cell network on its own SIM, which is the same path a customer's phone uses.
Scroll the diagram sideways to see all of it.
Bill of materials
This is the part list for one variant A kit. The kit is a phone gateway. MTN's RHEL 9 VM runs the whole backend, so the kit needs no N100 computer, no SSD and no switch. The kit has no UPS, because MTN server rooms already have UPS and generator power. We saw the prices on 8 Oct 2026. The phones and the SIMs are not in this list. The Phones section covers them.
| Part | Pick | Where | Price to Lagos | Status | Delivery |
|---|---|---|---|---|---|
| Phone gateway | Raspberry Pi 5, 4 GBBrand new (listing). A Pi 4, 4 GB costs ₦249,999 on Jiji (Oshodi), so it is not much cheaper. | Jiji · MarketPlaces NG, Gbagada | ₦250,000 | Price seen | Not shown |
| Pi power supply | USB-C 5V 3A (15 W) supply, sold for the Pi 4The official 27 W Pi 5 supply was not found on Jiji (Lagos), Jumia or Konga. On 15 W the Pi 5 limits its USB current. The hub has its own power, so 15 W is likely enough (not confirmed). The photo shows a 2-pin European plug, so a UK socket needs an adapter (not confirmed). | Konga · RUMARSEL ONLINE STORE | ₦9,500 | Stopgap | 1 to 9 business days |
| Pi case | Case with a fan, or a heatsink case, for the Pi 5No Pi 5 case was found on Jiji (Lagos), Jumia or Konga. Konga sells a Pi 4 case with a fan for ₦15,000. Its fit with the Pi 5 is not confirmed. | Not found | Not found | Not found | Not confirmed |
| microSD card | SanDisk Extreme PRO 64 GB microSDXCNo 64 GB high-endurance card was found in Lagos listings. This is the nearest card. It is not a high-endurance card, and the listing does not state A2. | Jiji · DGS Store, Ikeja | ₦36,000 | Nearest match | Not shown |
| USB hub | RSHTECH RSH-A10, 10 ports, 36 W, per-port power switching (uhubctl) | AliExpress | ₦56,449.11Free shipping | Test 1 unit firstThe chip revision is not confirmed. Only the Realtek-chip version is confirmed to cut port power. | Oct 19 to 26 |
| Switch | Not needed (one device per kit) | Not applicable | ₦0 | Not needed | Not applicable |
| USB-C cables | 0.25 m, 90-degree, USB-A to USB-C. Qty 10.Data support and which end bends are not confirmed. | AliExpress | ₦22,160for 10 (₦2,216 each), free shipping | Price seen | Nov 4 to 11 |
| Micro-USB cables | AQJG 27 cm, right-angle, USB 2.0 data. Qty 4. | AliExpress | ₦12,082.08for 4 (₦3,020.52 each) | Price seen | Not confirmed |
| Phone holder | A: plain metal stand, 10 slots, 336 × 100 × 85 mmThe 1.5 cm slot is tight for a 12 mm phone. The cable gap is not confirmed. B: the printed 3U module. | AliExpress (A)B: print service not chosen | A: ₦79,587Free shipping. B: not confirmed. | Price seen | Not confirmed |
| Rack tray | 600 × 450 rack tray, 1U. Qty 1.Tray depth not confirmed. Fit in MTN's rack not confirmed. | Jiji · Ikeja | ₦10,000 | Price seen | Not shown |
| Power strip | APC SurgeArrest, 5 outletsModel number not shown. It plugs into MTN's rack PDU. | Jiji · Lagos Island | ₦7,500 | Price seen | Not shown |
| 6U wall cabinet | Millennals 6U, 600 × 450Standalone kits only. Front door not confirmed. Variant A fits it with today's phones. | Jiji · Ikeja | ₦65,000 | Price seen Standalone only | Not shown |
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SD cards can corrupt in a power cut. The server room's UPS protects the kit. The Pi runs with a read-only system so a cut cannot damage it.
- Both subtotals are for variant A. They include the Pi, its power supply and the microSD card. They also include the USB hub, 10 USB-C cables, 4 micro-USB cables, the phone stand, 1 tray and the power strip.
- Not included: the Pi case (not found) and the delivery fees that the listings do not show.
- Variant B swaps the stand (₦79,587) for the printed module. The module cost is not confirmed. B also uses 1 tray.
What we buy today
This is what we bought today, through our contact in Computer Village. The NVIDIA PC has USB-A ports, so we need no USB-C adapter.
Today's list
| Item | Detail | Price |
|---|---|---|
| Router plan | MTN router plan Gold, 30 days (MTN router plans)Up to 50 Mbps, then 5 Mbps after 400 GB. | ₦40,000 |
| Powered USB hub |  4-port USB 3.0 hub |
₦15,000 |
| Second item | Vendor quote | ₦15,000 |
| Remaining items | Vendor quote | ₦4,500 |
| Dispatch | Dispatch to Lekki | ₦8,500 |
5V only. A 9V or 12V router adapter can burn the hub and the phones.
We already have an extension socket, so today's list has no power strip.
Other options seen on Jiji
| Item | Listing | Place | Price |
|---|---|---|---|
| Powered USB hub | Onten OTN-8108, 7-port USB 3.0 data hubThe listing says "includes an external power adapter". The adapter rating is not confirmed. | Lagos, Ikeja (Computer Village) | ₦18,000Not yet confirmed by phone |
| 3 micro-USB data cables | Havit CB6159, USB-A to micro-USB, 1 m, "Fast Data Sync" | Lagos (Ikeja or Ikorodu) | ₦6,000for 3 (₦2,000 each). Not yet confirmed by phone. |
Other options seen on Jumia and Konga
| Item | Pick | Where | Price | Delivery |
|---|---|---|---|---|
| 3 micro-USB cables | SHPLUS 1 m micro-USB data cable | Jumia | ₦7,470for 3 with door delivery (₦1,990 each) | Oct 9 to 12 |
| Powered USB hub | 10-port USB 2.0 hub with adapter | Konga | ₦7,000 | 1 to 9 business days |
| Powered USB hub | 7-port USB hubAdapter not confirmed. | Jumia | ₦7,328₦5,878 + ₦1,450 | Oct 13 to 14 |
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Phones
Today the kit has 3 phones, all Samsung Galaxy A6 and all rooted. All 3 connect by micro-USB. A new Redmi phone joins later. Its exact model is not known yet.
| Phone | Count | Root | Port | Size (mm) |
|---|---|---|---|---|
| Samsung Galaxy A6 | 3 | Rooted | micro-USB | 150 × 71 × 8 |
Root is only for API capture
We do not need root to control a phone. adb, uiautomator2, screen capture and the live view all work over USB without root.
We need root only for API capture, which decrypts the app's HTTPS traffic. The reason is that the app trusts only the system certificate store.
So most phones stay unrooted and match what customers own. 1 or 2 rooted phones do API capture, and they also run the keeper module.
Recommended additions
Root is optional for these phones. We saw the prices on 8 Oct 2026, between 15:10 and 16:30 WAT.
| Phone | Role | Where | Price | Status |
|---|---|---|---|---|
| Samsung Galaxy A06, 4/64 GB | Budget Samsung | Jiji · Ikeja | ₦120,000 | Price seen |
| Tecno Spark 40, 4/128 GB | Budget. Tecno is the top brand family in Nigeria. | Jiji · Ikeja | ₦162,000 | Price seen |
| Infinix Note 50 Pro, 8/256 GB | Mid-range | Jiji · Ikeja | ₦389,999 | Price seen |
| Tecno Phantom V Flip 2 5G, 8/256 GB | Foldable. The cheapest foldable on the Nigerian market. | Konga | ₦750,0001-year Tecno warranty | Price seenDelivery not shown. |
| Samsung Galaxy Z Flip 7, 256 GB | Premium foldable. Optional. | Jiji · Ikeja | ₦740,000 | Not confirmedModel code not shown. It may be a US unit. |
| Google Pixel 9 Pro, 128 GB | Rooted capture phone | Jiji · Ikeja | ₦665,000 | Check before you payFactory unlock not stated. A 256 GB unit that states "factory unlocked" costs ₦825,000 on Jiji. Check that you can enable "OEM unlocking". |
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The slots of variant B take phones up to 170 × 78 × 9 mm. This page does not confirm the sizes of the foldables. Check them before you order.
Dropped: The Nothing Phone (3a) is import only (₦733,647 + customs). The Infinix Hot 50i is out of stock everywhere.
Brand share in Nigeria, June 2026
Browsing share, not unit sales. Source: Statcounter, mobile browsing traffic.
The top 4 brands are within 2.2 points of each other. Statcounter, Nigeria.
When something fails
Each failure has one layer that brings the system back. A person is only needed when hardware fails for good.
| What fails | What brings it back | Handled by | Person needed |
|---|---|---|---|
| A phone restarts (crash, power blip) | adb over USB needs no network. When the phone connects again, the Pi gateway reapplies its settings over USB. It keeps the screen awake, disables doze and blocks system updates. | Pi gateway | No |
| A phone freezes and adb stops answering | The kit watchdog restarts the phone over adb. If that fails, it cuts the power to the phone's USB port and then restores it. | Pi gateway | No |
| Grid power cut | The room's UPS and generator keep MTN's rack power on. The Pi gateway and the hub stay on. The phones keep charging. | MTN room | No |
| A long power cut | The Pi gateway starts by itself when power returns. A fully drained phone may not start by itself. This varies by model. | kit | Sometimes |
| A system update arrives | The Pi gateway blocks system updates over USB every time the phone connects. On the 1 or 2 rooted capture phones, the keeper module also blocks them, so root survives. | Pi gateway | No |
| The kit's link to the centre drops | Tests in that state pause. The AI model is in the data centre, so a bigger kit could not run them either. The Pi keeps the phones charged and healthy, and testing resumes when the link returns. | Pi gateway | No |
| Wi-Fi or the tailnet drops | Does not apply. Nothing controls the phones over Wi-Fi or Tailscale. | none | No |
| A phone loses cellular signal | The VM still drives the phone through the Pi gateway. The report records "no signal" as the cause. | Pi gateway | No |
| A phone dies for good (swollen battery, hardware) | The centre alerts the named contact in that state. The contact puts a spare phone in its place, and the kit enrols it in one step. A capture phone needs a pre-rooted spare. | centre + people | Yes |
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Decisions
- MTNVery likelyKits sit in MTN offices, on MTN's internal network.
- MTNMaybeA small phone gateway (a Raspberry Pi) in each office rack, with adb open to the VM only. This is the open risk.
- MTNVery likelyTest SIMs with data for every phone.
- MTNVery likelyA named contact in each state. The design aims for zero routine visits.
- MTNTo agreeMTN plugs each kit into the rack power strip (PDU) on the room's protected power (UPS and generator), not into an office wall socket.