How to Plan a 100+ Camera CCTV System for Shopping Centres: Network Design & PoE Budgeting

A shopping centre isn't a house with more cameras bolted on — once you cross into the 100+ camera range, the network itself becomes the hard part of the project. Get the switch hierarchy, power budget and bandwidth planning wrong, and you end up with cameras that randomly drop offline, footage that stutters during the exact peak-hour incident you needed clean video of, or a system that simply can't grow when a new wing gets built. Here's what actually goes into planning one of these systems properly.

Why Scale Changes the Whole Approach

A handful of cameras on a single switch is forgiving — if something's underpowered or a cable run is a bit long, you notice and fix it. At 100+ cameras spread across a large-format building, food court, car park and multiple tenancies, small miscalculations compound: an underestimated power budget doesn't fail gracefully, it takes out a whole bank of cameras the moment the switch hits its limit, often after dark when infrared kicks in and demand spikes. Planning at this scale means treating power, bandwidth and network topology as three separate engineering questions, not one shopping list of camera models.

PoE Power Budgeting: Beyond Just Adding Up the Wattage

Power over Ethernet (PoE) lets cameras run on the same cable that carries their data, which is what makes large deployments practical — but the power side needs real budgeting, not a quick tally of nameplate wattage. There are several PoE standards in play, each delivering a different amount of usable power to the camera:

• 802.3af (PoE): up to roughly 12.95W delivered to the device — suitable for basic fixed cameras without heavy IR.
• 802.3at (PoE+): up to roughly 25.5W delivered — the common baseline for IR-equipped cameras.
• 802.3bt Type 3 (PoE++): up to roughly 51W delivered — used for PTZ cameras and higher-draw devices.
• 802.3bt Type 4 (PoE++): up to roughly 71W delivered — reserved for the highest-power devices on a network, PTZ or otherwise.

As a rough guide, fixed cameras without much IR typically draw somewhere in the 4-6W range, IR-equipped fixed cameras closer to 6-10W, and PTZ cameras anywhere from 10-25W depending on the model — but these are ballpark figures, and the only way to know for certain is to check the actual spec sheet of the cameras you're specifying.

The part that catches large projects out isn't the daytime number — it's what happens after dark. Infrared illuminators draw meaningfully more power than a camera's daytime baseline, and a switch sized exactly to the sum of daytime spec sheets can be pushed past its limit the moment the sun goes down and every IR-equipped camera in the centre switches on at once. The general industry guidance is to size total PoE switch capacity at least 20-30% above your projected nighttime peak draw, not the arithmetic sum of manufacturer specs — that headroom also covers startup power surges and leaves room to add cameras later without a switch upgrade.

Network Design: Building a Hierarchy, Not a Flat Network

At 100+ cameras, plugging everything into one big switch (or a chain of unmanaged ones) isn't a realistic option. Enterprise-scale CCTV networks are generally built in tiers:

• Access layer. Managed PoE switches distributed around the building (often one per communications closet or IDF, close to the cameras they serve) — this is where cameras physically connect.
• Distribution/core layer. Higher-capacity switches that aggregate traffic from every access switch and connect back to the recording servers. On larger commercial projects it's common practice to run these in a redundant pair, so a single switch failure doesn't take the whole system offline.
• Uplinks between them. As the combined camera traffic from an access switch or a whole wing approaches roughly a gigabit, that's generally the point at which a 10-gigabit uplink (often over fibre between buildings or distant IDFs) becomes worth planning for, rather than continuing to add gigabit links.

Rather than trying to fix a number like "20 cameras per switch," the more reliable approach is to work bandwidth backwards from the cameras: add up the expected bitrate of every camera feeding into a switch, and use that total — not a headcount — to decide when you need to step up to a higher-capacity uplink.

Bandwidth: Resolution and Codec Decide More Than People Expect

Two centres with an identical camera count can have wildly different network requirements depending on resolution and video codec. As a general guide:

• 720p: roughly 1-2 Mbps with H.265, or 2-4 Mbps with older H.264 compression.
• 1080p: roughly 2-4 Mbps with H.265, or 4-8 Mbps with H.264.
• 4K: roughly 4-8 Mbps with H.265, or 16-32 Mbps with H.264.

H.265 compression generally delivers similar image quality at roughly half the bitrate of H.264, which is a significant saving once you multiply it across 100+ cameras — but it's only a saving if every camera and the NVR actually support it consistently, since a fallback to H.264 anywhere in the chain can double that segment's bandwidth use. It's also worth building in margin for busy periods: real-world traffic from a large multi-camera site can look very different at 2am compared to a busy Saturday afternoon food court, when motion, activity and bitrate all climb well above idle levels — one documented large-venue example saw traffic jump from roughly 150 Mbps at idle to 800-900 Mbps at full occupancy, which illustrates how large that swing can be, even though every site's actual numbers will differ.

Cabling and Physical Layout

Standard copper PoE cabling is limited to around 100 metres between a switch and a camera — a real constraint in a large-format building where cameras can sit well beyond that from the nearest switch room. Extended PoE modes on some switches can stretch that to roughly 250 metres, generally at the cost of reduced link speed (often down to around 10 Mbps), which is usually still adequate for a single camera stream but worth factoring into your bandwidth planning. Beyond that distance, or between separate buildings or car park structures, fibre uplinks become the practical option rather than a cable-length workaround.

Network Segmentation

A shopping centre's CCTV network shouldn't sit on the same network as tenant Wi-Fi, retail POS systems or general office traffic — cameras are effectively networked computers, and treating them as an isolated segment (via VLANs) limits what can go wrong if one part of the network has an issue. Some NVR platforms offer a degree of automatic isolation for their own cameras out of the box, but a realistic shopping-centre deployment usually mixes camera types, PTZs, and possibly third-party or tenant-owned devices over time — which means proper VLAN segmentation configured at the switch level, rather than relying on any single vendor's built-in isolation feature, is the safer long-term approach.

Storage and Redundancy

Storage sizing follows the same logic as bandwidth: multiply each camera's expected bitrate by your target retention period and camera count, then convert to total capacity — with motion-triggered recording substantially reducing the total compared to continuous 24/7 recording across every camera. Commercial sites commonly retain footage for somewhere between 30 and 90 days, though the right figure for any given centre depends on its own risk profile, tenancy agreements and available budget rather than a single industry standard. On very large sites, it's also common to distribute recording servers across buildings rather than centralising everything in one server room, so a single point of failure doesn't take every camera's storage down with it.

Why This Is a Site Survey, Not a Shopping List

Every number above is a starting point, not a substitute for proper design work. The right switch capacity, cable topology and camera mix for your specific centre depends on its floor plan, existing cabling infrastructure, tenancy layout and growth plans — which is exactly the kind of project where a proper site survey and network design pays for itself many times over compared to discovering a power or bandwidth shortfall after 100+ cameras are already mounted.

Why Choose Total Security Equipment

We supply and help design large-scale security camera network installations for commercial sites across Melbourne and Sydney, including managed PoE switches, network racks and cabinets, and the cameras to match — and we work with facility managers and installers to properly budget power and bandwidth before a single cable is run, not after.

Planning a large commercial CCTV rollout and want a proper network design and PoE budget worked out first?

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