The 5G at Bukit Chagar Belongs to MRT Corp

On 23 October 2026, U Mobile and Mass Rapid Transit Corporation signed a memorandum of understanding to bring 4G and 5G in-building coverage to the Immigration, Customs and Quarantine Complex at Bukit Chagar in Johor Bahru. The complex sits beside the Malaysian terminus of the RTS Link, the 4 km rail shuttle to Woodlands North that is now expected to start carrying passengers in February 2027.

Most reports led with U Mobile "providing" 5G at the border. The joint statement is narrower, and the narrowness is the story: U Mobile will "connect its network to MRT Corp's IBC infrastructure" and extend coverage "throughout the facility". The indoor system is already there. The telco is negotiating to plug into it.

That is a different transaction from the one the headline implies, and it is worth understanding, because it is the shape most public buildings will take as 5G moves indoors.

What the MoU actually commits to

Very little, on its own terms. The operative verbs are explore and connect. The two parties will work out "the commercial, technical, and operational framework required to provide 4G and 5G in-building coverage within the ICQC", and any coverage will be "subject to a definitive agreement, technical requirements, and relevant approvals".

No capacity target. No sector count. No commissioning date. No price. No exclusivity clause, at least not in the text published on 23 October.

What the release does quantify is the building, not the network: about 40,000 passengers a day at opening, and roughly 600 government agency personnel already based at the complex. Both are inputs to a design. Neither is a design.

IBC is plumbing, and the landlord owns the pipes

In-building coverage is not a tower with an antenna on top. It is a distributed antenna system: a head-end where the operator's signal enters, fibre or coax risers through the building, and antennas placed to cover the halls, the queue lanes, the escalators and the back offices. On 3.5 GHz, where a large share of Malaysia's 5G capacity sits, signal does not travel far through a concrete slab and does almost nothing through a metal-clad wall. Indoor coverage is a construction decision long before it is an RF tuning exercise.

Whoever builds that system controls it. For a public building, having the landlord build it is usually the sane option: one set of cable trays, one set of access permits, one commissioning window before the doors open, and no three-way race between operators installing overlapping hardware into the same ceiling void. MRT Corp is the developer and owner of the civil infrastructure for the Malaysian section of the line, so it is the natural owner of the indoor network too.

Ownership then becomes the interesting question. Under a neutral-host model the building owner can admit any operator on published terms, and passengers keep the network their phone already uses. Under a single-tenant model one operator gets the hall and everyone else gets whatever leaks in from the car park.

The 23 October statement does not say which model MRT Corp is running. It confirms that U Mobile will connect to existing infrastructure and does not name another operator. That is not evidence of exclusivity. It is an absence of information, in a document about U Mobile. Still, it is the first question worth asking, and it is cheap to answer: publish the access terms and the sector plan.

The number that sizes a hall is not 40,000

The figure in every story is 40,000 passengers a day. Indoor capacity is not sized by a daily total. It is sized by how many people are standing inside at the same time during the worst hour, which is a function of throughput and dwell time.

The line is designed for up to 10,000 passengers an hour in each direction. The door-to-platform target at Bukit Chagar is 25 minutes, a figure MRT Corp's project director Zulkifli Mohamed gave to reporters in August, with a stretch goal of 20.

# Size an indoor system by the crowd standing in it, not by the daily total.
DAILY_RIDERS = 40_000              # RTS Link estimate at opening (U Mobile/MRT Corp)
PEAK_HOUR_SHARE = 0.10             # assumption: busiest hour = 10% of the day
DWELL_MIN = 25                     # door-to-platform target at Bukit Chagar (MRT Corp)
ULTIMATE_PER_HOUR_PER_DIRECTION = 10_000  # line design capacity (LTA/MOT joint release)


def people_inside(per_hour_total: float, dwell_min: float) -> float:
    """Little's law: concurrency = arrival rate x time spent in the system."""
    return per_hour_total * (dwell_min / 60)


scenarios = {
    "opening peak hour": DAILY_RIDERS * PEAK_HOUR_SHARE,
    "ultimate capacity": ULTIMATE_PER_HOUR_PER_DIRECTION * 2,
}

for label, per_hour in scenarios.items():
    inside = people_inside(per_hour, DWELL_MIN)
    print(f"{label:18s} {per_hour:>7,.0f} riders/h -> {inside:>7,.0f} people inside")

opening peak hour    4,000 riders/h ->   1,667 people inside
ultimate capacity   20,000 riders/h ->   8,333 people inside

At opening, with a busy hour carrying a tenth of the day, that is roughly 1,700 people inside. At the line's ultimate throughput the same arithmetic gives about 8,300, plus the 600 staff. That is the population an indoor system has to serve, and it is the number that should appear in a technical annex. Nobody has published it.

Treat the model as a prompt rather than a result. Change the peak-hour share to 8% and the opening figure drops to 1,333; change it to 12% and it rises to 2,000. The point is not the decimal. The point is that 40,000 a day is compatible with a hall designed for 2,000 people or for 8,000, and only one of those guesses is safe.

A QR lane turns coverage into throughput

The ICQC is built around 100 e-gate lanes, 10 body-screening lanes and 18 baggage scanners, with dedicated lanes for travellers without luggage. The e-gates accept a passport or a QR code from the MyNIISe app; CNA reported in August that app users can clear in as little as seven seconds.

That is a good design, and it moves the network into the critical path. A passport works without a signal. A QR code lives on a phone, and the phone is on a network. If the indoor coverage has a hole in the hall, the fast lane slows down and the queue shifts to the passport lanes and the manual counters. The building does not stop. It just stops being fast, which is the thing the whole project is selling.

So the question to settle before February is unglamorous and specific: does the MyNIISe QR survive a dead zone? A QR is generated locally by the app in most implementations, which would make the hall's coverage irrelevant to clearance and relevant only to everything else. I could not find a public document that states which it is for MyNIISe, and that answer should be published rather than discovered by 4,000 people in a queue.

Ninety per cent of populated areas is not a border metric

U Mobile has a genuine achievement to point at. On 7 October 2026 it announced 90% 5G coverage of populated areas, more than nine months ahead of the July 2027 commitment, after clearing 80% in March 2026.

That number counts residents. Ten days later, at the launch of Penang Port's private 5G network, Communications Minister Fahmi Fadzil said the ministry and MCMC will study whether the coverage metric should also count ports, rail lines and highways, with a Cabinet memorandum to follow and a proposal to raise at the ITU meeting in Doha in November.

He put the problem plainly: ports may have no residents, but they are centres of economic activity. Bukit Chagar is the same problem in a smaller box. It is a clearance hall, not a neighbourhood, and the metric counts the neighbours. Forty thousand people a day will use it, and 600 people will work in it. A national percentage can be entirely honest and still tell you nothing about the one building where everyone stands still.

That is not a scandal. It is a metric that measures the wrong population for a border post, and the ministry has now said so out loud.

What to check before February

• The definitive agreement. The MoU turns into a contract or into silence. When it is signed, the annexes matter more than the press release.
• The capacity figure. Concurrent users, sectors and backhaul. If a hall is designed for 2,000 simultaneous users and the line eventually delivers 8,000, the fix is expensive once the ceiling closes.
• Access terms for the other operators. A neutral host with published rates is public infrastructure. A single tenant is a concession.
• Scope. The MoU names the ICQC. It does not name the station's own departure levels, the train, the viaduct or the Woodlands North terminus. Coverage that ends at the door is a seam.
• Offline behaviour. One paragraph in the MyNIISe documentation would settle the queue question.

The lesson generalises past this building. When a telco announces 5G inside a public facility, the useful questions are not about the telco. They are about who owns the cable trays, who else is allowed in, and whether the crowd was the input to the design or an afterthought. Public infrastructure tends to get this wrong in the same way, which is why the ownership clause is worth reading before the coverage map.

Sources

• U Mobile And MRT Corp To Power The JB-Singapore RTS Link Gateway With 5G — U Mobile
• U Mobile, MRT Corp To Explore 4G, 5G Coverage At RTS Link Gateway — Bernama
• U Mobile, MRT Corp ink MoU to provide 5G coverage at RTS Link complex — The Star
• U Mobile to provide 5G indoor coverage at Bukit Chagar RTS Link immigration complex — SoyaCincau
• First look at Bukit Chagar station, and Malaysia's 25-minute target — CNA
• RTS Link Service Commencement Targeted for February 2027 — Land Transport Authority of Singapore
• RTS Link At Bukit Chagar ICQ To Feature 100 E-gate Lanes — Bernama
• Malaysia may review 5G coverage measurement to include economic hubs — The Star